1
|
Xie L, Gao X, Liu Y, Zhao J, Xing Q. The joint effects of atmospheric dry and wet deposition on organic carbon cycling in a mariculture area in North China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162715. [PMID: 36907398 DOI: 10.1016/j.scitotenv.2023.162715] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
In this research, the atmospheric dry and wet deposition fluxes of particulate organic carbon (POC) over the coastal waters around the Yangma Island in North Yellow Sea were investigated. Combining the results of this research and previous reports about the wet deposition fluxes of dissolved organic carbon (DOC) in precipitation (FDOC-wet) and dry deposition fluxes of water-dissolvable organic carbon in atmospheric total suspended particles (FDOC-dry) in this area, a synthetic assessment of the influence of atmospheric deposition on the eco-environment was conducted. It was found that the annual dry deposition flux of POC was 1097.9 mg C m-2 a-1, which was approximately 4.1 times that of FDOC-dry (266.2 mg C m-2 a-1). For wet deposition, the annual flux of POC was 445.4 mg C m-2 a-1, accounting for 46.7 % that of FDOC-wet (954.3 mg C m-2 a-1). Therefore, atmospheric POC was mainly deposited through dry process with the contribution of 71.1 %, which was contrary to the deposition of DOC. Considering the indirect input of organic carbon (OC) from atmospheric deposition, that is, the new productivity supported by nutrient input from dry and wet deposition, the total OC input from atmospheric deposition to the study area could be up to 12.0 g C m-2 a-1, highlighting the important role of atmospheric deposition in the carbon cycling of coastal ecosystems. The contribution of direct and indirect input of OC through atmospheric deposition to the dissolved oxygen consumption in total seawater column was assessed to be lower than 5.2 % in summer, suggesting a relatively smaller contribution to the deoxygenation in summer in this region.
Collapse
Affiliation(s)
- Lei Xie
- CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; Shandong Key Laboratory of Coastal Environmental Processes, Yantai, Shandong 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuelu Gao
- CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; Shandong Key Laboratory of Coastal Environmental Processes, Yantai, Shandong 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong 266071, China.
| | - Yongliang Liu
- CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; Shandong Key Laboratory of Coastal Environmental Processes, Yantai, Shandong 264003, China
| | - Jianmin Zhao
- CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; Shandong Key Laboratory of Coastal Environmental Processes, Yantai, Shandong 264003, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong 266071, China
| | - Qianguo Xing
- CAS Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; Shandong Key Laboratory of Coastal Environmental Processes, Yantai, Shandong 264003, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong 266071, China
| |
Collapse
|
2
|
Zhang S, Yin Y, Yang P, Yao C, Tian S, Lei P, Jiang T, Wang D. Using the end-member mixing model to evaluate biogeochemical reactivities of dissolved organic matter (DOM): autochthonous versus allochthonous origins. WATER RESEARCH 2023; 232:119644. [PMID: 36736245 DOI: 10.1016/j.watres.2023.119644] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 01/02/2023] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
Dissolved organic matter (DOM) is an essential component of environmental systems. It usually originates from two end-members, including allochthonous and autochthonous sources. Previously, links have been established between DOM origins/sources and its biogeochemical reactivities. However, the influence of changes in DOM characteristics driven by end-member mixing on DOM biogeochemical reactivities has not been clarified. In this study, we investigated variations of DOM reactivities responding to the dynamics of DOM characteristics induced by different mixing ratios of two DOM end-members derived from humic acid (HA) and algae, respectively. Four biogeochemical reactivities of DOM were evaluated, including biodegradation, ·OH production, photodegradation, and redox capacity. Results showed that the variations of DOM characteristics due to the two end-members mixing significantly impact its biogeochemical reactivities. However, not all spectral parameters and reactivities followed the conservative mixing behavior. In contrast to reactivities of ·OH production and redox capacity, mixed samples showed apparent deviations from conservative linear relationships in biodegradation and photodegradation due to the interaction between the two end-members. Regarding the role of DOM properties influencing reactivity changes, peak A and M were recognized as the most stable parameters. However, peak C and SUVA254 were identified as the most vital contributors for explaining DOM reactivity variations. These findings suggest that a general model for describing the dynamic relationship between DOM source and reactivity cannot be proposed. Thus, the dynamics of DOM reactivity in diverse ecosystems cannot be estimated simply by the "plus or minus" of the reactivity from individual end-member. The effect of end-member mixing should be evaluated in a given reactivity instead of generalization. This study provides important insights for further understanding the dynamics of DOM's environmental role in different ecosystems influenced by variations of source inputs. In future, more field investigations are needed to further verify our findings in this study, especially in the scenario of end-member mixing.
Collapse
Affiliation(s)
- Siqi Zhang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Yongguang Yin
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China
| | - Peijie Yang
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Cong Yao
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Shanyi Tian
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Pei Lei
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Tao Jiang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China.
| | - Dingyong Wang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, College of Resources and Environment, Southwest University, Chongqing 400716, China
| |
Collapse
|
3
|
Striebel M, Kallajoki L, Kunze C, Wollschläger J, Deininger A, Hillebrand H. Marine primary producers in a darker future: a meta‐analysis of light effects on pelagic and benthic autotrophs. OIKOS 2023. [DOI: 10.1111/oik.09501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Maren Striebel
- Inst. for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Univ. Oldenburg Wilhelmshaven Germany
| | - Liisa Kallajoki
- Inst. for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Univ. Oldenburg Wilhelmshaven Germany
| | - Charlotte Kunze
- Inst. for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Univ. Oldenburg Wilhelmshaven Germany
| | - Jochen Wollschläger
- Inst. for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Univ. Oldenburg Wilhelmshaven Germany
| | - Anne Deininger
- Centre for Coastal Research, Univ. of Agder Kristiansand Norway
- Norwegian Inst. for Water Research (NIVA) Oslo Norway
| | - Helmut Hillebrand
- Inst. for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Univ. Oldenburg Wilhelmshaven Germany
- Helmholtz Inst. for Functional Marine Biodiversity (HIFMB), Univ. Oldenburg Oldenburg Germany
- Alfred Wegener Inst., Helmholtz Centre for Polar and Marine Research Bremerhaven Germany
| |
Collapse
|
4
|
High capacity for a dietary specialist consumer population to cope with increasing cyanobacterial blooms. Sci Rep 2022; 12:22169. [PMID: 36550191 PMCID: PMC9780316 DOI: 10.1038/s41598-022-26611-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
We present a common-garden experiment to examine the amphipod Monoporeia affinis, a key deposit-feeder in the Baltic Sea, a low diversity system offering a good model for studying local adaptations. In the northern part of this system, the seasonal development of phytoplankton is characterized by a single diatom bloom (high nutritional quality), whereas in the south, the diatom bloom is followed by a cyanobacteria bloom (low nutritional quality) during summer. Therefore, the nutrient input to the benthic system differs between the sea basins. Accordingly, the amphipod populations were expected to be dietary specialists in the north and generalists in the south. We tested this hypothesis using a combination of stable isotope tracers, trophic niche analyses, and various endpoints of growth and health status. We found that when mixed with diatomes, the toxin-producing cyanobacteria, were efficiently incorporated and used for growth by both populations. However, contrary to expectations, the feeding plasticity was more pronounced in the northern population, indicating genetically-based divergence and suggesting that these animals can develop ecological adaptations to the climate-induced northward cyanobacteria expansion in this system. These findings improve our understanding regarding possible adaptations of the deposit-feeders to increasing cyanobacteria under global warming world in both limnic and marine ecosystems. It is possible that the observed effects apply to other consumers facing altered food quality due to environmental changes.
Collapse
|
5
|
Retelletti Brogi S, Cossarini G, Bachi G, Balestra C, Camatti E, Casotti R, Checcucci G, Colella S, Evangelista V, Falcini F, Francocci F, Giorgino T, Margiotta F, Ribera d'Alcalà M, Sprovieri M, Vestri S, Santinelli C. Evidence of Covid-19 lockdown effects on riverine dissolved organic matter dynamics provides a proof-of-concept for needed regulations of anthropogenic emissions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 812:152412. [PMID: 34923016 PMCID: PMC9752488 DOI: 10.1016/j.scitotenv.2021.152412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
The fast spread of SARS-CoV-2 virus in Italy resulted in a 3-months lockdown of the entire country. During this period, the effect of the relieved anthropogenic activities on the environment was plainly clear all over the country. Herein, we provide the first evidence of the lockdown effects on riverine dissolved organic matter (DOM) dynamics. The strong reduction in anthropogenic activities resulted in a marked decrease in dissolved organic carbon (DOC) concentration in the Arno River (-44%) and the coastal area affected by its input (-15%), compared to previous conditions. The DOM optical properties (absorption and fluorescence) showed a change in its quality, with a shift toward smaller and less aromatic molecules during the lockdown. The reduced human activity and the consequent change in DOM dynamics affected the abundance and annual dynamics of heterotrophic prokaryotes. The results of this study highlight the extent to which DOM dynamics in small rivers is affected by secondary and tertiary human activities as well as the quite short time scales to return to the impacted conditions. Our work also supports the importance of long-term research to disentangle the effects of casual events from the natural variability.
Collapse
Affiliation(s)
| | - G Cossarini
- Istituto Nazionale di Oceanografia e Geofisica Sperimentale. Sgonico (TS), Italy.
| | - G Bachi
- Istituto di Biofisica, CNR, Pisa, Italy
| | - C Balestra
- Istituto Nazionale di Oceanografia e Geofisica Sperimentale. Sgonico (TS), Italy.
| | - E Camatti
- Istituto di Biofisica, CNR, Pisa, Italy; Istituto di Scienze Marine, CNR, Venezia, Italy.
| | - R Casotti
- Stazione Zoologica Anton Dohrn, Napoli, Italy.
| | | | - S Colella
- Istituto di Scienze Marine, CNR, Roma, Italy.
| | | | - F Falcini
- Istituto di Scienze Marine, CNR, Roma, Italy.
| | - F Francocci
- Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino, CNR, Roma, Italy.
| | - T Giorgino
- Istituto di Biofisica, CNR. Milano, Italy.
| | - F Margiotta
- Stazione Zoologica Anton Dohrn, Napoli, Italy.
| | - M Ribera d'Alcalà
- Stazione Zoologica Anton Dohrn, Napoli, Italy; Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino, CNR, Roma, Italy.
| | - M Sprovieri
- Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino, CNR. Campobello di Mazara (TP), Italy.
| | - S Vestri
- Istituto di Biofisica, CNR, Pisa, Italy.
| | | |
Collapse
|
6
|
Zhao L, Brugel S, Ramasamy KP, Andersson A. Response of Coastal Shewanella and Duganella Bacteria to Planktonic and Terrestrial Food Substrates. Front Microbiol 2022; 12:726844. [PMID: 35250896 PMCID: PMC8888917 DOI: 10.3389/fmicb.2021.726844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Global warming scenarios indicate that in subarctic regions, the precipitation will increase in the future. Coastal bacteria will thus receive increasing organic carbon sources from land runoff. How such changes will affect the function and taxonomic composition of coastal bacteria is poorly known. We performed a 10-day experiment with two isolated bacteria: Shewanella baltica from a seaside location and Duganella sp. from a river mouth, and provided them with a plankton and a river extract as food substrate. The bacterial growth and carbon consumption were monitored over the experimental period. Shewanella and Duganella consumed 40% and 30% of the plankton extract, respectively, while the consumption of the river extract was low for both bacteria, ∼1%. Shewanella showed the highest bacterial growth efficiency (BGE) (12%) when grown on plankton extract, while when grown on river extract, the BGE was only 1%. Duganella showed low BGE when grown on plankton extract (< 1%) and slightly higher BGE when grown on river extract (2%). The cell growth yield of Duganella was higher than that of Shewanella when grown on river extract. These results indicate that Duganella is more adapted to terrestrial organic substrates with low nutritional availability, while Shewanella is adapted to eutrophied conditions. The different growth performance of the bacteria could be traced to genomic variations. A closely related genome of Shewanella was shown to harbor genes for the sequestration of autochthonously produced carbon substrates, while Duganella contained genes for the degradation of relatively refractive terrestrial organic matter. The results may reflect the influence of environmental drivers on bacterial community composition in natural aquatic environments. Elevated inflows of terrestrial organic matter to coastal areas in subarctic regions would lead to increased occurrence of bacteria adapted to the degradation of complex terrestrial compounds with a low bioavailability.
Collapse
Affiliation(s)
- Li Zhao
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
- Umeå Marine Sciences Centre, Umeå University, Hörnefors, Sweden
| | - Sonia Brugel
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
- Umeå Marine Sciences Centre, Umeå University, Hörnefors, Sweden
| | - Kesava Priyan Ramasamy
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
- Umeå Marine Sciences Centre, Umeå University, Hörnefors, Sweden
| | - Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
- Umeå Marine Sciences Centre, Umeå University, Hörnefors, Sweden
| |
Collapse
|
7
|
Wang Y, Liu J, Liem-Nguyen V, Tian S, Zhang S, Wang D, Jiang T. Binding strength of mercury (II) to different dissolved organic matter: The roles of DOM properties and sources. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150979. [PMID: 34687708 DOI: 10.1016/j.scitotenv.2021.150979] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/09/2021] [Accepted: 10/10/2021] [Indexed: 06/13/2023]
Abstract
Dissolved organic matter (DOM) influences the environmental fate and toxic effects of trace metals such as mercury (Hg). However, because of limits in DOM analytical techniques and lack of sample diversity in past studies, it remains unclear whether the binding strength of DOM complexed with Hg(II) is related to the DOM properties. In this study, different DOM isolates (n = 26) from various sources were used to determine the conditional stability constant (logK) of DOM-Hg complexes using the equilibrium dialysis ligand exchange (EDLE) method. UV-Vis and fluorescence spectrometry were used to evaluate the correlation between logK values and DOM properties, such as chromophoric moieties, aromaticity, and molecular weight. Results demonstrated that the DOM from different sources presented an extensive range of binding strengths to Hg(II), because of their heterogeneous properties. Moreover, DOM chromophores, including aromaticity and molecular weight, are critical indicators of the DOM-Hg affinity in ambient-relevant circumstances. Significantly, higher terrestrial DOM led to greater DOM-Hg affinity. Additionally, this study supports that UV-Vis and fluorescence spectroscopy can be used to estimate DOM composition and its binding strength with Hg(II). Furthermore, the observed relationship between logK and DOM properties provided a possible pathway of explanation for the spatial co-variations between Hg(II) concentrations and DOM characters observed in previous field investigations.
Collapse
Affiliation(s)
- Yuqin Wang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Jiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
| | - Van Liem-Nguyen
- Laboratory of Advanced Materials Chemistry, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Viet Nam; Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Viet Nam
| | - Shanyi Tian
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Siqi Zhang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Dingyong Wang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Tao Jiang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China.
| |
Collapse
|
8
|
Hollarsmith JA, Andrews K, Naar N, Starko S, Calloway M, Obaza A, Buckner E, Tonnes D, Selleck J, Therriault TW. Toward a conceptual framework for managing and conserving marine habitats: A case study of kelp forests in the Salish Sea. Ecol Evol 2022; 12:e8510. [PMID: 35136559 PMCID: PMC8809449 DOI: 10.1002/ece3.8510] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/30/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022] Open
Abstract
Kelp forests are in decline across much of their range due to place-specific combinations of local and global stressors. Declines in kelp abundance can lead to cascading losses of biodiversity and productivity with far-reaching ecological and socioeconomic consequences. The Salish Sea is a hotspot of kelp diversity where many species of kelp provide critical habitat and food for commercially, ecologically, and culturally important fish and invertebrate species. However, like other regions, kelp forests in much of the Salish Sea are in rapid decline. Data gaps and limited long-term monitoring have hampered attempts to identify and manage for specific drivers of decline, despite the documented urgency to protect these important habitats. To address these knowledge gaps, we gathered a focus group of experts on kelp in the Salish Sea to identify perceived direct and indirect stressors facing kelp forests. We then conducted a comprehensive literature review of peer-reviewed studies from the Salish Sea and temperate coastal ecosystems worldwide to assess the level of support for the pathways identified by the experts, and we identified knowledge gaps to prioritize future research. Our results revealed major research gaps within the Salish Sea and highlighted the potential to use expert knowledge for making informed decisions in the region. We found high support for the pathways in the global literature, with variable consensus on the relationship between stressors and responses across studies, confirming the influence of local ecological, oceanographic, and anthropogenic contexts and threshold effects on stressor-response relationships. Finally, we prioritized areas for future research in the Salish Sea. This study demonstrates the value expert opinion has to inform management decisions. These methods are readily adaptable to other ecosystem management contexts, and the results of this case study can be immediately applied to kelp management.
Collapse
Affiliation(s)
- Jordan A. Hollarsmith
- Alaska Fisheries Science CenterNational Marine Fisheries ServiceNational Oceanic and Atmospheric AdministrationSeattleWashingtonUSA
- Department of Biological SciencesSimon Fraser UniversityBurnabyBritish ColumbiaCanada
- Pacific Biological Station, Fisheries and Oceans CanadaNanaimoBritish ColumbiaCanada
| | - Kelly Andrews
- Conservation Biology DivisionNorthwest Fisheries Science CenterNational Marine Fisheries ServiceNational Oceanic and Atmospheric AdministrationSeattleWashingtonUSA
| | - Nicole Naar
- Washington Sea GrantCollege of the EnvironmentUniversity of WashingtonSeattleWashingtonUSA
| | - Samuel Starko
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Max Calloway
- Aquatic Resources DivisionWashington Department of Natural ResourcesNearshore Habitat ProgramOlympiaWashingtonUSA
| | - Adam Obaza
- Paua Marine Research GroupSan DiegoCaliforniaUSA
| | - Emily Buckner
- Washington Sea GrantCollege of the EnvironmentUniversity of WashingtonSeattleWashingtonUSA
- Puget Sound Restoration FundBainbridge IslandWashingtonUSA
| | - Daniel Tonnes
- West Coast RegionNational Marine Fisheries ServiceNational Oceanic and Atmospheric AdministrationSeattleWashingtonUSA
| | - James Selleck
- West Coast RegionNational Marine Fisheries ServiceNational Oceanic and Atmospheric AdministrationSeattleWashingtonUSA
| | - Thomas W. Therriault
- Pacific Biological Station, Fisheries and Oceans CanadaNanaimoBritish ColumbiaCanada
| |
Collapse
|
9
|
Huss M, van Dorst RM, Gårdmark A. Larval fish body growth responses to simultaneous browning and warming. Ecol Evol 2021; 11:15132-15140. [PMID: 34765165 PMCID: PMC8571572 DOI: 10.1002/ece3.8194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/16/2021] [Accepted: 09/02/2021] [Indexed: 12/25/2022] Open
Abstract
Organisms are facing global climate change and other anthropogenic pressures, but most research on responses to such changes only considers effects of single drivers. Observational studies and physiological experiments suggest temperature increases will lead to faster growth of small fish. Whether this effect of warming holds in more natural food web settings with concurrent changes in other drivers, such as darkening water color ("browning") is, however, unknown. Here, we set up a pelagic mesocosm experiment with large bags in the Baltic Sea archipelago, inoculated with larval Eurasian perch (Perca fluviatilis) and zooplankton prey and varying in temperature and color, to answer the question how simultaneous warming and browning of coastal food webs impact body growth and survival of larval perch. We found that browning decreased body growth and survival of larval perch, whereas warming increased body growth but had no effect on survival. Based on daily fish body growth estimates based on otolith microstructure analysis, and size composition and abundance of available prey, we explain how these results may come about through a combination of physiological responses to warming and lower foraging efficiency in brown waters. We conclude that larval fish responses to climate change thus may depend on the relative rate and extent of both warming and browning, as they may even cancel each other out.
Collapse
Affiliation(s)
- Magnus Huss
- Department of Aquatic ResourcesSwedish University of Agricultural SciencesÖregrundSweden
| | - Renee M. van Dorst
- Department of Aquatic ResourcesSwedish University of Agricultural SciencesÖregrundSweden
- Department of Biology and Ecology of FishesLeibniz‐Institute of Freshwater Ecology and Inland FisheriesBerlinGermany
| | - Anna Gårdmark
- Department of Aquatic ResourcesSwedish University of Agricultural SciencesÖregrundSweden
| |
Collapse
|
10
|
Figueroa D, Capo E, Lindh MV, Rowe OF, Paczkowska J, Pinhassi J, Andersson A. Terrestrial dissolved organic matter inflow drives temporal dynamics of the bacterial community of a subarctic estuary (northern Baltic Sea). Environ Microbiol 2021; 23:4200-4213. [PMID: 33998121 DOI: 10.1111/1462-2920.15597] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/29/2021] [Accepted: 04/15/2021] [Indexed: 11/29/2022]
Abstract
Climate change is projected to cause increased inflow of terrestrial dissolved organic matter to coastal areas in northerly regions. Estuarine bacterial community will thereby receive larger loads of organic matter and inorganic nutrients available for microbial metabolism. The composition of the bacterial community and its ecological functions may thus be affected. We studied the responses of bacterial community to inflow of terrestrial dissolved organic matter in a subarctic estuary in the northern Baltic Sea, using a 16S rRNA gene metabarcoding approach. Betaproteobacteria dominated during the spring river flush, constituting ~ 60% of the bacterial community. Bacterial diversity increased as the runoff decreased during summer, when Verrucomicrobia, Betaproteobacteria, Bacteroidetes, Gammaproteobacteria and Planctomycetes dominated the community. Network analysis revealed that a larger number of associations between bacterial populations occurred during the summer than in spring. Betaproteobacteria and Bacteroidetes populations appeared to display similar correlations to environmental factors. In spring, freshly discharged organic matter favoured specialists, while in summer a mix of autochthonous and terrestrial organic matter promoted the development of generalists. Our study indicates that increased inflows of terrestrial organic matter-loaded freshwater to coastal areas would promote specialist bacteria, which in turn might enhance the transformation of terrestrial organic matter in estuarine environments.
Collapse
Affiliation(s)
- Daniela Figueroa
- Department of Ecology and Environmental Science, Umeå University, Umeå, SE-901 87, Sweden.,Umeå Marine Sciences Centre, Hörnefors, SE-905 71, Sweden
| | - Eric Capo
- Department of Ecology and Environmental Science, Umeå University, Umeå, SE-901 87, Sweden
| | - Markus V Lindh
- Ecology and Evolution in Microbial Model Systems, EEMiS, Linnaeus University, Kalmar, SE-391 82, Sweden
| | - Owen F Rowe
- Baltic Marine Environment Protection Commission HELCOM, Helsinki, FI-00160, Finland
| | - Joanna Paczkowska
- Department of Ecology and Environmental Science, Umeå University, Umeå, SE-901 87, Sweden.,Umeå Marine Sciences Centre, Hörnefors, SE-905 71, Sweden
| | - Jarone Pinhassi
- Ecology and Evolution in Microbial Model Systems, EEMiS, Linnaeus University, Kalmar, SE-391 82, Sweden
| | - Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, Umeå, SE-901 87, Sweden.,Umeå Marine Sciences Centre, Hörnefors, SE-905 71, Sweden
| |
Collapse
|
11
|
Abstract
The ocean is a lifeline for human existence, but current practices risk severely undermining ocean sustainability. Present and future social−ecological challenges necessitate the maintenance and development of knowledge and action by stimulating collaboration among scientists and between science, policy, and practice. Here we explore not only how such collaborations have developed in the Nordic countries and adjacent seas but also how knowledge from these regions contributes to an understanding of how to obtain a sustainable ocean. Our collective experience may be summarized in three points: 1) In the absence of long-term observations, decision-making is subject to high risk arising from natural variability; 2) in the absence of established scientific organizations, advice to stakeholders often relies on a few advisors, making them prone to biased perceptions; and 3) in the absence of trust between policy makers and the science community, attuning to a changing ocean will be subject to arbitrary decision-making with unforeseen and negative ramifications. Underpinning these observations, we show that collaboration across scientific disciplines and stakeholders and between nations is a necessary condition for appropriate actions.
Collapse
|
12
|
Kritzberg ES, Hasselquist EM, Škerlep M, Löfgren S, Olsson O, Stadmark J, Valinia S, Hansson LA, Laudon H. Browning of freshwaters: Consequences to ecosystem services, underlying drivers, and potential mitigation measures. AMBIO 2020; 49:375-390. [PMID: 31367885 PMCID: PMC6965042 DOI: 10.1007/s13280-019-01227-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/03/2019] [Accepted: 07/10/2019] [Indexed: 05/05/2023]
Abstract
Browning of surface waters, as a result of increasing dissolved organic carbon and iron concentrations, is a widespread phenomenon with implications to the structure and function of aquatic ecosystems. In this article, we provide an overview of the consequences of browning in relation to ecosystem services, outline what the underlying drivers and mechanisms of browning are, and specifically focus on exploring potential mitigation measures to locally counteract browning. These topical concepts are discussed with a focus on Scandinavia, but are of relevance also to other regions. Browning is of environmental concern as it leads to, e.g., increasing costs and risks for drinking water production, and reduced fish production in lakes by limiting light penetration. While climate change, recovery from acidification, and land-use change are all likely factors contributing to the observed browning, managing the land use in the hydrologically connected parts of the landscape may be the most feasible way to counteract browning of natural waters.
Collapse
Affiliation(s)
- Emma S. Kritzberg
- Biology Department, Lund University, Ecology Building, Sölvegatan 37, 223 62 Lund, Sweden
| | - Eliza Maher Hasselquist
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Skogsmarksgränd, 901 83 Umeå, Sweden
| | - Martin Škerlep
- Biology Department, Lund University, Ecology Building, Sölvegatan 37, 223 62 Lund, Sweden
| | - Stefan Löfgren
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), P.O. Box 7050, 750 07 Uppsala, Sweden
| | - Olle Olsson
- Stockholm Environment Institute, Linnégatan 87D, P.O. Box 242 18, 104 51 Stockholm, Sweden
| | - Johanna Stadmark
- IVL Svenska Miljöinstitutet, Box 530 21, 400 14 Göteborg, Sweden
| | | | - Lars-Anders Hansson
- Biology Department, Lund University, Ecology Building, Sölvegatan 37, 223 62 Lund, Sweden
| | - Hjalmar Laudon
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Skogsmarksgränd, 901 83 Umeå, Sweden
| |
Collapse
|
13
|
Paczkowska J, Rowe OF, Figueroa D, Andersson A. Drivers of phytoplankton production and community structure in nutrient-poor estuaries receiving terrestrial organic inflow. MARINE ENVIRONMENTAL RESEARCH 2019; 151:104778. [PMID: 31488340 DOI: 10.1016/j.marenvres.2019.104778] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
The influence of nutrient availability and light conditions on phytoplankton size-structure, nutritional strategy and production was studied in a phosphorus-poor estuary in the northern Baltic Sea receiving humic-rich river water. The relative biomass of mixotrophic nanophytoplankton peaked in spring when heterotrophic bacterial production was high, while autotrophic microphytoplankton had their maximum in summer when primary production displayed highest values. Limiting substance (phosphorus) only showed small temporal variations, and the day light was at saturating levels all through the study period. We also investigated if the phytoplankton taxonomic richness influences the production. Structural equation modelling indicated that an increase of the taxonomic richness during the warm summer combined with slightly higher phosphorus concentration lead to increased resource use efficiency, which in turn caused higher phytoplankton biomass and primary production. Our results suggest that climate warming would lead to higher primary production in northerly shallow coastal areas, which are influenced by humic-rich river run-off from un-disturbed terrestrial systems.
Collapse
Affiliation(s)
- Joanna Paczkowska
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden; Umeå Marine Sciences Centre, SE-905 71, Hörnefors, Sweden; Centro para el Estudio de Sistemas Marinos CESIMAR-CONICET, Blvd. Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina
| | - Owen F Rowe
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden; Umeå Marine Sciences Centre, SE-905 71, Hörnefors, Sweden; Guest researcher: Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, Viikki Biocenter 1, University of Helsinki, Helsinki, Finland; Helsinki Commission, HELCOM Secretariat, Baltic Marine Environment Protection Commission, Helsinki, Finland
| | - Daniela Figueroa
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden; Umeå Marine Sciences Centre, SE-905 71, Hörnefors, Sweden; Swedish Meteorological and Hydrological Institute, SMHI, Göteborg, Sweden
| | - Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden; Umeå Marine Sciences Centre, SE-905 71, Hörnefors, Sweden.
| |
Collapse
|
14
|
Sundell K, Wrange AL, Jonsson PR, Blomberg A. Osmoregulation in Barnacles: An Evolutionary Perspective of Potential Mechanisms and Future Research Directions. Front Physiol 2019; 10:877. [PMID: 31496949 PMCID: PMC6712927 DOI: 10.3389/fphys.2019.00877] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/24/2019] [Indexed: 11/13/2022] Open
Abstract
Barnacles form a globally ubiquitous group of sessile crustaceans that are particularly common in the coastal intertidal. Several barnacle species are described as highly euryhaline and a few species even have the ability to colonize estuarine and brackish habitats below 5 PSU. However, the physiological and/or morphological adaptations that allow barnacles to live at low salinities are poorly understood and current knowledge is largely based on classical eco-physiological studies offering limited insight into the molecular mechanisms. This review provides an overview of available knowledge of salinity tolerance in barnacles and what is currently known about their osmoregulatory strategies. To stimulate future studies on barnacle euryhalinity, we briefly review and compare barnacles to other marine invertebrates with known mechanisms of osmoregulation with focus on crustaceans. Different mechanisms are described based on the current understanding of molecular biology and integrative physiology of osmoregulation. We focus on ion and water transport across epithelial cell layers, including transport mechanisms across cell membranes and paracellular transfer across tight junctions as well as on the use of intra- and extracellular osmolytes. Based on this current knowledge, we discuss the osmoregulatory mechanisms possibly present in barnacles. We further discuss evolutionary consequences of barnacle osmoregulation including invasion-success in new habitats and life-history evolution. Tolerance to low salinities may play a crucial role in determining future distributions of barnacles since forthcoming climate-change scenarios predict decreased salinity in shallow coastal areas. Finally, we outline future research directions to identify osmoregulatory tissues, characterize physiological and molecular mechanisms, and explore ecological and evolutionary implications of osmoregulation in barnacles.
Collapse
Affiliation(s)
- Kristina Sundell
- Department of Biological and Environmental Sciences and Swedish Mariculture Research Center (SWEMARC), University of Gothenburg, Gothenburg, Sweden
| | - Anna-Lisa Wrange
- IVL Swedish Environmental Research Institute, Fiskebäckskil, Sweden
| | - Per R Jonsson
- Department of Marine Sciences, Tjärnö Marine Laboratory, University of Gothenburg, Gothenburg, Sweden
| | - Anders Blomberg
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
15
|
Havenhand JN, Filipsson HL, Niiranen S, Troell M, Crépin AS, Jagers S, Langlet D, Matti S, Turner D, Winder M, de Wit P, Anderson LG. Ecological and functional consequences of coastal ocean acidification: Perspectives from the Baltic-Skagerrak System. AMBIO 2019; 48:831-854. [PMID: 30506502 PMCID: PMC6541583 DOI: 10.1007/s13280-018-1110-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/21/2018] [Accepted: 10/03/2018] [Indexed: 05/03/2023]
Abstract
Ocean temperatures are rising; species are shifting poleward, and pH is falling (ocean acidification, OA). We summarise current understanding of OA in the brackish Baltic-Skagerrak System, focussing on the direct, indirect and interactive effects of OA with other anthropogenic drivers on marine biogeochemistry, organisms and ecosystems. Substantial recent advances reveal a pattern of stronger responses (positive or negative) of species than ecosystems, more positive responses at lower trophic levels and strong indirect interactions in food-webs. Common emergent themes were as follows: OA drives planktonic systems toward the microbial loop, reducing energy transfer to zooplankton and fish; and nutrient/food availability ameliorates negative impacts of OA. We identify several key areas for further research, notably the need for OA-relevant biogeochemical and ecosystem models, and understanding the ecological and evolutionary capacity of Baltic-Skagerrak ecosystems to respond to OA and other anthropogenic drivers.
Collapse
Affiliation(s)
- Jonathan N. Havenhand
- Department of Marine Sciences, Tjärnö Marine Laboratory, University of Gothenburg, Strömstad, 45296 Gothenburg, Sweden
| | | | - Susa Niiranen
- Stockholm Resilience Centre, Stockholm University, Kräftriket 2B, 10691 Stockholm, Sweden
| | - Max Troell
- Stockholm Resilience Centre, Stockholm University, Kräftriket 2B, 10691 Stockholm, Sweden
- Beijer Institute of Ecological Economics, Royal Swedish Academy of Science, Lilla Frescativägen 4, 10405 Stockholm, Sweden
| | - Anne-Sophie Crépin
- Beijer Institute of Ecological Economics, Royal Swedish Academy of Science, Lilla Frescativägen 4, 10405 Stockholm, Sweden
| | - Sverker Jagers
- Department of Political Sciences, University of Gothenburg, Box 711, Sprängkullsgatan 19, 40530 Gothenburg, Sweden
| | - David Langlet
- Department of Law, University of Gothenburg, Box 650, 40530 Gothenburg, Sweden
| | - Simon Matti
- Department of Political Sciences, Luleå University of Technology, 97187 Luleå, Sweden
| | - David Turner
- Department of Marine Sciences, University of Gothenburg, Box 461, 40530 Gothenburg, Sweden
| | - Monika Winder
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691 Stockholm, Sweden
| | - Pierre de Wit
- Department of Marine Sciences, Tjärnö Marine Laboratory, University of Gothenburg, Strömstad, 45296 Gothenburg, Sweden
| | - Leif G. Anderson
- Department of Marine Sciences, University of Gothenburg, Box 461, 40530 Gothenburg, Sweden
| |
Collapse
|
16
|
Ejsmond MJ, Blackburn N, Fridolfsson E, Haecky P, Andersson A, Casini M, Belgrano A, Hylander S. Modeling vitamin B 1 transfer to consumers in the aquatic food web. Sci Rep 2019; 9:10045. [PMID: 31296876 PMCID: PMC6624374 DOI: 10.1038/s41598-019-46422-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 06/26/2019] [Indexed: 11/10/2022] Open
Abstract
Vitamin B1 is an essential exogenous micronutrient for animals. Mass death and reproductive failure in top aquatic consumers caused by vitamin B1 deficiency is an emerging conservation issue in Northern hemisphere aquatic ecosystems. We present for the first time a model that identifies conditions responsible for the constrained flow of vitamin B1 from unicellular organisms to planktivorous fishes. The flow of vitamin B1 through the food web is constrained under anthropogenic pressures of increased nutrient input and, driven by climatic change, increased light attenuation by dissolved substances transported to marine coastal systems. Fishing pressure on piscivorous fish, through increased abundance of planktivorous fish that overexploit mesozooplankton, may further constrain vitamin B1 flow from producers to consumers. We also found that key ecological contributors to the constrained flow of vitamin B1 are a low mesozooplankton biomass, picoalgae prevailing among primary producers and low fluctuations of population numbers of planktonic organisms.
Collapse
Affiliation(s)
- M J Ejsmond
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, 30-387, Kraków, Poland.
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, 39182, Kalmar, Sweden.
| | - N Blackburn
- BIORAS, Hejreskovvej 18B, Copenhagen, Denmark
| | - E Fridolfsson
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, 39182, Kalmar, Sweden
| | - P Haecky
- BIORAS, Hejreskovvej 18B, Copenhagen, Denmark
| | - A Andersson
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden
- Umeå Marine Sciences Centre, SE-905 71, Hörnefors, Sweden
| | - M Casini
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Turistgatan 5, 45330, Lysekil, Sweden
| | - A Belgrano
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Turistgatan 5, 45330, Lysekil, Sweden
- Swedish Institute for the Marine Environment (SIME), University of Gothenburg, Box 260, SE-405 30, Gothenburg, Sweden
| | - S Hylander
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, 39182, Kalmar, Sweden
| |
Collapse
|
17
|
Soares ARA, Berggren M. Indirect link between riverine dissolved organic matter and bacterioplankton respiration in a boreal estuary. MARINE ENVIRONMENTAL RESEARCH 2019; 148:39-45. [PMID: 31078961 DOI: 10.1016/j.marenvres.2019.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 02/21/2019] [Accepted: 04/18/2019] [Indexed: 06/09/2023]
Abstract
Increasing loading of terrestrially derived dissolved organic matter tends to enhance bacterioplankton respiration (BR) in boreal estuaries, but knowledge on the mechanisms behind this effect is not complete. We determined the stable isotopic signature of the reactive estuarine dissolved organic carbon (DOC) in the Öre estuary (Baltic Sea) by using the Keeling plot method. The δ13C ratio of the estuarine labile DOC varied from -26.0‰ to -18.7‰ with most values resembling those typical for DOC of coastal phytoplanktonic origin (-18 to -24‰), while being distinctly higher than those of DOC from ter-res-trial sources (-28‰ to -27‰). Furthermore, the δ13C of the respired carbon was positively correlated to DOC concentrations, indicating that carbon of marine origin increasingly dominated the reactive substrates when input of organic matter into the estuary became higher. This suggests that riverine organic matter mainly affects BR indirectly, by providing nutrients that stimulate the production of phytoplankton-derived reactive DOC in the estuary. Thus, riverine derived DOC per se may not be as important for coastal CO2 emissions as previously thought.
Collapse
Affiliation(s)
- Ana R A Soares
- Department Of Physical Geography And Ecosystem Science, Lund University, SE-223 62, Lund, Sweden.
| | - Martin Berggren
- Department Of Physical Geography And Ecosystem Science, Lund University, SE-223 62, Lund, Sweden
| |
Collapse
|
18
|
Carstensen J, Duarte CM. Drivers of pH Variability in Coastal Ecosystems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4020-4029. [PMID: 30892892 DOI: 10.1021/acs.est.8b03655] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A synthesis of long-term changes in pH of coastal ecosystems shows that, in contrast to the uniform trends of open-ocean acidification (-0.0004 to -0.0026 pH units yr-1) driven by increased atmospheric CO2, coastal ecosystems display a much broader range of trends (-0.023 to 0.023 pH units yr-1) and are as likely to show long-term increase as decline in pH. The majority of the 83 investigated coastal ecosystems displayed nonlinear trends, with seasonal and interannual variations exceeding 1 pH unit for some sites. The high pH variability of coastal ecosystems is primarily driven by inputs from land. These include freshwater inputs that typically dilute the alkalinity of seawater thereby resulting in reduced buffering, nutrients enhancing productivity and pH, as well as organic matter supporting excess respiration driving acidification. For some coastal ecosystems, upwelling of nutrient-rich and corrosive water may also contribute to variability in pH. Metabolic control of pH was the main factor governing variability for the majority of coastal sites, displaying larger variations in coastal ecosystems with low alkalinity buffering. pH variability was particularly pronounced in coastal ecosystems with strong decoupling of production and respiration processes, seasonally or through stratification. Our analysis demonstrate that coastal pH can be managed by controlling inputs of nutrients, organic matter, and alkalinity. In well-mixed coastal waters, increasing productivity can improve resistance to ocean acidification, whereas increasing productivity enhances acidification in bottom waters of stratified coastal ecosystems. Environmental management should consider the balance between the negative consequences of eutrophication versus those of acidification, to maintain biodiversity and ecosystem services of our coastal ecosystems.
Collapse
Affiliation(s)
- Jacob Carstensen
- Aarhus University , Department of Bioscience , Frederiksborgvej 399 , DK-4000 Roskilde , Denmark
| | - Carlos M Duarte
- King Abdullah University of Science and Technology (KAUST) , Red Sea Research Center (RSRC) , Thuwal , 23955-6900 , Saudi Arabia
- Arctic Research Centre, Department of Bioscience , Aarhus University , C.F. Møllers Allé 8 , DK-8000 Århus C , Denmark
| |
Collapse
|
19
|
Vikström K, Wikner J. Importance of Bacterial Maintenance Respiration in a Subarctic Estuary: a Proof of Concept from the Field. MICROBIAL ECOLOGY 2019; 77:574-586. [PMID: 30135980 PMCID: PMC6469616 DOI: 10.1007/s00248-018-1244-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 08/07/2018] [Indexed: 06/08/2023]
Abstract
Bacterial respiration contributes to atmospheric carbon dioxide accumulation and development of hypoxia and is a critical, often overlooked, component of ecosystem function. This study investigates the concept that maintenance respiration is a significant proportion of bacterial respiration at natural nutrient levels in the field, advancing our understanding of bacterial living conditions and energy strategies. Two river-sea transects of respiration and specific growth rates were analyzed representing low- and high-productivity conditions (by in situ bacterial biomass production) in a subarctic estuary, using an established ecophysiological linear model (the Pirt model) estimating maintenance respiration. The Pirt model was applicable to field conditions during high, but not low, bacterial biomass production. However, a quadratic model provided a better fit to observed data, accounting for the maintained respiration at low μ. A first estimate of maintenance respiration was 0.58 fmol O2 day-1 cell-1 by the quadratic model. Twenty percent to nearly all of the bacterial respiration was due to maintenance respiration over the observed range of μ (0.21-0.002 day-1). In the less productive condition, bacterial specific respiration was high and without dependence on μ, suggesting enhanced bacterial energy expenditure during starvation. Annual maintenance respiration accounted for 58% of the total bacterioplankton respiration based on μ from monitoring data. Phosphorus availability occasionally, but inconsistently, explained some of the remaining variation in bacterial specific respiration. Bacterial maintenance respiration can constitute a large share of pelagic respiration and merit further study to understand bacterial energetics and oxygen dynamics in the aquatic environment.
Collapse
Affiliation(s)
- Kevin Vikström
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden
| | - Johan Wikner
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden.
- Umeå Marine Sciences Center, Norrbyn 557, SE-905 71, Hörnefors, Sweden.
| |
Collapse
|
20
|
Bunse C, Israelsson S, Baltar F, Bertos-Fortis M, Fridolfsson E, Legrand C, Lindehoff E, Lindh MV, Martínez-García S, Pinhassi J. High Frequency Multi-Year Variability in Baltic Sea Microbial Plankton Stocks and Activities. Front Microbiol 2019; 9:3296. [PMID: 30705671 PMCID: PMC6345115 DOI: 10.3389/fmicb.2018.03296] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/18/2018] [Indexed: 11/17/2022] Open
Abstract
Marine bacterioplankton are essential in global nutrient cycling and organic matter turnover. Time-series analyses, often at monthly sampling frequencies, have established the paramount role of abiotic and biotic variables in structuring bacterioplankton communities and productivities. However, fine-scale seasonal microbial activities, and underlying biological principles, are not fully understood. We report results from four consecutive years of high-frequency time-series sampling in the Baltic Proper. Pronounced temporal dynamics in most investigated microbial variables were observed, including bacterial heterotrophic production, plankton biomass, extracellular enzyme activities, substrate uptake rate constants of glucose, pyruvate, acetate, amino acids, and leucine, as well as nutrient limitation bioassays. Spring blooms consisting of diatoms and dinoflagellates were followed by elevated bacterial heterotrophic production and abundances. During summer, bacterial productivity estimates increased even further, coinciding with an initial cyanobacterial bloom in early July. However, bacterial abundances only increased following a second cyanobacterial bloom, peaking in August. Uptake rate constants for the different measured carbon compounds varied seasonally and inter-annually and were highly correlated to bacterial productivity estimates, temperature, and cyanobacterial abundances. Further, we detected nutrient limitation in response to environmental conditions in a multitude of microbial variables, such as elevated productivities in nutrient bioassays, changes in enzymatic activities, or substrate preferences. Variations among biotic variables often occurred on time scales of days to a few weeks, yet often spanning several sampling occasions. Such dynamics might not have been captured by sampling at monthly intervals, as compared to more predictable transitions in abiotic variables such as temperature or nutrient concentrations. Our study indicates that high resolution analyses of microbial biomass and productivity parameters can help out in the development of biogeochemical and food web models disentangling the microbial black box.
Collapse
Affiliation(s)
- Carina Bunse
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Stina Israelsson
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Federico Baltar
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Mireia Bertos-Fortis
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Emil Fridolfsson
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Catherine Legrand
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Elin Lindehoff
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Markus V Lindh
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Sandra Martínez-García
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| | - Jarone Pinhassi
- Centre for Ecology and Evolution in Microbial Model Systems - EEMiS, Linnaeus University, Kalmar, Sweden
| |
Collapse
|
21
|
Kataržytė M, Mėžinė J, Vaičiūtė D, Liaugaudaitė S, Mukauskaitė K, Umgiesser G, Schernewski G. Fecal contamination in shallow temperate estuarine lagoon: Source of the pollution and environmental factors. MARINE POLLUTION BULLETIN 2018; 133:762-772. [PMID: 30041374 DOI: 10.1016/j.marpolbul.2018.06.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 06/05/2018] [Accepted: 06/08/2018] [Indexed: 06/08/2023]
Abstract
In inner coastal waters such as lagoons, which are very turbid and rich in suspended particles, the survival of fecal pollution microorganisms may find favorable environments. In order to better characterize the sources and dynamics of fecal pollution in a strongly turbid environment, in situ observations were made in the Curonian Lagoon. A combination of traditional monitoring and molecular methods were used. To monitor the water quality, the indicator Escherichia coli (EC) was selected as a proxy for fecal contamination. E. coli concentration correlated with environmental parameters as pH, oxygen and turbidity. The main pollution sources are the sewage outlets in the lagoon area, while the pollution coming via rivers did not play a significant role. Still the human associated E. coli consisted only of 0 up to 20% of analyzed isolates, and did not correlate with the E. coli concentrations in the study sites. The role of birds, especially for potentially virulent E. coli may be underestimated in the lagoon.
Collapse
Affiliation(s)
- M Kataržytė
- Marine Research Institute, Klaipėda University, H. Manto 84, LT-92294 Klaipeda, Lithuania.
| | - J Mėžinė
- Marine Research Institute, Klaipėda University, H. Manto 84, LT-92294 Klaipeda, Lithuania
| | - D Vaičiūtė
- Marine Research Institute, Klaipėda University, H. Manto 84, LT-92294 Klaipeda, Lithuania
| | - S Liaugaudaitė
- Marine Research Institute, Klaipėda University, H. Manto 84, LT-92294 Klaipeda, Lithuania
| | - K Mukauskaitė
- Marine Research Institute, Klaipėda University, H. Manto 84, LT-92294 Klaipeda, Lithuania
| | - G Umgiesser
- ISMAR-CNR, Institute of Marine Sciences - National Research Council, Castello 2737/F, 30122 Venice, Italy; Marine Research Institute, Klaipėda University, H. Manto 84, LT-92294 Klaipeda, Lithuania
| | - G Schernewski
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Seestrasse 15, D-18119 Rostock, Germany; Marine Research Institute, Klaipėda University, H. Manto 84, LT-92294 Klaipeda, Lithuania
| |
Collapse
|
22
|
Soares ARA, Kritzberg ES, Custelcean I, Berggren M. Bacterioplankton Responses to Increased Organic Carbon and Nutrient Loading in a Boreal Estuary-Separate and Interactive Effects on Growth and Respiration. MICROBIAL ECOLOGY 2018; 76:144-155. [PMID: 29255936 PMCID: PMC6061467 DOI: 10.1007/s00248-017-1115-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/20/2017] [Indexed: 06/07/2023]
Abstract
Increases in the terrestrial export of dissolved organic carbon (C) to rivers may be associated with additional loading of organic nitrogen (N) and phosphorus (P) to the coastal zone. However, little is known about how these resources interact in the regulation of heterotrophic bacterioplankton metabolism in boreal coastal ecosystems. Here, we measured changes in bacterioplankton production (BP) and respiration (BR) in response to full-factorial (C, N, and P) enrichment experiments at two sites within the Öre estuary, northern Sweden. The BR was stimulated by single C additions and further enhanced by combined additions of C and other nutrients. Single addition of N or P had no effect on BR rates. In contrast, BP was primarily limited by P at the site close to the river mouth and did not respond to C or N additions. However, at the site further away from the near the river mouth, BP was slightly stimulated by single additions of C. Possibly, the natural inflow of riverine bioavailable dissolved organic carbon induced local P limitation of BP near the river mouth, which was then exhausted and resulted in C-limited BP further away from the river mouth. We observed positive interactions between all elements on all responses except for BP at the site close to the river mouth, where P showed an independent effect. In light of predicted increases in terrestrial P and C deliveries, we expect future increases in BP and increases of BR of terrestrially delivered C substrates at the Öre estuary and similar areas.
Collapse
Affiliation(s)
- Ana R A Soares
- Department of Physical Geography and Ecosystem Science, Lund University, SE-223 62, Lund, Sweden.
| | - Emma S Kritzberg
- Department of Biology/Aquatic Ecology, Lund University, SE-223 62, Lund, Sweden
| | - Ioana Custelcean
- Department of Physical Geography and Ecosystem Science, Lund University, SE-223 62, Lund, Sweden
| | - Martin Berggren
- Department of Physical Geography and Ecosystem Science, Lund University, SE-223 62, Lund, Sweden
| |
Collapse
|
23
|
Allochthonous Organic Matter Supports Benthic but Not Pelagic Food Webs in Shallow Coastal Ecosystems. Ecosystems 2018. [DOI: 10.1007/s10021-018-0233-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
24
|
Tamelander T, Spilling K, Winder M. Organic matter export to the seafloor in the Baltic Sea: Drivers of change and future projections. AMBIO 2017; 46:842-851. [PMID: 28647909 PMCID: PMC5639801 DOI: 10.1007/s13280-017-0930-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/05/2017] [Accepted: 06/09/2017] [Indexed: 06/10/2023]
Abstract
The impact of environmental change and anthropogenic stressors on coastal marine systems will strongly depend on changes in the magnitude and composition of organic matter exported from the water column to the seafloor. Knowledge of vertical export in the Baltic Sea is synthesised to illustrate how organic matter deposition will respond to climate warming, climate-related changes in freshwater runoff, and ocean acidification. Pelagic heterotrophic processes are suggested to become more important in a future warmer climate, with negative feedbacks to organic matter deposition to the seafloor. This is an important step towards improved oxygen conditions in the near-bottom layer that will reduce the release of inorganic nutrients from the sediment and hence counteract further eutrophication. The evaluation of these processes in ecosystem models, validated by field observations, will significantly advance the understanding of the system's response to environmental change and will improve the use of such models in management of coastal areas.
Collapse
Affiliation(s)
- Tobias Tamelander
- Tvärminne Zoological Station, University of Helsinki, 10900 Hanko, Finland
| | - Kristian Spilling
- Marine Research Centre, Finnish Environment Institute, P.O. Box 140, 00251 Helsinki, Finland
| | - Monica Winder
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691 Stockholm, Sweden
| |
Collapse
|
25
|
Analyzing the effects of estuarine freshwater fluxes on fish abundance using artificial neural network ensembles. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2017.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
26
|
Sipler RE, Kellogg CTE, Connelly TL, Roberts QN, Yager PL, Bronk DA. Microbial Community Response to Terrestrially Derived Dissolved Organic Matter in the Coastal Arctic. Front Microbiol 2017. [PMID: 28649233 PMCID: PMC5465303 DOI: 10.3389/fmicb.2017.01018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Warming at nearly twice the global rate, higher than average air temperatures are the new ‘normal’ for Arctic ecosystems. This rise in temperature has triggered hydrological and geochemical changes that increasingly release carbon-rich water into the coastal ocean via increased riverine discharge, coastal erosion, and the thawing of the semi-permanent permafrost ubiquitous in the region. To determine the biogeochemical impacts of terrestrially derived dissolved organic matter (tDOM) on marine ecosystems we compared the nutrient stocks and bacterial communities present under ice-covered and ice-free conditions, assessed the lability of Arctic tDOM to coastal microbial communities from the Chukchi Sea, and identified bacterial taxa that respond to rapid increases in tDOM. Once thought to be predominantly refractory, we found that ∼7% of dissolved organic carbon and ∼38% of dissolved organic nitrogen from tDOM was bioavailable to receiving marine microbial communities on short 4 – 6 day time scales. The addition of tDOM shifted bacterial community structure toward more copiotrophic taxa and away from more oligotrophic taxa. Although no single order was found to respond universally (positively or negatively) to the tDOM addition, this study identified 20 indicator species as possible sentinels for increased tDOM. These data suggest the true ecological impact of tDOM will be widespread across many bacterial taxa and that shifts in coastal microbial community composition should be anticipated.
Collapse
Affiliation(s)
- Rachel E Sipler
- The Virginia Institute of Marine Science, College of William & Mary, Gloucester PointVA, United States
| | - Colleen T E Kellogg
- Department of Microbiology & Immunology, University of British Columbia, VancouverBC, Canada
| | - Tara L Connelly
- Department of Marine Sciences, University of Georgia, AthensGA, United States
| | - Quinn N Roberts
- The Virginia Institute of Marine Science, College of William & Mary, Gloucester PointVA, United States
| | - Patricia L Yager
- Department of Marine Sciences, University of Georgia, AthensGA, United States
| | - Deborah A Bronk
- The Virginia Institute of Marine Science, College of William & Mary, Gloucester PointVA, United States
| |
Collapse
|
27
|
Griffiths JR, Kadin M, Nascimento FJA, Tamelander T, Törnroos A, Bonaglia S, Bonsdorff E, Brüchert V, Gårdmark A, Järnström M, Kotta J, Lindegren M, Nordström MC, Norkko A, Olsson J, Weigel B, Žydelis R, Blenckner T, Niiranen S, Winder M. The importance of benthic-pelagic coupling for marine ecosystem functioning in a changing world. GLOBAL CHANGE BIOLOGY 2017; 23:2179-2196. [PMID: 28132408 DOI: 10.1111/gcb.13642] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 12/22/2016] [Accepted: 01/06/2017] [Indexed: 05/12/2023]
Abstract
Benthic-pelagic coupling is manifested as the exchange of energy, mass, or nutrients between benthic and pelagic habitats. It plays a prominent role in aquatic ecosystems, and it is crucial to functions from nutrient cycling to energy transfer in food webs. Coastal and estuarine ecosystem structure and function are strongly affected by anthropogenic pressures; however, there are large gaps in our understanding of the responses of inorganic nutrient and organic matter fluxes between benthic habitats and the water column. We illustrate the varied nature of physical and biological benthic-pelagic coupling processes and their potential sensitivity to three anthropogenic pressures - climate change, nutrient loading, and fishing - using the Baltic Sea as a case study and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. Traditionally measured benthic-pelagic coupling processes (e.g., nutrient exchange and sedimentation of organic material) are to some extent quantifiable, but the magnitude and variability of biological processes are rarely assessed, preventing quantitative comparisons. Changing oxygen conditions will continue to have widespread effects on the processes that govern inorganic and organic matter exchange among habitats while climate change and nutrient load reductions may have large effects on organic matter sedimentation. Many biological processes (predation, bioturbation) are expected to be sensitive to anthropogenic drivers, but the outcomes for ecosystem function are largely unknown. We emphasize how improved empirical and experimental understanding of benthic-pelagic coupling processes and their variability are necessary to inform models that can quantify the feedbacks among processes and ecosystem responses to a changing world.
Collapse
Affiliation(s)
- Jennifer R Griffiths
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
| | - Martina Kadin
- Stockholm Resilience Centre, Stockholm University, 10691, Stockholm, Sweden
| | - Francisco J A Nascimento
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
| | - Tobias Tamelander
- Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, 10900, Hangö, Finland
| | - Anna Törnroos
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
- Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark, Kavalergården 6, 2920, Charlottenlund, Denmark
| | - Stefano Bonaglia
- Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
- Department of Geology, Lund University, 22362, Lund, Sweden
| | - Erik Bonsdorff
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | - Volker Brüchert
- Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
| | - Anna Gårdmark
- Department of Aquatic Resources, Swedish University of Agricultural Sciences, Skolgatan 6, 74242, Öregrund, Sweden
| | - Marie Järnström
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | - Jonne Kotta
- Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618, Tallinn, Estonia
| | - Martin Lindegren
- Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark, Kavalergården 6, 2920, Charlottenlund, Denmark
| | - Marie C Nordström
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | - Alf Norkko
- Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, 10900, Hangö, Finland
- Baltic Sea Centre, Stockholm University, Stockholm, 106 91, Sweden
| | - Jens Olsson
- Department of Aquatic Resources, Swedish University of Agricultural Sciences, Skolgatan 6, 74242, Öregrund, Sweden
| | - Benjamin Weigel
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | | | - Thorsten Blenckner
- Stockholm Resilience Centre, Stockholm University, 10691, Stockholm, Sweden
| | - Susa Niiranen
- Stockholm Resilience Centre, Stockholm University, 10691, Stockholm, Sweden
| | - Monika Winder
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
| |
Collapse
|
28
|
Herlemann DPR, Manecki M, Dittmar T, Jürgens K. Differential responses of marine, mesohaline and oligohaline bacterial communities to the addition of terrigenous carbon. Environ Microbiol 2017; 19:3098-3117. [PMID: 28474480 DOI: 10.1111/1462-2920.13784] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 04/13/2017] [Accepted: 04/26/2017] [Indexed: 12/21/2022]
Abstract
In response to global warming, increasing quantities of tDOM are transported through estuaries from land to the sea. In this study, we investigated microbial responses to increased tDOM concentrations in three salinity regimes (salinity: 32, 7 and 3) characteristic of the Baltic Sea. Mesocosm experiments performed in May and November revealed low (0-6%) dissolved organic carbon (DOC) utilisation. Molecular DOM analyses using ultrahigh-resolution mass spectrometry identified the terrigenous signal in the tDOM manipulation, but the molecular changes in DOM levels over the course of the experiment were subtle. However, tDOM had significant stimulatory effects on bacterial production in the oligohaline mesocosms. The shift in the bacterial community composition was especially prominent in the tDOM-amended marine and mesohaline mesocosms, but not in the oligohaline mesocosms after 7 and 11 days of incubation. These results suggested the inherent ability of oligohaline bacterial communities to adapt to high tDOM concentrations and therefore to use tDOM. The higher rates of bacterial activity and DOC removal in mesocosms containing UV-pretreated tDOM supported the increased bioavailability of photoinduced, modified tDOM. The overall low rates of microbial tDOM utilisation highlights the importance of abiotic factors in determining the distribution and dynamics of tDOM in estuaries.
Collapse
Affiliation(s)
- D P R Herlemann
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Biological Oceanography, Seestrasse 15, Rostock, D-18119, Germany
| | - M Manecki
- Research Group for Marine Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Str, Oldenburg, 9-11 D-26129, Germany.,Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Marine Chemistry, Seestrasse 15, Rostock, D-18119, Germany
| | - T Dittmar
- Research Group for Marine Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Str, Oldenburg, 9-11 D-26129, Germany
| | - K Jürgens
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Biological Oceanography, Seestrasse 15, Rostock, D-18119, Germany
| |
Collapse
|
29
|
Hemraj DA, Hossain A, Ye Q, Qin JG, Leterme SC. Anthropogenic shift of planktonic food web structure in a coastal lagoon by freshwater flow regulation. Sci Rep 2017; 7:44441. [PMID: 28327643 PMCID: PMC5361161 DOI: 10.1038/srep44441] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/08/2017] [Indexed: 01/08/2023] Open
Abstract
Anthropogenic modification of aquatic systems has diverse impacts on food web interactions and ecosystem states. To reverse the adverse effects of modified freshwater flow, adequate management of discharge is required, especially due to higher water requirements and abstractions for human use. Here, we look at the effects of anthropogenically controlled freshwater flow regimes on the planktonic food web of a Ramsar listed coastal lagoon that is under recovery from degradation. Our results show shifts in water quality and plankton community interactions associated to changes in water flow. These shifts in food web interactions represent modifications in habitat complexity and water quality. At high flow, phytoplankton-zooplankton interactions dominate the food web. Conversely, at low flow, bacteria, viruses and nano/picoplankton interactions are more dominant, with a substantial switch of the food web towards heterotrophy. This switch can be associated with excess organic matter loading, decomposition of dead organisms, and synergistic and antagonistic interactions. We suggest that a lower variability in flow amplitude could be beneficial for the long-term sustaining of water quality and food web interactions, while improving the ecosystem health of systems facing similar stresses as the Coorong.
Collapse
Affiliation(s)
- Deevesh A Hemraj
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia
| | - A Hossain
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia
| | - Qifeng Ye
- South Australian Research and Development Institute, PO Box 120, Henley Beach, SA 5022, Australia
| | - Jian G Qin
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia
| | - Sophie C Leterme
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia
| |
Collapse
|
30
|
Ward EJ, Adkison M, Couture J, Dressel SC, Litzow MA, Moffitt S, Hoem Neher T, Trochta J, Brenner R. Evaluating signals of oil spill impacts, climate, and species interactions in Pacific herring and Pacific salmon populations in Prince William Sound and Copper River, Alaska. PLoS One 2017; 12:e0172898. [PMID: 28296895 PMCID: PMC5351843 DOI: 10.1371/journal.pone.0172898] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/10/2017] [Indexed: 11/19/2022] Open
Abstract
The Exxon Valdez oil spill occurred in March 1989 in Prince William Sound, Alaska, and was one of the worst environmental disasters on record in the United States. Despite long-term data collection over the nearly three decades since the spill, tremendous uncertainty remains as to how significantly the spill affected fishery resources. Pacific herring (Clupea pallasii) and some wild Pacific salmon populations (Oncorhynchus spp.) in Prince William Sound declined in the early 1990s, and have not returned to the population sizes observed in the 1980s. Discerning if, or how much of, this decline resulted from the oil spill has been difficult because a number of other physical and ecological drivers are confounded temporally with the spill; some of these drivers include environmental variability or changing climate regimes, increased production of hatchery salmon in the region, and increases in populations of potential predators. Using data pre- and post-spill, we applied time-series methods to evaluate support for whether and how herring and salmon productivity has been affected by each of five drivers: (1) density dependence, (2) the EVOS event, (3) changing environmental conditions, (4) interspecific competition on juvenile fish, and (5) predation and competition from adult fish or, in the case of herring, humpback whales. Our results showed support for intraspecific density-dependent effects in herring, sockeye, and Chinook salmon, with little overall support for an oil spill effect. Of the salmon species, the largest driver was the negative impact of adult pink salmon returns on sockeye salmon productivity. Herring productivity was most strongly affected by changing environmental conditions; specifically, freshwater discharge into the Gulf of Alaska was linked to a series of recruitment failures-before, during, and after EVOS. These results highlight the need to better understand long terms impacts of pink salmon on food webs, as well as the interactions between nearshore species and freshwater inputs, particularly as they relate to climate change and increasing water temperatures.
Collapse
Affiliation(s)
- Eric J. Ward
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle Washington, United States of America
- * E-mail:
| | - Milo Adkison
- School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, United States of America
| | - Jessica Couture
- National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America
| | - Sherri C. Dressel
- Alaska Department of Fish and Game, Division of Commercial Fisheries, Juneau, Alaska, United States of America
| | - Michael A. Litzow
- Farallon Institute for Advanced Ecosystem Research, Petaluma, California, United States of America
| | - Steve Moffitt
- Alaska Department of Fish and Game, Division of Commercial Fisheries, Cordova, Alaska, United States of America
| | - Tammy Hoem Neher
- Kasitsna Bay Laboratory, National Ocean Service, National Oceanic and Atmospheric Administration, Homer, Alaska, United States of America
| | - John Trochta
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, United States of America
| | - Rich Brenner
- Alaska Department of Fish and Game, Division of Commercial Fisheries, Juneau, Alaska, United States of America
| |
Collapse
|
31
|
Traving SJ, Rowe O, Jakobsen NM, Sørensen H, Dinasquet J, Stedmon CA, Andersson A, Riemann L. The Effect of Increased Loads of Dissolved Organic Matter on Estuarine Microbial Community Composition and Function. Front Microbiol 2017; 8:351. [PMID: 28337180 PMCID: PMC5343018 DOI: 10.3389/fmicb.2017.00351] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/20/2017] [Indexed: 11/13/2022] Open
Abstract
Increased river loads are projected as one of the major consequences of climate change in the northern hemisphere, leading to elevated inputs of riverine dissolved organic matter (DOM) and inorganic nutrients to coastal ecosystems. The objective of this study was to investigate the effects of elevated DOM on a coastal pelagic food web from the coastal northern Baltic Sea, in a 32-day mesocosm experiment. In particular, the study addresses the response of bacterioplankton to differences in character and composition of supplied DOM. The supplied DOM differed in stoichiometry and quality and had pronounced effects on the recipient bacterioplankton, driving compositional changes in response to DOM type. The shifts in bacterioplankton community composition were especially driven by the proliferation of Bacteroidetes, Gemmatimonadetes, Planctomycetes, and Alpha- and Betaproteobacteria populations. The DOM additions stimulated protease activity and a release of inorganic nutrients, suggesting that DOM was actively processed. However, no difference between DOM types was detected in these functions despite different community compositions. Extensive release of re-mineralized carbon, nitrogen and phosphorus was associated with the bacterial processing, corresponding to 25–85% of the supplied DOM. The DOM additions had a negative effect on phytoplankton with decreased Chl a and biomass, particularly during the first half of the experiment. However, the accumulating nutrients likely stimulated phytoplankton biomass which was observed to increase towards the end of the experiment. This suggests that the nutrient access partially outweighed the negative effect of increased light attenuation by accumulating DOM. Taken together, our experimental data suggest that parts of the future elevated riverine DOM supply to the Baltic Sea will be efficiently mineralized by microbes. This will have consequences for bacterioplankton and phytoplankton community composition and function, and significantly affect nutrient biogeochemistry.
Collapse
Affiliation(s)
- Sachia J Traving
- Centre for Ocean Life, Marine Biological Section, University of Copenhagen Helsingør, Denmark
| | - Owen Rowe
- Umeå Marine Sciences Centre, Umeå UniversityHörnefors, Sweden; Department of Ecology and Environmental Science, Umeå UniversityUmeå, Sweden
| | - Nina M Jakobsen
- Laboratory for Applied Statistics, Department of Mathematical Sciences, University of Copenhagen Copenhagen, Denmark
| | - Helle Sørensen
- Laboratory for Applied Statistics, Department of Mathematical Sciences, University of Copenhagen Copenhagen, Denmark
| | - Julie Dinasquet
- Marine Biological Section, University of Copenhagen Helsingør, Denmark
| | - Colin A Stedmon
- Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark Charlottenlund, Denmark
| | - Agneta Andersson
- Umeå Marine Sciences Centre, Umeå UniversityHörnefors, Sweden; Department of Ecology and Environmental Science, Umeå UniversityUmeå, Sweden
| | - Lasse Riemann
- Centre for Ocean Life, Marine Biological Section, University of CopenhagenHelsingør, Denmark; Marine Biological Section, University of CopenhagenHelsingør, Denmark
| |
Collapse
|
32
|
Jonsson S, Andersson A, Nilsson MB, Skyllberg U, Lundberg E, Schaefer JK, Åkerblom S, Björn E. Terrestrial discharges mediate trophic shifts and enhance methylmercury accumulation in estuarine biota. SCIENCE ADVANCES 2017; 3:e1601239. [PMID: 28138547 PMCID: PMC5271591 DOI: 10.1126/sciadv.1601239] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/27/2016] [Indexed: 05/03/2023]
Abstract
The input of mercury (Hg) to ecosystems is estimated to have increased two- to fivefold during the industrial era, and Hg accumulates in aquatic biota as neurotoxic methylmercury (MeHg). Escalating anthropogenic land use and climate change are expected to alter the input rates of terrestrial natural organic matter (NOM) and nutrients to aquatic ecosystems. For example, climate change has been projected to induce 10 to 50% runoff increases for large coastal regions globally. A major knowledge gap is the potential effects on MeHg exposure to biota following these ecosystem changes. We monitored the fate of five enriched Hg isotope tracers added to mesocosm scale estuarine model ecosystems subjected to varying loading rates of nutrients and terrestrial NOM. We demonstrate that increased terrestrial NOM input to the pelagic zone can enhance the MeHg bioaccumulation factor in zooplankton by a factor of 2 to 7 by inducing a shift in the pelagic food web from autotrophic to heterotrophic. The terrestrial NOM input also enhanced the retention of MeHg in the water column by up to a factor of 2, resulting in further increased MeHg exposure to pelagic biota. Using mercury mass balance calculations, we predict that MeHg concentration in zooplankton can increase by a factor of 3 to 6 in coastal areas following scenarios with 15 to 30% increased terrestrial runoff. The results demonstrate the importance of incorporating the impact of climate-induced changes in food web structure on MeHg bioaccumulation in future biogeochemical cycling models and risk assessments of Hg.
Collapse
Affiliation(s)
- Sofi Jonsson
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
- Umeå Marine Sciences Centre, Umeå University, SE-910 20 Hörnefors, Sweden
| | - Agneta Andersson
- Umeå Marine Sciences Centre, Umeå University, SE-910 20 Hörnefors, Sweden
- Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden
| | - Mats B. Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Ulf Skyllberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Erik Lundberg
- Umeå Marine Sciences Centre, Umeå University, SE-910 20 Hörnefors, Sweden
| | - Jeffra K. Schaefer
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - Staffan Åkerblom
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
| | - Erik Björn
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
- Corresponding author.
| |
Collapse
|
33
|
Bidleman TF, Agosta K, Andersson A, Haglund P, Liljelind P, Hegmans A, Jantunen LM, Nygren O, Poole J, Ripszam M, Tysklind M. Sea-air exchange of bromoanisoles and methoxylated bromodiphenyl ethers in the Northern Baltic. MARINE POLLUTION BULLETIN 2016; 112:58-64. [PMID: 27575397 DOI: 10.1016/j.marpolbul.2016.08.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/11/2016] [Accepted: 08/18/2016] [Indexed: 06/06/2023]
Abstract
Halogenated natural products in biota of the Baltic Sea include bromoanisoles (BAs) and methoxylated bromodiphenyl ethers (MeO-BDEs). We identified biogenic 6-MeO-BDE47 and 2'-MeO-BDE68 in Baltic water and air for the first time using gas chromatography - high resolution mass spectrometry. Partial pressures in air were related to temperature by: log p/Pa=m/T(K)+b. We determined Henry's law constants (HLCs) of 2,4-dibromoanisole (2,4-DiBA) and 2,4,6-tribromoanisole (2,4,6-TriBA) from 5 to 30°C and revised our assessment of gas exchange in the northern Baltic. The new water/air fugacity ratios (FRs) were lower, but still indicated net volatilization in May-June for 2,4-DiBA and May - September for 2,4,6-TriBA. The net flux (negative) of BAs from Bothnian Bay (38,000km2) between May - September was revised from -1319 to -532kg. FRs of MeO-BDEs were >1, suggesting volatilization, although this is tentative due to uncertainties in their HLCs and binding to dissolved organic carbon.
Collapse
Affiliation(s)
- Terry F Bidleman
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden.
| | - Kathleen Agosta
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden
| | - Peter Haglund
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Per Liljelind
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Alyse Hegmans
- Department of Environmental Science, Royal Roads University, Victoria, BC, V9B 5Y2, Canada
| | - Liisa M Jantunen
- Air Quality Processes Research Section, Environment and Climate Change Canada, 6248 Eighth Line, Egbert, ON L0L 1N0, Canada
| | - Olle Nygren
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Justen Poole
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Matyas Ripszam
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Mats Tysklind
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| |
Collapse
|
34
|
Ask J, Rowe O, Brugel S, Strömgren M, Byström P, Andersson A. Importance of coastal primary production in the northern Baltic Sea. AMBIO 2016; 45:635-648. [PMID: 27075572 PMCID: PMC5012998 DOI: 10.1007/s13280-016-0778-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 12/26/2015] [Accepted: 03/18/2016] [Indexed: 06/05/2023]
Abstract
In this study, we measured depth-dependent benthic microalgal primary production in a Bothnian Bay estuary to estimate the benthic contribution to total primary production. In addition, we compiled data on benthic microalgal primary production in the entire Baltic Sea. In the estuary, the benthic habitat contributed 17 % to the total annual primary production, and when upscaling our data to the entire Bothnian Bay, the corresponding value was 31 %. This estimated benthic share (31 %) is three times higher compared to past estimates of 10 %. The main reason for this discrepancy is the lack of data regarding benthic primary production in the northern Baltic Sea, but also that past studies overestimated the importance of pelagic primary production by not correcting for system-specific bathymetric variation. Our study thus highlights the importance of benthic communities for the northern Baltic Sea ecosystem in general and for future management strategies and ecosystem studies in particular.
Collapse
Affiliation(s)
- Jenny Ask
- Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Owen Rowe
- Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
- Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, Helsinki, Finland
| | - Sonia Brugel
- Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Mårten Strömgren
- Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Pär Byström
- Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
- Umeå Marine Sciences Centre, 905 70 Hörnefors, Umeå, Sweden
| |
Collapse
|
35
|
Säwström C, Hyndes GA, Eyre BD, Huggett MJ, Fraser MW, Lavery PS, Thomson PG, Tarquinio F, Steinberg PD, Laverock B. Coastal connectivity and spatial subsidy from a microbial perspective. Ecol Evol 2016; 6:6662-6671. [PMID: 27777738 PMCID: PMC5058536 DOI: 10.1002/ece3.2408] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 08/06/2016] [Indexed: 01/04/2023] Open
Abstract
The transfer of organic material from one coastal environment to another can increase production in recipient habitats in a process known as spatial subsidy. Microorganisms drive the generation, transformation, and uptake of organic material in shallow coastal environments, but their significance in connecting coastal habitats through spatial subsidies has received limited attention. We address this by presenting a conceptual model of coastal connectivity that focuses on the flow of microbially mediated organic material in key coastal habitats. Our model suggests that it is not the difference in generation rates of organic material between coastal habitats but the amount of organic material assimilated into microbial biomass and respiration that determines the amount of material that can be exported from one coastal environment to another. Further, the flow of organic material across coastal habitats is sensitive to environmental change as this can alter microbial remineralization and respiration rates. Our model highlights microorganisms as an integral part of coastal connectivity and emphasizes the importance of including a microbial perspective in coastal connectivity studies.
Collapse
Affiliation(s)
- Christin Säwström
- School of Science Centre for Marine Ecosystems Research Edith Cowan University Joondalup WA Australia
| | - Glenn A Hyndes
- School of Science Centre for Marine Ecosystems Research Edith Cowan University Joondalup WA Australia
| | - Bradley D Eyre
- School of Environment Science and Engineering Centre for Coastal Biogeochemistry Research Southern Cross University Lismore NSW Australia
| | - Megan J Huggett
- School of Science Centre for Marine Ecosystems Research Edith Cowan University Joondalup WA Australia
| | - Matthew W Fraser
- The UWA Oceans Institute and the School of Plant Biology The University of Western Australia Crawley WA Australia
| | - Paul S Lavery
- School of Science Centre for Marine Ecosystems Research Edith Cowan University Joondalup WA Australia
| | - Paul G Thomson
- The School of Civil, Environmental and Mining Engineering and The UWA Oceans Institute The University of Western Australia Crawley WA Australia
| | - Flavia Tarquinio
- School of Science Centre for Marine Ecosystems Research Edith Cowan University Joondalup WA Australia
| | - Peter D Steinberg
- Sydney Institute of Marine Science Mosman NSW Australia; Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW Australia
| | - Bonnie Laverock
- The UWA Oceans Institute and the School of Plant Biology The University of Western Australia Crawley WA Australia; Plant Functional Biology and Climate Change Cluster University of Technology Sydney Sydney NSW Australia
| |
Collapse
|
36
|
Figueroa D, Rowe OF, Paczkowska J, Legrand C, Andersson A. Allochthonous Carbon--a Major Driver of Bacterioplankton Production in the Subarctic Northern Baltic Sea. MICROBIAL ECOLOGY 2016; 71:789-801. [PMID: 26677860 PMCID: PMC4823372 DOI: 10.1007/s00248-015-0714-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 11/30/2015] [Indexed: 05/22/2023]
Abstract
Heterotrophic bacteria are, in many aquatic systems, reliant on autochthonous organic carbon as their energy source. One exception is low-productive humic lakes, where allochthonous dissolved organic matter (ADOM) is the major driver. We hypothesized that bacterial production (BP) is similarly regulated in subarctic estuaries that receive large amounts of riverine material. BP and potential explanatory factors were measured during May-August 2011 in the subarctic Råne Estuary, northern Sweden. The highest BP was observed in spring, concomitant with the spring river-flush and the lowest rates occurred during summer when primary production (PP) peaked. PLS correlations showed that ∼60% of the BP variation was explained by different ADOM components, measured as humic substances, dissolved organic carbon (DOC) and coloured dissolved organic matter (CDOM). On average, BP was threefold higher than PP. The bioavailability of allochthonous dissolved organic carbon (ADOC) exhibited large spatial and temporal variation; however, the average value was low, ∼2%. Bioassay analysis showed that BP in the near-shore area was potentially carbon limited early in the season, while BP at seaward stations was more commonly limited by nitrogen-phosphorus. Nevertheless, the bioassay indicated that ADOC could contribute significantly to the in situ BP, ∼60%. We conclude that ADOM is a regulator of BP in the studied estuary. Thus, projected climate-induced increases in river discharge suggest that BP will increase in subarctic coastal areas during the coming century.
Collapse
Affiliation(s)
- D Figueroa
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden
- Umeå Marine Sciences Centre, SE-905 71, Hörnefors, Sweden
| | - O F Rowe
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden
- Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, Viikki Biocenter 1, University of Helsinki, Helsinki, Finland
| | - J Paczkowska
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden
| | - C Legrand
- Ecology and Evolution in Microbial Model Systems, EEMiS, Department of Biology and Environmental Sciences, Linnaeus University, SE-391 82, Kalmar, Sweden
| | - A Andersson
- Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden.
- Umeå Marine Sciences Centre, SE-905 71, Hörnefors, Sweden.
| |
Collapse
|
37
|
Smoliński S, Całkiewicz J. A fish-based index for assessing the ecological status of Polish transitional and coastal waters. MARINE POLLUTION BULLETIN 2015; 101:497-506. [PMID: 26522163 DOI: 10.1016/j.marpolbul.2015.10.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 10/21/2015] [Accepted: 10/23/2015] [Indexed: 06/05/2023]
Abstract
Fish assemblages are considered indicators of aquatic ecosystem quality. Based on how fish communities respond to anthropogenic pressures, we developed a multimetric fish index for evaluating the health of both coastal and transitional waters. Fish data were collected along the Polish coast in the years 2011, 2013 and 2014 using different types of gear. Redundancy analysis showed that the most important environmental factor affecting fish community was salinity. Responses to anthropogenic disturbances of 20 candidate metrics were tested by generalized linear models, taking into account salinity, sampling protocol and the proxy of human pressures described by the Baltic Sea Impact Index (BSII). Five selected metrics were combined in a Multimetric Index, which showed negative significant correlation with BSII. The index presented herein appeared to be a good tool for assessing the ecological state of highly impacted Polish transitional and coastal areas and complies with the Water Framework Directive requirements.
Collapse
Affiliation(s)
- Szymon Smoliński
- Department of Fisheries Resources, National Marine Fisheries Research Institute, Kołłątaja 1, 81-332 Gdynia, Poland.
| | - Joanna Całkiewicz
- Department of Logistics and Monitoring, National Marine Fisheries Research Institute, Poland
| |
Collapse
|
38
|
Caruso G, La Ferla R, Azzaro M, Zoppini A, Marino G, Petochi T, Corinaldesi C, Leonardi M, Zaccone R, Fonda Umani S, Caroppo C, Monticelli L, Azzaro F, Decembrini F, Maimone G, Cavallo RA, Stabili L, Hristova Todorova N, K. Karamfilov V, Rastelli E, Cappello S, Acquaviva MI, Narracci M, De Angelis R, Del Negro P, Latini M, Danovaro R. Microbial assemblages for environmental quality assessment: Knowledge, gaps and usefulness in the European Marine Strategy Framework Directive. Crit Rev Microbiol 2015; 42:883-904. [DOI: 10.3109/1040841x.2015.1087380] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
39
|
Andersson A, Meier HEM, Ripszam M, Rowe O, Wikner J, Haglund P, Eilola K, Legrand C, Figueroa D, Paczkowska J, Lindehoff E, Tysklind M, Elmgren R. Projected future climate change and Baltic Sea ecosystem management. AMBIO 2015; 44 Suppl 3:345-56. [PMID: 26022318 PMCID: PMC4447695 DOI: 10.1007/s13280-015-0654-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 °C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase ~30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.
Collapse
Affiliation(s)
- Agneta Andersson
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - H. E. Markus Meier
- />Swedish Meteorological and Hydrological Institute, 601 76 Norrköping, Sweden
| | - Matyas Ripszam
- />Department of Occupational Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Owen Rowe
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Johan Wikner
- />Umeå Marine Science Centre, Umeå University, 905 71 Hörnefors, Sweden
| | - Peter Haglund
- />Department of Chemistry, Umeå University, 901 87 Umeå, Sweden
| | - Kari Eilola
- />Swedish Meteorological and Hydrological Institute, 426 71 Västra Frölunda, Sweden
| | - Catherine Legrand
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Linnaeus University, 391 82 Kalmar, Sweden
| | - Daniela Figueroa
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Joanna Paczkowska
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Elin Lindehoff
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Linnaeus University, 391 82 Kalmar, Sweden
| | - Mats Tysklind
- />Department of Chemistry, Umeå University, 901 87 Umeå, Sweden
| | - Ragnar Elmgren
- />Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
| |
Collapse
|
40
|
Abstract
Severe environmental problems documented in the Baltic Sea in the 1960s led to the 1974 creation of the Helsinki Convention for the Protection of the Marine Environment of the Baltic Sea Area. We introduce this special issue by briefly summarizing successes and failures of Baltic environmental management in the following 40 years. The loads of many polluting substances have been greatly reduced, but legacy pollution slows recovery. Top predator populations have recovered, and human exposure to potential toxins has been reduced. The cod stock has partially recovered. Nutrient loads are decreasing, but deep-water anoxia and cyanobacterial blooms remain extensive, and climate change threatens the advances made. Ecosystem-based management is the agreed principle, but in practice the various environmental problems are still handled separately, since we still lack both basic ecological knowledge and appropriate governance structures for managing them together, in a true ecosystem approach.
Collapse
Affiliation(s)
- Ragnar Elmgren
- />Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
| | - Thorsten Blenckner
- />Stockholm Resilience Centre, Stockholm University, 106 91 Stockholm, Sweden
| | - Agneta Andersson
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| |
Collapse
|
41
|
Harvey ET, Kratzer S, Andersson A. Relationships between colored dissolved organic matter and dissolved organic carbon in different coastal gradients of the Baltic Sea. AMBIO 2015; 44 Suppl 3:392-401. [PMID: 26022322 PMCID: PMC4447701 DOI: 10.1007/s13280-015-0658-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Due to high terrestrial runoff, the Baltic Sea is rich in dissolved organic carbon (DOC), the light-absorbing fraction of which is referred to as colored dissolved organic matter (CDOM). Inputs of DOC and CDOM are predicted to increase with climate change, affecting coastal ecosystems. We found that the relationships between DOC, CDOM, salinity, and Secchi depth all differed between the two coastal areas studied; the W Gulf of Bothnia with high terrestrial input and the NW Baltic Proper with relatively little terrestrial input. The CDOM:DOC ratio was higher in the Gulf of Bothnia, where CDOM had a greater influence on the Secchi depth, which is used as an indicator of eutrophication and hence important for Baltic Sea management. Based on the results of this study, we recommend regular CDOM measurements in monitoring programmes, to increase the value of concurrent Secchi depth measurements.
Collapse
Affiliation(s)
- E. Therese Harvey
- />Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
| | - Susanne Kratzer
- />Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
| | - Agneta Andersson
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| |
Collapse
|
42
|
Blenckner T, Österblom H, Larsson P, Andersson A, Elmgren R. Baltic Sea ecosystem-based management under climate change: Synthesis and future challenges. AMBIO 2015; 44 Suppl 3:507-515. [PMID: 26022332 PMCID: PMC4447697 DOI: 10.1007/s13280-015-0661-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ecosystem-based management (EBM) has emerged as the generally agreed strategy for managing ecosystems, with humans as integral parts of the managed system. Human activities have substantial effects on marine ecosystems, through overfishing, eutrophication, toxic pollution, habitat destruction, and climate change. It is important to advance the scientific knowledge of the cumulative, integrative, and interacting effects of these diverse activities, to support effective implementation of EBM. Based on contributions to this special issue of AMBIO, we synthesize the scientific findings into four components: pollution and legal frameworks, ecosystem processes, scale-dependent effects, and innovative tools and methods. We conclude with challenges for the future, and identify the next steps needed for successful implementation of EBM in general and specifically for the Baltic Sea.
Collapse
Affiliation(s)
- Thorsten Blenckner
- />Stockholm Resilience Centre, Stockholm University, 106 91 Stockholm, Sweden
| | - Henrik Österblom
- />Stockholm Resilience Centre, Stockholm University, 106 91 Stockholm, Sweden
| | - Per Larsson
- />Institute of Biology and Environmental Science, Linnaeus University, 391 82 Kalmar, Sweden
| | - Agneta Andersson
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Ragnar Elmgren
- />Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
| |
Collapse
|
43
|
Legrand C, Fridolfsson E, Bertos-Fortis M, Lindehoff E, Larsson P, Pinhassi J, Andersson A. Interannual variability of phyto-bacterioplankton biomass and production in coastal and offshore waters of the Baltic Sea. AMBIO 2015; 44 Suppl 3:427-438. [PMID: 26022325 PMCID: PMC4447688 DOI: 10.1007/s13280-015-0662-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The microbial part of the pelagic food web is seldom characterized in models despite its major contribution to biogeochemical cycles. In the Baltic Sea, spatial and temporal high frequency sampling over three years revealed changes in heterotrophic bacteria and phytoplankton coupling (biomass and production) related to hydrographic properties of the ecosystem. Phyto- and bacterioplankton were bottom-up driven in both coastal and offshore areas. Cold winter temperature was essential for phytoplankton to conform to the successional sequence in temperate waters. In terms of annual carbon production, the loss of the spring bloom (diatoms and dinoflagellates) after mild winters tended not to be compensated for by other taxa, not even summer cyanobacteria. These results improve our ability to project Baltic Sea ecosystem response to short- and long-term environmental changes.
Collapse
Affiliation(s)
- Catherine Legrand
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Department of Biology and Environmental Science, Linnæus University, 39182 Kalmar, Sweden
| | - Emil Fridolfsson
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Department of Biology and Environmental Science, Linnæus University, 39182 Kalmar, Sweden
| | - Mireia Bertos-Fortis
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Department of Biology and Environmental Science, Linnæus University, 39182 Kalmar, Sweden
| | - Elin Lindehoff
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Department of Biology and Environmental Science, Linnæus University, 39182 Kalmar, Sweden
| | - Per Larsson
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Department of Biology and Environmental Science, Linnæus University, 39182 Kalmar, Sweden
| | - Jarone Pinhassi
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Department of Biology and Environmental Science, Linnæus University, 39182 Kalmar, Sweden
| | - Agneta Andersson
- />Department of Ecology and Environmental Science, Umeå University, 90187 Umeå, Sweden
| |
Collapse
|
44
|
Lindh MV, Lefébure R, Degerman R, Lundin D, Andersson A, Pinhassi J. Consequences of increased terrestrial dissolved organic matter and temperature on bacterioplankton community composition during a Baltic Sea mesocosm experiment. AMBIO 2015; 44 Suppl 3:402-12. [PMID: 26022323 PMCID: PMC4447689 DOI: 10.1007/s13280-015-0659-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Predicted increases in runoff of terrestrial dissolved organic matter (DOM) and sea surface temperatures implicate substantial changes in energy fluxes of coastal marine ecosystems. Despite marine bacteria being critical drivers of marine carbon cycling, knowledge of compositional responses within bacterioplankton communities to such disturbances is strongly limited. Using 16S rRNA gene pyrosequencing, we examined bacterioplankton population dynamics in Baltic Sea mesocosms with treatments combining terrestrial DOM enrichment and increased temperature. Among the 200 most abundant taxa, 62 % either increased or decreased in relative abundance under changed environmental conditions. For example, SAR11 and SAR86 populations proliferated in combined increased terrestrial DOM/temperature mesocosms, while the hgcI and CL500-29 clades (Actinobacteria) decreased in the same mesocosms. Bacteroidetes increased in both control mesocosms and in the combined increased terrestrial DOM/temperature mesocosms. These results indicate considerable and differential responses among distinct bacterial populations to combined climate change effects, emphasizing the potential of such effects to induce shifts in ecosystem function and carbon cycling in the future Baltic Sea.
Collapse
Affiliation(s)
- Markus V. Lindh
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Linnaeus University, 391 82 Kalmar, Sweden
| | - Robert Lefébure
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
- />Marine Stewardship Council, 1 Snow Hill, London, EC1A 2DH UK
| | - Rickard Degerman
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Daniel Lundin
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Linnaeus University, 391 82 Kalmar, Sweden
| | - Agneta Andersson
- />Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
| | - Jarone Pinhassi
- />Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Linnaeus University, 391 82 Kalmar, Sweden
| |
Collapse
|
45
|
Lindh MV, Figueroa D, Sjöstedt J, Baltar F, Lundin D, Andersson A, Legrand C, Pinhassi J. Transplant experiments uncover Baltic Sea basin-specific responses in bacterioplankton community composition and metabolic activities. Front Microbiol 2015; 6:223. [PMID: 25883589 PMCID: PMC4381636 DOI: 10.3389/fmicb.2015.00223] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 03/05/2015] [Indexed: 11/21/2022] Open
Abstract
Anthropogenically induced changes in precipitation are projected to generate increased river runoff to semi-enclosed seas, increasing loads of terrestrial dissolved organic matter and decreasing salinity. To determine how bacterial community structure and functioning adjust to such changes, we designed microcosm transplant experiments with Baltic Proper (salinity 7.2) and Bothnian Sea (salinity 3.6) water. Baltic Proper bacteria generally reached higher abundances than Bothnian Sea bacteria in both Baltic Proper and Bothnian Sea water, indicating higher adaptability. Moreover, Baltic Proper bacteria growing in Bothnian Sea water consistently showed highest bacterial production and beta-glucosidase activity. These metabolic responses were accompanied by basin-specific changes in bacterial community structure. For example, Baltic Proper Pseudomonas and Limnobacter populations increased markedly in relative abundance in Bothnian Sea water, indicating a replacement effect. In contrast, Roseobacter and Rheinheimera populations were stable or increased in abundance when challenged by either of the waters, indicating an adjustment effect. Transplants to Bothnian Sea water triggered the initial emergence of particular Burkholderiaceae populations, and transplants to Baltic Proper water triggered Alteromonadaceae populations. Notably, in the subsequent re-transplant experiment, a priming effect resulted in further increases to dominance of these populations. Correlated changes in community composition and metabolic activity were observed only in the transplant experiment and only at relatively high phylogenetic resolution. This suggested an importance of successional progression for interpreting relationships between bacterial community composition and functioning. We infer that priming effects on bacterial community structure by natural episodic events or climate change induced forcing could translate into long-term changes in bacterial ecosystem process rates.
Collapse
Affiliation(s)
- Markus V Lindh
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar Sweden
| | - Daniela Figueroa
- Department of Ecology and Environmental Science, Umeå University, Umeå Sweden ; Umeå Marine Sciences Centre, Umeå University, Umeå Sweden
| | - Johanna Sjöstedt
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar Sweden
| | - Federico Baltar
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar Sweden ; Department of Marine Science, University of Otago, Dunedin New Zealand
| | - Daniel Lundin
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar Sweden
| | - Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, Umeå Sweden ; Umeå Marine Sciences Centre, Umeå University, Umeå Sweden
| | - Catherine Legrand
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar Sweden
| | - Jarone Pinhassi
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar Sweden
| |
Collapse
|
46
|
Infections may select for filial cannibalism by impacting egg survival in interactions with water salinity and egg density. Oecologia 2015; 178:673-83. [DOI: 10.1007/s00442-015-3246-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 01/19/2015] [Indexed: 10/24/2022]
|
47
|
Ripszam M, Paczkowska J, Figueira J, Veenaas C, Haglund P. Dissolved organic carbon quality and sorption of organic pollutants in the Baltic Sea in light of future climate change. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1445-1452. [PMID: 25581499 DOI: 10.1021/es504437s] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Regional climate change scenarios predict increased temperature and precipitation in the northern Baltic Sea, leading to a greater runoff of fresh water and terrestrial dissolved organic carbon (DOC) within the second part of the 21st century. As a result, the current north to south gradient in temperature and salinity is likely to be shifted further toward the south. To examine if such climate change effects would cause alterations in the environmental fate of organic pollutants, spatial variations of DOC quality and sorption behavior toward organic contaminants were examined using multiple analytical methods. The results showed declining contents of aromatic functional groups in DOC along a north to south gradient. Similarly, the sorption of a diverse set of organic contaminants to DOC also showed spatial differences. The sorption behavior of these contaminants was modeled using poly parameter linear energy relationships. The resulting molecular descriptors indicated clear differences in the sorption properties of DOC sampled in northern and southern parts of the Baltic Sea, which imply that more organic contaminants are sorbed to DOC in the northern part. The extent of this sorption process determines whether individual contaminants will partition to biota via direct uptake or through sorption to DOC, which serves as food source for bacteria-based food-webs.
Collapse
Affiliation(s)
- Matyas Ripszam
- Department of Chemistry, Umeå University , 901 87 Umeå, Sweden
| | | | | | | | | |
Collapse
|
48
|
Abstract
Deoxygenation is a global problem in coastal and open regions of the ocean, and has led to expanding areas of oxygen minimum zones and coastal hypoxia. The recent expansion of hypoxia in coastal ecosystems has been primarily attributed to global warming and enhanced nutrient input from land and atmosphere. The largest anthropogenically induced hypoxic area in the world is the Baltic Sea, where the relative importance of physical forcing versus eutrophication is still debated. We have analyzed water column oxygen and salinity profiles to reconstruct oxygen and stratification conditions over the last 115 y and compare the influence of both climate and anthropogenic forcing on hypoxia. We report a 10-fold increase of hypoxia in the Baltic Sea and show that this is primarily linked to increased inputs of nutrients from land, although increased respiration from higher temperatures during the last two decades has contributed to worsening oxygen conditions. Although shifts in climate and physical circulation are important factors modulating the extent of hypoxia, further nutrient reductions in the Baltic Sea will be necessary to reduce the ecosystems impacts of deoxygenation.
Collapse
|
49
|
Lefébure R, Degerman R, Andersson A, Larsson S, Eriksson LO, Båmstedt U, Byström P. Impacts of elevated terrestrial nutrient loads and temperature on pelagic food-web efficiency and fish production. GLOBAL CHANGE BIOLOGY 2013; 19:1358-72. [PMID: 23505052 DOI: 10.1111/gcb.12134] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Revised: 11/26/2012] [Accepted: 12/03/2012] [Indexed: 05/05/2023]
Abstract
Both temperature and terrestrial organic matter have strong impacts on aquatic food-web dynamics and production. Temperature affects vital rates of all organisms, and terrestrial organic matter can act both as an energy source for lower trophic levels, while simultaneously reducing light availability for autotrophic production. As climate change predictions for the Baltic Sea and elsewhere suggest increases in both terrestrial matter runoff and increases in temperature, we studied the effects on pelagic food-web dynamics and food-web efficiency in a plausible future scenario with respect to these abiotic variables in a large-scale mesocosm experiment. Total basal (phytoplankton plus bacterial) production was slightly reduced when only increasing temperatures, but was otherwise similar across all other treatments. Separate increases in nutrient loads and temperature decreased the ratio of autotrophic:heterotrophic production, but the combined treatment of elevated temperature and terrestrial nutrient loads increased both fish production and food-web efficiency. CDOM: Chl a ratios strongly indicated that terrestrial and not autotrophic carbon was the main energy source in these food webs and our results also showed that zooplankton biomass was positively correlated with increased bacterial production. Concomitantly, biomass of the dominant calanoid copepod Acartia sp. increased as an effect of increased temperature. As the combined effects of increased temperature and terrestrial organic nutrient loads were required to increase zooplankton abundance and fish production, conclusions about effects of climate change on food-web dynamics and fish production must be based on realistic combinations of several abiotic factors. Moreover, our results question established notions on the net inefficiency of heterotrophic carbon transfer to the top of the food web.
Collapse
Affiliation(s)
- R Lefébure
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden.
| | | | | | | | | | | | | |
Collapse
|
50
|
Andersson A, Jurgensone I, Rowe OF, Simonelli P, Bignert A, Lundberg E, Karlsson J. Can humic water discharge counteract eutrophication in coastal waters? PLoS One 2013; 8:e61293. [PMID: 23637807 PMCID: PMC3630215 DOI: 10.1371/journal.pone.0061293] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 03/12/2013] [Indexed: 11/18/2022] Open
Abstract
A common and established view is that increased inputs of nutrients to the sea, for example via river flooding, will cause eutrophication and phytoplankton blooms in coastal areas. We here show that this concept may be questioned in certain scenarios. Climate change has been predicted to cause increased inflow of freshwater to coastal areas in northern Europe. River waters in these areas are often brown from the presence of high concentrations of allochthonous dissolved organic carbon (humic carbon), in addition to nitrogen and phosphorus. In this study we investigated whether increased inputs of humic carbon can change the structure and production of the pelagic food web in the recipient seawater. In a mesocosm experiment unfiltered seawater from the northern Baltic Sea was fertilized with inorganic nutrients and humic carbon (CNP), and only with inorganic nutrients (NP). The system responded differently to the humic carbon addition. In NP treatments bacterial, phytoplankton and zooplankton production increased and the systems turned net autotrophic, whereas the CNP-treatment only bacterial and zooplankton production increased driving the system to net heterotrophy. The size-structure of the food web showed large variations in the different treatments. In the enriched NP treatments the phytoplankton community was dominated by filamentous >20 µm algae, while in the CNP treatments the phytoplankton was dominated by picocyanobacteria <5 µm. Our results suggest that climate change scenarios, resulting in increased humic-rich river inflow, may counteract eutrophication in coastal waters, leading to a promotion of the microbial food web and other heterotrophic organisms, driving the recipient coastal waters to net-heterotrophy.
Collapse
Affiliation(s)
- Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden.
| | | | | | | | | | | | | |
Collapse
|