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Kosek K, Kukliński P. Impact of kelp forest on seawater chemistry - A review. MARINE POLLUTION BULLETIN 2023; 196:115655. [PMID: 37839130 DOI: 10.1016/j.marpolbul.2023.115655] [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: 07/26/2023] [Revised: 09/18/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023]
Abstract
Kelp forests, globally distributed in cool temperate and polar waters, are renowned for their pivotal role in supporting species diversity and fostering macroalgae productivity. These high-canopy algal ecosystems dynamically influence their surroundings, particularly by altering the physicochemical properties of seawater. This review article aims to underscore the significance of kelp forests in modifying water masses. By serving as effective carbon sinks through the absorption of bicarbonate (HCO3-) and carbon dioxide (CO2) for photosynthesis, kelp forests mitigate nearby acidity levels while enhancing dissolved oxygen concentrations, essential for sustaining diverse marine communities. Additionally, kelp beds have exhibited the need to use inorganic ions (NO3-, NO2-, PO43-) from seawater in order to grow, albeit with associated increases in NH4+ concentrations. Specific examples and findings from relevant studies will be presented to illustrate the profound impact of kelp forests on seawater chemistry, emphasizing their vital role in marine ecosystems.
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Affiliation(s)
- Klaudia Kosek
- Marine Ecology Department, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland.
| | - Piotr Kukliński
- Marine Ecology Department, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland
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2
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Ramus AP, Lefcheck JS, Long ZT. Foundational biodiversity effects propagate through coastal food webs via multiple pathways. Ecology 2022; 103:e3796. [PMID: 35724974 PMCID: PMC9787374 DOI: 10.1002/ecy.3796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/12/2022] [Accepted: 05/23/2022] [Indexed: 12/30/2022]
Abstract
Relatively few studies have attempted to resolve the pathways through which the effects of biodiversity on ecosystem functioning cascade from one trophic level to another. Here, we manipulated the richness of habitat-forming seaweeds in a western Atlantic estuary to explore how changes in foundation species diversity affect the structure and functioning of the benthic consumer communities that they support. Structural equation modeling revealed that macroalgal richness enhanced invertebrate abundance, biomass, and diversity, both directly by changing the quality and palatability of the foundational substrate and indirectly by increasing the total biomass of available habitat. Consumer responses were largely driven by a single foundational seaweed, although stronger complementarity among macroalgae was observed for invertebrate richness. These findings with diverse foundational phyla extend earlier inferences from terrestrial grasslands by showing that biodiversity effects can simultaneously propagate through multiple independent pathways to maintain animal foodwebs. Our work also highlights the potential ramifications of human-induced changes in marine ecosystems.
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Affiliation(s)
- Aaron P. Ramus
- Department of Biology and Marine BiologyUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
| | - Jonathan S. Lefcheck
- Tennenbaum Marine Observatories NetworkMarineGEO, Smithsonian Environmental Research CenterEdgewaterMarylandUSA
| | - Zachary T. Long
- Department of Biology and Marine BiologyUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
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3
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Combining Multispectral and Radar Imagery with Machine Learning Techniques to Map Intertidal Habitats for Migratory Shorebirds. REMOTE SENSING 2022. [DOI: 10.3390/rs14143260] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Migratory shorebirds are notable consumers of benthic invertebrates on intertidal sediments. The distribution and abundance of shorebirds will strongly depend on their prey and on landscape and sediment features such as mud and surface water content, topography, and the presence of ecosystem engineers. An understanding of shorebird distribution and ecology thus requires knowledge of the various habitat types which may be distinguished in intertidal areas. Here, we combine Sentinel-1 and Sentinel-2 imagery and a digital elevation model (DEM), using machine learning techniques to map intertidal habitat types of importance to migratory shorebirds and their benthic prey. We do this on the third most important non-breeding area for migratory shorebirds in the East Atlantic Flyway, in the Bijagós Archipelago in West Africa. Using pixel-level random forests, we successfully mapped rocks, shell beds, and macroalgae and distinguished between areas of bare sediment and areas occupied by fiddler crabs, an ecosystem engineer that promotes significant bioturbation on intertidal flats. We also classified two sediment types (sandy and mixed) within the bare sediment and fiddler crab areas, according to their mud content. The overall classification accuracy was 82%, and the Kappa Coefficient was 73%. The most important predictors were elevation, the Sentinel-2-derived water and moisture indexes, and Sentinel-1 VH band. The association of Sentinel-2 with Sentinel-1 and a DEM produced the best results compared to the models without these variables. This map provides an overall picture of the composition of the intertidal habitats in a site of international importance for migratory shorebirds. Most of the intertidal flats of the Bijagós Archipelago are covered by bare sandy sediments (59%), and ca. 22% is occupied by fiddler crabs. This likely has significant implications for the spatial arrangement of the shorebird and benthic invertebrate communities due to the ecosystem engineering by the fiddler crabs, which promotes two vastly different intertidal species assemblages. This large-scale mapping provides an important product for the future monitoring of this high biodiversity area, particularly for ecological research related to the distribution and feeding ecology of the shorebirds and their prey. Such information is key from a conservation and management perspective. By delivering a successful and comprehensive mapping workflow, we contribute to the filling of the current knowledge gap on the application of remote sensing and machine learning techniques within intertidal areas, which are among the most challenging environments to map using remote sensing techniques.
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Li C, Wang H, Liao X, Xiao R, Liu K, Bai J, Li B, He Q. Heavy metal pollution in coastal wetlands: A systematic review of studies globally over the past three decades. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127312. [PMID: 34600393 DOI: 10.1016/j.jhazmat.2021.127312] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Coastal wetlands are ecosystems lying between land and ocean and are subject to inputs of heavy metals (HMs) from terrestrial, oceanic and atmospheric sources. Although the study on HM pollution in coastal wetlands has been rapidly developing over the past three decades, systematic reviews are still unavailable. Here, by analyzing 3343 articles published between 1990 and 2019, we provided the first holistic systematic review of studies on HM pollution in coastal wetlands globally. The results showed a trend of rapid increases in publications in this field globally, especially over the past ten years. Trends varied greatly among coastal countries, and global trends were primarily driven by the US before 2000, and in China after 2010. We also found that mercury (Hg), cadmium (Cd), and copper (Cu) were the most widely studied HM elements globally, but patterns differed geographically, with Hg being most widely examined in the Americas, Cd in China and India, and lead (Pb) in the western Europe and Australia, respectively. Among different types of coastal wetlands, salt marshes, mangrove forests, and estuaries were the most widely studied, in contrast to seagrass beds and tidal flats. As for ecosystem components, soils/sediments and plants were most extensively investigated, while algae, microbes, and animals were much less examined. Our analysis further revealed rapid emergence of topics on anthropogenic sources, interactions with other anthropogenic environmental changes (climate change in particular), and control and remediation methodology in the literature in the recent ten years. Moving forward, we highlight that future studies are needed to i) better understand the impacts of HM pollution in less studied coastal wetland systems and species, ii) deepen current understanding of the biogeochemical behaviors of HMs under anthropogenic activities, iii) examine interactions with other anthropogenic environmental changes, iv) conceive ecological remediation (i.e., "ecoremediation" as compared to traditional physiochemical remediation and bioremediation) strategies, and v) develop advanced analysis instruments and methods. The perspectives we brought forward can help stimulate many new advances in this field.
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Affiliation(s)
- Chunming Li
- Coastal Ecology Lab, National Observation and Research Station for Wetland Ecosystems of the Yangtze Estuary (Shanghai), MOE Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Hanchen Wang
- Coastal Ecology Lab, National Observation and Research Station for Wetland Ecosystems of the Yangtze Estuary (Shanghai), MOE Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Xiaolin Liao
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Rong Xiao
- College of Environment and Resources, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Kehui Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), The Ministry of Education, Guilin, Guangxi 541004, China
| | - Junhong Bai
- School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, China
| | - Bo Li
- Coastal Ecology Lab, National Observation and Research Station for Wetland Ecosystems of the Yangtze Estuary (Shanghai), MOE Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Qiang He
- Coastal Ecology Lab, National Observation and Research Station for Wetland Ecosystems of the Yangtze Estuary (Shanghai), MOE Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai 200438, China.
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5
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Fish Assemblages in Seagrass (Zostera marina L.) Meadows and Mussel Reefs (Mytilus edulis): Implications for Coastal Fisheries, Restoration and Marine Spatial Planning. WATER 2021. [DOI: 10.3390/w13223268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Seagrass meadows and mussel reefs provide favorable habitats for many fish species, but few studies have compared the associated fish assemblages directly and examined the influence of environmental variables. Knowledge of fish assemblages associated with disparate habitats is needed for the conservation of coastal fisheries and marine spatial planning. Catch per unit effort data derived from fyke nets showed similar species richness and diversity in seagrass meadows and mussel reefs, suggesting that both habitats support elevated marine biodiversity of mobile fauna. However, it was shown that fish assemblage structure differed between those habitats, and also fish abundance in seagrass meadows was significantly higher than in mussel reefs by comparing the data with a multivariate extension of Generalized Linear Models (GLM). Furthermore, employing underwater video recordings to compare fish abundances in high and low water current speed mussel reefs with a Generalized Linear Mixed Model with negative binomial distribution, data revealed similar fish abundances (in terms of the MaxN metric) despite the variation in current speed, probably because the mussel formations provide sufficient shelter, even from high water currents. The commercially important species Atlantic cod (G. morhua), however, was significantly more abundant in the low water current mussel reef. Therefore, restoration efforts targeting G. morhua could benefit from restoring low current mussel reefs. Our study provides input for the conservation of coastal recreational and commercial fisheries, habitat restoration and marine spatial planning where certain habitats may be prioritized.
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Microbial Composition and Genes for Key Metabolic Attributes in the Gut Digesta of Sea Urchins Lytechinus variegatus and Strongylocentrotus purpuratus Using Shotgun Metagenomics. Curr Issues Mol Biol 2021; 43:978-995. [PMID: 34563039 PMCID: PMC8929034 DOI: 10.3390/cimb43020070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/11/2021] [Accepted: 08/18/2021] [Indexed: 11/17/2022] Open
Abstract
This paper describes the microbial community composition and genes for key metabolic genes, particularly the nitrogen fixation of the mucous-enveloped gut digesta of green (Lytechinus variegatus) and purple (Strongylocentrotus purpuratus) sea urchins by using the shotgun metagenomics approach. Both green and purple urchins showed high relative abundances of Gammaproteobacteria at 30% and 60%, respectively. However, Alphaproteobacteria in the green urchins had higher relative abundances (20%) than the purple urchins (2%). At the genus level, Vibrio was dominant in both green (~9%) and purple (~10%) urchins, whereas Psychromonas was prevalent only in purple urchins (~24%). An enrichment of Roseobacter and Ruegeria was found in the green urchins, whereas purple urchins revealed a higher abundance of Shewanella, Photobacterium, and Bacteroides (q-value < 0.01). Analysis of key metabolic genes at the KEGG-Level-2 categories revealed genes for amino acids (~20%), nucleotides (~5%), cofactors and vitamins (~6%), energy (~5%), carbohydrates (~13%) metabolisms, and an abundance of genes for assimilatory nitrogen reduction pathway in both urchins. Overall, the results from this study revealed the differences in the microbial community and genes designated for the metabolic processes in the nutrient-rich sea urchin gut digesta, suggesting their likely importance to the host and their environment.
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Polymetallic nodules are essential for food-web integrity of a prospective deep-seabed mining area in Pacific abyssal plains. Sci Rep 2021; 11:12238. [PMID: 34112864 PMCID: PMC8192577 DOI: 10.1038/s41598-021-91703-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/31/2021] [Indexed: 02/05/2023] Open
Abstract
Polymetallic nodule fields provide hard substrate for sessile organisms on the abyssal seafloor between 3000 and 6000 m water depth. Deep-seabed mining targets these mineral-rich nodules and will likely modify the consumer-resource (trophic) and substrate-providing (non-trophic) interactions within the abyssal food web. However, the importance of nodules and their associated sessile fauna in supporting food-web integrity remains unclear. Here, we use seafloor imagery and published literature to develop highly-resolved trophic and non-trophic interaction webs for the Clarion-Clipperton Fracture Zone (CCZ, central Pacific Ocean) and the Peru Basin (PB, South-East Pacific Ocean) and to assess how nodule removal may modify these networks. The CCZ interaction web included 1028 compartments connected with 59,793 links and the PB interaction web consisted of 342 compartments and 8044 links. We show that knock-down effects of nodule removal resulted in a 17.9% (CCZ) to 20.8% (PB) loss of all taxa and 22.8% (PB) to 30.6% (CCZ) loss of network links. Subsequent analysis identified stalked glass sponges living attached to the nodules as key structural species that supported a high diversity of associated fauna. We conclude that polymetallic nodules are critical for food-web integrity and that their absence will likely result in reduced local benthic biodiversity.
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8
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van der Heide T, Angelini C, de Fouw J, Eklöf JS. Facultative mutualisms: A double-edged sword for foundation species in the face of anthropogenic global change. Ecol Evol 2021; 11:29-44. [PMID: 33437413 PMCID: PMC7790659 DOI: 10.1002/ece3.7044] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/18/2020] [Accepted: 10/28/2020] [Indexed: 11/09/2022] Open
Abstract
Ecosystems worldwide depend on habitat-forming foundation species that often facilitate themselves with increasing density and patch size, while also engaging in facultative mutualisms. Anthropogenic global change (e.g., climate change, eutrophication, overharvest, land-use change), however, is causing rapid declines of foundation species-structured ecosystems, often typified by sudden collapse. Although disruption of obligate mutualisms involving foundation species is known to precipitate collapse (e.g., coral bleaching), how facultative mutualisms (i.e., context-dependent, nonbinding reciprocal interactions) affect ecosystem resilience is uncertain. Here, we synthesize recent advancements and combine these with model analyses supported by real-world examples, to propose that facultative mutualisms may pose a double-edged sword for foundation species. We suggest that by amplifying self-facilitative feedbacks by foundation species, facultative mutualisms can increase foundation species' resistance to stress from anthropogenic impact. Simultaneously, however, mutualism dependency can generate or exacerbate bistability, implying a potential for sudden collapse when the mutualism's buffering capacity is exceeded, while recovery requires conditions to improve beyond the initial collapse point (hysteresis). Thus, our work emphasizes the importance of acknowledging facultative mutualisms for conservation and restoration of foundation species-structured ecosystems, but highlights the potential risk of relying on mutualisms in the face of global change. We argue that significant caveats remain regarding the determination of these feedbacks, and suggest empirical manipulation across stress gradients as a way forward to identify related nonlinear responses.
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Affiliation(s)
- Tjisse van der Heide
- Department of Coastal SystemsRoyal Netherlands Institute of Sea Research and Utrecht UniversityDen BurgThe Netherlands
- Conservation Ecology GroupGroningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Christine Angelini
- Department of Environmental Engineering SciencesEngineering School for Sustainable Infrastructure and the EnvironmentUniversity of FloridaGainesvilleFLUSA
| | - Jimmy de Fouw
- Department of Aquatic Ecology & Environmental BiologyInstitute for Water and Wetland ResearchRadboud UniversityNijmegenThe Netherlands
| | - Johan S. Eklöf
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
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9
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El-Hacen EHM, Sidi Cheikh MA, Bouma TJ, Olff H, Piersma T. Long-term changes in seagrass and benthos at Banc d’Arguin, Mauritania, the premier intertidal system along the East Atlantic Flyway. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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10
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Gagnon K, Rinde E, Bengil EGT, Carugati L, Christianen MJA, Danovaro R, Gambi C, Govers LL, Kipson S, Meysick L, Pajusalu L, Tüney Kızılkaya İ, Koppel J, Heide T, Katwijk MM, Boström C. Facilitating foundation species: The potential for plant–bivalve interactions to improve habitat restoration success. J Appl Ecol 2020. [DOI: 10.1111/1365-2664.13605] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Karine Gagnon
- Environmental and Marine Biology Åbo Akademi University Turku Finland
| | - Eli Rinde
- Norwegian Institute for Water Research Oslo Norway
| | - Elizabeth G. T. Bengil
- Mediterranean Conservation Society Izmir Turkey
- Girne American UniversityMarine School Girne TRNC via Turkey
| | - Laura Carugati
- Department of Life and Environmental Sciences Polytechnic University of Marche Ancona Italy
| | - Marjolijn J. A. Christianen
- Aquatic Ecology and Water Quality Management Group Wageningen University Wageningen The Netherlands
- Department of Environmental Science Institute for Wetland and Water Research Radboud University Nijmegen Nijmegen The Netherlands
| | - Roberto Danovaro
- Department of Life and Environmental Sciences Polytechnic University of Marche Ancona Italy
- Stazione Zoologica Anton Dohrn Naples Italy
| | - Cristina Gambi
- Department of Life and Environmental Sciences Polytechnic University of Marche Ancona Italy
| | - Laura L. Govers
- Department of Environmental Science Institute for Wetland and Water Research Radboud University Nijmegen Nijmegen The Netherlands
- Groningen Institute for Evolutionary Life Sciences University of Groningen Groningen The Netherlands
| | - Silvija Kipson
- Faculty of Science Department of Biology University of Zagreb Zagreb Croatia
| | - Lukas Meysick
- Environmental and Marine Biology Åbo Akademi University Turku Finland
| | - Liina Pajusalu
- Estonian Marine Institute University of Tartu Tallinn Estonia
| | - İnci Tüney Kızılkaya
- Mediterranean Conservation Society Izmir Turkey
- Faculty of Science Ege University Izmir Turkey
| | - Johan Koppel
- Groningen Institute for Evolutionary Life Sciences University of Groningen Groningen The Netherlands
- Royal Netherlands Institute for Sea Research and Utrecht University Yerseke The Netherlands
| | - Tjisse Heide
- Department of Environmental Science Institute for Wetland and Water Research Radboud University Nijmegen Nijmegen The Netherlands
- Groningen Institute for Evolutionary Life Sciences University of Groningen Groningen The Netherlands
- Department of Coastal Systems Royal Netherlands Institute of Sea Research and Utrecht University Den Burg The Netherlands
| | - Marieke M. Katwijk
- Department of Environmental Science Institute for Wetland and Water Research Radboud University Nijmegen Nijmegen The Netherlands
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11
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Julien AR, McGlinn DJ, Tweel AW, Kingsley-Smith PR. Associations between Nekton Assemblages and Ribbed Mussel (Geukensia demissa) Patches in a South Carolina Salt Marsh. SOUTHEAST NAT 2020. [DOI: 10.1656/058.019.0104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Asa R. Julien
- Marine Resources Research Institute, South Carolina Department of Natural Resources, 217 Fort Johnson Road, Charleston, SC 29412
| | - Daniel J. McGlinn
- Grice Marine Laboratory, College of Charleston, 205 Fort Johnson Road, Charleston, SC 29412
| | - Andrew W. Tweel
- Marine Resources Research Institute, South Carolina Department of Natural Resources, 217 Fort Johnson Road, Charleston, SC 29412
| | - Peter R. Kingsley-Smith
- Marine Resources Research Institute, South Carolina Department of Natural Resources, 217 Fort Johnson Road, Charleston, SC 29412
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12
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Ellison AM. Foundation Species, Non-trophic Interactions, and the Value of Being Common. iScience 2019; 13:254-268. [PMID: 30870783 PMCID: PMC6416672 DOI: 10.1016/j.isci.2019.02.020] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 01/27/2019] [Accepted: 02/21/2019] [Indexed: 11/26/2022] Open
Abstract
Foundation species define ecosystems, control the biological diversity of associated species, modulate critical ecosystem processes, and often have important cultural values and resonance. This review summarizes current understanding of the characteristics and traits of foundation species and how to distinguish them from other “important” species in ecological systems (e.g., keystone, dominant, and core species); illustrates how analysis of the structure and function of ecological networks can be improved and enriched by explicit incorporation of foundation species and their non-trophic interactions; discusses the importance of pro-active identification and management of foundation species as a cost-effective and efficient method of sustaining valuable ecosystem processes and services and securing populations of associated rare, threatened, or endangered species; and suggests broader engagement of citizen-scientists and non-specialists in the identification and study of foundation species and their biological and cultural values.
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Affiliation(s)
- Aaron M Ellison
- Harvard Forest, Harvard University, Petersham, MA 01366, USA.
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13
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Why Do We Need to Document and Conserve Foundation Species in Freshwater Wetlands? WATER 2019. [DOI: 10.3390/w11020265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Foundation species provide habitat to other organisms and enhance ecosystem functions, such as nutrient cycling, carbon storage and sequestration, and erosion control. We focus on freshwater wetlands because these ecosystems are often characterized by foundation species; eutrophication and other environmental changes may cause the loss of some of these species, thus severely damaging wetland ecosystems. To better understand how wetland primary producer foundation species support other species and ecosystem functions across environmental gradients, we reviewed ~150 studies in subtropical, boreal, and temperate freshwater wetlands. We look at how the relative dominance of conspicuous and well-documented species (i.e., sawgrass, benthic diatoms and cyanobacteria, Sphagnum mosses, and bald cypress) and the foundational roles they play interact with hydrology, nutrient availability, and exposure to fire and salinity in representative wetlands. Based on the evidence analyzed, we argue that the foundation species concept should be more broadly applied to include organisms that regulate ecosystems at different spatial scales, notably the microscopic benthic algae that critically support associated communities and mediate freshwater wetlands’ ecosystem functioning. We give recommendations on how further research efforts can be prioritized to best inform the conservation of foundation species and of the freshwater wetlands they support.
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14
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Layton C, Shelamoff V, Cameron MJ, Tatsumi M, Wright JT, Johnson CR. Resilience and stability of kelp forests: The importance of patch dynamics and environment-engineer feedbacks. PLoS One 2019; 14:e0210220. [PMID: 30682047 PMCID: PMC6347235 DOI: 10.1371/journal.pone.0210220] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/17/2018] [Indexed: 12/02/2022] Open
Abstract
Habitat forming 'ecosystem engineers' such as kelp species create complex habitats that support biodiverse and productive communities. Studies of the resilience and stability of ecosystem engineers have typically focussed on the role of external factors such as disturbance. However, their population dynamics are also likely to be influenced by internal processes, such that the environmental modifications caused by engineer species feedback to affect their own demography (e.g. recruitment, survivorship). In numerous regions globally, kelp forests are declining and experiencing reductions in patch size and kelp density. To explore how resilience and stability of kelp habitats is influenced by this habitat degradation, we created an array of patch reefs of various sizes and supporting adult Ecklonia radiata kelp transplanted at different densities. This enabled testing of how sub-canopy abiotic conditions change with reductions in patch size and adult kelp density, and how this influenced demographic processes of microscopic and macroscopic juvenile kelp. We found that ecosystem engineering by adult E. radiata modified the environment to reduce sub-canopy water flow, sedimentation, and irradiance. However, the capacity of adult kelp canopy to engineer abiotic change was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp. These results are consistent with the hypothesis that ecosystem engineering by adult E. radiata facilitates development of juvenile conspecifics. Habitat degradation seems to impair the ability of E. radiata to engineer abiotic change, causing breakdown of positive intraspecific feedback and collapse of demographic functions, and overall, leading to reductions in ecosystem stability and resilience well before local extirpation.
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Affiliation(s)
- Cayne Layton
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Victor Shelamoff
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Matthew J. Cameron
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Masayuki Tatsumi
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Jeffrey T. Wright
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Craig R. Johnson
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
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15
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El-Hacen EHM, Bouma TJ, Fivash GS, Sall AA, Piersma T, Olff H, Govers LL. Evidence for 'critical slowing down' in seagrass: a stress gradient experiment at the southern limit of its range. Sci Rep 2018; 8:17263. [PMID: 30467336 PMCID: PMC6250700 DOI: 10.1038/s41598-018-34977-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/23/2018] [Indexed: 11/08/2022] Open
Abstract
The theory of critical slowing down, i.e. the increasing recovery times of complex systems close to tipping points, has been proposed as an early warning signal for collapse. Empirical evidence for the reality of such warning signals is still rare in ecology. We studied this on Zostera noltii intertidal seagrass meadows at their southern range limit, the Banc d'Arguin, Mauritania. We analyse the environmental covariates of recovery rates using structural equation modelling (SEM), based on an experiment in which we assessed whether recovery after disturbances (i.e. seagrass & infauna removal) depends on stress intensity (increasing with elevation) and disturbance patch size (1 m2 vs. 9 m2). The SEM analyses revealed that higher biofilm density and sediment accretion best explained seagrass recovery rates. Experimental disturbances were followed by slow rates of recovery, regrowth occurring mainly in the coolest months of the year. Macrofauna recolonisation lagged behind seagrass recovery. Overall, the recovery rate was six times slower in the high intertidal zone than in the low zone. The large disturbances in the low zone recovered faster than the small ones in the high zone. This provides empirical evidence for critical slowing down with increasing desiccation stress in an intertidal seagrass system.
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Affiliation(s)
- El-Hacen M El-Hacen
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands.
- Parc National du Banc d'Arguin (PNBA), Rue Gleiguime Ould Habiboullah, B Nord No. 100, B.P. 5355, Nouakchott, Mauritania.
| | - Tjeerd J Bouma
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems and Utrecht University, P.O. Box 140, 4400 AC, Yerseke, The Netherlands
| | - Gregory S Fivash
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems and Utrecht University, P.O. Box 140, 4400 AC, Yerseke, The Netherlands
| | - Amadou Abderahmane Sall
- Institut Mauritanien de Recherches Océanographiques et des Pêches (IMROP), BP 22, Nouadhibou, Mauritania
| | - Theunis Piersma
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, P.O. Box 59, 1790 AB, Den Burg, Texel, The Netherlands
| | - Han Olff
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
| | - Laura L Govers
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research (IWWR), Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
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Foundation species enhance food web complexity through non-trophic facilitation. PLoS One 2018; 13:e0199152. [PMID: 30169517 PMCID: PMC6118353 DOI: 10.1371/journal.pone.0199152] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 06/03/2018] [Indexed: 11/24/2022] Open
Abstract
Food webs are an integral part of every ecosystem on the planet, yet understanding the mechanisms shaping these complex networks remains a major challenge. Recently, several studies suggested that non-trophic species interactions such as habitat modification and mutualisms can be important determinants of food web structure. However, it remains unclear whether these findings generalize across ecosystems, and whether non-trophic interactions affect food webs randomly, or affect specific trophic levels or functional groups. Here, we combine analyses of 58 food webs from seven terrestrial, freshwater and coastal systems to test (1) the general hypothesis that non-trophic facilitation by habitat-forming foundation species enhances food web complexity, and (2) whether these enhancements have either random or targeted effects on particular trophic levels, functional groups, and linkages throughout the food web. Our empirical results demonstrate that foundation species consistently enhance food web complexity in all seven ecosystems. Further analyses reveal that 15 out of 19 food web properties can be well-approximated by assuming that foundation species randomly facilitate species throughout the trophic network. However, basal species are less strongly, and carnivores are more strongly facilitated in foundation species' food webs than predicted based on random facilitation, resulting in a higher mean trophic level and a longer average chain length. Overall, we conclude that foundation species strongly enhance food web complexity through non-trophic facilitation of species across the entire trophic network. We therefore suggest that the structure and stability of food webs often depends critically on non-trophic facilitation by foundation species.
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Ocean acidification drives community shifts towards simplified non-calcified habitats in a subtropical-temperate transition zone. Sci Rep 2018; 8:11354. [PMID: 30054497 PMCID: PMC6063920 DOI: 10.1038/s41598-018-29251-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 07/09/2018] [Indexed: 11/15/2022] Open
Abstract
Rising atmospheric concentrations of carbon dioxide are causing surface seawater pH and carbonate ion concentrations to fall in a process known as ocean acidification. To assess the likely ecological effects of ocean acidification we compared intertidal and subtidal marine communities at increasing levels of pCO2 at recently discovered volcanic seeps off the Pacific coast of Japan (34° N). This study region is of particular interest for ocean acidification research as it has naturally low levels of surface seawater pCO2 (280–320 µatm) and is located at a transition zone between temperate and sub-tropical communities. We provide the first assessment of ocean acidification effects at a biogeographic boundary. Marine communities exposed to mean levels of pCO2 predicted by 2050 experienced periods of low aragonite saturation and high dissolved inorganic carbon. These two factors combined to cause marked community shifts and a major decline in biodiversity, including the loss of key habitat-forming species, with even more extreme community changes expected by 2100. Our results provide empirical evidence that near-future levels of pCO2 shift sub-tropical ecosystems from carbonate to fleshy algal dominated systems, accompanied by biodiversity loss and major simplification of the ecosystem.
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Miller RJ, Lafferty KD, Lamy T, Kui L, Rassweiler A, Reed DC. Giant kelp, Macrocystis pyrifera, increases faunal diversity through physical engineering. Proc Biol Sci 2018; 285:20172571. [PMID: 29540514 PMCID: PMC5879622 DOI: 10.1098/rspb.2017.2571] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 02/20/2018] [Indexed: 11/12/2022] Open
Abstract
Foundation species define the ecosystems they live in, but ecologists have often characterized dominant plants as foundational without supporting evidence. Giant kelp has long been considered a marine foundation species due to its complex structure and high productivity; however, there is little quantitative evidence to evaluate this. Here, we apply structural equation modelling to a 15-year time series of reef community data to evaluate how giant kelp affects the reef community. Although species richness was positively associated with giant kelp biomass, most direct paths did not involve giant kelp. Instead, the foundational qualities of giant kelp were driven mostly by indirect effects attributed to its dominant physical structure and associated engineering influence on the ecosystem, rather than by its use as food by invertebrates and fishes. Giant kelp structure has indirect effects because it shades out understorey algae that compete with sessile invertebrates. When released from competition, sessile species in turn increase the diversity of mobile predators. Sea urchin grazing effects could have been misinterpreted as kelp effects, because sea urchins can overgraze giant kelp, understorey algae and sessile invertebrates alike. Our results confirm the high diversity and biomass associated with kelp forests, but highlight how species interactions and habitat attributes can be misconstrued as direct consequences of a foundation species like giant kelp.
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Affiliation(s)
- Robert J Miller
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Kevin D Lafferty
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
- Geological Survey, Western Ecological Research Center, Santa Barbara, CA, USA
| | - Thomas Lamy
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Li Kui
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Andrew Rassweiler
- Department of Biological Science, Florida State University, Tallahassee, FL 32304, USA
| | - Daniel C Reed
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
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Johnson DS, Fleeger JW, Riggio MR, Mendelssohn IA, Lin Q, Graham SA, Deis DR, Hou A. Saltmarsh plants, but not fertilizer, facilitate invertebrate recolonization after an oil spill. Ecosphere 2018. [DOI: 10.1002/ecs2.2082] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- David Samuel Johnson
- Department of Biological Sciences Virginia Institute of Marine Science College of William and Mary Gloucester Point Virginia 23062 USA
| | - John W. Fleeger
- Department of Biological Sciences Louisiana State University Baton Rouge Louisiana 70803 USA
| | - Maria Rita Riggio
- Department of Biological Sciences Louisiana State University Baton Rouge Louisiana 70803 USA
| | - Irving A. Mendelssohn
- Department of Oceanography and Coastal Sciences Louisiana State University Baton Rouge Louisiana 70803 USA
| | - Qianxin Lin
- Department of Oceanography and Coastal Sciences Louisiana State University Baton Rouge Louisiana 70803 USA
| | - Sean A. Graham
- Department of Biological Sciences Nicholls State University Thibodaux Louisiana 70310 USA
| | - Donald R. Deis
- Atkins 7406 Fullerton Street Jacksonville Florida 32256 USA
| | - Aixin Hou
- Department of Environmental Sciences Louisiana State University Baton Rouge Louisiana 70803 USA
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Altieri AH, Irving AD. Species coexistence and the superior ability of an invasive species to exploit a facilitation cascade habitat. PeerJ 2017; 5:e2848. [PMID: 28243523 PMCID: PMC5322755 DOI: 10.7717/peerj.2848] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/28/2016] [Indexed: 12/04/2022] Open
Abstract
Facilitation cascades generated by co-occurring foundation species can enhance the abundance and diversity of associated organisms. However, it remains poorly understood how differences among native and invasive species in their ability to exploit these positive interactions contribute to emergent patterns of community structure and biotic acceptance. On intertidal shorelines in New England, we examined the patterns of coexistence between the native mud crabs and the invasive Asian shore crab in and out of a facilitation cascade habitat generated by mid intertidal cordgrass and ribbed mussels. These crab species co-occurred in low intertidal cobbles adjacent to the cordgrass–mussel beds, despite experimental findings that the dominant mud crabs can kill and displace Asian shore crabs and thereby limit their successful recruitment to their shared habitat. A difference between the native and invasive species in their utilization of the facilitation cascade likely contributes to this pattern. Only the Asian shore crabs inhabit the cordgrass–mussel beds, despite experimental evidence that both species can similarly benefit from stress amelioration in the beds. Moreover, only Asian shore crabs settle in the beds, which function as a nursery habitat free of lethal mud crabs, and where their recruitment rates are particularly high (nearly an order of magnitude higher than outside beds). Persistence of invasive adult Asian shore crabs among the dominant native mud crabs in the low cobble zone is likely enhanced by a spillover effect of the facilitation cascade in which recruitment-limited Asian shore crabs settle in the mid intertidal cordgrass–mussel beds and subsidize their vulnerable populations in the adjacent low cobble zone. This would explain why the abundances of Asian shore crabs in cobbles are doubled when adjacent to facilitation cascade habitats. The propensity for this exotic species to utilize habitats created by facilitation cascades, despite the lack of a shared evolutionary history, contributes to species coexistence and the acceptance of invasives into a diverse community.
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Affiliation(s)
- Andrew H Altieri
- Smithsonian Tropical Research Institute , Balboa, Ancon , Republic of Panama
| | - Andrew D Irving
- School of Medical and Applied Sciences, Central Queensland University , Rockhampton, QLD , Australia
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Govers LL, van der Zee EM, Meffert JP, van Rijswick PCJ, Man in ‘t Veld WA, Heusinkveld JHT, van der Heide T. Copper treatment during storage reduces Phytophthora and Halophytophthora infection of Zostera marina seeds used for restoration. Sci Rep 2017; 7:43172. [PMID: 28225072 PMCID: PMC5320552 DOI: 10.1038/srep43172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/20/2017] [Indexed: 11/16/2022] Open
Abstract
Restoration is increasingly considered an essential tool to halt and reverse the rapid decline of vital coastal ecosystems dominated by habitat-forming foundation species such as seagrasses. However, two recently discovered pathogens of marine plants, Phytophthora gemini and Halophytophthora sp. Zostera, can seriously hamper restoration efforts by dramatically reducing seed germination. Here, we report on a novel method that strongly reduces Phytophthora and Halophytophthora infection of eelgrass (Zostera marina) seeds. Seeds were stored in seawater with three different copper sulphate concentrations (0.0, 0.2, 2.0 ppm) crossed with three salinities (0.5, 10.0, 25.0 ppt). Next to reducing seed germination, infection significantly affected cotyledon colour: 90% of the germinated infected seeds displayed a brown cotyledon upon germination that did not continue development into the seedling stage, in contrast to only 13% of the germinated non-infected seeds. Copper successfully reduced infection up to 86% and the 0.2 ppm copper sulphate treatment was just as successful as the 2.0 ppm treatment. Infection was completely eliminated at low salinities, but green seed germination was also dramatically lowered by 10 times. We conclude that copper sulphate treatment is a suitable treatment for disinfecting Phytophthora or Halophytophthora infected eelgrass seeds, thereby potentially enhancing seed-based restoration success.
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Affiliation(s)
- Laura L. Govers
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland research (IWWR), Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen (GELIFES), Post Office Box 11103, 9700 CC The Netherlands
| | - Els M. van der Zee
- Altenburg & Wymenga Ecological Consultants, Suderwei 2, 9269 TZ Veenwouden, The Netherlands
| | - Johan P. Meffert
- Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC Wageningen, The Netherlands
| | - Patricia C. J. van Rijswick
- Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC Wageningen, The Netherlands
| | - Willem A. Man in ‘t Veld
- Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC Wageningen, The Netherlands
| | | | - Tjisse van der Heide
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland research (IWWR), Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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