1
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Hung CC, Chang JS, Liao CH, Lee TM. Exploring the impact of ocean warming and nutrient overload on macroalgal blooms and carbon sequestration in deep-sea sediments of the subtropical western North Pacific. MARINE POLLUTION BULLETIN 2024; 208:116918. [PMID: 39265309 DOI: 10.1016/j.marpolbul.2024.116918] [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: 05/07/2024] [Revised: 08/27/2024] [Accepted: 08/29/2024] [Indexed: 09/14/2024]
Abstract
The role of macroalgae as blue carbon (BC) under changing climate was investigated in the subtropical western North Pacific. Sea surface temperatures (SSTs) and nutrient influx increased over the past two decades (2001-2021). The proliferation of climate-resilient macroalgae was facilitated. Using Pterocladiella capillacea and Turbinaria ornata, outdoor laboratory experiments and elemental assays underscored the influence of nutrient enrichment on their resilience under ocean warming and low salinity. Macroalgal incorporation into marine sediments, indicated by environmental DNA barcoding, total organic carbon (TOC), and stable isotope analysis. Over time, an increase in δ13C and δ15N values, particularly at greater depths, suggests a tendency of carbon signature towards macroalgaeand nitrogen pollution or high tropic levels. eDNA analysis revealed selective deposition of these species. The species-dependent nature of macroalgae in deep-sea sediments highlights the role of nutrients on climate-resilient macroalgal blooms as carbon sinks in the western North Pacific.
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Affiliation(s)
- Chin-Chang Hung
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Jui-Sheng Chang
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20234, Taiwan
| | - Chin-Hsin Liao
- Department of Marine Biotechnology and Resource, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Tse-Min Lee
- Department of Marine Biotechnology and Resource, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
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2
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Wang H, Chen K, Jin H, Hu R. Interspecific Differences in Carbon and Nitrogen Metabolism and Leaf Epiphytic Bacteria among Three Submerged Macrophytes in Response to Elevated Ammonia Nitrogen Concentrations. PLANTS (BASEL, SWITZERLAND) 2024; 13:1427. [PMID: 38891236 PMCID: PMC11174776 DOI: 10.3390/plants13111427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/08/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024]
Abstract
Submerged macrophytes in eutrophic aquatic environments adapt to changes in ammonia nitrogen (NH4-N) levels by modifying their levels of free amino acids (FAAs) and soluble carbohydrates (SCs). As symbionts of submerged macrophytes, epiphytic bacteria have obvious host specificity. In the present study, the interspecific differences in the FAA and SC contents of Hydrilla verticillata (Linn. f.) Roylep, Vallisneria natans Hara and Chara braunii Gmelin and their leaf epiphytic bacterial communities were assessed in response to increased NH4-N concentrations. The results revealed that the response of the three submerged macrophytes to NH4-N stress involved the consumption of SCs and the production of FAAs. The NH4-N concentration had a greater impact on the variation in the FAA content, whereas the variation in the SC content was primarily influenced by the species. At the phylum level, the relative abundance of Nitrospirota on the leaves exhibited specific differences, with the order H. verticillata > V. natans > C. braunii. The dominant genera of epiphytic bacteria with denitrification effects on V. natans, H. verticillata and C. braunii leaves were Halomonas, Acinetobacter and Bacillus, respectively. When faced with NH4-N stress, the variation in epiphytic bacterial populations associated with ammonia oxidation and denitrification among submerged macrophytes could contribute to their divergent responses to heightened nitrogen levels.
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Affiliation(s)
- Heyun Wang
- Key Laboratory of Intelligent Health Perception and Ecological Restoration of River and Lake, Ministry of Education, Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes, School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, China; (K.C.)
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3
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Helbling EW, Villafañe VE, Narvarte MA, Burgueño GM, Saad JF, González RA, Cabrerizo MJ. The impact of extreme weather events exceeds those due to global-change drivers on coastal phytoplankton assemblages. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170644. [PMID: 38320708 DOI: 10.1016/j.scitotenv.2024.170644] [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: 11/15/2023] [Revised: 01/28/2024] [Accepted: 01/31/2024] [Indexed: 02/13/2024]
Abstract
Extreme wind and rainfall events have become more frequent phenomena, impacting coastal ecosystems by inducing increased mixing regimes in the upper mixed layers (UML) and reduced transparency (i.e. browning), hence affecting phytoplankton photosynthesis. In this study, five plankton assemblages from the South Atlantic Ocean, from a gradient of environmental variability and anthropogenic exposure, were subjected to simulated extreme weather events under a global change scenario (GCS) of increased temperature and nutrients and decreased pH, and compared to ambient conditions (Control). Using multiple linear regression (MLR) analysis we determined that evenness and the ratio of diatoms/ (flagellates + dinoflagellates) significantly explained the variations (81-91 %) of the photosynthesis efficiency (i.e. Pchla/ETRchla ratio) for each site under static conditions. Mixing speed and the optical depth (i.e. attenuation coefficient * depth, kdz), as single drivers, explained 40-76 % of the variability in the Pchla/ETRchla ratio, while GCS drivers <9 %. Overall, assemblages with high diversity and evenness were less vulnerable to extreme weather events under a GCS. Extreme weather events should be considered in global change studies and conservation/management plans as even at local/regional scales, they can exceed the predicted impacts of mean global climate change on coastal primary productivity.
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Affiliation(s)
- E Walter Helbling
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina.
| | - Virginia E Villafañe
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Maite A Narvarte
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Giuliana M Burgueño
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Juan F Saad
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Raúl A González
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Marco J Cabrerizo
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina; Departamento de Ecología, Facultad de Ciencias, Campus de Fuentenueva s/n & Instituto Universitario de Investigación del Agua, Universidad de Granada, 18071 Granada, Spain
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4
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Lao Q, Lu X, Chen F, Chen C, Jin G, Zhu Q. A comparative study on source of water masses and nutrient supply in Zhanjiang Bay during the normal summer, rainstorm, and typhoon periods: Insights from dual water isotopes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166853. [PMID: 37673256 DOI: 10.1016/j.scitotenv.2023.166853] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 08/27/2023] [Accepted: 09/03/2023] [Indexed: 09/08/2023]
Abstract
Typhoons and rainstorms (rainfall >250 mm day-1) are extreme weather events that seriously impact coastal oceanography and biogeochemical cycles. However, changes in the mixing of water masses and nutrient supply induced by typhoons and rainstorms can hardly be identified and quantified by traditional methods owing to the complex hydrological conditions in coastal waters. In this study, we analysed a comparative data set of dual water isotopes (δD and δ18O), hydrological parameters, nutrients, and chlorophyll-a from three periods (normal summer, rainstorm, and typhoon periods) in Zhanjiang Bay, a typical semi-enclosed mariculture bay in South China, to address this issue. The results revealed a significant increase in contributions from freshwater during rainstorms and typhoons. Correspondingly, nutrient supplies from freshwater during these periods remarkably increased compared to the normal summer, indicating that heavy rainfall can transport substantial amounts of terrestrial nutrients into the bay. Furthermore, disparities in hydrodynamic processes between typhoon and rainstorm periods were notable due to inconsistencies in freshwater diffusion paths. During rainstorms, freshwater primarily diffuses towards the outer bay in the upper layer due to strong stratification and cannot form an ocean front. However, under intense external forces caused by the typhoon, high-salinity water intruded into the bay, and enhancement of vertical mixing disrupted stratification. The massive influx of freshwater column during the typhoon mixed with higher salinity seawater column in the bay led to the formation of an ocean front, which could retain contaminants. This study suggests that although both rainstorms and typhoons can discharge large quantities of terrestrial nutrients into Zhanjiang Bay, the front formed during the typhoon period impedes the contaminant transportation to open sea thereby deteriorating water quality and affecting mariculture activities within the bay.
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Affiliation(s)
- Qibin Lao
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory for Coastal Ocean Variation and Disaster Prediction, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang 524088, China
| | - Xuan Lu
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory for Coastal Ocean Variation and Disaster Prediction, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang 524088, China
| | - Fajin Chen
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory for Coastal Ocean Variation and Disaster Prediction, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang 524088, China.
| | - Chunqing Chen
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory for Coastal Ocean Variation and Disaster Prediction, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang 524088, China
| | - Guangzhe Jin
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory for Coastal Ocean Variation and Disaster Prediction, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang 524088, China
| | - Qingmei Zhu
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory for Coastal Ocean Variation and Disaster Prediction, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang 524088, China
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5
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Winston M, Fuller K, Neilson BJ, Donovan MK. Complex drivers of invasive macroalgae boom and bust in Kāne'ohe Bay, Hawai'i. MARINE POLLUTION BULLETIN 2023; 197:115744. [PMID: 37951125 DOI: 10.1016/j.marpolbul.2023.115744] [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: 09/16/2023] [Revised: 10/26/2023] [Accepted: 10/31/2023] [Indexed: 11/13/2023]
Abstract
Invasive macroalgae Eucheuma sp. and Kappaphycus spp. (E/K) became a dominant benthic feature in Kāne'ohe Bay throughout the past four decades - occurring on up to 74 ha of reef area and growing up to three meters thick, which prompted intensive management action. In 2013, E/K cover began decreasing at managed and unmanaged sites. This study examined the extent and timing of the E/K decline and evaluated environmental and ecological drivers beyond management contributing to the decline. E/K continued to recede into 2017 and remains sparse in Kāne'ohe Bay today. Increasing over the sampling period, herbivore biomass was negatively correlated with E/K cover, and other significant, non-linear relationships emerged between E/K cover and coral cover, sea surface temperature, wind, and rainfall. This study uncovers several possible mechanisms explaining a boom and bust in E/K abundance, emphasizes the importance of herbivory, and highlights the resilience of coral reefs in Kāne'ohe Bay.
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Affiliation(s)
- Morgan Winston
- School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, AZ 85281, USA; Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI, USA 96720.
| | - Kimberly Fuller
- State of Hawai'i Division of Aquatic Resources, Honolulu, HI 96813, USA
| | - Brian J Neilson
- State of Hawai'i Division of Aquatic Resources, Honolulu, HI 96813, USA
| | - Mary K Donovan
- School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, AZ 85281, USA; Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI, USA 96720
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6
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Helbling EW, Banaszak AT, Valiñas MS, Vizzo JI, Villafañe VE, Cabrerizo MJ. Browning, nutrient inputs, and fast vertical mixing from simulated extreme rainfall and wind stress alter estuarine phytoplankton productivity. THE NEW PHYTOLOGIST 2023; 238:1876-1888. [PMID: 36908076 DOI: 10.1111/nph.18874] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 02/25/2023] [Indexed: 05/04/2023]
Abstract
Browning and nutrient inputs from extreme rainfall, together with increased vertical mixing due to strong winds, are more frequent in coastal ecosystems; however, their interactive effects on phytoplankton are poorly understood. We conducted experiments to quantify how browning, together with different mixing speeds (fluctuating radiation), and a nutrient pulse alter primary productivity and photosynthetic efficiency in estuarine phytoplankton communities. Phytoplankton communities (grazers excluded) were exposed simultaneously to these drivers, and key photosynthetic targets were quantified: oxygen production, electron transport rates (ETRs), and carbon fixation immediately following collection and after a 2-d acclimation/adaptation period. Increasing mixing speeds in a turbid water column (e.g. browning) significantly decreased ETRs and carbon fixation in the short term. Acclimation/adaptation to this condition for 2 d resulted in an increase in nanoplanktonic diatoms and a community that was photosynthetically more efficient; however, this did not revert the decreasing trend in carbon fixation with increased mixing speed. The observed interactive effects (resulting from extreme rainfall and strong winds) may have profound implications in the trophodynamics of highly productive system such as the Southwest Atlantic Ocean due to changes in the size structure of the community and reduced productivity.
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Affiliation(s)
- E Walter Helbling
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Anastazia T Banaszak
- Integrative Reef Conservation Research Laboratory, Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Prol. Av. Niños Héroes S/N, Puerto Morelos, CP 77580, Mexico
| | - Macarena S Valiñas
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Juan I Vizzo
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Virginia E Villafañe
- Estación de Fotobiología Playa Unión, 9103, Chubut, Rawson, Casilla de Correos 15, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Marco J Cabrerizo
- Departamento de Ecología y Biología Animal, Facultad de Ciencias del Mar, Universidad de Vigo, Campus Lagoas Marcosende, s/n, Vigo, 36310, Spain
- Centro de Investigación Mariña da Universidade de Vigo (CIM-UVigo), Illa de Toralla s/n, Vigo, 36331, Spain
- Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, Granada, 18071, Spain
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7
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Yuan G, Tan X, Guo P, Xing K, Chen Z, Li D, Yu S, Peng H, Li W, Fu H, Jeppesen E. Linking trait network to growth performance of submerged macrophytes in response to ammonium pulse. WATER RESEARCH 2023; 229:119403. [PMID: 36446174 DOI: 10.1016/j.watres.2022.119403] [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: 08/16/2022] [Revised: 10/17/2022] [Accepted: 11/20/2022] [Indexed: 06/16/2023]
Abstract
Extreme precipitation events caused by climate change leads to large variation of nitrogen input to aquatic ecosystems. Our previous study demonstrated the significant effect of different ammonium pulse patterns (differing in magnitude and frequency) on submersed macrophyte growth based on six plant morphological traits. However, how connectivity among plant traits responds to nitrogen pulse changes, which in turn affects plant performance, has not yet been fully elucidated. The response of three common submersed macrophytes (Myriophyllum spicatum, Vallisneria natans and Potamogeton maackianus) to three ammonium pulse patterns was tested using plant trait network (PTN) analysis based on 18 measured physiological and morphological traits. We found that ammonium pulses enhanced trait connectivity in PTN, which may enable plants to assimilate ammonium and/or mitigate ammonium toxicity. Large input pulses with low frequency had stronger effects on PTNs compared to low input pulses with high frequency. Due to the cumulative and time-lagged effect of the plant response to the ammonium pulse, there was a profound and prolonged effect on plant performance after the release of the pulse. The highly connected traits in PTN were those related to biomass allocation (e.g., plant biomass, stem ratio, leaf ratio and ramet number) rather than physiological traits, while phenotype-related traits (e.g., plant height, root length and AB ratio) and energy storage-related traits (e.g., stem starch) were least connected. V. natans showed clear functional divergence among traits, making it more flexible to cope with unfavorable habitats (i.e., high input pulses with low frequencies). M. spicatum with high RGR revealed strong correlations among traits and thus supported nitrogen accumulation from favourable environments (i.e., low input pulses with high frequencies). Our study highlights the responses of PTN for submerged macrophytes to ammonium pulses depends on their intrinsic metabolic rates, the magnitude, frequency and duration of the pulses, and our results contribute to the understanding of the impact of resource pulses on the population dynamics of submersed macrophytes within the context of global climate change.
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Affiliation(s)
- Guixiang Yuan
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China.
| | - Xiaoyao Tan
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Peiqin Guo
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Ke Xing
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Zhenglong Chen
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Dongbo Li
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Sizhe Yu
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Hui Peng
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Wei Li
- Research Institute of Ecology & Environmental Sciences, Nanchang Institute of Technology, Nanchang, 330099, China.
| | - Hui Fu
- Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China
| | - Erik Jeppesen
- Lake section, Department of Ecoscience, Aarhus University, Aarhus, Denmark; Sino-Danish Centre for Education and Research, Beijing, 100049, China; Limnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, Ankara, Turkey; Institute of Marine Sciences, Middle East Technical University, Mersin, Turkey
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8
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Hu W, Zheng X, Li Y, Du J, Lv Y, Su S, Xiao B, Ye X, Jiang Q, Tan H, Liao B, Chen B. High vulnerability and a big conservation gap: Mapping the vulnerability of coastal scleractinian corals in South China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157363. [PMID: 35843331 DOI: 10.1016/j.scitotenv.2022.157363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/29/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
Scleractinian corals build the most complex and diverse ecosystems in the ocean with various ecosystem services, yet continue to be degraded by natural and anthropogenic stressors. Despite the rapid decline in scleractinian coral habitats in South China, they are among the least concerning in global coral vulnerability maps. This study developed a rapid assessment approach that combines vulnerability components and species distribution models to map coral vulnerability within a large region based on limited data. The approach contained three aspects including, exposure, habitat suitability, and coral-conservation-based adaptive capacity. The exposure assessment was based on seven indicators, and the habitat suitability was mapped using Maximum Entropy and Random Forest models. Vulnerability of scleractinian corals in South China was spatially evaluated using the approach developed here. The results showed that the average exposure of the study region was 0.62, indicating relatively high pressure. The highest exposure occurred from the east coast of the Leizhou Peninsula to the Pearl River Estuary. Aquaculture and shipping were the most common causes of exposure. Highly suitable habitats for scleractinian corals are concentrated between 18°N-22°N. Only 21.6 % of the potential coral habitats are included in marine protected areas, indicating that there may still be large conservation gaps for scleractinian corals in China. In total, 37.7 % of the potential coral habitats were highly vulnerable, with the highest vulnerability appearing in the Guangdong Province. This study presents the first attempt to map the vulnerability of scleractinian corals along the coast of South China. The proposed approach and findings provide an essential tool and information supporting the sustainable management and conservation of coral reef ecosystems, addressing an important gap on the world's coral reef vulnerability map.
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Affiliation(s)
- Wenjia Hu
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; Observation and Research Station of Island and Coastal Ecosystems in the Western Taiwan Strait, Ministry of Natural Resources, Xiamen 361005, China; Fujian Provincial Station for Field Observation and Research of Island and Coastal Zone, Zhangzhou 363216, China
| | - Xinqing Zheng
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; Observation and Research Station of Island and Coastal Ecosystems in the Western Taiwan Strait, Ministry of Natural Resources, Xiamen 361005, China; Fujian Provincial Station for Field Observation and Research of Island and Coastal Zone, Zhangzhou 363216, China; Observation and Research Station of wetland Ecosystem in the Beibu Gulf, Ministry of Natural Resources, Xiamen 361005, China.
| | - Yuanchao Li
- Hainan Academy of Ocean and Fisheries Sciences, Haikou 571199, China
| | - Jianguo Du
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; Observation and Research Station of Island and Coastal Ecosystems in the Western Taiwan Strait, Ministry of Natural Resources, Xiamen 361005, China; Fujian Provincial Station for Field Observation and Research of Island and Coastal Zone, Zhangzhou 363216, China
| | - Yihua Lv
- South China Sea Environmental Monitoring Center, State Oceanic Administration, Guangzhou 528248, China
| | - Shangke Su
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Baohua Xiao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen 518120, China
| | - Xiaomin Ye
- Key Laboratory of Space Ocean Remote Sensing and Application, National Satellite Ocean Application Service, Ministry of Natural Resources, Beijing 100081, China
| | - Qutu Jiang
- Department of Geography, The University of Hong Kong, Hong Kong 999077, China
| | - Hongjian Tan
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Baolin Liao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen 518120, China
| | - Bin Chen
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; Observation and Research Station of Island and Coastal Ecosystems in the Western Taiwan Strait, Ministry of Natural Resources, Xiamen 361005, China; Fujian Provincial Station for Field Observation and Research of Island and Coastal Zone, Zhangzhou 363216, China; Observation and Research Station of wetland Ecosystem in the Beibu Gulf, Ministry of Natural Resources, Xiamen 361005, China.
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Barbee BE, Lin MKR, Min IA, Takenami AM, Philson CS, Blumstein DT. Nutrient enrichment alters risk assessment in Giant clams. J Zool (1987) 2022. [DOI: 10.1111/jzo.13030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- B. E. Barbee
- Department of Ecology and Evolutionary Biology University of California at Los Angeles Los Angeles CA USA
| | - M. K. R. Lin
- Department of Ecology and Evolutionary Biology University of California at Los Angeles Los Angeles CA USA
| | - I. A. Min
- Department of Ecology and Evolutionary Biology University of California at Los Angeles Los Angeles CA USA
| | - A. M. Takenami
- Department of Ecology and Evolutionary Biology University of California at Los Angeles Los Angeles CA USA
| | - C. S. Philson
- Department of Ecology and Evolutionary Biology University of California at Los Angeles Los Angeles CA USA
| | - D. T. Blumstein
- Department of Ecology and Evolutionary Biology University of California at Los Angeles Los Angeles CA USA
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10
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Valenca R, Garcia L, Espinosa C, Flor D, Mohanty SK. Can water composition and weather factors predict fecal indicator bacteria removal in retention ponds in variable weather conditions? THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156410. [PMID: 35662595 DOI: 10.1016/j.scitotenv.2022.156410] [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: 02/16/2022] [Revised: 05/16/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Retention ponds provide benefits including flood control, groundwater recharge, and water quality improvement, but changes in weather conditions could limit the effectiveness in improving microbial water quality metrics. The concentration of fecal indicator bacteria (FIB), which is used as regulatory standards to assess microbial water quality in retention ponds, could vary widely based on many factors including local weather and influent water chemistry and composition. In this critical review, we analyzed 7421 data collected from 19 retention ponds across North America listed in the International Stormwater BMP Database to examine if variable FIB removal in the field conditions can be predicted based on changes in these weather and water composition factors. Our analysis confirms that FIB removal in retention ponds is sensitive to weather conditions or seasons, but temperature and precipitation data may not describe the variable FIB removal. These weather conditions affect suspended solid and nutrient concentrations, which in turn could affect FIB concentration in the ponds. Removal of total suspended solids and total P only explained 5% and 12% of FIB removal data, respectively, and TN removal had no correlation with FIB removal. These results indicate that regression-based modeling with a single parameter as input has limited use to predict FIB removal due to the interactive nature of their effects on FIB removal. In contrast, machine learning algorithms such as the random forest method were able to predict 65% of the data. The overall analysis indicates that the machine learning model could play a critical role in predicting microbial water quality of surface waters under complex conditions where the variation of both water composition and weather conditions could deem regression-based modeling less effective.
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Affiliation(s)
- Renan Valenca
- Department of Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
| | - Lilly Garcia
- Department of Civil and Environmental Engineering, University of California Los Angeles, CA, USA
| | - Christina Espinosa
- Department of Civil and Environmental Engineering, University of California Los Angeles, CA, USA
| | - Dilara Flor
- Department of Civil and Environmental Engineering, University of California Los Angeles, CA, USA
| | - Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
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11
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The Key Impact on Water Quality of Coral Reefs in Kenting National Park. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10020270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Southern Taiwan’s Kenting National Park is a popular retreating place for many domestic and international tourists, with increasing tourist numbers potentially over-burdening the coastal ecosystems. To better understand human impacts, a long-term ecological research program was initiated in 2001 to track water quality at 14 coral reef-abutting sites throughout the park since then. Extracting the data from this 20-year survey, we found that increasing in the nutrient levels during the summer rainy season, together with the drops in salinity led by freshwater inputs (land- & rainfall-derived), was the main impact to coral reef ecosystem of Kenting. Cluster analysis further confirmed the nutrient influx was mainly attributed to the local discharge outlets with dense of villages and hotels at upstream. Therefore, more efforts are needed to input to control tourist number, treat waste water discharge and strengthen land protection facilities.
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12
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Abstract
Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.
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13
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Vizzo JI, Cabrerizo MJ, Helbling EW, Villafañe VE. Extreme and gradual rainfall effects on winter and summer estuarine phytoplankton communities from Patagonia (Argentina). MARINE ENVIRONMENTAL RESEARCH 2021; 163:105235. [PMID: 33338796 DOI: 10.1016/j.marenvres.2020.105235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
Rainfall events bring both, terrigenous materials (including DOM) and nutrients to the aquatic system (e.g., via riverine runoff) having potential effects on the structure and metabolism of the phytoplankton communities. As extreme rainfall events in Patagonia occurred more frequently in the last decade (2010-2019) as compared to the previous ones (1972-2009), we exposed winter and summer phytoplankton communities (using microcosms) to solar radiation, simulating two rainfall conditions - a single extreme vs. intermittent i.e., with gradual inputs, and we assessed their photosynthetic and growth rates responses and taxonomic changes. Rainfall scenarios significantly increased growth of both communities, mainly of small nanoplanktonic species, as compared to the control. Small nanoplanktonic centric diatoms increased and dominated in both rainfall scenarios, as compared to the control, during winter and summer, with significantly smaller cells during summer as compared to winter. Photosynthetic efficiency increased in both rainfall scenarios at the end of the experiment as compared to the control. Overall, the change towards small cells (associated to rainfall events) that can use more effectively solar radiation and nutrients (as compared to large cells) may have a significant impact on the trophic webs of the South West Atlantic Ocean by favoring grazing pressure by microzooplankton, especially during summer.
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Affiliation(s)
- Juan I Vizzo
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103, Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
| | - Marco J Cabrerizo
- Centro de Investigación Mariña da Universidade de Vigo (CIM-UVigo), Illa de Toralla s/n, 36331, Vigo, Spain; Departamento de Ecología y Biología Animal, Universidade de Vigo, Facultad de Ciencias del Mar, Campus Lagoas Marcosende s/n, 36310, Vigo, Spain.
| | - E Walter Helbling
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103, Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
| | - Virginia E Villafañe
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103, Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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14
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Hayes HG, Kalhori PS, Weiss M, Grier SR, Fong P, Fong CR. Storms may disrupt top-down control of algal turf on fringing reefs. CORAL REEFS (ONLINE) 2021; 40:269-273. [PMID: 33424105 PMCID: PMC7784215 DOI: 10.1007/s00338-020-02045-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/23/2020] [Indexed: 05/05/2023]
Abstract
Storms strongly affect coral reefs; one unstudied but potentially important outcome may be a decrease in herbivory, presumably through changes to freshwater, sediment and nutrient influx. Algal turfs are sensitive early indicators of reef condition, and experimental evidence demonstrates low sediment loads and strong herbivory maintain short, healthy turf. While unknown, storms likely disrupt these controlling forces. We have observed storms that generate frequent, visible sediment plumes in Moorea, French Polynesia. To evaluate the effects of storms on herbivory, we conducted a set of field experiments manipulating herbivore access to naturally occurring turf under three rainfall regimes: no rain, light rain, and heavy rain that generated a plume event. We found strong effects of herbivores except following the storm, indicating disruption of typically strong top-down control by herbivores on algal turfs. Further research into the underlying mechanisms is critical as storm intensities and watershed development increase in many tropical regions.
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Affiliation(s)
- Hannah G. Hayes
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
| | - Pooneh S. Kalhori
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
| | - Marcus Weiss
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
| | - Shalanda R. Grier
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
| | - Peggy Fong
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
| | - Caitlin R. Fong
- Department of Biology, California State University, Northridge, Los Angeles, USA
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Fong CR, Gaynus CJ, Carpenter RC. Complex interactions among stressors evolve over time to drive shifts from short turfs to macroalgae on tropical reefs. Ecosphere 2020. [DOI: 10.1002/ecs2.3130] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Caitlin R. Fong
- Department of Biology California State University Northridge Northridge California USA
| | - Camille J. Gaynus
- Department of Ecology and Evolutionary Biology University of California Los Angeles Los Angeles California USA
| | - Robert C. Carpenter
- Department of Ecology and Evolutionary Biology University of California Los Angeles Los Angeles California USA
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