Pub Date : 2024-11-16DOI: 10.1016/j.marenvres.2024.106841
Sara Lopes-Santos , José C. Xavier , José Seco , João P. Coelho , Philip R. Hollyman , Eduarda Pereira , Richard A. Phillips , José P. Queirós
Cephalopods play a major role in marine food webs as both predators and prey. Although most of the Hg in cephalopods is present in the muscle, most studies on its accumulation by predators are based on concentrations in beaks. Here, using upper and lower beaks and buccal masses of Moroteuthopsis longimana, we evaluated the relationship between Hg concentrations in different cephalopod tissues. Hg concentrations in muscle tissue (329.9 ± 166.4 ng.g−1 dw) were ≈100-fold higher than in different sections of the upper (3.5 ± 1.4 ng.g−1 dw) and lower (3.5 ± 1.0 ng.g−1 dw) beaks. A positive linear relationship was found between the Hg in the beak wing and in the muscle. Hg concentrations in the wing are therefore a useful proxy for the total Hg body burden, and their analysis provides a means of assessing the levels, transport and fate of Hg in marine ecosystems.
{"title":"Squid beaks as a proxy for mercury concentrations in muscle of the giant warty squid Moroteuthopsis longimana","authors":"Sara Lopes-Santos , José C. Xavier , José Seco , João P. Coelho , Philip R. Hollyman , Eduarda Pereira , Richard A. Phillips , José P. Queirós","doi":"10.1016/j.marenvres.2024.106841","DOIUrl":"10.1016/j.marenvres.2024.106841","url":null,"abstract":"<div><div>Cephalopods play a major role in marine food webs as both predators and prey. Although most of the Hg in cephalopods is present in the muscle, most studies on its accumulation by predators are based on concentrations in beaks. Here, using upper and lower beaks and buccal masses of <em>Moroteuthopsis longimana</em>, we evaluated the relationship between Hg concentrations in different cephalopod tissues. Hg concentrations in muscle tissue (329.9 ± 166.4 ng.g<sup>−1</sup> dw) were ≈100-fold higher than in different sections of the upper (3.5 ± 1.4 ng.g<sup>−1</sup> dw) and lower (3.5 ± 1.0 ng.g<sup>−1</sup> dw) beaks. A positive linear relationship was found between the Hg in the beak wing and in the muscle. Hg concentrations in the wing are therefore a useful proxy for the total Hg body burden, and their analysis provides a means of assessing the levels, transport and fate of Hg in marine ecosystems.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"204 ","pages":"Article 106841"},"PeriodicalIF":3.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142693280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.marenvres.2024.106850
M. Lastra , E. Jaramillo , J. López , J. Troncoso , I.F. Rodil , J. Vergara , A. Maracava
Six sandy beaches located on the south coast of Viti-Levu, Fiji, were sampled to provide as a first aim, an environmental description based upon their physical and biological attributes, to serve as a reference tool for further monitoring programs. Beach face slopes were measured at 4 replicated transects stretching from the front dunes or the seaward reach of the tree vegetation (upper shore level) to the low tide level. Samples for analyses of sand particle size were collected at 4 tidal levels: the upper shore, the drift and effluent lines, and the low tide level. Samples for macroinvertebrates were sampled at the dry, retention, and resurgence/swash zones. Beach sites were categorized in terms of their morphodynamic types by means of photographs taken on site and expert analysis, taking into consideration beach width, beach face slopes and mean grain sizes of sands. Three of the studied beaches were labeled as reflective, two were intermediate and one was in between these two morphodynamic types. The mean number of intertidal species and abundance of macroinvertebrates (dominated by crustaceans and polychaetes) across all sites were 4.1 taxa (±1.7, ranges = 2–6) and 917 individuals per linear meter of beach (m−1) (±490, ranges = 133–1154). The second aim was to test the hypothesis that, along this coast, those biotic attributes are related to beach morphodynamic types. Our data allowed us to reject this hypothesis, since i) species richness and abundances of macroinvertebrates, did not differ significantly among beaches, ii) beach slope, beach width, and sediment grain size did not account for significant variations in the number of species and abundance of macroinvertebrates, and iii) multivariate analysis indicated that sediment grain size and beach slope just accounted for 31 % of the biotic richness variation. The third aim, was to evaluate the hypotheses that biotic richness in open ocean sandy beaches is not only affected by local environmental factors, but also by regional scale processes, such as ocean productivity. Thus, biotic information and coastal productivity data of ocean exposed sandy beaches along the tropical and subtropical belt at global scale were gathered from scientific literature. Based on upwelling and downwelling measurements, we conclude that oligotrophic ocean conditions, account for the low biodiversity and abundance of macroinvertebrate assemblages inhabiting the Fijian beaches studied. Our study establishes, for the first time, a reliable baseline for future studies and projects aimed at the protection of natural sandy beaches along the shores of the Fiji Islands and other isolated archipelagos of the tropical Pacific Ocean, where oligotrophic conditions prevail in their aquatic environment.
{"title":"Sandy beach macrofauna along the shore of Fiji: Low species richness due to beach morphodynamics or low productivity in coastal waters?","authors":"M. Lastra , E. Jaramillo , J. López , J. Troncoso , I.F. Rodil , J. Vergara , A. Maracava","doi":"10.1016/j.marenvres.2024.106850","DOIUrl":"10.1016/j.marenvres.2024.106850","url":null,"abstract":"<div><div>Six sandy beaches located on the south coast of Viti-Levu, Fiji, were sampled to provide as a first aim, an environmental description based upon their physical and biological attributes, to serve as a reference tool for further monitoring programs. Beach face slopes were measured at 4 replicated transects stretching from the front dunes or the seaward reach of the tree vegetation (upper shore level) to the low tide level. Samples for analyses of sand particle size were collected at 4 tidal levels: the upper shore, the drift and effluent lines, and the low tide level. Samples for macroinvertebrates were sampled at the dry, retention, and resurgence/swash zones. Beach sites were categorized in terms of their morphodynamic types by means of photographs taken on site and expert analysis, taking into consideration beach width, beach face slopes and mean grain sizes of sands. Three of the studied beaches were labeled as reflective, two were intermediate and one was in between these two morphodynamic types. The mean number of intertidal species and abundance of macroinvertebrates (dominated by crustaceans and polychaetes) across all sites were 4.1 taxa (±1.7, ranges = 2–6) and 917 individuals per linear meter of beach (m<sup>−1</sup>) (±490, ranges = 133–1154). The second aim was to test the hypothesis that, along this coast, those biotic attributes are related to beach morphodynamic types. Our data allowed us to reject this hypothesis, since i) species richness and abundances of macroinvertebrates, did not differ significantly among beaches, ii) beach slope, beach width, and sediment grain size did not account for significant variations in the number of species and abundance of macroinvertebrates, and iii) multivariate analysis indicated that sediment grain size and beach slope just accounted for 31 % of the biotic richness variation. The third aim, was to evaluate the hypotheses that biotic richness in open ocean sandy beaches is not only affected by local environmental factors, but also by regional scale processes, such as ocean productivity. Thus, biotic information and coastal productivity data of ocean exposed sandy beaches along the tropical and subtropical belt at global scale were gathered from scientific literature. Based on upwelling and downwelling measurements, we conclude that oligotrophic ocean conditions, account for the low biodiversity and abundance of macroinvertebrate assemblages inhabiting the Fijian beaches studied. Our study establishes, for the first time, a reliable baseline for future studies and projects aimed at the protection of natural sandy beaches along the shores of the Fiji Islands and other isolated archipelagos of the tropical Pacific Ocean, where oligotrophic conditions prevail in their aquatic environment.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"204 ","pages":"Article 106850"},"PeriodicalIF":3.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.marenvres.2024.106853
Xiao Liang , John A. Raven , John Beardall , Sebastian Overmans , Jianrong Xia , Peng Jin
Trade-offs play vital roles in evolutionary theory, linking organism performance to changing environments in the context of global change. Marine microalgae, as one of the most important groups of primary producers in the biosphere, exhibit significant trade-offs across multiple traits in response to environmental changes, such as elevated CO2 (and consequent ocean acidification) and warming. In this review, we synthesize recent findings on the trade-offs associated with both short-term phenotypic acclimation and long-term genotypic adaptation of marine microalgae. Specifically, we discuss distinct classes of trade-offs (i.e., allocation trade-offs, acquisition trade-offs and specialist-generalist trade-offs) between multiple traits, such as growth rate, photosynthesis, nutrient acquisition, and stress tolerance. We also explored the underlying mechanisms driving these trade-offs. Finally, we discuss the broader ecological consequences of these trade-offs, such as potential shifts in species composition and ecosystem functions, and outline key research directions to better predict marine ecosystem responses to future global change scenarios.
{"title":"The trade-offs associated with the adaptions of marine microalgae to high CO2 and warming","authors":"Xiao Liang , John A. Raven , John Beardall , Sebastian Overmans , Jianrong Xia , Peng Jin","doi":"10.1016/j.marenvres.2024.106853","DOIUrl":"10.1016/j.marenvres.2024.106853","url":null,"abstract":"<div><div>Trade-offs play vital roles in evolutionary theory, linking organism performance to changing environments in the context of global change. Marine microalgae, as one of the most important groups of primary producers in the biosphere, exhibit significant trade-offs across multiple traits in response to environmental changes, such as elevated CO<sub>2</sub> (and consequent ocean acidification) and warming. In this review, we synthesize recent findings on the trade-offs associated with both short-term phenotypic acclimation and long-term genotypic adaptation of marine microalgae. Specifically, we discuss distinct classes of trade-offs (i.e., allocation trade-offs, acquisition trade-offs and specialist-generalist trade-offs) between multiple traits, such as growth rate, photosynthesis, nutrient acquisition, and stress tolerance. We also explored the underlying mechanisms driving these trade-offs. Finally, we discuss the broader ecological consequences of these trade-offs, such as potential shifts in species composition and ecosystem functions, and outline key research directions to better predict marine ecosystem responses to future global change scenarios.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"204 ","pages":"Article 106853"},"PeriodicalIF":3.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142693281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.marenvres.2024.106852
Jinyan Liu , Qilin Gutang , Yingping Fan , Ran Bi , Puhui Zhao , Keqin Zhang , Zewei Sun , Ping Li , Wenhua Liu , Jianxin Wang
Microplastic (MP) pollution is widespread in aquatic environments, accumulating in organisms and transferring through the food web. This study investigated MP abundance, composition, and distribution in 15 fish species from eastern Guangdong, 11 of which are prey for Indo-Pacific humpback dolphins (Sousa chinensis). Results indicated the highest MP abundance in fish gastrointestinal tracts, with pelagic species being the most affected. Ethylene vinyl acetate (EVA) and polyethylene (PE), linked to local industrial activities, were the most prevalent polymers. Risk quotients (RQ) at 95th percentile for Indo-Pacific humpback dolphins exceeded one, suggesting significant MP exposure risk via prey ingestion. In contrast, the MPs risk for humans through fish consumption was minimal. These findings underscore the urgent need for improved plastic waste management to protect marine apex predators.
{"title":"Microplastics in fish species from the eastern Guangdong: Implications to Indo-Pacific humpback dolphin (Sousa chinensis) and human health","authors":"Jinyan Liu , Qilin Gutang , Yingping Fan , Ran Bi , Puhui Zhao , Keqin Zhang , Zewei Sun , Ping Li , Wenhua Liu , Jianxin Wang","doi":"10.1016/j.marenvres.2024.106852","DOIUrl":"10.1016/j.marenvres.2024.106852","url":null,"abstract":"<div><div>Microplastic (MP) pollution is widespread in aquatic environments, accumulating in organisms and transferring through the food web. This study investigated MP abundance, composition, and distribution in 15 fish species from eastern Guangdong, 11 of which are prey for Indo-Pacific humpback dolphins (<em>Sousa chinensis</em>). Results indicated the highest MP abundance in fish gastrointestinal tracts, with pelagic species being the most affected. Ethylene vinyl acetate (EVA) and polyethylene (PE), linked to local industrial activities, were the most prevalent polymers. Risk quotients (RQ) at 95th percentile for Indo-Pacific humpback dolphins exceeded one, suggesting significant MP exposure risk via prey ingestion. In contrast, the MPs risk for humans through fish consumption was minimal. These findings underscore the urgent need for improved plastic waste management to protect marine apex predators.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"204 ","pages":"Article 106852"},"PeriodicalIF":3.0,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.marenvres.2024.106845
Lina L. Fernandes, Pratima M. Kessarkar, Jayu Narvekar, Durbar Ray
Nutrient concentrations were studied seasonally along estuarine and fluvial regions of four micro/meso tidal rivers from Karnataka and Maharashtra, west coast of India. This study was performed to assess the pathway of nutrients across the salinity gradients and evaluate the impacts of weathering and human activity on nutrient concentrations. The rivers of Maharashtra had phosphate concentrations several orders of magnitude higher than the rivers of Karnataka. Nutrient vs salinity plots suggest nutrient addition for Maharashtra rivers and removal in Karnataka rivers. The nutrients in the Karnataka rivers were mostly affected by sewage outfall and anthropogenic activities (industries), while in the Maharashtra rivers, it was influenced by fertilizer application and wastewater discharge. The seasonal nutrient distribution suggests nutrient loadings occurred from the catchments during the wet (monsoon) season in all the rivers. Significant deviations from the Redfield ratio implied occurrences of algal blooms which could threaten those ecosystems.
{"title":"Seasonal nutrient loadings in four monsoonal micro/meso tidal tropical estuaries, west coast of India","authors":"Lina L. Fernandes, Pratima M. Kessarkar, Jayu Narvekar, Durbar Ray","doi":"10.1016/j.marenvres.2024.106845","DOIUrl":"10.1016/j.marenvres.2024.106845","url":null,"abstract":"<div><div>Nutrient concentrations were studied seasonally along estuarine and fluvial regions of four micro/meso tidal rivers from Karnataka and Maharashtra, west coast of India. This study was performed to assess the pathway of nutrients across the salinity gradients and evaluate the impacts of weathering and human activity on nutrient concentrations. The rivers of Maharashtra had phosphate concentrations several orders of magnitude higher than the rivers of Karnataka. Nutrient vs salinity plots suggest nutrient addition for Maharashtra rivers and removal in Karnataka rivers. The nutrients in the Karnataka rivers were mostly affected by sewage outfall and anthropogenic activities (industries), while in the Maharashtra rivers, it was influenced by fertilizer application and wastewater discharge. The seasonal nutrient distribution suggests nutrient loadings occurred from the catchments during the wet (monsoon) season in all the rivers. Significant deviations from the Redfield ratio implied occurrences of algal blooms which could threaten those ecosystems.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"203 ","pages":"Article 106845"},"PeriodicalIF":3.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142648481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.marenvres.2024.106833
Demus Matheus Huang , Muhammad Fikri Sigid , Yusri Yusup , Widad Fadhlullah , Sazlina Salleh
The Strait of Malacca is well-known as an important trade route with high marine biodiversity. Among the organisms residing in the strait are the reef-building hard corals. Studies have shown that climate change and other anthropogenic stressors have induced severe degradation of coral reefs through the disruption of coral productivity and metabolisms. Moreover, in-depth investigations of causal inference of coral degradation and its correlations with potential coral-affecting physicochemical factors within the strait are limited. Hence, this study presents the analyses of the latest bi-decadal time-series trend from 1995 to 2016 of the live hard coral coverage (or live coral cover) and six coral-affecting physicochemical factors (significant wave height, sea surface salinity, particulate inorganic carbon, particulate organic carbon, turbidity, and sea surface temperature) using remote sensing and reanalysis datasets. Their potential correlations were interpreted by implementing meta- and statistical analyses of past coral surveys and remote sensing data. This study revealed the overall persistent bi-decadal decline in live hard coral coverage within the Strait of Malacca and the complex correlations among the factors that correspond to the spatial stratification of the marine environment. Among the six physicochemical factors, sea surface temperature, turbidity, and sea surface salinity were determined to be the most influential parameters on live coral cover distribution within the strait.
{"title":"An assessment of live hard coral cover distribution and its physicochemical factors in the Strait of Malacca from 1995 to 2016","authors":"Demus Matheus Huang , Muhammad Fikri Sigid , Yusri Yusup , Widad Fadhlullah , Sazlina Salleh","doi":"10.1016/j.marenvres.2024.106833","DOIUrl":"10.1016/j.marenvres.2024.106833","url":null,"abstract":"<div><div>The Strait of Malacca is well-known as an important trade route with high marine biodiversity. Among the organisms residing in the strait are the reef-building hard corals. Studies have shown that climate change and other anthropogenic stressors have induced severe degradation of coral reefs through the disruption of coral productivity and metabolisms. Moreover, in-depth investigations of causal inference of coral degradation and its correlations with potential coral-affecting physicochemical factors within the strait are limited. Hence, this study presents the analyses of the latest bi-decadal time-series trend from 1995 to 2016 of the live hard coral coverage (or live coral cover) and six coral-affecting physicochemical factors (significant wave height, sea surface salinity, particulate inorganic carbon, particulate organic carbon, turbidity, and sea surface temperature) using remote sensing and reanalysis datasets. Their potential correlations were interpreted by implementing meta- and statistical analyses of past coral surveys and remote sensing data. This study revealed the overall persistent bi-decadal decline in live hard coral coverage within the Strait of Malacca and the complex correlations among the factors that correspond to the spatial stratification of the marine environment. Among the six physicochemical factors, sea surface temperature, turbidity, and sea surface salinity were determined to be the most influential parameters on live coral cover distribution within the strait.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"203 ","pages":"Article 106833"},"PeriodicalIF":3.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142622726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herbivore grazing on macroalgae promotes the release of macroalgal organic carbons into seawater and potentially impacts their bioavailability. However, the influence of herbivores on the fate of macroalgal organic carbon remains unclear, hindering a comprehensive and in-depth understanding of the role of macroalgae in ocean carbon cycle. Here, we cocultured suspended herbivore (Apohyale sp.) and benthic herbivore (Nereis diversicolor) with macroalgae (Ulva prolifera) in the laboratory, and found that the two grazers promote the release of macroalgal organic carbon through different pathways. Apohyale sp. Can simultaneously increase the release of different forms of organic carbon by feeding on U. prolifera thalli, including dissolved organic carbon (DOC), particluate organic carbon (POC), and algal organic detritus; while N. diversicolor demonstrated a preference for ingesting algal detritus and POC, thereby reducing the detrital carbon but greatly promoting their conversion to DOC. The amount of organic carbon released per day after predation by Apohyale sp. is much higher (7.2 vs 0.5 mg C d−1) than by N. diversicolor. Meanwhile, through long-term microbial degradation experiments, we found that herbivores significantly alter the fate of macroalgae organic carbon. Although the proportions of stable carbon (recalcitrant DOC and recalcitrant POC) in different forms of macroalgal organic carbon varied after predation, the absolute amount of their residuals in seawater were 2–3 times higher than those not ingested by herbivores. Our results highlight that herbivores play a pivotal role in promoting carbon flow in marine food webs and have a significant impact on macroalgal carbon sequestration.
食草动物捕食大型藻类会促进大型藻类有机碳释放到海水中，并可能影响其生物利用率。然而，食草动物对大型藻类有机碳归宿的影响仍不清楚，阻碍了对大型藻类在海洋碳循环中作用的全面深入了解。在此，我们在实验室中将悬浮食草动物（Apohyale sp.）和底栖食草动物（Nereis diversicolor）与大型藻类（Ulva prolifera）共培养，发现这两种食草动物通过不同途径促进大型藻类有机碳的释放。Apohyale sp.能同时增加不同形式有机碳的释放，包括溶解有机碳（DOC）、微粒有机碳（POC）和藻类有机碎屑；而 N. diversicolor 则更喜欢摄取藻类碎屑和 POC，从而减少了碎屑碳，但大大促进了它们向溶解有机碳的转化。Apohyale sp.捕食后每天释放的有机碳量（7.2 vs 0.5 mg C d-1）远高于 N. diversicolor。同时，通过长期的微生物降解实验，我们发现食草动物会显著改变大型藻类有机碳的命运。虽然捕食后不同形式的大型藻类有机碳中稳定碳（难降解的 DOC 和难降解的 POC）的比例不同，但它们在海水中残留的绝对量是未被食草动物摄取的大型藻类有机碳的 2-3 倍。我们的研究结果表明，食草动物在促进海洋食物网碳流动方面发挥着关键作用，并对大型藻类的碳封存产生重要影响。
{"title":"Herbivore grazing enhances macroalgal organic carbon release and alters their carbon sequestration fate in the ocean","authors":"Hongmei Li , Xiuting Feng , Tianqi Xiong , Zenghu Zhang , Shengrong Huang , Yongyu Zhang","doi":"10.1016/j.marenvres.2024.106842","DOIUrl":"10.1016/j.marenvres.2024.106842","url":null,"abstract":"<div><div>Herbivore grazing on macroalgae promotes the release of macroalgal organic carbons into seawater and potentially impacts their bioavailability. However, the influence of herbivores on the fate of macroalgal organic carbon remains unclear, hindering a comprehensive and in-depth understanding of the role of macroalgae in ocean carbon cycle. Here, we cocultured suspended herbivore (<em>Apohyale</em> sp.) and benthic herbivore (<em>Nereis diversicolor</em>) with macroalgae (<em>Ulva prolifera</em>) in the laboratory, and found that the two grazers promote the release of macroalgal organic carbon through different pathways. <em>Apohyale</em> sp. Can simultaneously increase the release of different forms of organic carbon by feeding on <em>U</em>. <em>prolifera</em> thalli, including dissolved organic carbon (DOC), particluate organic carbon (POC), and algal organic detritus; while <em>N</em>. <em>diversicolor</em> demonstrated a preference for ingesting algal detritus and POC, thereby reducing the detrital carbon but greatly promoting their conversion to DOC. The amount of organic carbon released per day after predation by <em>Apohyale</em> sp. is much higher (7.2 <em>vs</em> 0.5 mg C d<sup>−1</sup>) than by <em>N</em>. <em>diversicolor</em>. Meanwhile, through long-term microbial degradation experiments, we found that herbivores significantly alter the fate of macroalgae organic carbon. Although the proportions of stable carbon (recalcitrant DOC and recalcitrant POC) in different forms of macroalgal organic carbon varied after predation, the absolute amount of their residuals in seawater were 2–3 times higher than those not ingested by herbivores. Our results highlight that herbivores play a pivotal role in promoting carbon flow in marine food webs and have a significant impact on macroalgal carbon sequestration.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"203 ","pages":"Article 106842"},"PeriodicalIF":3.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142639256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.marenvres.2024.106844
Giuliana B. Santana , Kelven G. A Conceição , Eric M. Silva , Gabriela Z. Diaz , Juliene T. Oliveira , André G. Oliveira , Diego Q. Melo , Ronaldo F. Nascimento , Lizie D.T. Prola , Marcus V. Liz , Lucila A.A. Coral , Othon S. Campos , Carla B. Vidal
Microplastics (MP) are a global concern due to their small size, insolubility in water, and non-degradable nature, and long-term environmental persistence. Weathering processes, such as ultraviolet (UV) radiation, can alter their properties, enhancing their ability to absorb pollutants or release harmful substances, such as pesticides, which is also an environmental concern, thereby complicating their environmental impact and mitigation efforts. This study investigates the impact of UVB-induced photoaging on polyethylene (PE) microplastics and their sorption behavior towards the pesticide chlorpyrifos (CP). PE microplastics were exposed to varying UVB aging durations, leading to significant changes in their physicochemical and morphological properties. The sorption experiments revealed that aged microplastics exhibited increased affinity for CP, with adsorption capacity rising by 17.9% compared to pristine PE. This enhanced adsorption was attributed to the (1) introduction of oxygen-containing functional groups, facilitating the formation of hydrogen bonds between the microplastic surface and surrounding water molecules, thereby contributing to the adsorption of CP; (2) formation of irregular micropores and surface roughness, potentially providing ample sites for pesticide adsorption and (3) reduction in crystallinity from 35% to 30%, which favors the sorption of hydrophobic organic pollutants. Density Functional Theory (DFT) calculations supported these findings by showing changes in the electronic structure of PE that facilitate interactions with CP. These results provide critical insights into the environmental behavior of aged microplastics and their potential to adsorb hazardous chemicals, underscoring the need for further research on the environmental impact of microplastic aging.
{"title":"Photoaging effects on polyethylene microplastics: Structural changes and chlorpyrifos adsorption","authors":"Giuliana B. Santana , Kelven G. A Conceição , Eric M. Silva , Gabriela Z. Diaz , Juliene T. Oliveira , André G. Oliveira , Diego Q. Melo , Ronaldo F. Nascimento , Lizie D.T. Prola , Marcus V. Liz , Lucila A.A. Coral , Othon S. Campos , Carla B. Vidal","doi":"10.1016/j.marenvres.2024.106844","DOIUrl":"10.1016/j.marenvres.2024.106844","url":null,"abstract":"<div><div>Microplastics (MP) are a global concern due to their small size, insolubility in water, and non-degradable nature, and long-term environmental persistence. Weathering processes, such as ultraviolet (UV) radiation, can alter their properties, enhancing their ability to absorb pollutants or release harmful substances, such as pesticides, which is also an environmental concern, thereby complicating their environmental impact and mitigation efforts. This study investigates the impact of UVB-induced photoaging on polyethylene (PE) microplastics and their sorption behavior towards the pesticide chlorpyrifos (CP). PE microplastics were exposed to varying UVB aging durations, leading to significant changes in their physicochemical and morphological properties. The sorption experiments revealed that aged microplastics exhibited increased affinity for CP, with adsorption capacity rising by 17.9% compared to pristine PE. This enhanced adsorption was attributed to the (1) introduction of oxygen-containing functional groups, facilitating the formation of hydrogen bonds between the microplastic surface and surrounding water molecules, thereby contributing to the adsorption of CP; (2) formation of irregular micropores and surface roughness, potentially providing ample sites for pesticide adsorption and (3) reduction in crystallinity from 35% to 30%, which favors the sorption of hydrophobic organic pollutants. Density Functional Theory (DFT) calculations supported these findings by showing changes in the electronic structure of PE that facilitate interactions with CP. These results provide critical insights into the environmental behavior of aged microplastics and their potential to adsorb hazardous chemicals, underscoring the need for further research on the environmental impact of microplastic aging.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"203 ","pages":"Article 106844"},"PeriodicalIF":3.0,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142623116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.marenvres.2024.106843
Xing Liu , Yan Zhao , Xiaoqiu Yu , Ying Song , Yun Li , Guanpin Yang , Yuhang Li , Baohua Zhu , Kehou Pan
Benthic diatoms serve as exemplary indicators for the assessment of ecological conditions in freshwater ecosystems. However, an approach to assessing and managing transitional water zones by benthic diatoms is relatively less. This study entailed a detailed analysis and comparison of the seasonal dynamics in species- and guild-based benthic diatom communities and their driving factors in a small-scale transitional water zone of the Yellow River Delta. Our findings revealed substantial seasonal variations in the composition and abundance of dominant species, as well as in the α and β diversity of the species-based community. Temperature emerged as the predominant environmental factor driving significant seasonal variations in the species-based community. However, no significant seasonal changes were observed in the composition and relative abundance of dominant guilds, as well as in the α, β, and functional diversity of the guild-based community. Redundancy analysis and Mantel tests demonstrated the guild-based community exhibited a stronger correlation with environmental factors compared to the species-based community. The guild-based community exhibited resilience to the influence of seasonal temperature fluctuations and exhibited a strong correlation with phosphate concentration variations. Our findings suggest that the guild-based community is a feasible approach to assessing ecological status across various seasons in the transitional water zone of the Yellow River Delta.
{"title":"Seasonal changes of species- and guild-based benthic diatom communities in the transitional water zone of the Yellow River Delta","authors":"Xing Liu , Yan Zhao , Xiaoqiu Yu , Ying Song , Yun Li , Guanpin Yang , Yuhang Li , Baohua Zhu , Kehou Pan","doi":"10.1016/j.marenvres.2024.106843","DOIUrl":"10.1016/j.marenvres.2024.106843","url":null,"abstract":"<div><div>Benthic diatoms serve as exemplary indicators for the assessment of ecological conditions in freshwater ecosystems. However, an approach to assessing and managing transitional water zones by benthic diatoms is relatively less. This study entailed a detailed analysis and comparison of the seasonal dynamics in species- and guild-based benthic diatom communities and their driving factors in a small-scale transitional water zone of the Yellow River Delta. Our findings revealed substantial seasonal variations in the composition and abundance of dominant species, as well as in the α and β diversity of the species-based community. Temperature emerged as the predominant environmental factor driving significant seasonal variations in the species-based community. However, no significant seasonal changes were observed in the composition and relative abundance of dominant guilds, as well as in the α, β, and functional diversity of the guild-based community. Redundancy analysis and Mantel tests demonstrated the guild-based community exhibited a stronger correlation with environmental factors compared to the species-based community. The guild-based community exhibited resilience to the influence of seasonal temperature fluctuations and exhibited a strong correlation with phosphate concentration variations. Our findings suggest that the guild-based community is a feasible approach to assessing ecological status across various seasons in the transitional water zone of the Yellow River Delta.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"203 ","pages":"Article 106843"},"PeriodicalIF":3.0,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142623117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanoparticles, such as copper oxide nanoparticle (CuO NP) and polystyrene nanoplastic (PSNP), are increasingly released into aquatic environments, and pose potential risks to aquatic animals such as brine shrimps. Understanding the toxicity of these nanoparticles, especially when combined, is very important to assess their environmental effects. Therefore, this work describes the toxicity of polystyrene nanoplastic (PSNP) and CuO nanoparticles (CuO NPs) for brine shrimp (Artemiasalina). The body length and stress biomarkers, including the activity of SOD, CAT, GST, Acid phosphatase, AChE, level of MDA and GSH, and expression of the hsp70 gene were quantified. The 48h-EC50 values for PSNP, CuO NPs, and their combination were determined as 1.024 and 5.089, and 0.512 mg L−1, respectively. The combined exposure groups showed the highest growth inhibition. This was associated with increased activity of SOD and GST, decreased activity of CAT, a significant decrease in the level of GSH, a significant increase in the MDA level, and expression of the hsp70 gene (P < 0.05). Moreover, an increased ACP and reduced AChE activity were observed in exposure groups. This study indicated that PSNP and CuO NPs have synergistic toxicity for A.salina, underscoring the importance of further investigation into their combined effect on aquatic animals.
{"title":"Toxicity of polystyrene nanoplastic and copper oxide nanoparticle in Artemia salina: Single and combined effects on stress responses","authors":"Pouya Ahmadzadeh , Akram Sadat Naeemi , Borhan Mansouri","doi":"10.1016/j.marenvres.2024.106831","DOIUrl":"10.1016/j.marenvres.2024.106831","url":null,"abstract":"<div><div>Nanoparticles, such as copper oxide nanoparticle (CuO NP) and polystyrene nanoplastic (PSNP), are increasingly released into aquatic environments, and pose potential risks to aquatic animals such as brine shrimps. Understanding the toxicity of these nanoparticles, especially when combined, is very important to assess their environmental effects. Therefore, this work describes the toxicity of polystyrene nanoplastic (PSNP) and CuO nanoparticles (CuO NPs) for brine shrimp (<em>Artemia</em> <em>salina</em>). The body length and stress biomarkers, including the activity of SOD, CAT, GST, Acid phosphatase, AChE, level of MDA and GSH, and expression of the <em>hsp70</em> gene were quantified. The 48h-EC50 values for PSNP, CuO NPs, and their combination were determined as 1.024 and 5.089, and 0.512 mg L<sup>−1</sup>, respectively. The combined exposure groups showed the highest growth inhibition. This was associated with increased activity of SOD and GST, decreased activity of CAT, a significant decrease in the level of GSH, a significant increase in the MDA level, and expression of the <em>hsp70</em> gene (P < 0.05). Moreover, an increased ACP and reduced AChE activity were observed in exposure groups. This study indicated that PSNP and CuO NPs have synergistic toxicity for <em>A.</em> <em>salina</em>, underscoring the importance of further investigation into their combined effect on aquatic animals.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"203 ","pages":"Article 106831"},"PeriodicalIF":3.0,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142623058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号