Marine Ecology Progress Series最新文献_第8页

Temperature-dependent hypoxia tolerance of purple sea urchin Strongylocentrotus purpuratus across biogeography and ontogeny 紫色海胆（Strongylocentrotus purpuratus）在生物地理学和个体发育过程中对低氧的耐受性与温度有关

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14602

Murray I. Duncan, Fiorenza Micheli, J. Andres Marquez, Christopher J. Lowe, Scott L. Hamilton, Erik A. Sperling

{"title":"Temperature-dependent hypoxia tolerance of purple sea urchin Strongylocentrotus purpuratus across biogeography and ontogeny","authors":"Murray I. Duncan, Fiorenza Micheli, J. Andres Marquez, Christopher J. Lowe, Scott L. Hamilton, Erik A. Sperling","doi":"10.3354/meps14602","DOIUrl":"https://doi.org/10.3354/meps14602","url":null,"abstract":"ABSTRACT: Ocean warming is increasing organismal oxygen demand, yet at the same time the ocean’s oxygen supply is decreasing. For a patch of habitat to remain viable, there must be a minimum level of environmental oxygen available for an organism to fuel its metabolic demand—quantified as its critical oxygen partial pressure ( pO2crit). The temperature-dependence of pO2crit sets an absolute lower boundary on aerobically viable ocean space for a species, yet whether certain life stages or geographically distant populations differ in their temperature-dependent hypoxia tolerance remains largely unknown. To address these questions, we used the purple sea urchin Strongylocentrotus purpuratus as a model species and measured pO2crit for 3 populations of adult urchins (Clallam Bay, WA [n = 39], Monterey Bay, CA [91], San Diego, CA [34]) spanning 5-22°C and for key embryonic and larval developmental phases (blastula [n = 11], gastrula [21], prism [31], early-pluteus [21], late-pluteus [14], settled [12]) at temperatures of 10-19°C. We found that temperature-dependent hypoxia tolerance is consistent among adult populations exposed to different temperature and oxygen regimes, despite variable basal oxygen demands, suggesting differential capacity to provision oxygen. Moreover, we did not detect evidence for a hypoxia tolerance bottleneck for any developmental phase. Earlier larval phases are associated with higher hypoxia tolerance and greater temperature sensitivity, while this pattern shifts towards lower hypoxia tolerance and reduced temperature sensitivity as larvae develop. Our results indicate that, at least for S. purpuratus, models quantifying aerobically viable habitat based on pO2crit-temperature relationships from a single adult population will conservatively estimate viable habitat.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"15 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786140","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}

引用次数: 0

Quantification of marine metazooplankton: Do we need to include juveniles? 海洋浮游动物的定量：我们需要将幼体包括在内吗？

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14618

G. A. Paffenhöfer, M. Köster

引用次数: 0

Gulf Stream intrusions associated with extreme seasonal fluctuations among larval fishes 湾流入侵与幼鱼的极端季节性波动有关

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14592

Sarah J. Weisberg, Sarah M. Roberts, Laura K. Gruenburg, Teresa G. Schwemmer, Tyler Menz, Ileana F. Fenwick, Janet A. Nye, Rebecca G. Asch

{"title":"Gulf Stream intrusions associated with extreme seasonal fluctuations among larval fishes","authors":"Sarah J. Weisberg, Sarah M. Roberts, Laura K. Gruenburg, Teresa G. Schwemmer, Tyler Menz, Ileana F. Fenwick, Janet A. Nye, Rebecca G. Asch","doi":"10.3354/meps14592","DOIUrl":"https://doi.org/10.3354/meps14592","url":null,"abstract":"ABSTRACT: Change in phenology is one of the hallmarks of global climate change. In marine fishes, warming is expected to cause the advancement of a spring peak in larval occurrence or the delay of a fall peak. However, empirical evidence has not consistently upheld this broad prediction, implying that more nuanced hypotheses are needed. Our study investigates oceanic impacts on fish phenology by examining patterns in larval occurrence on the Northeast US continental shelf, one of the most rapidly warming regions of the global ocean. We use data from NOAA’s Ecosystem Monitoring Program, which samples larval fish taxa across the shelf on a bimonthly basis. The sampling program began in 1999, thus documenting changes during a period of rapid warming. We calculated the central tendency of seasonal larval occurrence for 38 taxa and tested for temporal relationships with oceanic drivers thought to influence larval seasonality in other ecosystems. We did not find evidence for warming-related changes in larval phenology over the last 2 decades. Rather, we found high interannual variability in larval timing among many populations, especially those along the shelf break. Among examined factors, salinity maximum intrusions associated with Gulf Stream warm core rings showed the strongest explanatory power for variation in larval fish phenology. Additionally, the occurrence timing of highly variable larval populations overlapped with that of salinity maximum intrusions. Our results suggest that uniform phenological responses to warming are unlikely in this ecosystem, and that hydrodynamic processes connecting widely dispersed regions can strongly influence the phenology of fish.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"11 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785043","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}

引用次数: 0

Seasonality influences the effect of warming on kelp photosynthesis 季节性影响气候变暖对海带光合作用的影响

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14623

Kiara Franke, Inka Bartsch, Ulf Karsten, Angelika Graiff

{"title":"Seasonality influences the effect of warming on kelp photosynthesis","authors":"Kiara Franke, Inka Bartsch, Ulf Karsten, Angelika Graiff","doi":"10.3354/meps14623","DOIUrl":"https://doi.org/10.3354/meps14623","url":null,"abstract":"ABSTRACT: The consequences of a year-round warming scenario on the photosynthetic performance of kelp species are unknown. In times of global warming, fundamental photosynthesis data are important due to the high temperature dependence. Seasonal photosynthetic performance was quantified in the kelp Laminaria hyperborea sampled along a depth gradient (2, 4 and 6 m below mean low water spring tide) at the island of Helgoland (North Sea, Germany). Blade discs were cultivated at in situ irradiances and temperatures (spring: 7°C; summer: 16°C; autumn: 14°C; winter: 6°C) and in parallel under warming scenarios (+4°C) for 3 d. The results highlighted that seasonality and collection depth had a stronger effect on oxygen formation (photosynthesis versus irradiance curve) and pigmentation than short-term warming, as there is a stronger correlation with changing irradiance levels than with temperature. Photosynthesis was highest in spring and summer, with small impacts of warming, indicating a high resilience to short-term temperature increases. In summer, algae exhibited reduced maximum quantum yields (Fv/Fm) at sub-lethal temperatures (20°C), pointing to a moderate stress response. Photosynthetic acclimation along the depth gradient was intensified by short-term warming, reflected in a stronger decrease in Pmax and chlorophyll content. Overall, the influence of short-term warming on the depth acclimation varied seasonally, underlining the importance of considering the season. In conclusion, L. hyperborea revealed distinct seasonal photosynthetic response patterns and a high photoacclimation potential at different depths. Therefore, seasonal and depth effects need to be considered when predicting the effects of warming on kelp primary production.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"9 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785109","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}

引用次数: 0

Influence of parasites on spawning success and egg quality in Antarctic krill Euphausia superba 寄生虫对南极磷虾产卵成功率和卵质量的影响

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14617

Alison C. Cleary, Frances Perry, Geraint A. Tarling

{"title":"Influence of parasites on spawning success and egg quality in Antarctic krill Euphausia superba","authors":"Alison C. Cleary, Frances Perry, Geraint A. Tarling","doi":"10.3354/meps14617","DOIUrl":"https://doi.org/10.3354/meps14617","url":null,"abstract":"ABSTRACT: Antarctic krill Euphausia superba are key components of Southern Ocean ecosystems and biogeochemical cycles, as well as the target of a growing commercial fishery. Understanding the drivers of variability in krill recruitment is key to managing this fishery sustainably. One potential driver which has received little attention is the role of parasites. We investigated the impact of natural parasite infestations in adult female krill on egg production and egg quality around South Georgia. DNA metabarcode sequencing was used to detect all eukaryotic parasites within krill bodies, while spawning success was determined through incubation experiments, and egg quality was assessed by quantifying key elements within each egg (carbon, nitrogen, hydrogen). E. superba in this area were infested with suctorian ciliates, eugregarine apicomplexans, and, less frequently, ellobiopsids. Parasite load was not associated with a reduced likelihood of producing eggs, but high parasite loads were associated with lower-quality eggs. This reduction in egg quality may reflect an energetic cost to parasite infestation, with implications for larval development and recruitment.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"8 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785110","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}

引用次数: 0

Reefs in no-take reserves host more oysters, macroparasites, and macrofauna than harvested reefs across an estuarine salinity gradient 在河口盐度梯度上，禁捕保护区的珊瑚礁比捕捞的珊瑚礁拥有更多的牡蛎、大型寄生虫和大型水底生物

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14615

Zofia B. Anchondo, Allison M. Tracy, Aiman Raza, Karli A. Meckler, Matthew B. Ogburn

{"title":"Reefs in no-take reserves host more oysters, macroparasites, and macrofauna than harvested reefs across an estuarine salinity gradient","authors":"Zofia B. Anchondo, Allison M. Tracy, Aiman Raza, Karli A. Meckler, Matthew B. Ogburn","doi":"10.3354/meps14615","DOIUrl":"https://doi.org/10.3354/meps14615","url":null,"abstract":"ABSTRACT: No-take reserves and habitat restoration are important management tools for reversing the effects of fishing on coastal habitats, associated faunal assemblages, and host-parasite interactions. Populations of the eastern oyster Crassostrea virginica have declined by 99% in areas of Chesapeake Bay, USA, due to overharvesting, disease, and other factors, and are now the focus of extensive restoration efforts. We surveyed subtidal oyster reefs using classic quantitative approaches and emerging videography methods to contrast pairs of harvested reefs and reefs protected in subtidal no-take marine reserves (oyster sanctuaries) in the Choptank, Great Wicomico, and James River tributaries of Chesapeake Bay. Overall, sanctuary oyster reefs contained more intact habitats and communities. Relative to nearby harvested reefs, sanctuary reefs (1) contained higher densities of oysters, (2) held larger oysters of lower condition, (3) hosted stronger oyster-macroparasite (boring sponge [Cliona spp.] and mud blister worm [Polydora spp.]) interactions, (4) had more complex habitat, and (5) supported a greater richness and abundance of macrofauna. Oyster and mobile macrofauna abundance increased with salinity, whereas macroparasite pre-valence peaked at mesohaline (5-20 psu) sites. Our results suggest that restored, sanctuary-protected oyster reefs are beginning to rebound from the effects of >100 yr of intensive harvest, as indicated by increased oyster density, recovery of host-parasite interactions, improved habitat characteristics, and more mobile macrofauna. Additionally, these patterns, observed across the salinity gradient in Chesapeake Bay, reflect a widespread trend in aquatic ecology: relative to fished areas, unfished areas have more complex habitats and communities, larger and higher densities of hosts, and stronger host-parasite interactions.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"37 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785107","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}

引用次数: 0

Diel movements and space use of Lutjanus analis at a spawning aggregation site, examined to evaluate the efficacy of a seasonal closed area for management 在产卵集结地考察虹鳟的昼夜移动和空间利用，以评估季节性禁渔区的管理效力

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14620

Sarah L. Heidmann, Richard S. Nemeth, Christopher R. Biggs, Elizabeth Kadison, Barbara L. Kojis

{"title":"Diel movements and space use of Lutjanus analis at a spawning aggregation site, examined to evaluate the efficacy of a seasonal closed area for management","authors":"Sarah L. Heidmann, Richard S. Nemeth, Christopher R. Biggs, Elizabeth Kadison, Barbara L. Kojis","doi":"10.3354/meps14620","DOIUrl":"https://doi.org/10.3354/meps14620","url":null,"abstract":"ABSTRACT: Designing place-based management for species that reproduce in transient fish spawning aggregations (FSAs) requires knowledge of movements and space use around aggregation sites. We examined the efficacy of the Mutton Snapper Seasonal Closed Area (MSSCA) in St. Croix, United States Virgin Islands, in protecting Lutjanus analis from fishing during the spawning season. We used acoustic telemetry to identify the spatial and temporal patterns of movement of 24 mutton snappers over 3 spawning seasons. L. analis aggregated from March to July with peak abundance during April, May, and June. Unlike its congeners, which spawn at sunset, L. analis spawns in the early afternoon. We were able to determine that L. analis used the MSSCA as a staging area during nighttime hours but migrated daily outside the MSSCA for spawning. We also used data from an acoustic Doppler current profiler to examine the relationship between fish movements and coastal current patterns. Fish migrated west in the morning with the prevailing current, occupied the presumed spawning site at slack tide, and then migrated east, again with the prevailing current, back to the MSSCA. We noted that chronic poaching was highly prevalent during the spawning season, reducing the effectiveness of the MSSCA and market closure. In light of our findings, to improve management of the L. analis FSA, we recommend re-evaluating the MSSCA boundaries and timing, improving enforcement, and engaging fishers and the community through co-management efforts. Pro-active management is of particular importance, given that this may be the only L. analis FSA site on St. Croix.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"73 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785039","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}

引用次数: 0

Seasonal growth and calcification of three species of crustose coralline algae in Moorea, French Polynesia 法属波利尼西亚穆雷阿岛三种甲壳珊瑚藻的季节性生长和钙化情况

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14626

Camille Vizon, Laura Lagourgue, Claude E. Payri, Maggy M. Nugues

{"title":"Seasonal growth and calcification of three species of crustose coralline algae in Moorea, French Polynesia","authors":"Camille Vizon, Laura Lagourgue, Claude E. Payri, Maggy M. Nugues","doi":"10.3354/meps14626","DOIUrl":"https://doi.org/10.3354/meps14626","url":null,"abstract":"ABSTRACT: Crustose coralline algae (CCA) play a critical role in the ecology and resilience of coral reefs by contributing to reef carbonate production and facilitating coral recruitment. However, little is known about their rates of in situ growth and calcification, particularly at the species level. To investigate the spatial and seasonal dynamics of CCA growth and calcification, we deployed CCA fragments embedded within epoxy rings at 3 mo intervals over 15 mo across 2 reef habitats in Moorea (French Polynesia). We studied 3 species differing in their microhabitat preferences (exposed, subcryptic and cryptic). Annual net calcification rates were highest in the exposed species Porolithon cf. onkodes (0.51 g CaCO3 cm-2 yr-1), intermediate in the subcryptic species Neogoniolithon cf. megalocystum (0.16 g CaCO3 cm-2 yr-1) and lowest in the cryptic species Lithophyllum sp. (0.03 g CaCO3 cm-2 yr-1). Growth and/or calcification rates differed between time intervals for all species. However, no consistent seasonal pattern was observed. P. cf. onkodes and N. cf. megalocystum had higher marginal growth rates at the fore reef habitat relative to the back reef habitat. This difference coincided with a lower occurrence of epiphytes on their crusts in the fore reef, suggesting that species interaction may be an important spatial driver of CCA growth. Our results show that CCA growth and calcification is species-specific and spatially and temporally variable. They highlight the need to consider subcryptic and cryptic CCA in reef carbonate budgets and provide important baseline information to understand how CCA communities are responding to environmental changes.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"46 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785108","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}

引用次数: 0

Genetic connectivity and isotopic niches of alvinocaridid shrimps from chemosynthetic habitats in Aotearoa/New Zealand, with a new Alvinocaris species 奥特亚罗瓦/新西兰化合栖息地阿尔维诺卡氏虾的遗传连接性和同位素壁龛，以及一个新的阿尔维诺卡氏虾物种

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14611

Pierre Methou, Nanako O. Ogawa, Hidetaka Nomaki, Naohiko Ohkouchi, Chong Chen, Kareen Schnabel

{"title":"Genetic connectivity and isotopic niches of alvinocaridid shrimps from chemosynthetic habitats in Aotearoa/New Zealand, with a new Alvinocaris species","authors":"Pierre Methou, Nanako O. Ogawa, Hidetaka Nomaki, Naohiko Ohkouchi, Chong Chen, Kareen Schnabel","doi":"10.3354/meps14611","DOIUrl":"https://doi.org/10.3354/meps14611","url":null,"abstract":"ABSTRACT: Chemosynthetic ecosystems off Aotearoa/New Zealand comprise both hydrothermal vents on the Kermadec Arc and methane seeps on the Hikurangi Margin which host rich communities of specialized fauna including 4 alvinocaridid shrimp species. The systematic positions of these New Zealand alvinocaridid shrimps have not been studied using genetic tools and little is known about their habitat use and feeding habits. Here, we re-evaluate the taxonomy of alvinocaridid shrimps from New Zealand using genetic barcoding and characterize their connectivity and isotopic niches across 8 localities. We describe a new species, Alvinocaris webberi sp. nov., previously confused with A. longirostris. We also show that A. alexander and A. chelys are junior synonyms of A. dissimilis, revealing a high genetic connectivity across hydrothermal vents and methane seeps from Japan to New Zealand, greatly extending its range. Finally, we find clear niche separation in co-occurring alvinocaridid shrimps, suggesting different diets and/or habitat use. Nevertheless, all species rely on chemosynthetic resources, regardless of the habitat depth, which ranges from 380 to 1650 m.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"116 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785112","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}

引用次数: 0

Proportional top-down effects of grapsoid crabs on growth of Spartina maritima cordgrass in southern African salt marshes 蟛蜞菊对南部非洲盐沼中脐带草生长的自上而下的比例效应

IF 2.5 3区环境科学与生态学

Marine Ecology Progress Series Pub Date : 2024-07-04 DOI: 10.3354/meps14612

Leigh-Ann Smit, Janine B. Adams, Sarah A. Hawkes, Nasreen Peer, Gavin M. Rishworth

{"title":"Proportional top-down effects of grapsoid crabs on growth of Spartina maritima cordgrass in southern African salt marshes","authors":"Leigh-Ann Smit, Janine B. Adams, Sarah A. Hawkes, Nasreen Peer, Gavin M. Rishworth","doi":"10.3354/meps14612","DOIUrl":"https://doi.org/10.3354/meps14612","url":null,"abstract":"ABSTRACT: Salt marsh productivity has historically been viewed as being driven primarily by bottom-up processes, but recent studies in North America, Europe, Asia and South America have shown that top-down forces by grazers also structure marsh vegetation. This generality of grazing pressure has not been tested to date in African salt marshes. Here, we investigated whether dominant crabs in South Africa’s estuarine marshes consume live plants and whether that interaction has direct effects on the foundational species Spartina maritima. We employed natural surveys, lab feeding trials, diet analysis and field experiments. Although we found no significant relationships between crabs and marsh plant structure in surveys, gut contents and stable isotope analysis showed that S. maritima is present but not prominent in their diet. All S. maritima components were consumed. Manipulation of crab density and size structure in the field (crabs >5 mm excluded) revealed small effects on S. maritima stem density and aboveground biomass compared to controls. Combined, this research demonstrates that crabs in these South African marshes do indeed eat live cordgrass, and their effects appear to be density dependent. Top-down impacts on marsh plants were not detected by natural density correlations, probably due to the different scales at which data were collected compared to field experiments. These results establish that grazing of live foundational marsh plants is globally common. Future studies in these systems should manipulate crab density through addition experiments or predator exclusions to understand the impact of crabs at high densities and what forces regulate their populations.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"25 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786196","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}

引用次数: 0