Júlio Henrique Garcia da Silva, Laura Carolina Leal, Gustavo Muniz Dias
ABSTRACT: Ascidians are marine sessile animals that have evolved many strategies to reduce predation. Previous manipulative experiments with ascidian tissues or pellets have shown that they have chemical defenses that render them unpalatable. However, predation-exclusion experiments on a community scale have shown that ascidians are almost entirely eaten when exposed to predators. Based on these contrasting results, we performed a meta-analysis to assess the importance of study site, experiment design, ascidian sociability, and predator identity to the efficacy of the ascidian defense. Our study is the first quantitative review of predation on ascidians, and it emphasizes the importance of ecological interactions beyond the specific defense tactics of the organisms. We found that multiple factors can interfere with the effectiveness of the ascidian defense. Palatability studies have shown evidence for ascidian defense mechanisms; however, they depend on the identity of the predators (e.g. fish, crab, amphipod). We did not find evidence of ascidian defense in community studies. There is a lack of field experiments, mainly on solitary ascidians, that evaluate their predation risk in communities. Research on ascidian defense mechanisms is also geographically biased toward the temperate region in the Northern Hemisphere. The commonly held belief that ascidians possess active defenses may be overestimated, and the defenses that do exist are probably restricted to only a few species. This misconception has been caused mainly by methodological and geographical bias that has resulted in tests being performed only on species with previous evidence of defenses. Therefore, we need more worldwide studies focusing on the ecological relationships between ascidians and predators, specifically in natural communities under field conditions.
{"title":"Palatability of ascidians: a meta-analysis of the predation effect on ascidians","authors":"Júlio Henrique Garcia da Silva, Laura Carolina Leal, Gustavo Muniz Dias","doi":"10.3354/meps14632","DOIUrl":"https://doi.org/10.3354/meps14632","url":null,"abstract":"ABSTRACT: Ascidians are marine sessile animals that have evolved many strategies to reduce predation. Previous manipulative experiments with ascidian tissues or pellets have shown that they have chemical defenses that render them unpalatable. However, predation-exclusion experiments on a community scale have shown that ascidians are almost entirely eaten when exposed to predators. Based on these contrasting results, we performed a meta-analysis to assess the importance of study site, experiment design, ascidian sociability, and predator identity to the efficacy of the ascidian defense. Our study is the first quantitative review of predation on ascidians, and it emphasizes the importance of ecological interactions beyond the specific defense tactics of the organisms. We found that multiple factors can interfere with the effectiveness of the ascidian defense. Palatability studies have shown evidence for ascidian defense mechanisms; however, they depend on the identity of the predators (e.g. fish, crab, amphipod). We did not find evidence of ascidian defense in community studies. There is a lack of field experiments, mainly on solitary ascidians, that evaluate their predation risk in communities. Research on ascidian defense mechanisms is also geographically biased toward the temperate region in the Northern Hemisphere. The commonly held belief that ascidians possess active defenses may be overestimated, and the defenses that do exist are probably restricted to only a few species. This misconception has been caused mainly by methodological and geographical bias that has resulted in tests being performed only on species with previous evidence of defenses. Therefore, we need more worldwide studies focusing on the ecological relationships between ascidians and predators, specifically in natural communities under field conditions.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930414","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}
ABSTRACT: Sardine species are known for multi-decadal-scale stock fluctuations. The Japanese sardine Sardinops melanostictus is one such species that is distributed near the Kuroshio western boundary current system. Like other sardines, food availability in the larval stage is thought to be an important factor in Japanese sardine stock fluctuations. Previous studies have suggested the significance of the feeding environment, particularly in the winter and spring seasons, within the Kuroshio axis area. However, collecting zooplankton, the primary food for larvae, along the strong current is challenging, and there is a lack of long-term observational data on zooplankton in this area. Therefore, in this study, we estimated zooplankton density in the Kuroshio axis area from 1967 to 2018 using a coupled physical-biological lower trophic level ecosystem model and compared it with the logarithm of recruitment per spawning stock biomass (LNRPS) and logarithm of recruitment per egg (LNRPE) of the Japanese sardine. Significant correlations were found between the zooplankton density and LNRPS from 1967 to 2004 and between zooplankton density and LNRPE from 1979 to 1996. Since, in this study, Granger causality was established between zooplankton density and LNRPS before 2005 and between zooplankton density and LNRPE before 1996, in these periods, namely 1967-2004 and 1979-1996, there is a high likelihood that zooplankton density influenced the interannual variation in recruitment. On the other hand, we found no relationship between recent food availability and LNRPS/LNRPE. This aspect remains a subject for future research.
{"title":"Long-term comparison between the Japanese sardine Sardinops melanostictus stock level and simulated zooplankton density around the Kuroshio region","authors":"Haruka Nishikawa, Hiroyuki Tsujino, Shiro Nishikawa, Shin-Ichiro Nakayama, Hideyuki Nakano, Toru Sugiyama, Yoichi Ishikawa","doi":"10.3354/meps14622","DOIUrl":"https://doi.org/10.3354/meps14622","url":null,"abstract":"ABSTRACT: Sardine species are known for multi-decadal-scale stock fluctuations. The Japanese sardine <i>Sardinops melanostictus</i> is one such species that is distributed near the Kuroshio western boundary current system. Like other sardines, food availability in the larval stage is thought to be an important factor in Japanese sardine stock fluctuations. Previous studies have suggested the significance of the feeding environment, particularly in the winter and spring seasons, within the Kuroshio axis area. However, collecting zooplankton, the primary food for larvae, along the strong current is challenging, and there is a lack of long-term observational data on zooplankton in this area. Therefore, in this study, we estimated zooplankton density in the Kuroshio axis area from 1967 to 2018 using a coupled physical-biological lower trophic level ecosystem model and compared it with the logarithm of recruitment per spawning stock biomass (LNRPS) and logarithm of recruitment per egg (LNRPE) of the Japanese sardine. Significant correlations were found between the zooplankton density and LNRPS from 1967 to 2004 and between zooplankton density and LNRPE from 1979 to 1996. Since, in this study, Granger causality was established between zooplankton density and LNRPS before 2005 and between zooplankton density and LNRPE before 1996, in these periods, namely 1967-2004 and 1979-1996, there is a high likelihood that zooplankton density influenced the interannual variation in recruitment. On the other hand, we found no relationship between recent food availability and LNRPS/LNRPE. This aspect remains a subject for future research.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868882","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}
A. Teles-Machado, S. M. Plecha, A. Peliz, S. Garrido
ABSTRACT: Unlike other upwelling areas where sardine and anchovy species dominate the pelagic ecosystems, the Western Iberian ecosystem has been consistently dominated by European sardine Engraulis encrasicolus, while anchovy had a residual presence from the start of acoustic surveys, in 1989, to 2014. Since 2015, the abundance of anchovy in the Western Iberian margins has sharply increased and continues to show an increasing trend as of 2023. It is unclear if this increase is a result of dispersal from nearby recruitment areas, higher survival rates of early life stages due to favorable environmental conditions, or both. We used a set of different models to simulate the dispersion and survival of anchovy early life stages in the Iberian region for the years preceding the increase in anchovy abundance. An ocean model simulation with the model CROCO provided the fields used as background for Lagrangian simulations coupled to an individual-based model of anchovy eggs and larvae. We simulated the years 2013-2015, and the results show that in 2014 and 2015, anomalous upper-ocean circulation patterns with strong and persistent westward currents transported a large number of eggs and larvae from the Bay of Biscay (BoB) westward along the Northern Iberian margin. The maximum transport occurred in June and July 2015, when 8 and 4%, respectively, of the eggs spawned in the BoB potentially reached the Iberian west coast as larvae. This process might explain the increase in anchovy abundance in the Western Iberian ecosystem. The results of the study show that episodes of anomalous intense ocean currents, when coincident with high presence of eggs, can lead to the colonization of new areas, and connectivity between areas varies dramatically with time.
{"title":"Anomalous ocean currents and European anchovy dispersal in the Iberian ecosystem","authors":"A. Teles-Machado, S. M. Plecha, A. Peliz, S. Garrido","doi":"10.3354/meps14526","DOIUrl":"https://doi.org/10.3354/meps14526","url":null,"abstract":"ABSTRACT: Unlike other upwelling areas where sardine and anchovy species dominate the pelagic ecosystems, the Western Iberian ecosystem has been consistently dominated by European sardine <i>Engraulis encrasicolus</i>, while anchovy had a residual presence from the start of acoustic surveys, in 1989, to 2014. Since 2015, the abundance of anchovy in the Western Iberian margins has sharply increased and continues to show an increasing trend as of 2023. It is unclear if this increase is a result of dispersal from nearby recruitment areas, higher survival rates of early life stages due to favorable environmental conditions, or both. We used a set of different models to simulate the dispersion and survival of anchovy early life stages in the Iberian region for the years preceding the increase in anchovy abundance. An ocean model simulation with the model CROCO provided the fields used as background for Lagrangian simulations coupled to an individual-based model of anchovy eggs and larvae. We simulated the years 2013-2015, and the results show that in 2014 and 2015, anomalous upper-ocean circulation patterns with strong and persistent westward currents transported a large number of eggs and larvae from the Bay of Biscay (BoB) westward along the Northern Iberian margin. The maximum transport occurred in June and July 2015, when 8 and 4%, respectively, of the eggs spawned in the BoB potentially reached the Iberian west coast as larvae. This process might explain the increase in anchovy abundance in the Western Iberian ecosystem. The results of the study show that episodes of anomalous intense ocean currents, when coincident with high presence of eggs, can lead to the colonization of new areas, and connectivity between areas varies dramatically with time.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868883","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}
ABSTRACT: Explaining variation in life history phenology requires us to disentangle environmental-dependent variability from that caused by adaptive change across time and space. Here, we offer thermal time models (models measuring time in temperature units) as tools to understand the spawning dynamics of small pelagic fish, such as Pacific herring Clupea pallasii. We hypothesised that thermal time explains the annual timing of spawning of Pacific herring across space and time. By testing this hypothesis, we identified developmental constants (thermal constants of spawning) that can be used to make spawning time predictions. We examined spatio-temporal changes in Pacific herring spawning time over a 69 yr period (1941-2010) across 6 regions off British Columbia (BC), Canada. We estimated the degree-days (DD, °C-days) from the onset of gonadal maturation to spawning by combining spawning time estimates with distribution-specific temperature estimates. We then fitted models to explore how DD to spawning can be used to explain observed spawning time patterns across space and time and identified temperature-independent sources of variability (e.g. adaptive differences among regions, spawner size). We found that, even though Pacific herring often spawned ∼5 d later with each increasing degree in latitude, the average thermal time in DD to spawning was ∼1700°C-days. We also found that DD to spawning explains linear variation in spawning time across years for some regions of the BC Pacific herring. Thermal time models can aid in predictions of environmental responses and forecasts of life-history phenology in a changing climate.
{"title":"Estimating a thermal constant of spawning to explain spawning time of Pacific herring Clupea pallasii across space and time","authors":"A. Sofia A. Ferreira, Anna B. Neuheimer","doi":"10.3354/meps14569","DOIUrl":"https://doi.org/10.3354/meps14569","url":null,"abstract":"ABSTRACT: Explaining variation in life history phenology requires us to disentangle environmental-dependent variability from that caused by adaptive change across time and space. Here, we offer thermal time models (models measuring time in temperature units) as tools to understand the spawning dynamics of small pelagic fish, such as Pacific herring <i>Clupea pallasii</i>. We hypothesised that thermal time explains the annual timing of spawning of Pacific herring across space and time. By testing this hypothesis, we identified developmental constants (thermal constants of spawning) that can be used to make spawning time predictions. We examined spatio-temporal changes in Pacific herring spawning time over a 69 yr period (1941-2010) across 6 regions off British Columbia (BC), Canada. We estimated the degree-days (DD, °C-days) from the onset of gonadal maturation to spawning by combining spawning time estimates with distribution-specific temperature estimates. We then fitted models to explore how DD to spawning can be used to explain observed spawning time patterns across space and time and identified temperature-independent sources of variability (e.g. adaptive differences among regions, spawner size). We found that, even though Pacific herring often spawned ∼5 d later with each increasing degree in latitude, the average thermal time in DD to spawning was ∼1700°C-days. We also found that DD to spawning explains linear variation in spawning time across years for some regions of the BC Pacific herring. Thermal time models can aid in predictions of environmental responses and forecasts of life-history phenology in a changing climate.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868884","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}
Kym C. Jacobson, David J. Marcogliese, Ken MacKenzie
ABSTRACT: Small pelagics occupy an intermediate trophic level in marine ecosystems, serving as prey for a variety of predators and thus playing a very important role in these ecosystems. This review collates information gleaned from parasitological studies of small pelagics (fish, squid and euphausiids) and describes the valuable biological information they can provide. We describe why parasitology studies are important and how they have contributed to our understanding of the role of small pelagics in marine ecosystems. Pertinent general patterns in marine parasite ecology relevant to trophic interactions in small pelagics, including variations in parasite faunas with features such as host size, depth distribution and feeding behaviour are synthesized. With their relatively long life spans relative to stomach contents and stable isotopes, trophically transmitted parasites can provide a unique dietary history for the host. Therefore, we summarize the trophically transmitted parasites found most frequently in small pelagics and assess the potential of different parasite taxa as indicators of host diet. The use of multiple techniques, including stomach contents and stable isotopes, along with parasites, are evaluated to better reveal fish diets. Parasites provide complementary, and additional, information compared to other techniques. Furthermore, we discuss how the presence of certain parasites in small pelagics can be used to infer their main predators and emphasize the neglected but important role of parasites in elucidating a host’s role in marine food webs. Lastly, we identify important gaps in our knowledge of the parasites of small pelagics and what can be done to fill these gaps.
{"title":"Parasites of small pelagics reflect their role in marine ecosystems","authors":"Kym C. Jacobson, David J. Marcogliese, Ken MacKenzie","doi":"10.3354/meps14529","DOIUrl":"https://doi.org/10.3354/meps14529","url":null,"abstract":"ABSTRACT: Small pelagics occupy an intermediate trophic level in marine ecosystems, serving as prey for a variety of predators and thus playing a very important role in these ecosystems. This review collates information gleaned from parasitological studies of small pelagics (fish, squid and euphausiids) and describes the valuable biological information they can provide. We describe why parasitology studies are important and how they have contributed to our understanding of the role of small pelagics in marine ecosystems. Pertinent general patterns in marine parasite ecology relevant to trophic interactions in small pelagics, including variations in parasite faunas with features such as host size, depth distribution and feeding behaviour are synthesized. With their relatively long life spans relative to stomach contents and stable isotopes, trophically transmitted parasites can provide a unique dietary history for the host. Therefore, we summarize the trophically transmitted parasites found most frequently in small pelagics and assess the potential of different parasite taxa as indicators of host diet. The use of multiple techniques, including stomach contents and stable isotopes, along with parasites, are evaluated to better reveal fish diets. Parasites provide complementary, and additional, information compared to other techniques. Furthermore, we discuss how the presence of certain parasites in small pelagics can be used to infer their main predators and emphasize the neglected but important role of parasites in elucidating a host’s role in marine food webs. Lastly, we identify important gaps in our knowledge of the parasites of small pelagics and what can be done to fill these gaps.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868728","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}
Susana Garrido, Marta Albo-Puigserver, Marta Moyano
ABSTRACT: Early life stages constitute a bottleneck for most fish populations, particularly for small pelagic fish (SPF), for which the interannual variability in recruitment strength is very high, and recruits frequently constitute the bulk of the population biomass. Finding the right prey (in terms of size and quality) during these early stages is critical for recruitment success. In this work, we synthesize the available literature on the trophic ecology of the early life stages of SPF, particularly clupeiforms. Works published during the last decade (2013-2022, 37 papers) were compared to those published previously (1920-2012, 107 papers). Gut content analysis of field-caught larvae is still the most commonly used technique (44%), while the use of biomarkers (e.g. stable isotopes and fatty acid composition), molecular tools (e.g. metabarcoding) and multitrophic approaches has increased in the last decade. Significant new knowledge was gained recently, such as that on larval feeding rates and behavior through laboratory experiments for species kept in culture (e.g. Atlantic herring, Pacific and Atlantic sardines), but some old challenges remain, such as the high vacuity rates of field-caught larvae. Lastly, we provide recommendations for future studies, such as the use of complementary techniques, the importance of studying ontogenetic shifts, the use of metabarcoding for analyzing the diet of early larvae that depend on microplankton, and the identification of prey with high taxonomic resolution. Such studies are essential to better understand larval growth and survival at sea, and thus to better understand and predict SPF population dynamics.
{"title":"Larval trophic ecology of small pelagic fishes: a review of recent advances and pathways to fill remaining knowledge gaps","authors":"Susana Garrido, Marta Albo-Puigserver, Marta Moyano","doi":"10.3354/meps14543","DOIUrl":"https://doi.org/10.3354/meps14543","url":null,"abstract":"ABSTRACT: Early life stages constitute a bottleneck for most fish populations, particularly for small pelagic fish (SPF), for which the interannual variability in recruitment strength is very high, and recruits frequently constitute the bulk of the population biomass. Finding the right prey (in terms of size and quality) during these early stages is critical for recruitment success. In this work, we synthesize the available literature on the trophic ecology of the early life stages of SPF, particularly clupeiforms. Works published during the last decade (2013-2022, 37 papers) were compared to those published previously (1920-2012, 107 papers). Gut content analysis of field-caught larvae is still the most commonly used technique (44%), while the use of biomarkers (e.g. stable isotopes and fatty acid composition), molecular tools (e.g. metabarcoding) and multitrophic approaches has increased in the last decade. Significant new knowledge was gained recently, such as that on larval feeding rates and behavior through laboratory experiments for species kept in culture (e.g. Atlantic herring, Pacific and Atlantic sardines), but some old challenges remain, such as the high vacuity rates of field-caught larvae. Lastly, we provide recommendations for future studies, such as the use of complementary techniques, the importance of studying ontogenetic shifts, the use of metabarcoding for analyzing the diet of early larvae that depend on microplankton, and the identification of prey with high taxonomic resolution. Such studies are essential to better understand larval growth and survival at sea, and thus to better understand and predict SPF population dynamics.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868887","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}
James Ruzicka, Luciano Chiaverano, Marta Coll, Susana Garrido, Jorge Tam, Hiroto Murase, Kelly Robinson, Giovanni Romagnoni, Lynne Shannon, Alexandra Silva, Dorota Szalaj, Shingo Watari
ABSTRACT: Small pelagic fish (SPF) are important forage species and a target of major fisheries within diverse ecosystems. SPF are a critical link between plankton and higher trophic levels. Understanding the network of dependencies among species and fisheries supported by SPF is required for effective resource management and assessment of risks posed by environmental and anthropogenic stressors. Food-web models represent a synthesis of knowledge of these dependencies and are a platform for evaluating the consequences of change in SPF productivity. From Ecopath food-web models archived within EcoBase (www.ecobase.ecopath.org) and from peer-reviewed literature, we compiled physiological parameters, biomasses, diets, and fishery catch rates that define SPF characteristics. From 199 models, metrics characterizing demand on ecosystem production, contribution to predators and fisheries, and sensitivities to changes in SPF were calculated. Across all models, globally, SPF represented 43% of total fish production and were supported by 8% of total primary production (14% in open ocean and 10% in upwelling models). In turn, SPF represented 18% of total fish and invertebrate catch (53% in upwelling models). From a services perspective, considering all direct and indirect trophic pathways, SPF were major contributors to predators and fisheries. On average, SPF supported 22% of seabird production, 15% of mammal production, and 34% of total fisheries catch. Support to upper trophic levels was greater in upwelling models (33% of seabird, 41% of mammal, and 62% of fishery production). These analyses show the importance of accounting for direct and indirect support by SPF to predators and fisheries when making management decisions.
{"title":"The role of small pelagic fish in diverse ecosystems: knowledge gleaned from food-web models","authors":"James Ruzicka, Luciano Chiaverano, Marta Coll, Susana Garrido, Jorge Tam, Hiroto Murase, Kelly Robinson, Giovanni Romagnoni, Lynne Shannon, Alexandra Silva, Dorota Szalaj, Shingo Watari","doi":"10.3354/meps14513","DOIUrl":"https://doi.org/10.3354/meps14513","url":null,"abstract":"ABSTRACT: Small pelagic fish (SPF) are important forage species and a target of major fisheries within diverse ecosystems. SPF are a critical link between plankton and higher trophic levels. Understanding the network of dependencies among species and fisheries supported by SPF is required for effective resource management and assessment of risks posed by environmental and anthropogenic stressors. Food-web models represent a synthesis of knowledge of these dependencies and are a platform for evaluating the consequences of change in SPF productivity. From Ecopath food-web models archived within EcoBase (www.ecobase.ecopath.org) and from peer-reviewed literature, we compiled physiological parameters, biomasses, diets, and fishery catch rates that define SPF characteristics. From 199 models, metrics characterizing demand on ecosystem production, contribution to predators and fisheries, and sensitivities to changes in SPF were calculated. Across all models, globally, SPF represented 43% of total fish production and were supported by 8% of total primary production (14% in open ocean and 10% in upwelling models). In turn, SPF represented 18% of total fish and invertebrate catch (53% in upwelling models). From a services perspective, considering all direct and indirect trophic pathways, SPF were major contributors to predators and fisheries. On average, SPF supported 22% of seabird production, 15% of mammal production, and 34% of total fisheries catch. Support to upper trophic levels was greater in upwelling models (33% of seabird, 41% of mammal, and 62% of fishery production). These analyses show the importance of accounting for direct and indirect support by SPF to predators and fisheries when making management decisions.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868729","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}
Jeroen van der Kooij, Niall McKeown, Fabio Campanella, Guillermo Boyra, Mathieu Doray, Maria Santos Mocoroa, Joana Fernandes da Silva, Martin Huret
ABSTRACT: European anchovy Engraulis encrasicolus is a widely distributed, warm-water species which has been postulated to be a climate change ‘winner’. For decades, the northern-most stock resided in the Bay of Biscay, where it typically spawned during late spring, mostly in the south. An apparent regime shift in the mid-1990s saw the sudden appearance and subsequent increase of anchovy further north. This northward range expansion was found to be driven by remnant spawning populations in the North Sea. During the autumn of 2019 and 2020, for the first time, post-larval anchovy were found in the English Channel, far from their nearest known spawning grounds. Identifying the origin of these anchovy is important for management purposes and to understand the mechanisms driving populations at the limits of their distribution. Microsatellite- and mtDNA-based analyses confirmed that the observed post-larval anchovy originated from the Bay of Biscay and were genetically distinct from English Channel and southern North Sea specimens. By combining acoustic and egg data from local surveys with larval drift modelling, we examined the processes underpinning this northward expansion. Our analysis suggests that due to population increase, spawning activity in the Bay of Biscay has expanded in space and time, increasing larval transport and survival into the Channel area. This newly recorded process underpinning an observed poleward shift is different from the one driving the anchovy expansion that started in the mid-1990s. However, both caused range expansion at the species’ northern distribution limit, demonstrating the potentially complex impacts of climate change.
{"title":"Northward range expansion of Bay of Biscay anchovy into the English Channel","authors":"Jeroen van der Kooij, Niall McKeown, Fabio Campanella, Guillermo Boyra, Mathieu Doray, Maria Santos Mocoroa, Joana Fernandes da Silva, Martin Huret","doi":"10.3354/meps14603","DOIUrl":"https://doi.org/10.3354/meps14603","url":null,"abstract":"ABSTRACT: European anchovy <i>Engraulis encrasicolus</i> is a widely distributed, warm-water species which has been postulated to be a climate change ‘winner’. For decades, the northern-most stock resided in the Bay of Biscay, where it typically spawned during late spring, mostly in the south. An apparent regime shift in the mid-1990s saw the sudden appearance and subsequent increase of anchovy further north. This northward range expansion was found to be driven by remnant spawning populations in the North Sea. During the autumn of 2019 and 2020, for the first time, post-larval anchovy were found in the English Channel, far from their nearest known spawning grounds. Identifying the origin of these anchovy is important for management purposes and to understand the mechanisms driving populations at the limits of their distribution. Microsatellite- and mtDNA-based analyses confirmed that the observed post-larval anchovy originated from the Bay of Biscay and were genetically distinct from English Channel and southern North Sea specimens. By combining acoustic and egg data from local surveys with larval drift modelling, we examined the processes underpinning this northward expansion. Our analysis suggests that due to population increase, spawning activity in the Bay of Biscay has expanded in space and time, increasing larval transport and survival into the Channel area. This newly recorded process underpinning an observed poleward shift is different from the one driving the anchovy expansion that started in the mid-1990s. However, both caused range expansion at the species’ northern distribution limit, demonstrating the potentially complex impacts of climate change.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868886","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}
Afonso Ferreira, Ana C. Brito, José Lino Costa, Vanda Brotas, Ana Teles-Machado, Susana Garrido
ABSTRACT: Since the mid-2010s, the abundance and recruitment of the European anchovy Engraulis encrasicolus has significantly increased off Western Iberia, leading to a 5-fold increase in anchovy catches. The potential environmental drivers impacting recruitment variability in anchovy in Atlantic Northwestern Iberian waters (NW Iberia) are unknown. Using data spanning 1999-2021, we identified regional changes in biological and physical factors most likely responsible for the persistent increased productivity of anchovy. Anchovy recruitment was strongest during periods with weak downwelling events (-500 to 0 m3 s-1 km-1), lower salinity (<35), and temperature between 15 and 17°C from April through June, months corresponding with annual peak spawning. Positive Winter North Atlantic Oscillation (NAOW) was also associated with years with strong anchovy recruitment. It is likely that local oceanographic features such as the Iberian Poleward Current and the Western Iberia Buoyant Plume contribute to a higher onshore retention of anchovy larvae, promoting life cycle closure and higher survival. The average lower salinity levels observed during spawning seasons since 2009 support this hypothesis. Moreover, random forest models suggested that years with relatively strong anchovy recruitment tended to be those with low abundance of European sardine Sardina pilchardus, suggesting that intra-guild processes such as foraging competition and egg predation are also important in establishing recruitment potential. We highlight future avenues of research needed to gain a mechanistic understanding of recruitment drivers of anchovy in this region to provide robust, science-based advice to managers and improve projections of the potential impacts of climate change.
{"title":"Anchovy on the rise: Investigating environmental drivers of recruitment strength in the northern Canary Current","authors":"Afonso Ferreira, Ana C. Brito, José Lino Costa, Vanda Brotas, Ana Teles-Machado, Susana Garrido","doi":"10.3354/meps14594","DOIUrl":"https://doi.org/10.3354/meps14594","url":null,"abstract":"ABSTRACT: Since the mid-2010s, the abundance and recruitment of the European anchovy <i>Engraulis encrasicolus</i> has significantly increased off Western Iberia, leading to a 5-fold increase in anchovy catches. The potential environmental drivers impacting recruitment variability in anchovy in Atlantic Northwestern Iberian waters (NW Iberia) are unknown. Using data spanning 1999-2021, we identified regional changes in biological and physical factors most likely responsible for the persistent increased productivity of anchovy. Anchovy recruitment was strongest during periods with weak downwelling events (-500 to 0 m<sup>3</sup> s<sup>-1</sup> km<sup>-1</sup>), lower salinity (<35), and temperature between 15 and 17°C from April through June, months corresponding with annual peak spawning. Positive Winter North Atlantic Oscillation (NAO<sub>W</sub>) was also associated with years with strong anchovy recruitment. It is likely that local oceanographic features such as the Iberian Poleward Current and the Western Iberia Buoyant Plume contribute to a higher onshore retention of anchovy larvae, promoting life cycle closure and higher survival. The average lower salinity levels observed during spawning seasons since 2009 support this hypothesis. Moreover, random forest models suggested that years with relatively strong anchovy recruitment tended to be those with low abundance of European sardine <i>Sardina pilchardus</i>, suggesting that intra-guild processes such as foraging competition and egg predation are also important in establishing recruitment potential. We highlight future avenues of research needed to gain a mechanistic understanding of recruitment drivers of anchovy in this region to provide robust, science-based advice to managers and improve projections of the potential impacts of climate change.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868820","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}
ABSTRACT: Atlantic herring Clupea harengus populations differ in their spawning time, and spring- and autumn-spawning populations are genetically distinct. Offspring of these populations encounter seasonal variations in productivity. We conducted a fertilization experiment using spring-spawning Atlantic herring. Offspring were reared for 3 yr with seasonal varying light cycles starting either in spring or autumn, using 2 fixed temperature levels and food provided in excess. Such long-term experiments from hatching to maturation in small pelagic fish are very rare. We hypothesized that longer daylengths early in life would provide an overall growth advantage resulting in larger size after 1 yr (same amount of light) compared to those experiencing prolonged daylight later in life due to higher size-dependent growth rates at smaller sizes. Larvae with initial spring conditions initially grew faster. However, contrary to our expectations, offspring with initial autumn conditions had caught up to similar size after 1 yr. Herring at higher temperatures grew faster, even when correcting for the amount of degree-days. After the first year, individuals hatched in spring showed higher growth at the higher temperature while herring hatched under autumn light conditions consistently had higher growth rates at lower temperatures. The somatic condition of herring followed the daylength, with best conditions during summer and poorest during winter. This was the first long-term experiment conducted on herring with varying light conditions from hatching to maturation. Our novel results indicate that herring display considerable growth plasticity, reflecting the wide range of environmental conditions and life histories sustaining herring populations.
{"title":"Growth of spring- and autumn-spawned larvae of Atlantic herring Clupea harengus: a long-term experiment mimicking seasonal light conditions","authors":"Florian Berg, Gaute Seljestad, Arild Folkvord","doi":"10.3354/meps14521","DOIUrl":"https://doi.org/10.3354/meps14521","url":null,"abstract":"ABSTRACT: Atlantic herring <i>Clupea harengus</i> populations differ in their spawning time, and spring- and autumn-spawning populations are genetically distinct. Offspring of these populations encounter seasonal variations in productivity. We conducted a fertilization experiment using spring-spawning Atlantic herring. Offspring were reared for 3 yr with seasonal varying light cycles starting either in spring or autumn, using 2 fixed temperature levels and food provided in excess. Such long-term experiments from hatching to maturation in small pelagic fish are very rare. We hypothesized that longer daylengths early in life would provide an overall growth advantage resulting in larger size after 1 yr (same amount of light) compared to those experiencing prolonged daylight later in life due to higher size-dependent growth rates at smaller sizes. Larvae with initial spring conditions initially grew faster. However, contrary to our expectations, offspring with initial autumn conditions had caught up to similar size after 1 yr. Herring at higher temperatures grew faster, even when correcting for the amount of degree-days. After the first year, individuals hatched in spring showed higher growth at the higher temperature while herring hatched under autumn light conditions consistently had higher growth rates at lower temperatures. The somatic condition of herring followed the daylength, with best conditions during summer and poorest during winter. This was the first long-term experiment conducted on herring with varying light conditions from hatching to maturation. Our novel results indicate that herring display considerable growth plasticity, reflecting the wide range of environmental conditions and life histories sustaining herring populations.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868885","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：