Benny K. K. Chan, Jyun-Cheng Guo, Chien-Lin Chen, Tin-Yam Chan
ABSTRACT: The activity pattern of the shallow-water hydrothermal vent crab Xenograpsus testudinatus in the vent and peripheral regions of Kueishan Island, Taiwan, was observed using an underwater time-lapse camera with infrared lighting during 7 consecutive 2-3 d periods. Hourly tide levels, in situ water temperature, pH, and light intensity were recorded to examine any effects of these environmental factors on crab activity. Time series analysis using spectral density plots indicated that crab activities were not rhythmic. Nevertheless, cross-correlation analysis and Pearson’s correlation showed that crab density in the vent region was negatively correlated with tide but positively correlated with water temperature and light intensity. Stepwise multiple regression analysis showed that water temperature, tide levels, and light intensity are significant predictors of crab density. There were no significant differences in crab density among specific tide periods, and thus, a previous hypothesis that vent crabs emerge in large swarms during slack waters was rejected. The vent region is a refuge from predators, with crabs more active during daytime low tides and during periods with higher water temperatures. Crab density in the peripheral region is positively correlated with tide but negatively correlated with pH, indicating that crabs there are more active at high tides while foraging and during periods with lower pH, probably when there are fewer predators. Stepwise multiple regression revealed pH and tides were significant predictors for crab density in the peripheral region.
{"title":"Activity of the shallow-water hydrothermal vent crab Xenograpsus testudinatus is affected by tides, water temperature, and light intensity","authors":"Benny K. K. Chan, Jyun-Cheng Guo, Chien-Lin Chen, Tin-Yam Chan","doi":"10.3354/meps14668","DOIUrl":"https://doi.org/10.3354/meps14668","url":null,"abstract":"ABSTRACT: The activity pattern of the shallow-water hydrothermal vent crab <i>Xenograpsus testudinatus</i> in the vent and peripheral regions of Kueishan Island, Taiwan, was observed using an underwater time-lapse camera with infrared lighting during 7 consecutive 2-3 d periods. Hourly tide levels, <i>in situ</i> water temperature, pH, and light intensity were recorded to examine any effects of these environmental factors on crab activity. Time series analysis using spectral density plots indicated that crab activities were not rhythmic. Nevertheless, cross-correlation analysis and Pearson’s correlation showed that crab density in the vent region was negatively correlated with tide but positively correlated with water temperature and light intensity. Stepwise multiple regression analysis showed that water temperature, tide levels, and light intensity are significant predictors of crab density. There were no significant differences in crab density among specific tide periods, and thus, a previous hypothesis that vent crabs emerge in large swarms during slack waters was rejected. The vent region is a refuge from predators, with crabs more active during daytime low tides and during periods with higher water temperatures. Crab density in the peripheral region is positively correlated with tide but negatively correlated with pH, indicating that crabs there are more active at high tides while foraging and during periods with lower pH, probably when there are fewer predators. Stepwise multiple regression revealed pH and tides were significant predictors for crab density in the peripheral region.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"23 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195317","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}
Megan E. Moore, Michael J. Malick, Austen C. Thomas, Matthew M. Klungle, Barry A. Berejikian
ABSTRACT: After decades of historic exploitation, harbor seal Phoca vitulina populations in many marine ecosystems are increasing, and in some cases causing alarm over predation impacts on prey species of conservation concern. To gauge the magnitude of harbor seal predation impact on juvenile Puget Sound steelhead Oncorhynchus mykiss, a threatened population under the US Endangered Species Act, we quantified harbor seal predation rates in the Nisqually River estuary and nearshore marine environment of south Puget Sound in Washington State, USA, using 2 independent assessments. First, we developed a prey consumption model for the years 2016-2018 using the proportion of steelhead in seal scat (assessed using DNA metabarcoding, bioinformatics, and hard parts), seal daily energetic requirements, steelhead smolt size and abundance information, and seal abundance estimates. Second, we used acoustic telemetry data from individually tagged steelhead smolts (2014-2019 and 2021) to quantify predation events in the Nisqually River estuary based on spatial and temporal behavioral patterns of both predator and prey. The consumption model estimated that 9.0% (2017) to 32.8% (2018) of steelhead outmigrants (i.e. ‘smolts’) were eaten by harbor seals, accounting for most of the total mortality incurred in the Nisqually estuary and South Puget Sound (23 km) in 2 out of 3 years. Predation mortality rates through the estuary (5 km), assessed using acoustic telemetry analysis, ranged from 11.0% (2014) to 24.8% (2016). Our results demonstrate that a large proportion of a threatened salmonid population can be lost to harbor seal predation over a small segment of their migration route, even in a relatively natural delta estuary.
{"title":"Harbor seal predation on migrating steelhead smolts entering marine waters","authors":"Megan E. Moore, Michael J. Malick, Austen C. Thomas, Matthew M. Klungle, Barry A. Berejikian","doi":"10.3354/meps14639","DOIUrl":"https://doi.org/10.3354/meps14639","url":null,"abstract":"ABSTRACT: After decades of historic exploitation, harbor seal <i>Phoca vitulina</i> populations in many marine ecosystems are increasing, and in some cases causing alarm over predation impacts on prey species of conservation concern. To gauge the magnitude of harbor seal predation impact on juvenile Puget Sound steelhead <i>Oncorhynchus mykiss</i>, a threatened population under the US Endangered Species Act, we quantified harbor seal predation rates in the Nisqually River estuary and nearshore marine environment of south Puget Sound in Washington State, USA, using 2 independent assessments. First, we developed a prey consumption model for the years 2016-2018 using the proportion of steelhead in seal scat (assessed using DNA metabarcoding, bioinformatics, and hard parts), seal daily energetic requirements, steelhead smolt size and abundance information, and seal abundance estimates. Second, we used acoustic telemetry data from individually tagged steelhead smolts (2014-2019 and 2021) to quantify predation events in the Nisqually River estuary based on spatial and temporal behavioral patterns of both predator and prey. The consumption model estimated that 9.0% (2017) to 32.8% (2018) of steelhead outmigrants (i.e. ‘smolts’) were eaten by harbor seals, accounting for most of the total mortality incurred in the Nisqually estuary and South Puget Sound (23 km) in 2 out of 3 years. Predation mortality rates through the estuary (5 km), assessed using acoustic telemetry analysis, ranged from 11.0% (2014) to 24.8% (2016). Our results demonstrate that a large proportion of a threatened salmonid population can be lost to harbor seal predation over a small segment of their migration route, even in a relatively natural delta estuary.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"10 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195321","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}
Alice V. Cunnington, Peter Shum, Craig S. Wilding, Stefano Mariani
ABSTRACT: Biodiversity in coastal marine environments is under unprecedented threat from anthropogenic impacts, which highlights a need for cost-effective and expedient survey methods. The analysis of environmental DNA (eDNA)—typically obtained through artificially filtered water samples—can paint a detailed picture of fish diversity in marine coastal environments. More recently, the analysis of natural sampler DNA (nsDNA, based on filter-feeding invertebrates that naturally trap eDNA in their tissues) has emerged as a potential alternative to water filtering. In this study, we investigate the widely distributed beadlet anemone Actinia equina as a potential natural eDNA sampler. Anemone samples were collected from 2 coastal locations in the UK: Rhosneigr (Anglesey, North Wales) and New Brighton (Wirral, north-western England). Sampling took place over 2 different months, and samples were compared to concomitantly sampled water. DNA metabarcoding via 12S Tele02 fish-specific primers revealed successful detection of a range of fish and other vertebrate species. We observed differences in species detected between conventional eDNA and sea anemone nsDNA samples, as well as a significant difference in seasonality detected through nsDNA. Our results indicate that the beadlet anemone can be a successful natural eDNA sampler, but that its value is more likely to reside in its complementarity alongside established eDNA methods.
{"title":"Exploring intertidal sea anemones Actinia equina as natural eDNA samplers for coastal biodiversity assessment","authors":"Alice V. Cunnington, Peter Shum, Craig S. Wilding, Stefano Mariani","doi":"10.3354/meps14650","DOIUrl":"https://doi.org/10.3354/meps14650","url":null,"abstract":"ABSTRACT: Biodiversity in coastal marine environments is under unprecedented threat from anthropogenic impacts, which highlights a need for cost-effective and expedient survey methods. The analysis of environmental DNA (eDNA)—typically obtained through artificially filtered water samples—can paint a detailed picture of fish diversity in marine coastal environments. More recently, the analysis of natural sampler DNA (nsDNA, based on filter-feeding invertebrates that naturally trap eDNA in their tissues) has emerged as a potential alternative to water filtering. In this study, we investigate the widely distributed beadlet anemone <i>Actinia equina</i> as a potential natural eDNA sampler. Anemone samples were collected from 2 coastal locations in the UK: Rhosneigr (Anglesey, North Wales) and New Brighton (Wirral, north-western England). Sampling took place over 2 different months, and samples were compared to concomitantly sampled water. DNA metabarcoding via 12S Tele02 fish-specific primers revealed successful detection of a range of fish and other vertebrate species. We observed differences in species detected between conventional eDNA and sea anemone nsDNA samples, as well as a significant difference in seasonality detected through nsDNA. Our results indicate that the beadlet anemone can be a successful natural eDNA sampler, but that its value is more likely to reside in its complementarity alongside established eDNA methods.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"16 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195348","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}
Jenny A. Allen, Ross C. Nichols, Logan J. Pallin, David W. Johnston, Ari S. Friedlaender
ABSTRACT: The innovation of new foraging strategies allows species to optimize their foraging in response to changing conditions. Humpback whales provide a good study species for this concept, as they utilize multiple novel foraging tactics across populations in diverse environments. Bubble-net feeding (BNF), commonly seen in the Northern Hemisphere, has emerged as a foraging innovation in the past 20 yr within the Western Antarctic Peninsula. Using sightings data from 2015-2023, we found that BNF was present in every study year, with an annual average of 30% of foraging sightings. This data was supplemented with 26 animal-born tags deployed over the same study period. Of these tags, 12 detected instances of BNF, with BNF making up an average of 19% of the foraging lunges detected. There were seasonal trends in BNF sightings, as it was observed significantly more often at the beginning of the feeding season (January) before declining. BNF group sizes (mean: 3.41) were significantly larger than non-BNF surface feeding groups (mean: 2.21). This observation is consistent with BNF in the Northern Hemisphere, which also appears to primarily be a group foraging strategy. The seasonal pattern and relatively recent emergence of BNF suggests that its use is likely tied to specific environmental conditions, which should be investigated by comparing BNF with variables such as prey density and light availability. The social transmission of novel foraging strategies across other populations further suggests that the prevalence of this strategy likely occurs through social learning.
{"title":"Use and prevalence of novel bubble-net foraging strategy in Western Antarctic humpback whales","authors":"Jenny A. Allen, Ross C. Nichols, Logan J. Pallin, David W. Johnston, Ari S. Friedlaender","doi":"10.3354/meps14654","DOIUrl":"https://doi.org/10.3354/meps14654","url":null,"abstract":"ABSTRACT: The innovation of new foraging strategies allows species to optimize their foraging in response to changing conditions. Humpback whales provide a good study species for this concept, as they utilize multiple novel foraging tactics across populations in diverse environments. Bubble-net feeding (BNF), commonly seen in the Northern Hemisphere, has emerged as a foraging innovation in the past 20 yr within the Western Antarctic Peninsula. Using sightings data from 2015-2023, we found that BNF was present in every study year, with an annual average of 30% of foraging sightings. This data was supplemented with 26 animal-born tags deployed over the same study period. Of these tags, 12 detected instances of BNF, with BNF making up an average of 19% of the foraging lunges detected. There were seasonal trends in BNF sightings, as it was observed significantly more often at the beginning of the feeding season (January) before declining. BNF group sizes (mean: 3.41) were significantly larger than non-BNF surface feeding groups (mean: 2.21). This observation is consistent with BNF in the Northern Hemisphere, which also appears to primarily be a group foraging strategy. The seasonal pattern and relatively recent emergence of BNF suggests that its use is likely tied to specific environmental conditions, which should be investigated by comparing BNF with variables such as prey density and light availability. The social transmission of novel foraging strategies across other populations further suggests that the prevalence of this strategy likely occurs through social learning.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"4 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195349","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: The seed sheaths of eelgrass Zostera marina L. have recently been shown to possess photosynthetic capacity that can alleviate intra-seed hypoxic conditions and thereby enhance biosynthetic activity. However, nothing is known about how increasing seawater temperatures affect physiological responses in developing Z. marina seeds. We used an optical multi-analyte sensor system in combination with O2-sensitive sensor spots to measure rates of photosynthesis and dark respiration within custom-made gas exchange chambers. Exponential saturation models were then applied to determine key photosynthetic parameters, such as maximum photosynthesis rate, light use efficiency, saturating photon irradiance (EK), compensation photon irradiance, and net diel O2 budget. Our results showed that both photosynthetic activity and dark respiration rates in sheath-covered seeds increased with increasing seawater temperature (from 10 to 25°C) but with a 2-fold stronger response in dark respiration than in gross photosynthesis over the measured temperature range. These temperature responses resulted in increasing light requirements (from 47 to 183 µmol photons m-2 s-1 in EK) and decreasing net diel O2 budgets (from -5.4 to -126 nmol O2 mg wet weight [WW]-1 h-1) of the eelgrass seeds with increasing temperature. Eelgrass seed exposure to high temperature led thus to highly reduced net diel O2 balances, which is expected to have detrimental effects on seed development and germination success owing to negative effects on synthesis rates of storage products in the endosperm.
{"title":"Effects of increasing temperature on the photosynthetic activity and oxygen balance of sheath-covered seagrass Zostera marina seeds","authors":"Kasper Elgetti Brodersen, Morten Foldager Pedersen","doi":"10.3354/meps14657","DOIUrl":"https://doi.org/10.3354/meps14657","url":null,"abstract":"ABSTRACT: The seed sheaths of eelgrass <i>Zostera marina</i> L. have recently been shown to possess photosynthetic capacity that can alleviate intra-seed hypoxic conditions and thereby enhance biosynthetic activity. However, nothing is known about how increasing seawater temperatures affect physiological responses in developing <i>Z. marina</i> seeds. We used an optical multi-analyte sensor system in combination with O<sub>2</sub>-sensitive sensor spots to measure rates of photosynthesis and dark respiration within custom-made gas exchange chambers. Exponential saturation models were then applied to determine key photosynthetic parameters, such as maximum photosynthesis rate, light use efficiency, saturating photon irradiance (<i>E</i><sub>K</sub>), compensation photon irradiance, and net diel O<sub>2</sub> budget. Our results showed that both photosynthetic activity and dark respiration rates in sheath-covered seeds increased with increasing seawater temperature (from 10 to 25°C) but with a 2-fold stronger response in dark respiration than in gross photosynthesis over the measured temperature range. These temperature responses resulted in increasing light requirements (from 47 to 183 µmol photons m<sup>-2</sup> s<sup>-1</sup> in <i>E</i><sub>K</sub>) and decreasing net diel O<sub>2</sub> budgets (from -5.4 to -126 nmol O<sub>2</sub> mg wet weight [WW]<sup>-1</sup> h<sup>-1</sup>) of the eelgrass seeds with increasing temperature. Eelgrass seed exposure to high temperature led thus to highly reduced net diel O<sub>2</sub> balances, which is expected to have detrimental effects on seed development and germination success owing to negative effects on synthesis rates of storage products in the endosperm.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"47 8 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195355","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}
Rafael A. Cabral-Tena, J. J. A. Tortolero-Langarica, Juan P. Carricart-Ganivet, Alma P. Rodríguez-Troncoso, Israel Cruz-Ortega, Amílcar L. Cupul-Magaña, Eduardo F. Balart, Héctor Reyes-Bonilla, Andrés López-Pérez
ABSTRACT: The density banding patterns of the skeletons of massive reef-building corals can be used as historical records of their growth, life history, and environmental conditions. By analyzing these patterns, it is possible to estimate growth parameters such as skeletal density, extension rate, and calcification rate. The responses of stony corals to environmental stress depend on the amount of energy available for high-energetic metabolic processes, including skeletal calcification and sexual reproduction. The sex of a colony may also influence its calcification rate and resistance to environmental stressors like thermal anomalies. Here, we review and summarize the literature that focuses on sex-associated differences in coral calcification rates between male and female colonies and then we examine their differential responses to changes in sea surface temperature (SST) in Porites panamensis, P. lobata, Pavona gigantea, Siderastrea siderea, Montastraea cavernosa, Dichocoenia stokesi, and Dengrogyra cylindrus from the eastern Pacific and Caribbean regions through a reanalysis of published data. Differences in the calcification rates between sexes were due to the energy available for calcification and the strategy employed for skeletal growth. Female corals exhibited lower calcification rates than male colonies in all coral species. The results reveal that overall, the calcification rate was negatively related to SST when the data of both sexes were pooled. However, when data were analyzed separately by sex, only the calcification rate of females was significantly dependent on SST. These findings highlight the implications for paleoenvironmental reconstructions using coral skeletons and the potential disparities in the populations of gonochoric corals.
{"title":"Sex-associated differences in sclerochronology and sensitivity to thermal stress in Caribbean and eastern Pacific reef-building corals","authors":"Rafael A. Cabral-Tena, J. J. A. Tortolero-Langarica, Juan P. Carricart-Ganivet, Alma P. Rodríguez-Troncoso, Israel Cruz-Ortega, Amílcar L. Cupul-Magaña, Eduardo F. Balart, Héctor Reyes-Bonilla, Andrés López-Pérez","doi":"10.3354/meps14661","DOIUrl":"https://doi.org/10.3354/meps14661","url":null,"abstract":"ABSTRACT: The density banding patterns of the skeletons of massive reef-building corals can be used as historical records of their growth, life history, and environmental conditions. By analyzing these patterns, it is possible to estimate growth parameters such as skeletal density, extension rate, and calcification rate. The responses of stony corals to environmental stress depend on the amount of energy available for high-energetic metabolic processes, including skeletal calcification and sexual reproduction. The sex of a colony may also influence its calcification rate and resistance to environmental stressors like thermal anomalies. Here, we review and summarize the literature that focuses on sex-associated differences in coral calcification rates between male and female colonies and then we examine their differential responses to changes in sea surface temperature (SST) in <i>Porites panamensis</i>, <i>P. lobata</i>, <i>Pavona gigantea</i>, <i>Siderastrea siderea</i>, <i>Montastraea cavernosa</i>, <i>Dichocoenia stokesi</i>, and <i>Dengrogyra cylindrus</i> from the eastern Pacific and Caribbean regions through a reanalysis of published data. Differences in the calcification rates between sexes were due to the energy available for calcification and the strategy employed for skeletal growth. Female corals exhibited lower calcification rates than male colonies in all coral species. The results reveal that overall, the calcification rate was negatively related to SST when the data of both sexes were pooled. However, when data were analyzed separately by sex, only the calcification rate of females was significantly dependent on SST. These findings highlight the implications for paleoenvironmental reconstructions using coral skeletons and the potential disparities in the populations of gonochoric corals.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"86 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195319","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}
Yuki Uematsu, Taiki Ishihara, Tamaki Shimose, Kuo-Shu Chen, John A. Mohan, Jay R. Rooker, R. J. David Wells, Owyn E. Snodgrass, Heidi Dewar, Seiji Ohshimo, Yosuke Tanaka
ABSTRACT: Pacific bluefin tuna (PBF) Thunnus orientalis have 2 major spawning grounds and migrate widely in the North Pacific Ocean. To understand the population structure and migratory ecology, we analyzed vertebral samples collected from a wide range of ages and areas and then estimated their natal ground from the first annulus in the vertebra, which does not change significantly after formation. Both spawning groups of PBF, including fish that originated from the Sea of Japan (assigned as group SJ) and from the waters around the Ryukyu Archipelago and Taiwan (group RT), were observed in all sampling areas and age classes. In younger age classes, the percentages of group SJ were higher around Japan, whereas those of group RT were higher in the eastern Pacific Ocean (EPO). The percentage of group RT decreases around Japan as they migrate to the EPO and then increases when they return. These results suggest a tendency toward different migration patterns depending on the natal area. Interestingly, the results suggest that fish from the EPO rarely migrate to the Sea of Japan. The percentages of group RT for age 10+ were similar and higher in all sampling areas, and these are considered to be the final percentages of the relative contribution of the 2 natal grounds. This is a useful approach that enables us to easily examine the relative contribution of the 2 spawning grounds across time and space, providing insights into the dynamics of movement around the Pacific based on variations in the population composition.
{"title":"Distinct natal origins based on vertebral ring analysis corroborate the migration pattern of Pacific bluefin tuna in the North Pacific Ocean","authors":"Yuki Uematsu, Taiki Ishihara, Tamaki Shimose, Kuo-Shu Chen, John A. Mohan, Jay R. Rooker, R. J. David Wells, Owyn E. Snodgrass, Heidi Dewar, Seiji Ohshimo, Yosuke Tanaka","doi":"10.3354/meps14656","DOIUrl":"https://doi.org/10.3354/meps14656","url":null,"abstract":"ABSTRACT: Pacific bluefin tuna (PBF) <i>Thunnus orientalis</i> have 2 major spawning grounds and migrate widely in the North Pacific Ocean. To understand the population structure and migratory ecology, we analyzed vertebral samples collected from a wide range of ages and areas and then estimated their natal ground from the first annulus in the vertebra, which does not change significantly after formation. Both spawning groups of PBF, including fish that originated from the Sea of Japan (assigned as group SJ) and from the waters around the Ryukyu Archipelago and Taiwan (group RT), were observed in all sampling areas and age classes. In younger age classes, the percentages of group SJ were higher around Japan, whereas those of group RT were higher in the eastern Pacific Ocean (EPO). The percentage of group RT decreases around Japan as they migrate to the EPO and then increases when they return. These results suggest a tendency toward different migration patterns depending on the natal area. Interestingly, the results suggest that fish from the EPO rarely migrate to the Sea of Japan. The percentages of group RT for age 10+ were similar and higher in all sampling areas, and these are considered to be the final percentages of the relative contribution of the 2 natal grounds. This is a useful approach that enables us to easily examine the relative contribution of the 2 spawning grounds across time and space, providing insights into the dynamics of movement around the Pacific based on variations in the population composition.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"64 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195352","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}
M. Kurtis Trzcinski, Sheena Majewski, Chad A. Nordstrom, Angela D. Schulze, Kristi M. Miller, Strahan Tucker
ABSTRACT: Predation shapes ecosystems, and quantifying the impacts of predation on the distribution and abundance of prey requires substantial effort at appropriate spatial and temporal scales for diet estimation of predators. Here, we present diet estimates of a marine predator (harbour seal Phoca vitulina richardsi) from scat collections (n = 3420) sampled at multiple haulout sites (n = 64) in the Strait of Georgia and other coastal regions around Vancouver Island, British Columbia, Canada, between 2015 and 2019. DNA metabarcoding and hard part analysis were used to identify the proportion and sizes of prey species consumed, respectively. We found that harbour seals consumed 62 primary prey species. Diversity in the diet was highly affected by the number of samples collected and varied at small spatial scales (haulout sites) as well as among broad bioregions. Three to 5 species dominated the diet depending on location, season, and year, including Pacific hake Merluccius productus, Pacific herring Clupea pallasii, and walleye pollock Gadus chalcogrammus. Within the Strait of Georgia, both male and female harbour seals consumed more hake and walleye pollock in areas and seasons in which they were more abundant. Harbour seals consumed a wide size range of prey that also varied by species, season, and region. These results indicate that harbour seal foraging is influenced by both the local abundance and composition of prey. Attempts to model the impact of predation on species of concern risk bias in their estimates and underrepresenting uncertainty if spatial and temporal variation in the diet is not accounted for.
{"title":"DNA analysis of scats reveals spatial and temporal structure in the diversity of harbour seal diet from local haulouts to oceanographic bioregions","authors":"M. Kurtis Trzcinski, Sheena Majewski, Chad A. Nordstrom, Angela D. Schulze, Kristi M. Miller, Strahan Tucker","doi":"10.3354/meps14655","DOIUrl":"https://doi.org/10.3354/meps14655","url":null,"abstract":"ABSTRACT: Predation shapes ecosystems, and quantifying the impacts of predation on the distribution and abundance of prey requires substantial effort at appropriate spatial and temporal scales for diet estimation of predators. Here, we present diet estimates of a marine predator (harbour seal <i>Phoca vitulina richards</i><i>i</i>) from scat collections (n = 3420) sampled at multiple haulout sites (n = 64) in the Strait of Georgia and other coastal regions around Vancouver Island, British Columbia, Canada, between 2015 and 2019. DNA metabarcoding and hard part analysis were used to identify the proportion and sizes of prey species consumed, respectively. We found that harbour seals consumed 62 primary prey species. Diversity in the diet was highly affected by the number of samples collected and varied at small spatial scales (haulout sites) as well as among broad bioregions. Three to 5 species dominated the diet depending on location, season, and year, including Pacific hake <i>Merluccius productus</i>, Pacific herring <i>Clupea pallasii</i>, and walleye pollock <i>Gadus chalcogrammus</i>. Within the Strait of Georgia, both male and female harbour seals consumed more hake and walleye pollock in areas and seasons in which they were more abundant. Harbour seals consumed a wide size range of prey that also varied by species, season, and region. These results indicate that harbour seal foraging is influenced by both the local abundance and composition of prey. Attempts to model the impact of predation on species of concern risk bias in their estimates and underrepresenting uncertainty if spatial and temporal variation in the diet is not accounted for.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"865 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195347","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}
Johannes Chambon, Luca Börger, Henri Weimerskirch, Janos C. Hennicke
ABSTRACT: The Abbott’s booby Papasula abbotti is one of the most threatened seabirds in the world. The non-breeding behaviour and distribution of Abbott’s boobies are largely unknown but evidence suggests they migrate between breeding attempts. This lack of information impedes the identification and quantification of the threats the birds are exposed to outside of their breeding season. We studied the migratory movements of Abbott’s booby using geolocator-immersion loggers. A total of 22 adult birds were tracked between 2007 and 2014. Analysis of the 27 migratory trips revealed that birds migrated on average 2500 km east of Christmas Island to an area centred around the Banda Sea, Indonesia. The timing of Abbott’s booby migration (from November-December to April) coincides with the Indonesian-Australian monsoon, a period characterised by reversing prevailing winds and decreased regional oceanic primary productivity. The birds’ movements matched the pattern of reversal of the prevailing winds. No birds were recorded on migration between 17 May and 26 October, which suggests that the whole population of adult Abbott’s boobies is on Christmas Island during that period. Migrating Abbott’s boobies spent little time on the water during the day or at night (15%), and individuals preferred waters with a narrow range of sea surface salinity (32.5-34.5 PSU), rugged seafloor topography, and sea surface temperatures above ca. 28°C. Overall, these novel results identify the area within which potential threats, such as interactions with fisheries or effects of climate change on the species’ marine habitats, should be investigated.
{"title":"Migratory movements, distribution, habitat preference, and activity patterns of the endangered Abbott’s booby Papasula abbotti","authors":"Johannes Chambon, Luca Börger, Henri Weimerskirch, Janos C. Hennicke","doi":"10.3354/meps14660","DOIUrl":"https://doi.org/10.3354/meps14660","url":null,"abstract":"ABSTRACT: The Abbott’s booby <i>Papasula abbotti</i> is one of the most threatened seabirds in the world. The non-breeding behaviour and distribution of Abbott’s boobies are largely unknown but evidence suggests they migrate between breeding attempts. This lack of information impedes the identification and quantification of the threats the birds are exposed to outside of their breeding season. We studied the migratory movements of Abbott’s booby using geolocator-immersion loggers. A total of 22 adult birds were tracked between 2007 and 2014. Analysis of the 27 migratory trips revealed that birds migrated on average 2500 km east of Christmas Island to an area centred around the Banda Sea, Indonesia. The timing of Abbott’s booby migration (from November-December to April) coincides with the Indonesian-Australian monsoon, a period characterised by reversing prevailing winds and decreased regional oceanic primary productivity. The birds’ movements matched the pattern of reversal of the prevailing winds. No birds were recorded on migration between 17 May and 26 October, which suggests that the whole population of adult Abbott’s boobies is on Christmas Island during that period. Migrating Abbott’s boobies spent little time on the water during the day or at night (15%), and individuals preferred waters with a narrow range of sea surface salinity (32.5-34.5 PSU), rugged seafloor topography, and sea surface temperatures above ca. 28°C. Overall, these novel results identify the area within which potential threats, such as interactions with fisheries or effects of climate change on the species’ marine habitats, should be investigated.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"26 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195351","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}
Maria A. Herrera, Diego Cardeñosa, Yannis P. Papastamatiou, Jeremy Vaudo, Christian Bermúdez-Rivas, Mahmood Shivji
ABSTRACT: Hammerhead sharks are among the most iconic and threatened shark species. Research has focused on the large hammerhead species, with relatively little work conducted on their smaller-bodied relatives, which face many of the same threats. One such species, the scalloped bonnethead Sphyrna corona, is assessed as Critically Endangered by the IUCN Red List; however, there is no knowledge about its movements, which can compromise management and conservation efforts. Here, we used acoustic telemetry to describe the spatiotemporal movements of scalloped bonnetheads inside a national park’s marine protected area along the Colombian Pacific coast, where this species still occurs in high numbers. The movements of 25 adult sharks were monitored over a 1.4 km2 area for up to ~10 mo between 2022 and 2023. Scalloped bonnetheads exhibited high residency to the area (RImax = 0.78 ± 0.18, RImin = 0.59 ± 0.32, ±SD), with most sharks present during the majority of their monitoring period. Shark movements were influenced by tides and diel period, and the space sharks used was generally small (mean 50% utilization distribution: 0.3 ± 0.2 km2), with most of their movements detected by 2 (out of 5) receivers separated by less than 2 km. These results indicate that scalloped bonnetheads spend a large amount of time in a small area, suggesting that even a spatially limited no-take zone in the National Natural Park is likely to benefit the conservation of this species. This study provides the first insights into the movement behavior of the scalloped bonnethead, with important information for its protection and management.
{"title":"High residency of a Critically Endangered hammerhead shark to a small area: implications for marine protected area management and design","authors":"Maria A. Herrera, Diego Cardeñosa, Yannis P. Papastamatiou, Jeremy Vaudo, Christian Bermúdez-Rivas, Mahmood Shivji","doi":"10.3354/meps14658","DOIUrl":"https://doi.org/10.3354/meps14658","url":null,"abstract":"ABSTRACT: Hammerhead sharks are among the most iconic and threatened shark species. Research has focused on the large hammerhead species, with relatively little work conducted on their smaller-bodied relatives, which face many of the same threats. One such species, the scalloped bonnethead <i>Sphyrna corona</i>, is assessed as Critically Endangered by the IUCN Red List; however, there is no knowledge about its movements, which can compromise management and conservation efforts. Here, we used acoustic telemetry to describe the spatiotemporal movements of scalloped bonnetheads inside a national park’s marine protected area along the Colombian Pacific coast, where this species still occurs in high numbers. The movements of 25 adult sharks were monitored over a 1.4 km<sup>2</sup> area for up to ~10 mo between 2022 and 2023. Scalloped bonnetheads exhibited high residency to the area (RI<sub>max</sub> = 0.78 ± 0.18, RI<sub>min</sub> = 0.59 ± 0.32, ±SD), with most sharks present during the majority of their monitoring period. Shark movements were influenced by tides and diel period, and the space sharks used was generally small (mean 50% utilization distribution: 0.3 ± 0.2 km<sup>2</sup>), with most of their movements detected by 2 (out of 5) receivers separated by less than 2 km. These results indicate that scalloped bonnetheads spend a large amount of time in a small area, suggesting that even a spatially limited no-take zone in the National Natural Park is likely to benefit the conservation of this species. This study provides the first insights into the movement behavior of the scalloped bonnethead, with important information for its protection and management.","PeriodicalId":18193,"journal":{"name":"Marine Ecology Progress Series","volume":"175 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195353","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}
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