Pub Date : 2023-09-07DOI: 10.1017/S0025315423000528
Mohammad Jahed Hasan Bhuain, M. N. A. Sikder, Sayeed Mahmood Belal Haider, Abu Sayeed Muhammad Sharif, Sheikh Aftab Uddin, SM Sharifuzzaman, Henglong Xu
Abstract For the bioassessment of tropical marine ecosystem, a survey of protozoa colonizing artificial substrate was conducted in the coastal waters of northern Bay of Bengal, Bangladesh. Protozoan samples were collected using glass slides from 1 and 2 m water depths at time intervals of 3, 7, 10, 14, 21, and 28 days during winter and monsoon seasons. Thus, the colonization processes of protozoa were assigned into three stages namely the initial (3 days), transitional (7 days), and equilibrium stages (10–28 days) at two depths in two seasons. Regression analyses demonstrated that the colonization dynamics of protozoa were well fitted to the MacArthur-Wilson model and logistic equation. Species richness reached equilibrium after 10–14 days and species abundance was maximum at a depth of 1 m. These results suggest that samples of protozoa can be collected at 1 m depth in winter season for monitoring the ecological health of tropical marine ecosystems.
{"title":"Colonization dynamics of periphytic protozoa in a tropical marine ecosystem","authors":"Mohammad Jahed Hasan Bhuain, M. N. A. Sikder, Sayeed Mahmood Belal Haider, Abu Sayeed Muhammad Sharif, Sheikh Aftab Uddin, SM Sharifuzzaman, Henglong Xu","doi":"10.1017/S0025315423000528","DOIUrl":"https://doi.org/10.1017/S0025315423000528","url":null,"abstract":"Abstract For the bioassessment of tropical marine ecosystem, a survey of protozoa colonizing artificial substrate was conducted in the coastal waters of northern Bay of Bengal, Bangladesh. Protozoan samples were collected using glass slides from 1 and 2 m water depths at time intervals of 3, 7, 10, 14, 21, and 28 days during winter and monsoon seasons. Thus, the colonization processes of protozoa were assigned into three stages namely the initial (3 days), transitional (7 days), and equilibrium stages (10–28 days) at two depths in two seasons. Regression analyses demonstrated that the colonization dynamics of protozoa were well fitted to the MacArthur-Wilson model and logistic equation. Species richness reached equilibrium after 10–14 days and species abundance was maximum at a depth of 1 m. These results suggest that samples of protozoa can be collected at 1 m depth in winter season for monitoring the ecological health of tropical marine ecosystems.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45194125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-06DOI: 10.1017/S0025315423000504
Aiyang Wang, Jiao Cheng, Qian Xin, Z. Sha, Min Hui
Abstract The alvinocaridid shrimp Shinkaicaris leurokolos Kikuchi and Hashimoto, 2000, is an evolutionarily important deep-sea species in hydrothermal vents of north-western Pacific. A genome survey of S. leurokolos was carried out in order to provide a foundation for its whole-genome sequencing. A total of 599 Gb high-quality sequence data were obtained in the study, representing approximately 118× coverage of the S. leurokolos genome. According to the 17-mer distribution frequency, the estimated genome size was 5.08 Gb, and its heterozygosity ratio and percentage of repeated sequences were 2.85 and 87.03%, respectively, showing a complex genome. The final scaffold assembly accounted for a total size of 9.53 Gb (32,796,062 scaffolds, N50 = 597 bp). Repetitive elements nearly constituted 45% of the nuclear genome, among which the most ubiquitous were long interspersed nuclear elements, DNA transposons and long-terminal repeat elements. A total of 12,121,553 genomic simple sequence repeats were identified, with the most frequent repeat motif being di-nucleotide (70.27%), followed by tri-nucleotide and tetra-nucleotide. From the genome survey sequences, the mitochondrial genome of S. leurokolos was also constructed and 71 single nucleotide polymorphisms were identified by comparison with previous published reference. This is the first report of de novo whole-genome sequencing and assembly of S. leurokolos. These newly developed genomic data contribute to a better understanding of genomic characteristics of shrimps from deep-sea chemosynthetic ecosystems, and provides valuable resources for further molecular marker development.
{"title":"A first genome survey sequencing of alvinocaridid shrimp Shinkaicaris leurokolos in deep-sea hydrothermal vent environment","authors":"Aiyang Wang, Jiao Cheng, Qian Xin, Z. Sha, Min Hui","doi":"10.1017/S0025315423000504","DOIUrl":"https://doi.org/10.1017/S0025315423000504","url":null,"abstract":"Abstract The alvinocaridid shrimp Shinkaicaris leurokolos Kikuchi and Hashimoto, 2000, is an evolutionarily important deep-sea species in hydrothermal vents of north-western Pacific. A genome survey of S. leurokolos was carried out in order to provide a foundation for its whole-genome sequencing. A total of 599 Gb high-quality sequence data were obtained in the study, representing approximately 118× coverage of the S. leurokolos genome. According to the 17-mer distribution frequency, the estimated genome size was 5.08 Gb, and its heterozygosity ratio and percentage of repeated sequences were 2.85 and 87.03%, respectively, showing a complex genome. The final scaffold assembly accounted for a total size of 9.53 Gb (32,796,062 scaffolds, N50 = 597 bp). Repetitive elements nearly constituted 45% of the nuclear genome, among which the most ubiquitous were long interspersed nuclear elements, DNA transposons and long-terminal repeat elements. A total of 12,121,553 genomic simple sequence repeats were identified, with the most frequent repeat motif being di-nucleotide (70.27%), followed by tri-nucleotide and tetra-nucleotide. From the genome survey sequences, the mitochondrial genome of S. leurokolos was also constructed and 71 single nucleotide polymorphisms were identified by comparison with previous published reference. This is the first report of de novo whole-genome sequencing and assembly of S. leurokolos. These newly developed genomic data contribute to a better understanding of genomic characteristics of shrimps from deep-sea chemosynthetic ecosystems, and provides valuable resources for further molecular marker development.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46377608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-05DOI: 10.1017/S0025315423000516
Edward Lavallin, N. Øien, Richard Sears
Abstract Despite holding the accolade as the largest animal ever to live on planet earth and ubiquitously inhabiting the world's major oceans, an acute paucity of information surrounds the geographical distribution and migration phenology of the endangered blue whale (Balaenoptera musculus) in the northeast Atlantic. Current migration and distribution information derived from robust scientific studies is required to ensure the formulation and implementation of successful conservation measures with a vision to support the ongoing recovery of the northeast Atlantic population. At 10:21 (UTC) on the 9th of November 2020, two blue whales were observed at position 55°13.99′N, 01°13.62′W, 18 km off the coast of the UK in the central North Sea just north of Newcastle at a water depth of 76 m. This is the first paper that has confirmed an account of live blue whales frequenting shallow waters of the central North Sea and represents a new area of occurrence within the accepted range of the northeast Atlantic population, an area in which sightings are extremely rare and may provide insight into the intricacies of migration routes and behaviour.
{"title":"A fluke encounter: first record of the blue whale (Balaenoptera musculus) within the central North Sea, United Kingdom","authors":"Edward Lavallin, N. Øien, Richard Sears","doi":"10.1017/S0025315423000516","DOIUrl":"https://doi.org/10.1017/S0025315423000516","url":null,"abstract":"Abstract Despite holding the accolade as the largest animal ever to live on planet earth and ubiquitously inhabiting the world's major oceans, an acute paucity of information surrounds the geographical distribution and migration phenology of the endangered blue whale (Balaenoptera musculus) in the northeast Atlantic. Current migration and distribution information derived from robust scientific studies is required to ensure the formulation and implementation of successful conservation measures with a vision to support the ongoing recovery of the northeast Atlantic population. At 10:21 (UTC) on the 9th of November 2020, two blue whales were observed at position 55°13.99′N, 01°13.62′W, 18 km off the coast of the UK in the central North Sea just north of Newcastle at a water depth of 76 m. This is the first paper that has confirmed an account of live blue whales frequenting shallow waters of the central North Sea and represents a new area of occurrence within the accepted range of the northeast Atlantic population, an area in which sightings are extremely rare and may provide insight into the intricacies of migration routes and behaviour.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45029330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-25DOI: 10.1017/S0025315423000589
Helen S. Chadwick, James F. Barnett, Abigail Crosby, Anthea Hawtrey-Collier, Victoria J. Hobson, L. C. Omeyer, Ruth Williams, B. Godley
Abstract Changes in abundance and distribution of marine top predators can indicate environmental change or anthropogenic pressure requiring management response. Here, we used an extensive dataset (21 years) to conduct a spatial and temporal analysis of grey seal strandings in Cornwall and the Isles of Scilly, close to the southern edge of the breeding range of the species. A total of 2007 strandings were reported from 2000 to 2020, increasing by 474% from 35 to 201 individuals per year during this period. The continued rise in strandings was consistent across all life stages and timeframes (5, 10 and 20 years), underpinning the suggestion of increasing abundance in the region. The observed seasonality differed by life stage, coinciding with the increased presence of animals near the coast for key life phases such as breeding, moulting and pupping. Strandings are widely distributed across the coast of Cornwall and the Isles of Scilly; however, most strandings were recorded on the north coast of Cornwall (70%) where major pupping and haul out sites are found. Despite hosting several pupping and haul out sites, a small proportion was recorded on the Isles of Scilly (5%) where it is thought that strandings are particularly underreported. Describing baselines in magnitude of strandings and life-stage compositions across space and time allows future deviations in frequency, demographic composition or spatial distribution to be detected and investigated. We demonstrate the utility of long-term citizen science data to provide valuable and cost-effective information on the distribution and abundance of a highly mobile marine mammal.
{"title":"Insights obtained from a multidecadal citizen science scheme: grey seal (Halichoerus grypus) strandings in Cornwall and Isles of Scilly (2000–2020)","authors":"Helen S. Chadwick, James F. Barnett, Abigail Crosby, Anthea Hawtrey-Collier, Victoria J. Hobson, L. C. Omeyer, Ruth Williams, B. Godley","doi":"10.1017/S0025315423000589","DOIUrl":"https://doi.org/10.1017/S0025315423000589","url":null,"abstract":"Abstract Changes in abundance and distribution of marine top predators can indicate environmental change or anthropogenic pressure requiring management response. Here, we used an extensive dataset (21 years) to conduct a spatial and temporal analysis of grey seal strandings in Cornwall and the Isles of Scilly, close to the southern edge of the breeding range of the species. A total of 2007 strandings were reported from 2000 to 2020, increasing by 474% from 35 to 201 individuals per year during this period. The continued rise in strandings was consistent across all life stages and timeframes (5, 10 and 20 years), underpinning the suggestion of increasing abundance in the region. The observed seasonality differed by life stage, coinciding with the increased presence of animals near the coast for key life phases such as breeding, moulting and pupping. Strandings are widely distributed across the coast of Cornwall and the Isles of Scilly; however, most strandings were recorded on the north coast of Cornwall (70%) where major pupping and haul out sites are found. Despite hosting several pupping and haul out sites, a small proportion was recorded on the Isles of Scilly (5%) where it is thought that strandings are particularly underreported. Describing baselines in magnitude of strandings and life-stage compositions across space and time allows future deviations in frequency, demographic composition or spatial distribution to be detected and investigated. We demonstrate the utility of long-term citizen science data to provide valuable and cost-effective information on the distribution and abundance of a highly mobile marine mammal.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43201718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-15DOI: 10.1017/S002531542300053X
Hari Praved, K. B. Neethu, P. H. Praved, K. V. Neethu, Annette F. Govindarajan, S. Nandan, B. Aneesh, P. Jayachandran
Abstract The epibenthic euryhaline hydromedusa Vallentinia gabriellae Vannucci Mendes, 1948 is an olindiid species native to tropical Atlantic waters. Here, we describe the cryptic introduction of this species in an estuary along the coast of Kerala, in southwestern India. This study records the existence of V. gabriellae outside of Atlantic waters for the first time and documents its geographical range expansion. Our identification was based on a combined morphological and DNA barcoding assessment using the COI and 28S markers. Although we noted some morphological differences between our specimens and those from their native range, our findings were conclusive. We suggest that phenotypic plasticity may result from differences such as prey availability between the native and introduced habitats. V. gabriellae medusae are epibenthic and cling to a variety of hard and soft substrates, including bivalves. Our specimens were associated with the invasive fouling mussel Mytella strigata, and we suggest that V. gabriellae could have been transported along with these mussels to the Kerala coast.
{"title":"Introduction of the euryhaline epibenthic hydromedusa Vallentinia gabriellae Vannucci Mendes, 1948 (Hydrozoa: Limnomedusae) to Indian waters","authors":"Hari Praved, K. B. Neethu, P. H. Praved, K. V. Neethu, Annette F. Govindarajan, S. Nandan, B. Aneesh, P. Jayachandran","doi":"10.1017/S002531542300053X","DOIUrl":"https://doi.org/10.1017/S002531542300053X","url":null,"abstract":"Abstract The epibenthic euryhaline hydromedusa Vallentinia gabriellae Vannucci Mendes, 1948 is an olindiid species native to tropical Atlantic waters. Here, we describe the cryptic introduction of this species in an estuary along the coast of Kerala, in southwestern India. This study records the existence of V. gabriellae outside of Atlantic waters for the first time and documents its geographical range expansion. Our identification was based on a combined morphological and DNA barcoding assessment using the COI and 28S markers. Although we noted some morphological differences between our specimens and those from their native range, our findings were conclusive. We suggest that phenotypic plasticity may result from differences such as prey availability between the native and introduced habitats. V. gabriellae medusae are epibenthic and cling to a variety of hard and soft substrates, including bivalves. Our specimens were associated with the invasive fouling mussel Mytella strigata, and we suggest that V. gabriellae could have been transported along with these mussels to the Kerala coast.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47194384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.1017/S0025315423000498
Fredrik Broms, T. Bakken, A. Martynov, T. Korshunova
Abstract In the present contribution we report, for the first time, records of the nudibranch Zelentia ninel from Norway. The species is previously known only from the Barents Sea coast in northern Russia where it was described for the first time in 2017. Records of Z. ninel from six different localities in northern Norway from 2019–2023 are presented and discussed. The identity of the specimens was determined by investigation of external and internal morphology as well as molecular analysis of preserved specimens. Photographs of live specimens and radulae of preserved specimens are presented, and species delimitation is confirmed by molecular phylogenetic analysis. In order to assess the biogeographic distribution of Z. ninel based on all available information, recent unanticipated genetic data supporting a putative occurrence of Z. ninel at the Aleutian Islands, Alaska is also discussed where we provide arguments in support of occasional anthropogenic transportation outside its natural range. The present records significantly expand the known natural range of distribution for Z. ninel and demonstrate that the species is not restricted to the Russian Barents Sea coast but that the range encompasses also at least northern Norway. These data can provide important insights to the understanding of natural ranges of marine invertebrates across biogeographical regions affected by rapid ongoing climatic change.
{"title":"Biogeographic patterns of distribution of the mollusc Zelentia ninel (Nudibranchia, Trinchesiidae)","authors":"Fredrik Broms, T. Bakken, A. Martynov, T. Korshunova","doi":"10.1017/S0025315423000498","DOIUrl":"https://doi.org/10.1017/S0025315423000498","url":null,"abstract":"Abstract In the present contribution we report, for the first time, records of the nudibranch Zelentia ninel from Norway. The species is previously known only from the Barents Sea coast in northern Russia where it was described for the first time in 2017. Records of Z. ninel from six different localities in northern Norway from 2019–2023 are presented and discussed. The identity of the specimens was determined by investigation of external and internal morphology as well as molecular analysis of preserved specimens. Photographs of live specimens and radulae of preserved specimens are presented, and species delimitation is confirmed by molecular phylogenetic analysis. In order to assess the biogeographic distribution of Z. ninel based on all available information, recent unanticipated genetic data supporting a putative occurrence of Z. ninel at the Aleutian Islands, Alaska is also discussed where we provide arguments in support of occasional anthropogenic transportation outside its natural range. The present records significantly expand the known natural range of distribution for Z. ninel and demonstrate that the species is not restricted to the Russian Barents Sea coast but that the range encompasses also at least northern Norway. These data can provide important insights to the understanding of natural ranges of marine invertebrates across biogeographical regions affected by rapid ongoing climatic change.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44396112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.1017/S0025315423000474
Vasiliki Nikiforidou, E. Gkikas, C. Mytilineou, J. Haralabous, D. Koutsoubas, A. Anastasopoulou
Abstract Serranus hepatus is a bycatch species in the Mediterranean trawl fishery for which knowledge on biological features such as otolith morphology is generally poor in the Mediterranean Sea. In the present study, the weight–length relationship, age, growth and ten otolith morphometric variables of this species were investigated in two distant areas, the Eastern Ionian and southwestern Aegean Seas. Isometric growth in weight was defined in both areas. Growth parameters also did not differ between the two study areas. Six of the otolith variables (radius, otolith length, otolith width, otolith area, perimeter and ellipticity) showed a significant relationship with size without significant differences between the two areas. Significant differences between the two areas were only defined for five of the morphometric variables (otolith length, width and area being the most important). Further studies to discriminate between potential stocks of S. hepatus seem to be necessary, information that is needed for stock identification, stock assessment and fisheries management.
{"title":"Age, growth and otolith morphometrics of Serranus hepatus (L., 1758) in two areas of the Eastern Mediterranean","authors":"Vasiliki Nikiforidou, E. Gkikas, C. Mytilineou, J. Haralabous, D. Koutsoubas, A. Anastasopoulou","doi":"10.1017/S0025315423000474","DOIUrl":"https://doi.org/10.1017/S0025315423000474","url":null,"abstract":"Abstract Serranus hepatus is a bycatch species in the Mediterranean trawl fishery for which knowledge on biological features such as otolith morphology is generally poor in the Mediterranean Sea. In the present study, the weight–length relationship, age, growth and ten otolith morphometric variables of this species were investigated in two distant areas, the Eastern Ionian and southwestern Aegean Seas. Isometric growth in weight was defined in both areas. Growth parameters also did not differ between the two study areas. Six of the otolith variables (radius, otolith length, otolith width, otolith area, perimeter and ellipticity) showed a significant relationship with size without significant differences between the two areas. Significant differences between the two areas were only defined for five of the morphometric variables (otolith length, width and area being the most important). Further studies to discriminate between potential stocks of S. hepatus seem to be necessary, information that is needed for stock identification, stock assessment and fisheries management.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49157232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-28DOI: 10.1017/S0025315423000425
Natália Procksch, P. H. Ott, Natalia Bragiola Berchieri, D. Danilewicz, Rafael Kenji Horota, M. Guimarães, Marcelo Zagonel, M. Veronez, L. Oliveira
Abstract We present the most recent data on the seasonal and spatial occupation of South American sea lions (Otaria flavescens) and fur seals (Arctocephalus australis) in the Wildlife Refuge of Ilha dos Lobos (WRIL) in southern Brazil throughout the year, based on aerial photographic counts. Thirty-one aerial photographic counts were conducted between July 2019 and November 2020 to assess monthly differences in the abundance of pinnipeds in the WRIL. The results were analysed using a generalized linear model. Spatial analysis was performed using kernel density. Subadult males of South American sea lion were the most abundant pinniped in the WRIL, followed by juveniles of South American fur seal. A juvenile of Southern elephant seal (Mirounga leonina) was also recorded. South American fur seals showed a marked seasonality, occurring only between July and October, while South American sea lions occurred year-round. Among the months analysed, September exhibited the highest mean abundance (mean 113.75; SD: ± 8.58), followed by August (mean 103.00; SD: ± 15.69). The pinnipeds were more often concentrated in the northern and central parts of the island. This study reinforces the importance of the WRIL as a haulout site for pinnipeds. Considering the seasonal occupation of the island by South American pinnipeds, monitoring is recommended prior to the development of activities in the area.
摘要:本文基于航空摄影数据，介绍了巴西南部Ilha dos Lobos野生动物保护区(WRIL)南美洲海狮(Otaria flavescens)和海豹(Arctocephalus australis)全年的季节和空间分布情况。2019年7月至2020年11月期间进行了31次航空摄影计数，以评估wwrl中鳍足类动物丰度的月度差异。结果用广义线性模型进行了分析。利用核密度进行空间分析。其中，南美海狮的亚成年雄性鳍状肢数量最多，其次是南美海海豹的幼崽。南象海豹(miounga leonina)幼崽也有记录。南美海狗的活动具有明显的季节性，只在7月到10月之间发生，而南美海狮全年都有活动。在分析月份中，9月平均丰度最高，平均113.75;SD:±8.58)，其次是8月(平均103.00;Sd:±15.69)。鳍足类动物更多地集中在岛屿的北部和中部。这项研究强化了WRIL作为鳍足类拖出位点的重要性。考虑到南美洲鳍足类动物对该岛的季节性占领，建议在该地区开展活动之前进行监测。
{"title":"New data on South American fur seals and sea lions' occupation of the Wildlife Refuge of Ilha dos Lobos, southern Brazil","authors":"Natália Procksch, P. H. Ott, Natalia Bragiola Berchieri, D. Danilewicz, Rafael Kenji Horota, M. Guimarães, Marcelo Zagonel, M. Veronez, L. Oliveira","doi":"10.1017/S0025315423000425","DOIUrl":"https://doi.org/10.1017/S0025315423000425","url":null,"abstract":"Abstract We present the most recent data on the seasonal and spatial occupation of South American sea lions (Otaria flavescens) and fur seals (Arctocephalus australis) in the Wildlife Refuge of Ilha dos Lobos (WRIL) in southern Brazil throughout the year, based on aerial photographic counts. Thirty-one aerial photographic counts were conducted between July 2019 and November 2020 to assess monthly differences in the abundance of pinnipeds in the WRIL. The results were analysed using a generalized linear model. Spatial analysis was performed using kernel density. Subadult males of South American sea lion were the most abundant pinniped in the WRIL, followed by juveniles of South American fur seal. A juvenile of Southern elephant seal (Mirounga leonina) was also recorded. South American fur seals showed a marked seasonality, occurring only between July and October, while South American sea lions occurred year-round. Among the months analysed, September exhibited the highest mean abundance (mean 113.75; SD: ± 8.58), followed by August (mean 103.00; SD: ± 15.69). The pinnipeds were more often concentrated in the northern and central parts of the island. This study reinforces the importance of the WRIL as a haulout site for pinnipeds. Considering the seasonal occupation of the island by South American pinnipeds, monitoring is recommended prior to the development of activities in the area.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43717913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-25DOI: 10.1017/S0025315423000486
Inaê Guion de Almeida, A. Percequillo, M. M. Rollo
Abstract Accurate demographic data play a critical role in implementing conservation strategies and identifying key areas for species preservation. The population abundance and density of Sotalia guianensis were estimated in the estuarine-lagoon complex of Cananéia, Brazil, using distance sampling. The survey covered 1339.91 km with 83 h 05 min in effort. A half-normal model with cosine adjustments was evaluated as the best fit to estimate an abundance of 193 individuals (95% CI 158–237) and a density of 2.55 ind km−2. The majority of sightings occurred in the Baía de Trapandé (48.72%), followed by the Mar de Cananéia (32.72%) and Mar de Cubatão (18.56%), the three areas surrounding the Ilha de Cananéia. The study confirmed the heterogeneous distribution of the estuary and found that the Mar de Cananéia and the Baía de Trapandé were more densely populated, with 2.76 ind km−2 (95% CI 1.93–3.96) and 2.76 ind km−2 (95% CI 2.07–3.66), respectively, while the Mar de Cubatão was less densely populated, with 1.59 ind km−2 (95% CI 1.04–2.44). The findings support previous research indicating a stable population over the last few decades. The Cananéia estuary is an ecologically diverse region located between protected areas under different categories of environmental protection and harbours a significant population of S. guianensis, providing essential resources for feeding and breeding. Protected areas have proven to be effective tools for preserving both marine and terrestrial environments. Despite the close proximity to humans and constant threats, the study underscores the importance of the area for the conservation of the species.
摘要准确的人口统计数据在实施保护战略和确定物种保护的关键领域方面发挥着关键作用。采用距离采样法，对巴西卡纳尼亚河口泻湖复合体中的圭亚那苏塔利亚种群丰度和密度进行了估算。调查行程1339.91公里，耗时83小时05分钟。经过余弦调整的半正态模型被评估为最适合估计193个个体的丰度（95%CI 158–237）和2.55 ind km−2的密度。大多数目击事件发生在特拉潘湾（48.72%），其次是卡纳内亚岛（32.72%）和库巴托岛（18.56%），这三个地区都是卡纳内亚岛周围的地区。该研究证实了河口的不均匀分布，并发现Mar de Cananéia和Baía de Trapané的人口密度更高，分别为2.76 ind km−2（95%CI 1.93–3.96）和2.76 inde km−2，而Mar de Cubatão的人口密度较低，1.59 ind km−2（95%置信区间1.04–2.44）。这些发现支持了先前的研究，表明在过去几十年中人口稳定。Cananéia河口是一个生态多样的地区，位于不同环境保护类别的保护区之间，拥有大量圭亚那S.guianensis，为觅食和繁殖提供了重要资源。保护区已被证明是保护海洋和陆地环境的有效工具。尽管距离人类很近，威胁不断，但这项研究强调了该地区对保护该物种的重要性。
{"title":"Assessing Guiana dolphin abundance and density in the Southwestern Atlantic: insights from conservation areas","authors":"Inaê Guion de Almeida, A. Percequillo, M. M. Rollo","doi":"10.1017/S0025315423000486","DOIUrl":"https://doi.org/10.1017/S0025315423000486","url":null,"abstract":"Abstract Accurate demographic data play a critical role in implementing conservation strategies and identifying key areas for species preservation. The population abundance and density of Sotalia guianensis were estimated in the estuarine-lagoon complex of Cananéia, Brazil, using distance sampling. The survey covered 1339.91 km with 83 h 05 min in effort. A half-normal model with cosine adjustments was evaluated as the best fit to estimate an abundance of 193 individuals (95% CI 158–237) and a density of 2.55 ind km−2. The majority of sightings occurred in the Baía de Trapandé (48.72%), followed by the Mar de Cananéia (32.72%) and Mar de Cubatão (18.56%), the three areas surrounding the Ilha de Cananéia. The study confirmed the heterogeneous distribution of the estuary and found that the Mar de Cananéia and the Baía de Trapandé were more densely populated, with 2.76 ind km−2 (95% CI 1.93–3.96) and 2.76 ind km−2 (95% CI 2.07–3.66), respectively, while the Mar de Cubatão was less densely populated, with 1.59 ind km−2 (95% CI 1.04–2.44). The findings support previous research indicating a stable population over the last few decades. The Cananéia estuary is an ecologically diverse region located between protected areas under different categories of environmental protection and harbours a significant population of S. guianensis, providing essential resources for feeding and breeding. Protected areas have proven to be effective tools for preserving both marine and terrestrial environments. Despite the close proximity to humans and constant threats, the study underscores the importance of the area for the conservation of the species.","PeriodicalId":17477,"journal":{"name":"Journal of the Marine Biological Association of the United Kingdom","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49051214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.1017/S0025315423000449
Sebahat Semin, S. Tas, Fuat Dursun
Abstract Spatial–temporal variability of phytoplankton community and potentially harmful species in the Golden Horn Estuary (Sea of Marmara) was investigated from October 2018 to September 2019 together with some environmental factors. A total of 148 phytoplankton taxa were identified during the study period. Among these, 134 taxa (90.5%) consisted of diatoms (71 taxa, 48%) and dinoflagellates (63 taxa, 42.5%), while 14 taxa (9.5%) were other groups. Seventeen species were recorded for the first time in the study area. Species richness was highest in October, while it was lowest in August. The species diversity (H') varied according to sampling stations. Cell abundances were higher especially in the middle and upper estuary in spring and summer than in autumn and winter. The abundance of diatoms and euglenophyceans was highest in spring, while the abundance of raphidophycean and cryptophycean was highest in summer. Temperature was correlated positively with total abundance (P < 0.01), but negatively with species diversity (H') (P < 0.01). Several dense algal blooms causing discolouration in surface water occurred in spring and summer. A total of 12 microalgae species known as potentially toxic were detected during this study period. Among these, dinoflagellates Alexandrium cf. tamarense and Dinophysis infundibulum were recorded for the first time in the study area. The increase in species diversity and richness in the upper estuary, and the decrease in frequency of bloom events compared with the previous years indicated the changes in environmental conditions in this study period. Findings showed that phytoplankton might be used as an indicator of the changing environmental conditions in such ecosystems.
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