Western Indian Ocean journal of marine science最新文献

{"title":"First report of White Syndrome Disease on branching Acropora at Saya de Malha, Mascarene Plateau","authors":"R. Bhagooli, S. Jogee, D. Kaullysing, S. Ramah","doi":"10.4314/wiojms.si2021.2.15","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.15","url":null,"abstract":"Field note - N/A","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114524458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photo-physiology of healthy and bleached corals from the Mascarene Plateau","authors":"R. Bhagooli, M. Soondur, S. Ramah, Arvind Gopeechund, S. Jeetun, D. Kaullysing","doi":"10.4314/wiojms.si2021.2.8","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.8","url":null,"abstract":"This study presents the first report of variable photo-physiology of healthy-looking and bleached corals from the upper mesophotic waters of the Mascarene Plateau. In May 2018, during the FAO EAF-Nansen research expedition cruise, coral bleaching was visually observed. Five coral species from Saya de Malha Bank, namely Heliopora coerulea, Favites sp. and Porites sp. from 27 m and Acropora sp. and Lithophyllon repanda from 30 m, and three coral species from the Nazareth Bank, namely Acropora sp. and Galaxea fascicularis from 36 m and Stylophora-like species from 58 m were studied using the Video-Assisted Multi-Sampler (VAMS) and collected using a Van Veen grab. Chlorophyll a fluorescence parameters such as effective quantum yield at photosystem II (ΦPSII), relative maximum electron transport rate (rETRm), photosynthetic efficiency (α), photoinhibition (β), saturating light level (Ek), and  maximum non-photochemical quenching (NPQm) were measured using a Diving-Pulse-Amplitude-Modulated (D-PAM) fluorometer to study variable photo-physiology in bleached and non-bleached corals. All photo-physiological parameters varied significantly among coral species tested and between coral conditions, except for β. The interaction between species and coral conditions was only significant in the case of β, but generally not significant. A two-way ANOVA indicated significant effects of depth and coral conditions in Acropora sp. on almost all photo-physiological parameters, except for β, and the effect of depth on rETRmax and α, and the effect of depth along with its interaction with coral conditions on Ek. ΦPSII did not differ in bleached and healthy-looking coral parts of Porites and Lithophyllon from 27 m, Galaxea and Acropora from 36 m while it decreased significantly in Heliopora and Favites at 27 m, Acropora from 30 m, and Stylophora-like at 58 m. NPQm did not change for Porites, Acropora (30 m) and Galaxea but it tended to increase for Heliopora, Acropora (36 m), Lithophyllon, Galaxea, and decrease for Favities, Acropora (30 m) and Stylophora-like. The thermally tolerant coral Porites exhibited normal photo-physiology even in bleached conditions while the bleached parts of Favites, Acropora (30 m) and Stylophora-like corals exhibited photo-physiological dysfunctioning. This study revealed that the seven studied corals from the upper mesophotic waters of the Mascarene Plateau are not spared from the bleaching phenomenon and exhibit variable photo-physiology in bleached and non-bleached conditions. Further studies are warranted to thoroughly understand the coral bleaching patterns and severity during summer periods at the Saya de Malha and Nazareth Banks.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124042295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macro- and megafauna on the slopes of the Saya de Malha Bank of the Mascarene Plateau","authors":"O. Bergstad, K. Tabachnick, E. Rybakova, Gilberte Gendron, Andrew Souffre, R. Bhagooli, S. Ramah, M. Olsen, Åge S. Høines, T. Dautova","doi":"10.4314/wiojms.si2021.2.10","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.10","url":null,"abstract":"A first characterization of the distribution and composition of benthic and demersal macro- and megafauna was derived based on video records sampled along five pre-determined transects up the slope on the western, northern and eastern sides of the Saya de Malha Bank on the Mascarene Plateau, starting at a maximum depth of 1000 m. Abundance was highest in the upper parts of eastern slope locations, primarily reflecting a relatively higher abundance of black corals (Antipatharia) than in other locations. A consistent feature of several transects, but most prominent in eastern and northern slopes, was the occurrence of patchy coral and sponge aggregations along the margin where the substrate was mostly hard. In some cases, these aggregations might be considered ‘gardens’ but reefs were not observed. Higher-level taxonomical composition of the fauna is presented. Demersal fish were widespread but not abundant, and within the depth range studied, there was a transition from a marginal shallow fish assemblage to a deepwater assemblage. Fishes were in most cases only assigned to family level, and 49 families were recorded. To thoroughly assess the biodiversity and abundance of fauna of the slopes of Saya de Malha Bank, further studies conducting more detailed video transects and sampling of specimens are warranted.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128958054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First field observations of Halimeda beds at depths of 37-62 m at Saya de Malha and Nazareth banks, Mascarene Plateau","authors":"R. Bhagooli, S. Ramah, D. Kaullysing, Arvind Gopeechund, O. Bergstad","doi":"10.4314/wiojms.si2021.2.14","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.14","url":null,"abstract":"Field note - N/A","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130244050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in abundance, diversity, photo-physiology and estimated productivity of micro-phytoplankton with depth at the Saya de Malha Bank, Mascarene Plateau","authors":"M. Soondur, S. Ramah, R. Boojhawon, D. Kaullysing, R. Bhagooli","doi":"10.4314/wiojms.si2021.2.4","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.4","url":null,"abstract":"The variations in micro-phytoplankton abundance, diversity, photo-physiology, chlorophyll a (Chla) concentration and estimated productivity were assessed at depth ranges of 0-4, 5-10, and 11-29 m with 100, 28 and 11% of irradiance, respectively, in Saya de Malha waters. The total micro-phytoplankton abundance (TMPA) differed significantly (P < 0.001) with depth ranges, and between day and night samples. Out of the 34 genera identified, 27 showed a decrease in abundance of over 40% with depth. Chaetoceros, Coscinodiscus, Navicula, Nitzschia and Ceratium were most dominant. The Shannon-Wiener (H’) diversity index did not differ among depth ranges and between samples collected during day and night, but diatoms were more diverse than dinoflagellates. The effective quantum yield (ΦPSII) and the light-use efficiency factor (α) tended to decrease, while the maximum relative electron transport rate (rETRmax), the photo-inhibitory factor (β) and the maximum non-photochemical quenching (NPQmax) varied insignificantly from morning to afternoon sampling points at all depth ranges studied. The estimated productivity, rETRmax and Chla concentration decreased with depth ranges. The higher diversity of diatoms, better photosynthetic performance in the morning hours and higher near-surface estimated productivity provide new insights into micro-phytoplankton dynamics and productivity in Saya de Malha waters.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127157126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First field observation of a Thalassodendron ciliatum bed on the Nazareth Bank, Mascarene Plateau","authors":"S. Ramah, R. Bhagooli","doi":"10.4314/wiojms.si2021.2.13","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.13","url":null,"abstract":"Field note - N/A","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116288436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First in-situ observation of the endemic giant clam Tridacna rosewateri from the Nazareth Bank, Mascarene Plateau","authors":"S. Ramah, D. Kaullysing, R. Bhagooli","doi":"10.4314/wiojms.si2021.2.16","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.16","url":null,"abstract":"Field note - N/A","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122749290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ocean circulation over the Saya de Malha Bank in the South West Indian Ocean","authors":"Priscilla Coopen, Yuneeda Bibi Naheed Oozeeraully, M. Ostrowski","doi":"10.4314/wiojms.si2021.2.1","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.1","url":null,"abstract":"The Saya de Malha Bank is one of the major banks of the Mascarene Plateau in the South West Indian Ocean. It is known for its unique ecosystem, remoteness (nearest island is about 300 km away) and complex oceanographic conditions. This study presents the results of a survey conducted in May 2018 on-board the R/V Dr Fridtjof Nansen, and aims to provide a descriptive overview of the interaction of the large-scale South Equatorial Current (SEC) over the shallow Saya de Malha Bank. The analysis of the current pattern revealed a two-layered structure of the current over the shallow topography of the bank compared to the vertically rigid-structure of the SEC throughflow in its deeper region. This two-layered flow consists of a surface layer and a sub-thermocline layer. The top layer flow, carrying the lower salinity mass (Tropical Surface Water) is driven by the Ekman dynamics observed in the southern hemisphere whereas the sub-thermocline current layer is most likely governed by the tidal and internal wave dynamics generated by the topographic relief of the bank.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124266798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhodolith beds (Corallinaceae, Rhodophyta): An important marine ecosystem of the Saya de Malha and Nazareth Banks","authors":"S. Ramah, R. Bhagooli, D. Kaullysing, O. Bergstad","doi":"10.4314/wiojms.si2021.2.12","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.12","url":null,"abstract":"Field note - N/A","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115645807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pelagic and demersal fish diversity of the Saya de Malha and Nazareth Banks, Mascarene Plateau","authors":"L. Caussy, Rodney Melanie, Andrew Souffre, S. Hollanda, M. Olsen, Gilberte Gendron, S. Ramah","doi":"10.4314/wiojms.si2021.2.11","DOIUrl":"https://doi.org/10.4314/wiojms.si2021.2.11","url":null,"abstract":"The Saya de Malha (SMB) and Nazareth Banks (NB) are the main offshore locations where fishing activities are carried out by the Republic of Mauritius, targeting mainly shallow water Lethrinids, deep-water snappers and groupers. A multi-disciplinary survey was carried out on the two banks in May 2018 on-board the R/V Dr. Fridtjof Nansen with the objective of studying the diversity of fish on both banks using pelagic trawls, bottom trawls, basket traps and video using a Remotely Operated Vehicle (ROV). Analysis of data showed that the main fish family recorded in the pelagic waters of SMB, using pelagic trawl, was Myctophidae while the bottom trawls on NB showed the presence of fishes from the families Gobiidae, Triglidae and Synodontidae, mainly at depths between 200 and 300 m. The ROV video analysis highlighted principally the presence of demersal fishes of the family Lethrinidae and other reef-associated and commercial families recorded between 20 and 50 m. The main catch from the basket traps set at the SMB was Lethrinus mahsena, caught at a depth of 21 m. While previous studies focussed mainly on commercial fishes, this study brings forth new information on other fish families, contributing to the knowledge of the fish community that exists at these two banks.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"06 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114671820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}