Western Indian Ocean journal of marine science最新文献

{"title":"Supplementation of probiotics in Nile tilapia fingerling cultivation subjected to microbial challenge","authors":"Angélica A. Jossefa, Ivan C. Nerantzoulis, A. Mussagy","doi":"10.4314/wiojms.v21i2.1","DOIUrl":"https://doi.org/10.4314/wiojms.v21i2.1","url":null,"abstract":"The intensification of aquaculture has brought about the need to find alternative feed supplement sources to reduce production costs. One of the alternative sources of feed in fish farming is animal manure. However, the use of animal manure may cause health problems in fish cultures. The objective of this study was to determine the effects of probiotics on Nile tilapia fingerlings subjected to microbial challenge using swine manure. Three hundred (300) fingerlings weighing 2±0.05g and measuring 5±0.06 cm, were distributed among four treatments with three replications each. Swine manure was inoculated in water in the proportion of 10 % of fingerlings live weight. Probiotics Saccharomyces cerevisiae and Lactobacillus plantarum were used as ration supplements in the proportions of 0.5 % per 100 g of ration. The results showed no significant differences (P>0.05) in terms of growth between treatments. The inclusion of S. cerevisiae reduced the number of pathogenic bacteria in the intestine of fingerlings and resulted in better production performance. Feed supplementation with L. plantarum had no effect, neither on production, nor on intestinal microbial population. The fingerlings under study showed typical signs of yersiniosis, edwardiellosis and mycobacteriosis. From the experiment it was concluded that the supplementation of the probiotic S. cerevisiae on the Nile tilapia fingerlings treated with swine manure showed a positive effect in the sense that this probiotic avoided the intestinal colonization of fingerlings by pathogenic bacteria. Additionally, the presence of the probiotic seems to promote better grow performance and hence reinforce the results of previous studies on the role of probiotics in aquaculture. More experimental studies are required, particularly in situ experiments, with the addition of other performance analyses linked to the immune response of the fingerlings.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128448328","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":"Artificial reef structures and coral transplantation as potential tools for enhancing locally-managed inshore reefs: a case study from Wasini Island, Kenya","authors":"J. Mwaura, Dishon Murage, J. Karisa, L. Otwoma, Hashim O. Said","doi":"10.4314/wiojms.v21i2.8","DOIUrl":"https://doi.org/10.4314/wiojms.v21i2.8","url":null,"abstract":"Many severely degraded reefs in the western Indian Ocean region show no signs of natural recovery and have remained for decades as barren, unconsolidated coral rubble fields with depleted commercially important fish groups. Consequently, several restoration techniques have been designed and developed to mitigate the localized impacts on coral reefs. Evaluating the efficacy of combined use of artificial reef structures and coral transplantation in enhancing habitat and recovery of key functions in severely degraded reefs is key to improved conservation of coral reefs. In this study, the survivorship rate of corals transplanted on reef structures is assessed, and changes in coral and fish abundance on artificial reef units and nearby natural reefs over time are compared. Coral cover on artificial reef structures increased from a mean of 17 % one year after initial attachment of fragments to 41 % after two years, with Acropora corals providing the highest cover. The artificial reef structures were also rapidly colonized by reef fish, with fish densities of 18±13 indiv./100 m2 showing an increase of about three fold higher than on natural reefs after two years. Greater numbers of commercially important fish groups (e.g., Lutjanids and Acanthurids) were observed on artificial reefs while natural reefs harboured more small sized fish (Pomacentrids and Labrids). These findings provide insights for artificial reef projects that are capable of restoring the regenerative capacity of the human-induced coral rubble beds.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114265659","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":"Understanding of Sustainable Development Goals among communities living adjacent to mangroves in Kenya","authors":"Samson Obiene, K. Shilabukha, G. Muga, Lenice Ojwang, M. Owuor","doi":"10.4314/wiojms.si2022.1.5","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.5","url":null,"abstract":"Mangroves are among the most productive ecosystems, known for their diverse provisioning, regulating, supporting and aesthetic services. The ecosystem directly supports livelihoods and ensures food security and nutrition of people through its ecosystem services (ES) such as wood, fish and medicines while protecting them by stabilizing shorelines, reducing flooding, and mitigating climate change and natural disasters such as tsunamis. In so doing, the ecosystem promotes several sustainable development goals (SDGs) and co-benefits several others. This relationship however remains under explored with limited studies on the co-benefit scenarios and the cognitive views of mangrove resource users. This paper highlights gaps in knowledge of the role of mangroves in development and the implications on ecosystem governance. The study analysed the ‘ideal’ scenario presented in secondary data in comparison to community perspectives on mangrove-related development. Bearing in mind the complexity of the concept of sustainability, development was categorised at local, national and international levels, and community members were asked to mention any known links to mangrove ES at any of the three levels. Results indicate that 45.4 % (n=166) of the community understood the roles of mangroves in development. The majority (79.5 %) were able to link the ecosystem to local (village level) development, 43.1 % to both local and national development while only 13.5 % could link the ecosystem to local, national, and international development. Forty-three per cent (n=157) of the community did not know of the relationship between mangroves and development while 11.6 % (n=43) felt that mangroves do not contribute to development. The study further disaggregated this knowledge socio-demographically, highlighting opportunities for enhancing governance, conservation and the use of mangrove ecosystems in Kenya.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128608385","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":"Structural complexity of seagrass and environmental variables as a determinant of fish larvae assemblages in tropical coastal waters: Implications for seagrass management and conservation","authors":"Fadhili M. Malesa, Barnabas Tarimo, Serapio Kyewalyanga, George Rushingisha","doi":"10.4314/wiojms.si2022.1.7","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.7","url":null,"abstract":"Anthropogenic activities including climate change affect the development of structural complexity in seagrass and the state of environmental variables. It remains unclear whether these variables, alone or in combination, have an important influence on fish larvae assemblages. This study examined the influence of the structural complexity of seagrass meadows and various environmental variables on fish larvae assemblages in tropical coastal waters of Tanga, Tanzania. The study was conducted in four Thalassia hemprichii dominated seagrass meadows from June 2019 to January 2021. Multiple regression analysis indicated that the structural complexity of seagrass (canopy height, seagrass cover, and shoot density) and environmental variables (dissolved oxygen, temperature and salinity) were the foremost predictors for fish larvae assemblages; abundance and richness (R2 = 0.75, p = 0.0185, R2 = 0.54, p = 0.0396, respectively). Based on these findings, the structural complexity of seagrass and environmental variables are both important determinants of fish larvae assemblages in tropical coastal waters. The findings suggest that reducing anthropogenic activities that affect the development of structural complexity of seagrass and negatively impact environmental variables in seagrass meadows through more effective governance would result in increased production of fish larvae in meadows and, as a result, increased fish recruitment in tropical coastal waters.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134584897","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":"Sustainable Development Goal 14 in the Western Indian Ocean: a socio-ecological approach to understanding progress","authors":"M. Andriamahefazafy, G. Touron-Gardic, A. March, P. Failler, G. Hosch, Deng Palomares","doi":"10.4314/wiojms.si2022.1.1","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.1","url":null,"abstract":"The Sustainable Development Goals (SDGs) intend to “achieve a better and more sustainable future for all people in the world”1. They have become a key driver for policy and decision-making in many regions, including in the Western Indian Ocean (WIO) region. This paper analyses national and regional progress towards achieving SDG 14 in the WIO. Progress of four of the SDG 14 targets that were due in 2020 are analysed. SDG 14 has influenced regional and national policy agendas but current tools to measure this progress fail to provide a detailed picture of achievement towards each target for countries in the WIO. The paper highlights that the region has shown limited success in achieving the targets and SDG 14 targets are unlikely to be reached by 2030. The WIO region lags behind with regard to marine conservation related targets. More than half of the countries have low to average progress on SDG 14.2 on marine areas being covered by area-based management tools. Even more countries are far from achieving the 10 % coverage of marine protected areas under SDG 14.5. The region is performing better with regards to fisheries management targets with most countries classified as making average to good progress towards SDG 14.4 on sustainable stocks and SDG 14.6 on addressing harmful subsidies and IUU fishing. The diversity of the socio-economic and governance contexts in the WIO countries contributes to different levels of progress. The fairly positive ecological state of the WIO supports progress towards SDG 14. Understanding barriers to progress is fundamental to help with the prioritisation of the actions needed to meet the SDG 14 targets by 2030. Regional actors and policy-makers will need to increase their ambitions to meet the SDG 14 targets and ensure a healthy ocean and improved prospects for the region and its citizens. To account for barriers in progress towards SDG 14, the WIO region needs appropriate reporting and monitoring mechanisms and it should follow a holistic regional approach of ocean governance integrating conservation and sustainable resource use. It needs to build capacity and knowledge sharing for implementation of SDG 14 and ocean governance at various levels. Improved implementation of SDG targets will have social, economic and environmental benefits within the region.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131443442","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":"Africa Integrated Maritime Policy, blue growth and a new ocean governance: case studies from the Atlantic and the Indian Ocean","authors":"J. Guerreiro","doi":"10.4314/wiojms.si2022.1.2","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.2","url":null,"abstract":"Integrated maritime and blue economy policies are changing ocean governance by introducing new policy drivers, reshaping institutional frameworks, as well as demanding new management instruments (e.g., Maritime Spatial Planning (MSP)). This started in 2007 though the European Union Integrated Maritime Policy approach, and in 2009 the Africa Union initiated a similar process, leading both to the Africa integrated maritime strategy as well as a blue economy strategy. Several countries, particularly in sub-Saharan Africa, began to look to blue economy as a booster to socioeconomic welfare and initiated the development of national strategies, together with the necessary adaptation of institutional and legal networks. Case studies address those processes at the transition from the Atlantic to the Indian Oceans, focusing on Angola, Namibia, South Africa, Tanzania and Kenya in the Southern African Development Community (SADC) region, as well as several African Small Islands Developing States (SIDS), particularly Cape Verde, S. Tomé and Príncipe, Seychelles, Madagascar and Mauritius. Findings show that all countries covered in the case studies are developing national ocean and/or blue economy strategies and adapting their governmental, institutional, and legal frameworks, although there is a deeper political impact in SIDS. Overall, these new policy drivers are leading to a new model of ocean governance by addressing integrated maritime policies and blue growth strategies, as well as introducing MSP as a new EEZ governance tool.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122689672","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":"Small pelagic marine fisheries for food sovereignty? The case of the dagaa fishery at three coastal sites in Tanzania","authors":"Robert E. Katikiro, Jairos Mahenge","doi":"10.4314/wiojms.si2022.1.9","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.9","url":null,"abstract":"To implement effective ocean governance, development of policies and management strategies needs to incorporate input from communities that will be impacted by the decisions. People engaging in small-scale fisheries and aquaculture mobilize themselves in anticipation of various challenges, for example, food sovereignty. Food sovereignty is the right for people to access healthy and culturally appropriate food that is produced through ecologically sound and sustainable methods. Little attention has been paid to documenting and understanding the struggles and efforts of small-scale fishers to ensure their own food sovereignty. In the Western Indian Ocean region, and Tanzania in particular, there has been a limited number of initiatives among coastal fishers that seek to transform food systems. To better understand these initiatives, this study was designed to examine collective actions undertaken in pursuit of food sovereignty among small pelagic fishers at three landing sites on the coast of Tanzania. Collection of primary data involved a survey of 206 individuals, 25 key informant interviews, 3 focus group discussions and participant observation. Secondary data was also collected from official fisheries records and published materials to supplement the primary data. The study revealed limited current capacity of the small pelagic fisheries to satisfy local demand of fifish for food security and sovereignty purposes due to increased fish trade supplying markets beyond the study sites. The prospects of satisfying an increasing fish demand from existing production systems are limited. Small pelagic fisheries need to be linked to the global food system through appropriate mechanisms to allow them to contribute meaningfully to food security and sovereignty.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"04 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129983397","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 community perceptions of ecosystem services within the Tana River estuary, Kenya: Implications for ocean governance","authors":"P. Thoya, M. Owuor, Miriam von Thenen, J. Omukoto","doi":"10.4314/wiojms.si2022.1.4","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.4","url":null,"abstract":"Coastal communities in the Tana estuary, Kenya, rely on a variety of economic sectors linked to ecosystem services, including small-scale fisheries (SSF), commercial prawn fisheries, and tourism. Despite its environmental and social importance, the estuary has been negatively impacted by overexploitation, pollution, and climate change. As a result, developing integrated management approaches for this area is a priority. The integrated approach to ecosystem services (ES) evaluation has widespread support because it emphasizes people’s views of ecological value to human well-being and aims to provide a solution to the rapid depletion of our planet’s natural resources. This study applied mixed methods to understand the perspectives of the communities on ES. It was hypothesized that perceptions of ES differ across communities with different socioeconomic characteristics, and this hypothesis was tested in two communities (Ozi and Kipini) that share the same ecosystem but have different socioeconomic characteristics. Kipini is an area near the ocean, whereas Ozi is a rural area further upstream. Differences were noted in the valuation of cultural services, while there were similarities in provisioning and regulating services. Mangroves, other trees, and river systems were considered to have higher ES provision than the ocean, floodplains, and settlement areas. The Ozi community ranked the ocean higher than the Kipini community, even though Ozi was located further upstream from the ocean; consequently, the perception that communities benefit more from resources that they are close to could be false. The relevance of using social ES identification to determine the distribution of benefits from coastal ES is highlighted in this study and will be beneficial for informing decision-making and developing all-inclusive governance structures.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131696099","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":"Recent rise in exploitation of Tanzanian octopuses: a policy and management challenge","authors":"Cretus Mtonga, Narriman Jiddawi, Debora Benjamen","doi":"10.4314/wiojms.si2022.1.8","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.8","url":null,"abstract":"The artisanal octopus fishery is important for the coastal communities in Tanzania. In this work the octopi landing data from the United Nations Food and Agriculture Organization (FAO), Ministry of Livestock and Fishery Development (MLFD) and trade statistics from Comtrade of the United Nations were analysed. The FAO dataset show that from 1980 to 2017 annual octopus landings stayed below 2000 tons until 2018 when the catch increased to 2864 tons, and doubled to 5,687 tons in 2019. FAO datasets show large catches in 1995, 2003 and 2019, with 2019 recording the largest catch. For both Comtrade and MLFD export statistics, approximately 5,818 and 2,254 tons of octopus were exported globally from 2018 to 2020 with an equivalent value of approximately 13 and 19 million US$ respectively. Portugal was the largest importer of Tanzanian octopi, followed by Turkey, Italy, Spain, Netherlands, Israel, France and Panama. The current management interventions relating to octopi are presented, including the challenges needed to be addressed for sustainability of the octopi fishery. Voluntary octopi closures indicated some signs of success, but an in-depth assessment of the associated effects is required. The study recommends a need for verification mechanisms to ensure consistency of FAO and MLFD statistics, stock assessments, in-situ research on recruitment patterns of octopi, as well as innovation and research in designing sustainable fishing gear to support development of policies for sustainability.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131750773","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":"Paradox incentive structures and rules governing sharing of coastal and marine data in Kenya and Tanzania: Lessons for the Western Indian Ocean","authors":"Désirée Schwindenhammer, J. Francis, Mishal Gudka, Hauke Kegler, Cristopher Muhando, H. Reuter, Rushingisha George, N. Wambiji, A. Schlüter","doi":"10.4314/wiojms.si2022.1.3","DOIUrl":"https://doi.org/10.4314/wiojms.si2022.1.3","url":null,"abstract":"Comprehensive and timely data-sharing is essential for effective ocean governance. This institutional analysis investigates pervasive data-sharing barriers in Kenya and Tanzania, using a collective action perspective. Existing data-sharing rules and regulations are examined in respect to boundaries, contextuality and incentive structures, compliance and settlement mechanisms, and integration across scales. Findings show that current institutional configurations create insufficient or incoherent incentives, simultaneously reducing and reproducing sharing barriers. Regional harmonisation efforts and strategically aligned data-sharing institutions are still underdeveloped. This article discusses proposals to increase capacities and incentives for data-sharing, as well as the limitations of the chosen analytical framework. The debate is extended to aspects beyond institutional issues, i.e., structural data-sharing barriers or ethical concerns. Key recommendations include the establishment of more compelling incentives structures for data-sharing, increased funding of capacity-building and sharing infrastructure, and further awareness creation on the importance of data-sharing.","PeriodicalId":200681,"journal":{"name":"Western Indian Ocean journal of marine science","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131927964","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}