Artisanal fishers’ attitudes towards the adoption of eco-friendly fishing technologies (eFFTs) in Tanzania were investigated. Structured questionnaires were administered to a randomly selected sample of 105 respondents. Purposive sampling was employed to select a total of five key informants from Kivukoni, the National Environment Management Council (NEMC), and the Tanzania Fisheries Research Institute (TAFIRI) to obtain the types, benefits and acceptability of existing fishing technologies in Tanzania. SPSS Statistics software and ATLAS.ti, were used to analyse quantitative and qualitative data. Secondary data analysis employed Yeh’s Index of Perception (YIP). It was found that older fishers resisted adopting eFFTs while younger fishers were amenable, but encountered financial hurdles. Few respondents had secondary education, which may affect the level of technology adoption. Most artisanal fishers perceived eFFTs as beneficial, with the YIP index confirming a consistent viewpoint. A generally positive attitude towards eFFTs indicates potential for these technologies to be adopted. Future studies should focus on how to improve fishers’ knowledge of eFFTs and on exploring other barriers and enablers for technology adoption.
Flatfishes are important components of benthic communities and support small-scale fisheries that sustain livelihoods in the southwestern Indian Ocean. However, limited data on their diversity and distribution hinder effective management and conservation, especially under growing threats from destructive fishing and climate change. To address this, 134 flatfish specimens from the Tanzanian coast were analyzed. Specimens were initially identified through morphological examination and their species identities were confirmed using DNA barcoding. Partial fragments of the cytochrome c oxidase subunit I gene were sequenced and the resulting sequences matched against the Barcode of Life Data System and GenBank databases. Nine flatfish species across five families were recorded: Bothus pantherinus, Cynoglossus acaudatus, Cynoglossus attenuatus, Cynoglossus durbanensis, Engyprosopon grandisquama, Paraplagusia bilineata, Pardachirus marmoratus, Psettodes erumei, and Pseudorhombus arsius. Species composition and distribution varied by location, with P. marmoratus being the dominant species and P. erumei showing the widest distribution. Engyprosopon grandisquama and P. bilineata were rare and restricted to specific habitats, suggesting their current IUCN Least Concern status should be reassessed. One Bothus sp could not be identified using existing reference databases. These findings highlight the need to expand genetic databases, strengthen monitoring, and protect key habitats to support flatfish conservation in the region.
Reef fishes are a cornerstone of Seychelles’ Blue Economy, but their abundance is not static in space and time. To test whether monsoon season and the associated ocean temperature change drive variations in abundant reef fish assemblages, Baited Remote Underwater Video Systems (BRUVS) were used around Frégate Island, Seychelles. Overall, 30 BRUVS were deployed at 10 sites shortly after both the North-West (NW) and South-East (SE) seasonal monsoon periods in 2019 and again after the South-East monsoon in 2020. Twenty four abundant fish species were identified and effects on their abundance modelled (MaxN) by partitioning variation between monsoon season and within sites using zero inflated generalised models. It was found that 18 of the 24 species showed temporal stability in abundance across the two years and monsoon seasons. Only three species; epaulette surgeonfish (Acanthurus nigricauda), doubleband surgeonfish (Acanthurus tennentii) and blue-barred parrotfish (Scarus ghobban) increased in abundance during the NW monsoon sampling period when temperatures are warmer. The results suggest that observed seasonal changes in reef fish in Seychelles are more a result of monsoon associated sea conditions affecting direct access to fishing grounds rather than environmental effects on abundance. Furthermore, it was demonstrated that that BRUVS provide a standardized and repeatable method for quantifying reef fish abundance in Seychelles.
The perceived impacts of seaport development on the livelihoods of mangrove-dependent coastal communities was assessed in Lamu, Kenya, using a mixed-methods design. From a population of 37,963 households, 380 were selected through stratified random sampling. Participants for focus group discussions and key informant interviews were recruited purposively to provide in-depth perspectives. Qualitative data were analysed through content analysis, while quantitative data were processed using SPSS version 23. Paired t-test results revealed significant effects (p < 0.05) of the Lamu Port development on livelihoods relying on mangroves. Fish productivity was the most affected indicator with reductions in catch size and species diversity. Trade in mangrove products was the least affected, although still statistically significant. Other significant impacts included restricted area access, limited alternative employment opportunities, and interference with cultural practices. These findings can guide policy measures that balance port development with the conservation of mangrove ecosystems used by coastal communities, to maintain cultural practices and ensure the sustainability of local livelihoods.
This paper presents a comprehensive review of the evolving fisheries sector in Mauritius, examining recent governance reforms, emerging challenges, and strategic innovations aimed at sustainability. Anchored in the transition from the Fisheries and Marine Resources Act (2007) to the Fisheries Act (2023), the analysis highlights strengthened regulatory tools such as marine protected areas (MPAs), species moratoriums, and licensing reforms. The government’s Fisheries and Aquaculture Reform Program has prioritized small-scale fisher empowerment through co-management initiatives, digital tools like the RodMoFAD application, and the introduction of a national online fish auction platform. Despite these advancements, the sector continues to face systemic threats, including illegal, unreported, and unregulated (IUU) fishing and the impacts of climate change. A notable 17% decline in marine capture between 2015 and 2020 illustrates the urgency of adaptive and inclusive management. This review underscores the importance of sustained investment in research, participatory governance, and technological integration to ensure ecological resilience, economic viability, and cultural continuity within the Mauritian fisheries sector.
Small pelagic fish may play a significant role in the human diet. However, the consumption patterns have not been extensively studied in all areas. This study investigates dietary diversity and small pelagic fish consumption among women of reproductive age along the southern coast of Tanzania. A longitudinal study was conducted with 317 women during the southeast monsoon (SEM) and the northeast monsoon (NEM) to capture the seasonality in consumption, utilizing a 24-hour dietary recall and a short, specific food frequency questionnaire capturing consumption of small fish. The proportion of women who attain an adequate diet during SEM was lower (45%) than the NEM (55%). Fish and other seafood contributed with 52% and 76% of the total animal protein intake in SEM and NEM respectively, even though the weekly consumption frequency was higher during SEM than in NEM. The portion size was comparable across the seasons. Socioeconomic factors influence the consumption patterns of small pelagic fish species, with middle-aged women, those with children, widowed and divorced, and those engaging in the fish value chains showing higher consumption frequencies. Only a few participants (7%) were knowledgeable about the health benefits of small pelagic fish for women of reproductive age. Therefore, education and awareness campaigns should be provided to women concerning the potential of consuming small pelagic fish species for their health.
The Western Indian Ocean (WIO) hosts a rich diversity of marine ecosystems, including coral reefs, mangroves, seagrass beds, and pelagic habitats. Despite its ecological significance, the population genetic structures of marine species in the WIO are among the least studied globally. This review synthesizes data from 87 genetic studies conducted between 2005 and 2024, covering a total of 75 species and 45 families of marine fauna. Using various genetic markers, such as microsatellites and mitochondrial DNA, the review reveals complex genetic structuring patterns across species, with some showing restricted gene flow and significant population subdivision, while others exhibit genetic homogeneity. The review identifies key oceanographic features, such as the Mozambique Channel and local currents like the East African Coastal Current (EACC), as significant factors influencing population connectivity and genetic differentiation. The study also emphasizes the increasing use of advanced genetic markers, including single nucleotide polymorphisms (SNPs), which offer deeper insights into the adaptive processes and evolutionary histories of marine species. Overall, this review underscores the importance of understanding population genetic structures for effective conservation and management of marine biodiversity in the WIO.
Seaweed farming offers a sustainable solution to malnutrition and economic challenges in southwestern Madagascar. This study assessed the seasonal performance of 12 edible seaweed species and optimized cultivation parameters for Gracilaria corticata and Gracilaria salicornia using long-line aquaculture. Environmental factors, including temperature, light intensity, salinity, and current speed, were monitored across warm and cool seasons. G. corticata, G. salicornia, and Hormophysa cuneiformis exhibited the highest retention rates (>50 %) and growth performance, with G. corticata demonstrating significant superior growth in both seasons. Smaller cuttings (0–50 g) achieved higher retention and specific growth rates, particularly in the first 30 days. Growth was significantly influenced by light intensity (4209.35 ± 3274.72 lux in the warm season; 3107.77 ± 3194.22 lux in the cool season) and temperature (30.20 ± 1.26 °C in the warm season; 24.83 ± 0.35 °C in the cool season), with optimal conditions occurring in the warm season. These findings highlight the potential of G. corticata and G. salicornia for sustainable aquaculture, contributing to species diversification and food security. Optimizing environmental conditions and cutting sizes is crucial for maximizing seaweed productivity in Madagascar.
This study is structured around the objective of developing a macroeconomic definition of the sustainable welfare contribution of the South African ocean economy that is both feasible to evaluate and to track. It provides a rationale for developing this definition, discusses the concept and parts of an ocean economy and identifies three models through which this macroeconomic contribution can be assessed; one conventional model and two alternatives. The two alternative models are based respectively on the enhancement effect provided by access to the ocean and the value added to a regional economy by enterprises that locate near the ocean to take advantage of its economic benefits. The study defines the sustainable macroeconomic contribution of the South African ocean economy with reference to these models and to welfare-related criteria. For evaluating and monitoring the welfare-sustaining contribution of the South African ocean economy it recommends applying a combination of the two alternative models, rather than the conventional one, because they incorporate more of the contribution.
Over 60 % of all known cetacean species have been recorded in southern African waters. However, many of these are rarely seen and knowledge of their basic ecology is lacking, with most data acquired from stranded specimens. Odontocetes (toothed whales) that typically occur in offshore environments are particularly data-sparse and include dwarf and pygmy sperm whales, beaked whales, and five other species referred to as ‘blackfish’. The pygmy killer whale (Feresa attenuata) is one of the rare and data-poor ‘blackfish’ species, with the last confirmed at-sea sighting in South African waters recorded in 1969. Several individuals have subsequently stranded along the South African coastline providing valuable opportunities to investigate their biology. Here, both live (2021–2025) and stranded (1957–2021) records of pygmy killer whales in South African waters are updated, with a particular focus on the opportunistic sightings in shallow waters of the iSimangaliso Marine Protected Area on the northern KwaZulu-Natal coast.
Fish Aggregating Devices (FADs) are central to artisanal fisheries in many Small Island Developing States, yet their long-term socio-economic impacts remain underexplored. This study provides the first comprehensive assessment of the socio-economic effects of FAD fisheries in Mauritius since their introduction in 1985. Using a mixed-methods approach, we surveyed 35 artisanal fishers across three key coastal regions—Trou aux Biches, Trou d’Eau Douce, and Albion—and complemented by focus group discussions and multivariate statistical analysis. Findings show that 91% of respondents reported improved livelihoods through FAD fishing. Average monthly incomes ranged from Rs 13,000 to Rs 16,000, with Albion and Trou aux Biches fishers earning significantly more than those in Trou d’Eau Douce (p = 0.018). Income was a significant predictor of boat ownership (p = 0.038), while region, ownership status, and trip cost jointly explained 64.9% of income variation (Adjusted R² = 0.649). Despite these benefits, cluster analysis revealed disparities in FAD access, operational costs, and bait availability—key constraints to equity and efficiency. Additionally, fishers expressed growing concern about ecological unpredictability linked to rising sea temperatures and shifting currents. The study also highlights the underrepresentation of women’s roles in current FAD fisheries assessments, as well as the absence of monitoring and co-management frameworks. Fishers expressed a strong willingness to participate in community-led governance models. We recommend a national FAD management strategy that includes rotational zoning, bait infrastructure support, digital data collection, training programs, and climate-adaptive deployment. Aligning these efforts with Sustainable Development Goals and Blue Economy principles can help Mauritius build a more inclusive, resilient, and sustainable offshore artisanal fishery.
The Western Indian Ocean (WIO) hosts substantial marine biodiversity, which is better known from inshore and coastal hab- itats. The diversity from soft sediments of the shelf and slope is much less known regionally, which was the premise for the WIO-Benth Project. Existing seabed information and bottom trawl catch data were compiled for five countries (Kenya, Tanza- nia, Mozambique, South Africa, and Madagascar), to characterize seabed habitats and benthic (demersal trawl) communities of the continental shelf and upper slope in the western part of the WIO. Soft sediment (sand, mud) habitats were spatially dominant (54 %) relative to rock/mixed habitats; associated trawled fauna from these habitats were dominated by Chordata (fishes) and Arthropoda (mainly crustaceans). This overview of the special issue on the WIO-Benth Project provides a summary of the general results, greater details on which are provided in the issue’s constituent papers. In the process of compiling infor- mation and data from the region, the WIO-Benth Project has provided new knowledge to assist with marine spatial planning and decision-making in the WIO.
The microbial diversity of Tanzania remains largely understudied. We reviewed information on the diversity and biotechnological potential of Actinomycetota bacteria collected in the marine environment. Bacteria from this phylum are acknowledged as a source of bioactive compounds used in antibiotics, pesticides, growth promoters, and enzymes. To date, 32 species have been reported from marine habitats (sediments, seagrass beds, mangroves) in Tanzania, and more than 40 strains have been isolated. Further exploration of natural products from Actinomycetota is required, including for compounds with anti-inflammatory, anti-fungal, anti-tumor, cytotoxic, and anti-bacterial properties.
This study examined how habitat protection influences the feeding behavior and overall health of rabbit fish Siganus sutor, an important species in artisanal fisheries in coastal Kenya. Total length (cm) and weight (g) of 75 specimens landed by fishers in protected (Kiunga, Ishakani) and unprotected areas (Faza, Kizingitini) were measured, and used to assess length-weight ratios and the overall health condition of specimens. Stomach contents were evaluated for feeding intensity, frequency of occurrence, diversity and relative abundance of food items. Protected areas exhibited significantly higher diversity in stomach contents, forming distinct trophic guilds. Habitat protection influenced fish feeding strategies, with unprotected sites showing signs of food deprivation and probable facultative detritivory. Ontogenic feeding variations were evident, with fish size affecting dietary diversity. A Principal Component Analysis grouped the four sites into two major categories: protected (Kiunga and Ishakani) and unprotected (Faza and Kizingitini) based on fish health condition, food item diversity, and relative abundance. These findings suggest that habitat protection shapes the feeding ecology of S. sutor. A longer time series study of spillover effects of Kiunga Marine Reserve would inform policies and regulations for fish habitat protection measures and managing adjacent fisheries.
The biodiversity of the western Indian Ocean is known mostly from inshore habitats, but little is known from the most extensive habitat of the region, the soft, unconsolidated sediments. Demersal trawl data from Kenya, Tanzania, Mozambique, South Africa and Madagascar were analysed, using average taxonomic distinctness in association with various environmental factors, to determine the biodiversity, the dominant genera that characterise the community assemblages and the areas where biodiversity was highest. A decreasing trend in biodiversity was observed from Kenya to Mozambique, including Madagascar, but South Africa had the highest average biodiversity. The continental slope was more biodiverse than the shelf, and biodiversity increased with depth to approximately 500 m, whereafter it declined. Depth and turbidity were the factors that best accounted for differences in community assemblages. The deep-water fish genera, Chlorophthalmus and Chaunax, dominated the slope assemblages, while the shelf communities were dominated by the shallow-water shrimp genera, Penaeus and Metapenaeus. Areas that have higher diversity, in general, included off Durban, South Africa, the Delagoa Bight off Maputo, Mozambique, and most of the area off southern Kenya. The information presented has improved the knowledge of soft sediment habitats in the WIO, thereby supporting decision-makers when deciding on planning options.
Marine biodiversity research in Madagascar has mostly focused on coastal habitats and deep-sea ecosystems, with fewer studies on the shelf and upper slope. This study contributes to knowledge of the demersal communities on the west coast of Madagascar using data collected from 54 bottom trawls by the research vessel Dr Fridtjof Nansen in 2008 and 2009. The analyses focused on two factors: location along the coast and continental shelf versus slope. A total of 239 genera were identified, consisting of 31,194 individuals with a total weight of 3,335.61 kg. The Shannon-Wiener diversity index showed high diversity in the northwest. Diversity was higher on the slope than shelf. The genus Upeneus dominated all shelf catches (19.35 %) and Rexea (2.18 %) was strongly dominant on the slope. A clear distinction existed between the shelf and the slope communities shown by nMDS plots and ANOSIM tests, with R values of 0.67 for the presence/ absence dataset, 0.061 for the abundance dataset, and 0.57 for the biomass dataset. According to SIMPER analysis, the genera driving the dissimilarity between these two ecosystems are Rexea and Chlorophthalmus. These results suggest that depth is the most influential factor in determining community assemblages
The biodiversity of the east coast of South Africa differs markedly from that of the rest of the marine environment of the country. Data from commercial crustacean trawls were used in conjunction with environmental data to investigate biodiversity patterns of offshore habitats off the KwaZulu-Natal coast. Biodiversity was measured using taxa observed (genus and species) and average taxonomic distinctness. Community assemblages were determined through clustering, analysis of similarities and similarity percentage analysis. Factors influencing biodiversity were position on the continental margin (littoral/slope), location along the coast, turbidity and temperature. These were the same factors that influenced the community assemblages. Crustaceans were the most frequently occurring taxa followed by teleost fishes. This reflected the nature of the local trawl fisheries that target crustacean species. The community assemblages at the locations included in the study were highly dissimilar to each other and clear transitions in assemblages were obvious as depth increased. Substantial disparities in sampling effort reduced options for in depth analysis. This leaves scope to expand this work both through increased sampling in under-sampled areas but also to investigate areas with higher sampling effort more fully
In the Western Indian Ocean (WIO) elasmobranchs play important roles in ecosystems as apex and mesopredators and contribute high socio-economic value to coastal communities. Their diversity in the WIO is amongst the highest globally yet few studies have assessed the occur- rence of various species in catches. Demersal trawl catches from Kenya, Tanzania, Mozambique, Madagascar and South Africa (East Coast) were analysed using Generalised Linear Models to esti- mate the probabilities of non-zero catches of sharks and batoids. The data were further subjected to non-metric multidimensional scaling to establish clusters of various communities and to sim- ilarity percentage analyses to determine the dominant taxa. The probability of catching sharks and batoids in trawl nets was high. While communities were not highly separated within factors, it was depth that showed the greatest influence on community structures. The genus Squalus dom- inated the shark catches as depth increased while species dominance of batoids changed from stingrays (Dasyatidae) to guitarfishes (Rhinobatidae) and to skates (Rajidae) as depth increased. This study underlines the need for improved species identification of elasmobranch catches and for marine protected areas on soft sediment habitats to protect these important species.
Marine protected areas (MPAs) have become a crucial conservation strategy in response to anthropogenic threats impacting the world’s oceans. However, some MPAs have conflicting goals that compromise conservation effectiveness. To guide future MPA development, the conservation value of current MPAs need to be accurately quantify using diversity metrics, such as species richness and rarity. This study focused on the demersal soft-sediment fauna of the Western Indian Ocean (WIO) and explored their environmental predictors and distributions. Hotspot areas of high species richness and rare taxa were identified, comparing them to existing MPAs, to evaluate their value as a conservation strategy for these fauna. The results show that depth, which negatively correlates with water temperature, and latitude, which positively correlates with longitude, are the most influential predictors of demersal species richness and rarity. Various other environmental factors are significantly associated with these two diversity measures. Hotspots of species richness and rarity occur in deeper, cooler waters away from the coastline, which are less exposed to disturbances. Higher richness was found outside of MPAs, likely because most WIO MPAs are in shallow waters, while the studied demersal fauna favour deeper conditions. These findings underscore the need for MPAs to comprise a mosaic of habitat types to effectively conserve the diversity of demersal species.
While the Western Indian Ocean (WIO) hosts a large diversity of marine and coastal organisms, less is known about the biodiversity of deeper habitats, particularly from soft sediments. Consequently, there is less known about the vulnerability of these habitats to disturbance and degradation. This paper is a first attempt to assess this at the regional scale, using data on trawled fauna. In the absence of life history information, alternative indices of sensitivity were used: mobility, distribution, presence of cnidaria and porifera, and presence of IUCN Threatened species. Central and southern Mozambique and the east coast of South Africa have the most extensive areas of potentially highest sensitivity in soft sediment habitats, with smaller patches off central Tanzania and Kenya. Greater confidence in these findings requires greater sampling coverage and improved identification of fauna. Nevertheless, these preliminary findings draw attention to the relative sensitivity of these soft sediment habitats and provide a basis for assisting countries in identifying potential soft sediment areas for protection, contributing towards their Sustainable Development Goals (SDGs) and other marine conservation targets.
