Current State of Seagrasses in Zanzibar: Impacts of Coastal Economic Activities and Marine Protected Areas on Seagrass Cover

Seagrass meadows are located abundantly in Zanzibar, Tanzania and provide essential ecosystem services, such as sediment nutrient enrichment and blue carbon sequestration. However, seagrasses have been less researched or protected than other marine ecosystems. Although environmental variables affect seagrass health, evidence suggests that anthropogenic impacts are their greatest threats. The rapid expansion of seaweed farming and tourism and widespread use of harmful small-scale fishing practices in Zanzibar have contributed to the degradation and removal of seagrass meadows, disrupted coastal marine food chains, and reduced local biodiversity that seagrasses support. Public or private marine protected areas (MPAs) protect most of Zanzibar’s coastal marine ecosystems, yet evidence is unclear whether MPAs effectively conserve marine ecosystems. Using geographic information systems (GIS) to estimate the change in percent of seagrass cover from 2006 to 2019, we conducted Spearman’s rank correlation analyses to identify whether seagrass degradation was correlated with seaweed farming, fishing, or tourism and whether MPA management plans were protective. Tourism was negatively correlated with seagrass cover, r(9) = -0.74, p = 0.044, suggesting that tourism is an important driver of seagrass declines in Zanzibar. No other variables were significantly correlated with seagrass cover decline. To improve the management of seagrass meadows, plans must identify seagrasses as critical ecosystems, expand seagrass restoration projects, and address harmful practices in the tourism industry and other human impacts

Recent rise in exploitation of Tanzanian octopuses: a policy and management challenge

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

Comparison of Seaweed Growth, Fish Abundance and Diversity in Deep Water Floating Raft with Tubular Nets and Shallow Water Off-bottom lines Seaweed Farms

This study compared the growth performance of Eucheuma denticulatum, fish abundance anddiversity between deep water (using tubular nets) versus shallow water (off-bottom) seaweedfarming methods. For each farming method, three plots were set and fish abundance, diversity andseaweed growth rates were measured at intervals of 15 days. Belt transects measuring 10 m x 4 meach, were established on seaweed farms for fish observations. Fish were identified to the lowestpossible taxonomic level by underwater census. The results showed that the growth rate of E.denticulatum in deep water farms was slightly higher at an average daily growth rate (DGR) of3.42 ± 0.18% day−1 compared with 3.01 ± 0.27% day−1 for shallow water farms but with nosignificant differences (p = 0.079) likely due to higher herbivory in the deep water farms. Fishabundance and diversity were higher in deep water farms but insignificant (t (34) = 0.69, p = 0.49and t (34) = 0.424, p = 0.67, respectively). Habitat complexity and seaweed growth rate were almostsimilar for both farming methods hence attracting comparable numbers of fish. Further studies arerecommended on fish community structures, differences between the two farming methods andeffects of herbivory. Keywords: E. denticulatum; seaweed farming methods; growth; fish diversity and abundanc

Abundance, spatial distribution and threats to Indo-Pacific bottlenose dolphins (Tursiops aduncus) in an Important Marine Mammal Area in Tanzania

Funding: Thanks to the US Marine Mammal Commission (MMC) and the People’s Trust for Endangered Species who funded his work via the Wildlife Conservation Society (WCS).Abundance estimates of cetaceans in the western Indian Ocean are rare, but important, as many cetacean populations are under threat, especially those in coastal habitats. This study aimed to generate first estimates of abundance for Indo-Pacific bottlenose dolphins (Tursiops aduncus), assessed as Near Threatened on the IUCN Red List, in an area identified by the Marine Mammal Protected Area Task Force as an ‘Important Marine Mammal Area’. Two study sites were surveyed along the east and west coastlines of the Pemba Channel, Tanzania. In west Pemba, between 2014 and 2016 four boat-based visual surveys conducted a total of 2467 km of survey effort sighting a total of 16 groups of T. aduncus. Abundance was estimated using mark-recapture models of photo-identified individuals as 83 animals (CV 7.8%, 95% CI 72-97) in the 1084km2 study area. In the Tanga study area in 2016 two boat-based visual surveys covered 1254 km of effort during which 15 groups of T. aduncus were sighted, resulting in a photo-ID based mark-recapture abundance estimate of 196 (CV 8.9%, 95% CI 165-233) individuals in the 1562 km2 study site. Group encounter rate for this species in Tanga was double that recorded in the Pemba study site. A total of 23% of identified dolphins bore the scars of interactions with fishing gear.Publisher PDFPeer reviewe

Social, economic and trade characteristics of the elasmobranch fishery on Unguja Island, Zanzibar, East Africa

Understanding the socio-economic drivers underpinning fishers' decisions to target elasmobranchs is considered vital in determining sustainable management objectives for these species, yet limited empirical data is collected. This study presents an overview of elasmobranch catch, trade and socio-economic characteristics of Zanzibar's small-scale, artisanal fishery. The value of applying this information to future elasmobranch fisheries policy is demonstrated. In August 2015, interviews were conducted with fishers (n = 39) and merchants (n = 16) at two landing sites, Kizimkazi-Dimbani and Mkokotoni, along with the main market site in Stone Town. Additionally, elasmobranch catches were recorded across the same locations between June and August 2015. Elasmobranchs were listed as target species by 49% of fishers interviewed. Whilst most fishers (n = 30) stated that 76–100% of their household income came from fishing, there was variation in how elasmobranch catch and trade contributed. One-third of fishers (n = 36) that caught and sold elasmobranchs reported that 41–60% of their income came from elasmobranch catch. However, for some fishers (n = 8) elasmobranch catch represented 0–20% of their income, whilst for others (n = 4) it represented 81–100%. Differences in fisheries income and elasmobranch price could be attributed to several interacting factors including season, weather, fishing effort, fishing gear, target catch and consumer demand. Further, elasmobranch price was influenced by size and species. The study revealed information on catch, trade, markets and socio-economy that is important for future research, conservation and management of elasmobranchs and fisheries in Zanzibar. The methods utilised have potential for broader application to understudied, artisanal elasmobranch fisheries in the western Indian Ocean

Improving bycatch mitigation measures for marine megafauna in Zanzibar, Tanzania

This study was conducted to explore the governance processes and socio-economic factors relevant to the potential implementation of bycatch mitigation for various vulnerable marine megafauna (rays, sharks, marine mammals and turtles) in Zanzibar, Tanzania. Questionnaire-based interviews were conducted between February and April 2017 with fishers (n= 240) at eight landing sites. One focus group discussion was held in each site and eleven key informant interviews were carried out. The study showed that current measures to manage bycatch rates are not explicit; no rules govern rays and sharks bycatch; and rules regarding marine mammal and sea turtle bycatch are poorly enforced. Binary logistic regression was used to determine the effect of five selected socio-economic factors (education, age, proportional fishing income, fishing experience, and the number of adults who bring income into the household) on the willingness of fishers to participate in potential future bycatch mitigation measures for marine megafauna. The results indicate that only one factor (the number of adults who bring income into the household) had any significant effect (p=0.016). These findings could benefit the future governance and management of marine megafauna in Zanzibar through a better understanding of what mitigation measures are more likely to be supported

Indicators of stock status for large-pelagic fish based on length composition from driftnet fisheries in Zanzibar

Small-scale fisheries (SSF) contribute to approximately half of the total landings of tuna and tuna-like species in the Indian Ocean and are an important form of employment and source of protein. Research into the properties and dynamics of SSF in East Africa are important for the assessment and sustainable management of fish stocks, however, detailed fisheries data are often inadequate or absent. Fisheries-dependent data on driftnet fisheries in Zanzibar, Tanzania, was collected during the northeast monsoon seasons in 2014 and 2015. The data describes the properties of the driftnet fisheries and allows for comparisons of the length composition of the landings of the SSF with large-scale industrial fisheries (IF) fishing in Tanzania’s Exclusive Economic Zone (EEZ). This data also facil- itates the calculation of stock indicators for the five most abundant tuna and tuna-like species landed in Zanzibar. Results show that the two fisheries (SSF and IF) exploit the same stocks, and landings are representative of a similar length composition, while operating in different parts of Tanzania’s EEZ. High exploitation rates, above reference levels for all species were calculated, in agreement with official assessments by the IOTC, and suggest that calls for the expansion of the SSF should be reconsidered. The assessment and management of straddling stocks are dis- cussed, as well as solutions to challenges faced by local observer programmes

Community based aquaculture in the western Indian Ocean: Challenges and opportunities for developing sustainable coastal livelihoods

The small-fisheries social-ecological system in the western Indian Ocean (WIO) represents a typical social-ecological trap setting where very poor natural resources dependent coastal communities face local and global threats and engage in unsustainable practices of exploiting limited resources. Community-based aquaculture (CBA) has been implemented as an important alternative or supplementary income generating activity for minimizing the overdependence on marine natural resources and promoting biodiversity conservation. Despite its proliferation throughout the WIO region in recent decades, little is known about the degree to which CBA activities have contributed to achieving the objectives of breaking the cycle of poverty and environmental degradation and promoting community development and biodiversity conservation. In order to improve understanding of common challenges and to generate recommendations for best practice, we assessed the most common CBA activities practiced in the region through literature review and workshop discussion involving practitioners and key stakeholders. Findings indicated that despite favorable environmental conditions for various CBA practices, the sector remains underdeveloped, with few activities delivering the intended benefits for coastal livelihoods or conservation. Constraints included a shortage of seed and feed supplies, low investment, limited technical capacity and skills, insufficient political support, and lack of a clear strategy for aquaculture development. These are compounded by a lack of engagement of local stakeholders, with decision making often dominated by donors, development agencies, and private sector partners. Many of the region’s CBA projects are designed along unrealistically short time frames, driven by donors rather than entrepreneurs, and so are unable to achieve financial sustainability, which limits the opportunity for capacity building and longer-term development. There is little or no monitoring on ecological and socioeconomic impacts. Except for a few isolated cases, links between CBA and marine conservation outcomes have rarely been demonstrated. Realizing the potential of CBA in contributing toward food security in the WIO will necessitate concerted investment and capacity strengthening to overcome these systemic challenges in the sector. Lessons herein offer managers, scientists, and policy advisors guidance on addressing the challenges faced in building strategic development initiatives around aquaculture in developing countries

Invisible actors on a male dominated arena: female fish mongers’ roles, strategies and needs in the fisheries sector

In Zanzibar, an increasing number of women have entered fish markets acting as a link between fishers and consumers, i.e. a middleman. However, since fisheries are traditionally male dominated, women receive little recognition. Thus, gender analysis in the fisheries sector potentially can enhance management and development policies as well as environmental issues. In this study 23 women and 23 men from 12 fish markets in Zanzibar were interviewed to examine 1) women's and men's different strategies to succeed on the market, 2) how finance and social networks determine the access to different fish species, 3) knowledge about fish demand and markets, and 4) needs and challenges related to fish trade. Results show that even when women manage to penetrate typical male jobs, the execution of the activity differs greatly between the sexes. Men tend to dominate commercial channels and revenues of large valuable species such as tuna, kingfish and swordfish while women mainly have access to species of low economic value such as anchovies and small mackerels directed to local markets and consumption. The main reason for this was reported to be lack of access to economic and social resources. This, in combination with scarce knowledge about fish demand, market connections and limited mobility, exclude women from more profitable markets. The study suggests that a nuanced understanding of gender dynamics in fishing communities is needed and its relation to wider social, economic, cultural and political processes.This is part of the IIFET Special Session on Markets and Value Chains for Small Aquaculture & Fisheries Enterprises with a Focus on Gender that took place on 17 July 2012 in Dar Es Salaam, Tanzania in conjunction with 16th IIFET Conference. The complete proceedings of this special session are available ( http://aquafishcrsp.oregonstate.edu/Documents/Uploads/FileManager/IIFET%202012%20CRSP%20Session%20Proceedings%20Final_small.pdf) through the Aquaculture & Fisheries Collaborative Research Support Program gender web site, ( http://aquafishcrsp.oregonstate.edu/Gender/). Abstract only