Research Repository :: Browsing by Author "Bryceson, Ian"

Browsing by Author "Bryceson, Ian"

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Climate Change in Tanzania: Trends, Policies and Initiatives
(2008) Benjaminsen, Tor A.; Bryceson, Ian; Maganga, Faustin P.
Complementarity of fishers' traditional ecological knowledge and conventional science: Contributions to the management of groupers (Epinephelinae) fisheries around Mafia Island, Tanzania
(Ocean & Coastal Management, 2015) Gaspare, Lydia; Bryceson, Ian; Kulindwa, Kassim
Traditional ecological knowledge (TEK) is increasingly advocated as a complementary source of information that can potentially be integrated into mainstream science, particularly to help improve fisheries management. However, less attention has been paid to identifying specific areas where the TEK of fishers may confirm or contradict conventional scientific knowledge (CSK); or where TEK may provide new insights for fisheries systems characterized by multi-species and multi-gear usage. We conducted a qualitative exploration of TEK of grouper fishing patterns and compared the findings with an analysis of catch data in order to elucidate the extent of fishing pressure on groupers. We further compared TEK of the ecology and biology of groupers with published CSK to understand the complementarity between the two domains. Data collection methods included structured open-ended questionnaire, semi-structured interviews with key informants, focus group discussions, personal observations and a literature review. Results indicate that TEK complements CSK in terms of catch assessment and the ecology of groupers. TEK provides additional information on fishing gear, specific grouper species caught, habitat use and feeding habits; however, TEK contradicts CSK regarding spawning aggregation behavior. TEK offers new knowledge on environmental threats facing groupers, but fishers lack knowledge on reproductive modes and life history traits (i.e. hermaphroditism and spawning season) of groupers. We conclude that, in a conducive democratic setting based upon mutual respect and trust, TEK can complement conventional science and help to make more informed management decisions for sustainable fishing.
Mariculture in the WIO region
(WIOMSA, 2009) Troell, Max; Hecht, Tom; Beveridge, Malcolm; Stead, Selina; Bryceson, Ian; Kautsky, Nils; Ollevier, Frans; Mmochi, Aviti
Today aquatic products provide nearly 3 billion people with at least 15% of their animal protein intake and fish constitute the dominant source of animal protein in many island states and low income, food deficient countries (FAO, 2009; Smith et al., 2010). The world’s growing population consumes more and more fish and stagnating catches from our oceans cannot keep up (Pauly et al., 2003; FAO 2009). The rapid development of aquaculture has to some extent enabled us to meet this growing demand and currently the aquaculture sector provides half of all fish destined for human consumption (FAO, 2009). However, the gap between demand and supply is increasing and so the pressure on aquaculture to meet this shortfall has led to development of the sector rising up political agendas worldwide. The aquaculture industry is the fastest growing animal production sector but the question is whether it can double in a sustainable manner (Soto et al., 2008; Tacon & Metain, 2008) by 2020 to meet expected demand for fish products (Jacquet et al., 2009). Another interesting question is what role Africa will play in future development of aquaculture, in particular to what extent can the expansion of marine aquaculture offer alternative or supplementary livelihoods to fishery dependent communities?
Reproductive Biology and Fishery-Related Characteristics of the Malabar Grouper (Epinephelus malabaricus) Caught in the Coastal Waters of Mafia Island, Tanzania
(Journal of Marine Biology, 2013) Gaspare, Lydia; Bryceson, Ian
The reproductive biology and fishery-related characteristics of the Malabar grouper (Epinephelus malabaricus) (Bloch and Schneider, 1801) specimens were investigated. The size of females ranged from 25 to 113 cm total length (𝐿𝑇), with 50% sexually mature at 79 cm 𝐿𝑇, and the males (97 cm to 114 cm 𝐿𝑇) were larger than the females. Due to the sex ratios and size distribution of the sample, it appeared that the groupers change sex between 97 and 113 cm 𝐿𝑇. However, the gonadal histology data lacked specimens in the transitional stage. The spawning peak occurred in November, as defined by the presence of ripe females, and the spawning season lasted from September to February. The size of the fish correlated positively with the water depth at capture, which is also related to oxygen levels in deep water being more favourable for larger fish. Larger specimens (>100 cm𝐿𝑇) were targeted by fishers between December and February, when the northeast monsoon coincides with calmer weather and the spawning season. Fishers were interviewed, and observations were made on fishing gear, vessels, and grounds. There was no indication that small-scale fishers targeted spawning aggregations; therefore, fisheries independent research is recommended in order to verify the time, location, and behaviour of the spawning of Malabar groupers for management and conservation purposes.
Seeing Through Fishers’ Lenses
(SAGE Publications, 2016) Moshy, Victoria H.; Bryceson, Ian
Insights from traditional ecological knowledge (TEK) of the marine environment are difficult to integrate into conventional science knowledge (CSK) initiatives. Where TEK is integrated into CSK at all, it is usually either marginalized or restricted to CSK modes of interpretation, hence limiting its potential contribution to the understanding of social-ecological systems. This study uses semi-directive interviews, direct observations, and structured open-ended questionnaires (n = 103) to explore TEK of marine ecological changes occurring within the Mafia Island Marine Park, Tanzania, and factors contributing to these changes. It illuminates TEK insights that can be valuable in parallel with CSK to provide a more nuanced understanding of ecological changes. In some areas, fishers observed coral reef growth, increased fish abundance, and increased sea temperatures, whereas in others, they reported decreases in sea level, coral cover, fish abundance, catch composition, catch quantities, and fish size. They associated these changes with interrelated factors emanating from environmental processes, conservation outcomes, marketing constraints, population dynamics, and disappearance of cultural traditions. Utilizing TEK without restricting it to CSK modes of interpretation has the potential to improve CSK initiatives by promoting complementarity and mutual enrichment between the two kinds of knowledge, thereby contributing new insights that may enhance adaptive management and resilience in social-ecological systems.
Social-Ecological Changes, Livelihoods and Resilience among Fishing Communities in Mafia Island Marine Park, Tanzania
(Taylor & Francis, 2015) Moshy, Victoria H.; Bryceson, Ian; Mwaipopo, Rosemarie
Analysis of societal dimensions is increasingly receiving attention in social–ecological resilience research. This study investigates the impacts of neo-liberal marine conservation and economic policies, and environmental changes on the livelihoods of two fishing communities in Mafia Island Marine Park, Tanzania, and their response strategies towards attempting to maintain livelihood resilience. These communities are in similar geographical and administrative settings but differ in their proximity to Park headquarters, conformity to Park regulations and engagement in fish trade. Data were collected through in-depth interviews, focus group discussions, direct observation and questionnaire surveys. Interviewees from both villages reported increasing poverty in terms of reduced capacity to meet their basic needs, and decreases in numbers of meals per day, variety of foods and fish consumption, reduced access to resources, low productivity and prices of local produce. Women experienced raised household responsibilities for food security and meeting other household needs. Their main responses to these changes included loan seeking, reduction of expenditures, skipping meals, selling assets, collective fishing, livelihoods diversification, change of fishing techniques and gears, abandoning of fishing activity and outward migration. Their responses only contributed to survival without resolving the challenges. Paying attention to these societal experiences is therefore necessary, if resilience of social–ecological systems in a marine conservation area is to be maintained or enhanced.
Spatial and seasonal variations of fish assemblages in mangrove creek systems in Zanzibar (Tanzania). Estuarine, Coastal and Shelf Science
(2010) Mgaya, Yunus D.; Öhman, Marcus C; Andersson, Mathias H.; Gullström, Martin; Mwandya, Augustine W.; Bryceson, Ian
Spatial and seasonal variations of fish assemblage composition were studied in three non-estuarine mangrove creeks of Zanzibar (Tanzania). Fish were collected monthly for one year at three sites (lower, intermediate and upper reaches) in each creek using a seine net (each haul covering 170 m2). Density, species number and diversity of fish were all higher at sites with dense cover of macrophytes (seagrass and macroalgae) than over unvegetated sandy sites. In general, fish assemblages mainly comprised juveniles of a few abundant taxa, e.g. Mugil cephalus, Mugilidae spp. and Leiognathus equulus at sites with mud substratum and Gerres oyena, Lethrinus harak and Sillago sihama at sites dominated by macrophytes. Multivariate analyses revealed significant separations in fish assemblage composition within the two creeks where the bottom substratum differed among sites. Overall, season seemed to have little effect on density, species number, diversity index (H′) and assemblage structure of fish. Water condition variables were also relatively stable across the season, although a short-term fluctuation primarily induced by decreased salinity, occurred during the heavy rains in April and May. Fish assemblage structure was not significantly affected by any of the abiotic factors tested. However, significant regressions were found between the other fish variables and environmental variables, but since these associations were mostly species-specific and generally inconsistent, we suggest that the overall distribution patterns of fish were mainly an effect of particular substrate preferences of fish species rather than contemporary water conditions.
Tanzanian Coastal and Marine Resources: Some Examples Illustrating Questions of Sustainable Use
(2000) Francis, Julius; Bryceson, Ian
The coast of Tanzania is characterised by a wide diversity of biotopes and species, typical of the tropical Indo- west Pacific oceans, and the peoples living there utilise a variety of its natural resources. Because of the extent of the diversity and variety, several different examples are used by this study to elucidate the complexity of issues and multiplicity of management responses related to use of coastal and marine resources. It emerges that coastal management requires an integrated cross-sectoral approach to address the wide array of interrelated issues involved. The study describes the status of selected resources from the principal biotopes (coral reefs, mangroves, sea grass beds and beaches) as well as fish stocks, and it examines various forms of their utilisation. Some special cases of endangered species are also examined. The study attempts to analyse questions of sustainable use in relation to ecosystem dynamics, socio-economic processes, institutions and policies. The characteristics for what we consider as approaching a state of sustainable use are proposed, and the requirements considered necessary for ensuring sustainability are outlined. Past experience and the current status of coastal and marine resource uses are summarised through the examples chosen in order to explain the main constraints to the attainment of sustainability. Crosscutting issues related to the breakdown of traditional management systems for common property resources in the face of increasing commercialisation, privatisation, and external interventions appear to pose general problems. The general experiences of community projects, legislation, and mitigation measures are assessed from the examples we have chosen. We present an array of general lessons learned and key factors affecting sustainable use of coastal and marine resources. Amongst these we emphasise: • Dialogue and linkage between traditional and scientific knowledge systems. • Mechanisms for interaction between scientists, managers and decision-makers. • Continued human and technical capacity building of research institutions. • Essentiality of addressing land and sea tenure and common property rights. • Genuine involvement and empowerment of local communities and civil society including community- based organisations (CBOs), and local non-governmental organisations (NGOs). • Credible and equitable arrangements for benefit-sharing with communities. • Open availability of information for overall transparency and accountability. • Integration of socio-economic opportunities into conservation programmes. • Recognition of and respect for local and traditional institutions. • Openness in collaboration between traditional and government institutions. • Strengthening of relevant institutions providing entry to decision-making. • Management agreements between institutions for cross-sectoral co-ordination. • Long-term and broad-based visions in policy thinking. • Democratic process of public involvement in policy-making and implementation.
Temporal and spatial trends in size, biomass and abundance of groupers (Epinephelinae) in Mafia Island Marine Park: fishers’ perceptions and underwater visual census surveys
(Fisheries Management and Ecology, 2015) Gaspare, Lydia; Bryceson, Ian; Mgaya, Yunus D.
Fishers’ perceptions of changes in grouper size and abundance were compared with scientific data collected via underwater visual censuses (UVCs) before (1995) and after (2006 and 2011) the establishment of the Mafia Island Marine Park. Perceptions on changes in the size structure of groupers differed among communities due to differences in fishing capacities. Fishers in one village had mixed perceptions, while in another village the majority (66%) perceived a decline in size, with small groupers dominating the catch. Similarly, UVCs indicated that size structure was dominated by small groupers at all times surveyed. Consistent with fishers’ perceptions, UVC indicated that biomass and abundance of groupers declined in both no-take zones (NTZs) and specified-use zones (SUZs) between 1995 and 2006, with no substantial changes between 2006 and 2011. The NTZs had higher density and diversity of grouper species than SUZs, as would be expected from the differences in bottom topography in these two types of areas. The idea that NTZs could increase the biomass and abundance of groupers to benefit fished zones was not found, thus indicating that NTZs are not necessarily the best option for managing reef fisheries.
Trichodesmium in Coastal Waters of Tanzania: Diversity, Seasonality, Nitrogen and Carbon Fixation
(Springer Link, 2002) Lugomela, Charles; Lyimo, Thomas J.; Bryceson, Ian; Semesi, Adelaida K.; Bergman, Birgitta
Seasonal distribution, nitrogen fixation and primary productivity of Trichodesmium species were intermittently studied in the coastal waters of Tanzania. Samples were collected in 1975/6, 1980, 1993/4, 1994/5 and 1998/9. Four colony forming species were found, i.e. T. erythraeum, T. tenue, T. thiebautii and one unidentified Trichodesmium sp. while T. contortum was rarely encountered, and only as individual trichomes. T. erythraeum was most abundant, although other Trichodesmiumspecies dominated during particular periods of the year. The occurrence of Trichodesmium showed a consistent seasonal pattern. High Trichodesmium biomass was promoted by the NE monsoon (December–April) while it was low or absent during the SE monsoon (June–October). The biomass was highest at the surface especially during calm weather periods. The NE monsoon was characterized by elevated rainfall, temperature and nitrate concentrations while salinity, light intensity and turbidity tended to decrease. Phosphate concentrations did not show systematic variations with season. The rate of nitrogen fixation by Trichodesmium species in surface waters was 1.8 1.6 pmol N trichome–1 h–1 giving an average N2 fixation of 42.7 mmol N m–3y–1. The mean rate of carbon fixation was 1.15 0.3 ng C trichomes–1 h–1 in the upper 5 m depth. It is estimated that Trichodesmium contributes about 0.03–20% of the total CO2 fixation in the coastal surface waters during the SE and NE monsoon, respectively.
Undernutrition among Under-Five Children in Two Fishing Communities in Mafia Island Marine Park, Tanzania
(Canadian Center of Science and Education, 2013-06-01) Moshy, Victoria H.; Masenge, Theopista J.; Bryceson, Ian
Undernutrition and food insecurity are critical problems among under-five children in many developing countries. This study was carried out for eight months between 2009 and 2011. It combined quantitative data (N=156) and qualitative data to explore nutritional status among under-five children in Jibondo and Chole villages within Mafia Island Marine Park in Tanzania. Weight-for-age analysis was performed according to World Health Organization standards to determine the proportion of underweight children among the samples. The prevalence of underweight children was high in both villages, and in Jibondo village it was even higher (69%) than in Chole village (40%). Interviewees attributed the exceptionally high underweight problems in Jibondo to a substantial reduction in breast-feeding frequency. This was because mothers resumed seaweed farming and octopus fishing soon after delivery. Consequently, infants were fed poor-quality nutritional substitute foods at a tender age. Decreased family income, food insecurity, changes in gender roles and increased responsibilities for women were also perceived to be key underlying problems contributing to higher levels of undernutrition among children in the study areas. If healthy generations and sustainable social-ecological systems are to be achieved within the Park in the future, policies that review fishing restrictions, improve fish trading, increase household food security and liberate mother’s time for breastfeeding and child-caring activities would be essential to address the current undernutrition among the under-fives.

Browsing by Author "Bryceson, Ian"

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