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1.
Ambio ; 53(8): 1218-1233, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38647618

RESUMEN

Livelihood initiatives are common within marine protected areas (MPAs) aiming for poverty alleviation or higher income opportunities. However, results can be mixed in reality, as well as change over time. Furthermore, who benefits is a key consideration, as results can vary based on inequalities, including gender. Here, the monetary outcomes of different livelihood strategies were investigated across three MPA regions in Zanzibar, Tanzania. Using a quantitative approach, the results show that livelihoods have shifted in a six-year period, with livelihood strategies differing in poverty incidence and income. Livelihood initiatives, namely seaweed farming and tourism, did not provide significantly higher monetary returns compared to long-standing livelihoods, such as fisheries. Seaweed farming showed income stability but a high poverty incidence predominantly within women-headed households. During the study period, men primarily remained in fisheries, whilst women shifted to small-scale businesses and fisheries, largely exiting seaweed farming. This underscores a need for adaptive, gender sensitive management within fast changing coastal contexts.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Pobreza , Tanzanía , Femenino , Masculino , Explotaciones Pesqueras/economía , Humanos , Renta , Factores Sexuales , Factores Socioeconómicos , Algas Marinas , Turismo
2.
J Fish Biol ; 94(1): 29-39, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30515816

RESUMEN

Fish larvae abundances, diversity and trophic position across shallow seagrass, coral reef and open water habitats were examined to characterize their distribution in coastal East Africa. Larvae were identified to family and analysed for abundance differences between sites and habitats, trophic level using stable-isotope analysis and parental spawning mode. Abundances differed greatly between sites with the highest numbers of larvae occurring in the open-water and seagrass habitats. Larval fish diversity was high across habitats with 51 families identified with small differences between sites and among habitats. Notably, larvae of abundant large herbivorous fishes present in reef and seagrass habitats were almost completely absent at all sampling locations. In the seagrass, demersal spawned larvae were more abundant compared with the reef and open-water habitats. Stable-isotope analysis revealed that fish larvae have a varied diet, occupying trophic level two to three and utilizing planktonic prey. This study offers new insights into distributional aspects of fish larvae along the East African coast where such information is sparse.


Asunto(s)
Ecosistema , Peces/fisiología , África Oriental , Animales , Biodiversidad , Arrecifes de Coral , Demografía , Cadena Alimentaria , Larva/fisiología
3.
PLoS One ; 12(8): e0183999, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28854231

RESUMEN

Marine protected areas (MPAs) have been shown to increase long-term temporal stability of fish communities and enhance ecosystem resilience to anthropogenic disturbance. Yet, the potential ability of MPAs to buffer effects of environmental variability at shorter time scales remains widely unknown. In the tropics, the yearly monsoon cycle is a major natural force affecting marine organisms in tropical regions, and its timing and severity are predicted to change over the coming century, with potentially severe effects on marine organisms, ecosystems and ecosystem services. Here, we assessed the ability of MPAs to buffer effects of monsoon seasonality on seagrass-associated fish communities, using a field survey in two MPAs (no-take zones) and two unprotected (open-access) sites around Zanzibar (Tanzania). We assessed the temporal stability of fish density and community structure within and outside MPAs during three monsoon seasons in 2014-2015, and investigated several possible mechanisms that could regulate temporal stability. Our results show that MPAs did not affect fish density and diversity, but that juvenile fish densities were temporally more stable within MPAs. Second, fish community structure was more stable within MPAs for juvenile and adult fish, but not for subadult fish or the total fish community. Third, the observed effects may be due to a combination of direct and indirect (seagrass-mediated) effects of seasonality and, potentially, fluctuating fishing pressure outside MPAs. In summary, these MPAs may not have the ability to enhance fish density and diversity and to buffer effects of monsoon seasonality on the whole fish community. However, they may increase the temporal stability of certain groups, such as juvenile fish. Consequently, our results question whether MPAs play a general role in the maintenance of biodiversity and ecosystem functioning under changing environmental conditions in tropical seagrass fish communities.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Peces/fisiología , Magnoliopsida/fisiología , Animales , Organismos Acuáticos/fisiología , Arrecifes de Coral , Ecosistema , Explotaciones Pesqueras , Densidad de Población , Estaciones del Año , Tanzanía , Clima Tropical , Tiempo (Meteorología)
4.
PLoS One ; 11(12): e0168898, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28033328

RESUMEN

Natural resource users face a trade-off between present and future consumption. Using harmful methods or extracting unsustainably, lowers future consumption. Therefore, it is reasonable to posit that people with higher time preferences extract more as compared to people with lower time preferences. The present study combines experimental methods and questionnaire data in order to understand the relationship between individual time preferences and fishers' extraction behavior. We elicit individual time preferences using an incentivized experiment, linking the resulting time preference measures to extraction data from a questionnaire, as well as data collected from a framed Common Pool Resource (CPR) experiment. Both the experiments and questionnaire were conducted with artisanal fishers in Zanzibar. Our findings suggest that the relationship between time preferences and CPR extraction is not as straightforward as predicted by classical economic theory. In contrast to earlier studies, we find that fishers' time preferences are negatively correlated to their extraction rates. Our surprising findings can partly be explained by the fact that higher time preferences are associated with lower investment in extraction capability (the disinvestment effect of time preferences), and by fishers´ cognitive abilities.


Asunto(s)
Explotaciones Pesqueras/provisión & distribución , Recursos Naturales/provisión & distribución , Conservación de los Recursos Naturales , Explotaciones Pesqueras/economía , Autoinforme , Encuestas y Cuestionarios , Tanzanía , Factores de Tiempo
5.
Mar Pollut Bull ; 83(2): 398-407, 2014 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-24726772

RESUMEN

Small-scale fisheries (SSF) in tropical seascapes (mosaics of interconnected mangroves, seagrasses and corals) are crucial for food and income. However, management is directed mostly to corals and mangroves. This research analyzes the importance of seagrasses compared to adjacent ecosystems in Chwaka Bay, Zanzibar, Tanzania. Using fish landings; the study investigated: location of fishing effort, fish production (biomass and species), and monetary benefits (aggregated value and per capita income). Seagrasses were the most visited grounds providing highest community benefits. Per capita benefits were equivalent to those from corals and mangroves. All three habitats provided income just above extreme poverty levels; however catches from seagrass appeared more stable. Seagrass are key ecosystems supporting SSF and protection and management are urgently needed. Adoption of a seascape approach considering all ecosystems underpinning SSF and the social aspects of fishing and a shift in emphasis from pure conservation to sustainable resource management would be desirable.


Asunto(s)
Alismatales/fisiología , Ecosistema , Explotaciones Pesqueras/métodos , Animales , Antozoos , Biomasa , Cambio Climático , Explotaciones Pesqueras/economía , Peces/fisiología , Tanzanía
6.
PLoS One ; 9(3): e91161, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24614075

RESUMEN

Invertebrate harvesting is an important livelihood in tropical settings providing income and food for numerous populations throughout the world. However, the lack of research, policy and management directed towards this livelihood hinders the analysis of time trends to evaluate invertebrate resources status. Another missing aspect is the consideration of gender analysis, i.e., the different roles and interests of men and women engaged in this activity. Based on interviews, catch assessments and inventories this multi-disciplinary study from Chwaka Bay (Zanzibar, Tanzania) shows how unregulated harvesting of invertebrates may result in sharp declines in animal abundance over a relatively short period of time (2005 to 2010), threatening the sustainability of the fishery. Specifically, the results show that catches in general, and prime target species of gastropods and bivalves in particular, had been significantly reduced in number and size. Interviews revealed gender disparities; female harvesters experienced less access to good fishing/collecting grounds and species of high value, which subsequently resulted in lower individual income. This is tightly linked to women's reproductive roles, which not only leads to limited mobility but also lessen their chances to accumulate livelihood assets (natural, physical, financial, social and human capital) thus impacting livelihood strategies. To protect invertebrate resources from overexploitation, and assure a constant flow of income and food for future generations, this case study illustrates the need for formal monitoring to assess changes in invertebrate resources, and possible ecological consequences, over time. Managers and policy-makers must also address gender to evaluate the contribution of all resource users, their capacity to cope with changing conditions, as well as specific interests.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Invertebrados/crecimiento & desarrollo , Caracteres Sexuales , Clima Tropical , Animales , Femenino , Peces , Humanos , Islas , Masculino , Recursos Naturales , Especificidad de la Especie , Estadística como Asunto , Encuestas y Cuestionarios , Tanzanía , Factores de Tiempo
7.
Ambio ; 42(8): 951-62, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24213994

RESUMEN

This paper fills an important gap towards adaptive management of small-scale fisheries by analyzing the gender dimension of fish trade in Zanzibar, Tanzania. We hypothesize that gender-based differences are present in the fish value chain and to test the hypothesis interviews were performed to analyze: (i) markets, customers, and mobility, (ii) material and economic resources, (iii) traded fish species, (iv) contacts and organizations, and (v) perceptions and experiences. Additionally, management documents were analyzed to examine the degree to which gender is considered. Results show that women traders had less access to social and economic resources, profitable markets, and high-value fish, which resulted in lower income. These gender inequalities are linked, among others, to women's reproductive roles such as childcare and household responsibilities. Formal fisheries management was found to be gender insensitive, showing how a crucial feedback element of adaptive management is missing in Zanzibar's management system, i.e., knowledge about key actors, their needs and challenges.


Asunto(s)
Comercio , Explotaciones Pesqueras/economía , Peces/clasificación , Animales , Conservación de los Recursos Naturales , Culinaria , Femenino , Humanos , Masculino , Factores Sexuales , Tanzanía
8.
Ambio ; 31(7-8): 518-27, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12572817

RESUMEN

Fishery resources are a vital source of food and make valuable economic contributions to the local communities involved in fishery activities along the 850 km stretch of the Tanzania coastline and numerous islands. Small-scale artisanal fishery accounts for the majority of fish catch produced by more than 43 000 fishermen in the country, mainly operating in shallow waters within the continental shelf, using traditional fishing vessels including small boats, dhows, canoes, outrigger canoes and dinghys. Various fishing techniques are applied using uncomplicated passive fishing gears such as basket traps, fence traps, nets as well as different hook and line techniques. Species composition and size of the fish varies with gear type and location. More than 500 species of fish are utilized for food with reef fishes being the most important category including emperors, snappers, sweetlips, parrotfish, surgeonfish, rabbitfish, groupers and goatfish. Most of the fish products are used for subsistence purposes. However, some are exported. Destructive fishing methods such as drag nets and dynamite fishing pose a serious problem as they destroy important habitats for fish and other organisms, and there is a long-term trend of overharvested fishery resources. However, fishing pressure varies within the country as fishery resources are utilized in a sustainable manner in some areas. For this report more than 340 references about Tanzanian fishery and fish ecology were covered. There are many gaps in terms of information needed for successful fishery management regarding both basic and applied research. Most research results have been presented as grey literature (57%) with limited distribution; only one-fifth were scientific publications in international journals.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Animales , Antozoos , Comercio , Recolección de Datos , Monitoreo del Ambiente , Peces , Humanos , Dinámica Poblacional , Navíos , Tanzanía
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