Main courses I teach:

Management of Ecosystem Services 

Environmental Management for BIOGEO 

Climate and Society 

Responsible for the master/magister program in Environmental Health Protection

(2012 - 2018)

Responsible for the master program in Landscape Ecology

(2016 - 2020)

Current projects:

• Gender and adaptive capacity to climate change (VR project)
• Small-scale fisheries governance, management and overall sustainability
• Sea cucumbers as highly valued marine products
• Seagrasses as social-ecological systems mainly in the Western Indian Ocean

Doctoral students:

• Felicity Pike (Start 2019, main supervisor, assistant supervisor Lars Lindström and Regina Lindborg)
• Benjamin Jones (Start 2018, assistant supervisor, main Johan Eklöf)
• Hampus Eriksson (main Defended in 2012)
• Sara Fröcklin (main Defended in 2014)
• Sieglind Wallner-Hahn (main Defended in 2017)

Please see my page in ENGLISH for more information

I urval från Stockholms universitets publikationsdatabas

• Linking seagrass ecosystem services to food security

  2022. Sieglind Wallner-Hahn, Malin Dahlgren, Maricela de la Torre-Castro. Ecosystem Services 53

  Artikel

  Small-scale fisheries (SSF) are crucial for food security and poverty alleviation. Many SSF are however under pressure, and in need of better management paying special attention to the key seascape ecosystems which are supporting them. This study investigates the importance of seagrass beds for SSF households and their food security in southwestern Madagascar. The specific aims of this study were to: i) analyze if and how seagrassassociated fish contributes to subsistence and/or the economy of local fishing households, ii) identify and compare seagrass ecosystem goods and services valued by local fishers in a rural and an urban setting, and iii) analyze links between local people and seagrasses in terms of local ecological knowledge, use and traditions. The results showed that seagrasses were the most important fishing habitats for most fishers. Seagrass-associated fish species were both the economically most important and most commonly fished species, and are a major source of protein in the region. Further, seagrass-derived sea urchins are important complements to local people's diets. The findings illustrate that seagrasses contribute both through subsistence and income generation to food security and wellbeing of coastal people in southwestern Madagascar. This highlights the need to consider seagrass ecosystems in management towards sustainable SSF and their ability to sustain food security for future generations.

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• Fine-Tuning Climate Resilience in Marine Socio-Ecological Systems

  2021. Romeo Saldívar-Lucio (et al.). Frontiers in Marine Science 7

  Artikel

  Climate change triggers a wide mosaic of regional and local responses, often different to the large-scale variability in magnitude and direction. Because of the psychological connections (cognitive and emotional) with the frequency, intensity and age of a climatic event, people may have the capacity to recognize key variations at lower scales, especially those from which they perceive risk. Yet, the anticipatory actions and social engagement to respond or adapt to climate change are difficult to achieve, mostly when there exists a long psychological distance to climatic phenomena. Research about climate change communication provides clues about the relevance of place based discussion to gauge risk perception and improve response protocols, their design and prioritization. It argues that strategies and actions required to face climate risks may widely differ depending on the scale and accuracy of the local representations displayed during discussions of climate impacts. This work examines how local attributes (from climate to social) operate and control place-specific risks and priorities, by comparing coastal communities in two locations, Cabo Pulmo, Mexico and Zanzibar, Tanzania, which are subject to different climate dynamics. This paper discusses the need to identify relevant climate risks/responses at the local level and how psycho-social factors (e.g., psychological distance, collective memory, and social engagement) may operate positively for building climate resilience. We also illustrate a workflow to increase and enhance collaboration between researchers and local people by promoting dialogue, participation and narratives that rigorously consider the local knowledge.

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• Gender and Blue Justice in small-scale fisheries governance

  2021. Madeleine Gustavsson (et al.). Marine Policy 133

  Artikel

  This paper examines the need to embed gender in an empirical examination or conceptual use of Blue Justice. In developing the Blue Justice concept, there is a need to avoid reproducing ongoing and historical omissions of gender issues in small-scale fisheries governance and research. By drawing on the concepts of procedural and distributive justice, this paper explores how gender equity and equality and Blue Justice concerns interrelate, inform and shape each other in fisheries governance. These issues are explored through an analysis of four cases: Zanzibar (Tanzania), Chile, France and the United Kingdom (UK). We find that gendered power inequities in fisheries and women’s marginalised participation in fisheries governance are associated with procedural injustices. These further shape the distributive outcomes in fisheries governance. We argue that any effort to integrate gender into Blue Justice has to address the way that power relations are gendered in a particular fishery – extending the focus beyond the sea and including issues and concerns that are not always included in traditional fisheries governance arrangements revolving around fish resource management.

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• Adaptive capacity and coping strategies of small-scale coastal fisheries to declining fish catches

  2020. Mathew Ogalo Silas (et al.). Environmental Science and Policy 108, 67-76

  Artikel

  Small-scale fishing communities are expected to adapt to fish catch fluctuations linked to global environmental change. Notwithstanding, impacts from severe climate events and overexploitation of fisheries resources can compromise functions and resilience of ecosystems and associated species, and thereby jeopardize long-term population trend stability and fisheries productivity. To date, most assessments and vulnerability studies of fisheries-dependent populaces have focused on global, regional and national levels, while studies at village and community levels, where adaptive planning in the context of climate- and environmental changes is important, are less common. Based on data from official fishery records over a three-decadal period (1984–2016) and recent interviews with artisanal fishermen (319 fishers from eight communities) along the Tanzanian coast, we assessed small-scale fisheries with regard to (i) long-term trends in fishery landings, (ii) long-term alterations in fishing gear use, and (iii) fishers’ perceptions on how they have been coping and adapting to fluctuating fish landings. We further investigated (iv) the adaptive capacity of a wide range of coastal villages by assessing the fishers’ responses to an anticipated future scenario of a major (50 %) decline in landings from the current fisheries catch levels. The long-term trend records of fish landings showed a remarkable ∼50 % reduction in terms of both catch per vessel and catch per fisher from 1984 to 2016. According to the interviews, the majority of fishers (75 %) have changed fishing grounds from nearshore to offshore areas during the last decade, owing to a general perception that nearshore areas have suffered major reduction in fish stocks (due to overfishing and environmental changes related to extreme climate- or weather events), while offshore areas were considered still productive. The change in location of fishing grounds is probably a result of the clear switch in major gear type utilization from beach seine to ring net that occurred over the last decades. With a further progressive decline in fishery catches to a predictive level of 50 % of the current catch level, there is a general perception that artisanal fishers will continue fishing because alternative livelihoods (like crop farming, which employs more than 65 % of the population) have suffered similar negative impact. These findings highlight the need for building adaptive capacity in local coastal communities to develop alternative coping strategies for the impacts of climate- and environmental changes.

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• Economic value of small-scale sea cucumber fisheries under two contrasting management regimes

  2020. Maria Eggertsen (et al.). Ecology & society 25 (2)

  Artikel

  Small-scale fisheries supplying tropical sea cucumbers to Asian markets frequently overharvest stocks, incurring unknown loss of economic value. An indication of such value loss can provide economic incentives for better conservation and management. However, before and after time-series by which loss could be calculated are generally not available for most sea cucumber fisheries. In this study we provide a snapshot comparison of stocks of three characteristic sea cucumber species in two islands in the Western Indian Ocean: Zanzibar (open-access fishery) and Mayotte (stocks protected since 2004). Our aim is to provide an indication of reference economic value of holothurian populations under two contrasting management regimes. Comparisons were made from stock appraisals using transects, linked to the species-specific market value, and compared between similar habitats from both locations. Surveyed habitats in Mayotte held sea cucumber stocks with a mean economic value of USD556.90 +/- 110.30/ha, compared with USD1.73 +/- 0.58/ ha in Zanzibar. A 5% harvest of sea cucumbers from surveyed areas in Mayotte would yield about 20 times greater income than harvesting the total surveyed stock in Zanzibar. By illustrating the economic value when strong management measures are implemented, this study highlights existing economic values and shows that sea cucumber fisheries in the tropics are a resource worth investing in and with high potential for social-economic benefits if properly managed.

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• Inclusive Management Through Gender Consideration in Small-Scale Fisheries

  2019. Maricela de la Torre-Castro. Frontiers in Marine Science 6

  Artikel

  In a world in which ocean degradation is widespread and aggravated by the effects of climate change, there is a need to contribute with new management approaches to ameliorate the situation. Here, inclusive management is proposed as such an alternative. This contribution argues that including all genders in the management process is needed and the inclusion itself can generate new ways to solve problems. An assessment of findings from literature of the positive aspects when considering gender in environmental governance is presented and related to the specific situation of small-scale fisheries (SSF). These positive findings are explained in terms of (1) Participation, (2) Space, actors and activities, (3) Economic power, and (4) Equity and environmental stewardship. Further, a practical approach is taken and a model for gender inclusion in coastal/ocean management for SSF is presented and illustrated with a case of seagrass SSF in East Africa. The central argument is that in view of ongoing coastal/ocean degradation and the moderate governance and management success, it is worth trying management approaches that consciously and explicitly consider gender and diversity of actors. This will bring central actors (e.g., women not previously considered) into the management process and will provide the base for better governance and policy reform.

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• Early steps for successful management in small-scale fisheries

  2018. Sieglind Wallner-Hahn, Maricela de la Torre-Castro. Marine Pollution Bulletin 134, 186-196

  Artikel

  This study analyzes fishers', managers' and scientists' opinions on management measures to facilitate the initiation of management processes towards more sustainable small-scale seagrass fisheries in Zanzibar, Tanzania. The results show that most fishers and managers agreed on the need to include seagrasses specifically in future management. There was further agreement on dragnets being the most destructive gears, and the use of dragnets being a major threat to local seagrass ecosystems. Gear restrictions excluding illegal dragnets were the favored management measure among fishers. Differences between fishers and managers were found concerning seaweed farming, eutrophication and erosion being potential threats to seagrass meadows. A majority of the interviewed fishers were willing to participate in monitoring and controls, and most fishers thought that they themselves and their communities would benefit the most from establishing seagrass management. Co-managed gear restrictions and the inclusion of different key actos in the management process including enforcement are promising starting points for management implementation.

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• Small-scale innovations in coastal communities

  2018. Sara Fröcklin, Narriman S. Jiddawi, Maricela de la Torre-Castro. Ecology & society 23 (2)

  Artikel

  We analyzed the potential of small-scale innovations, such as shell-handicraft, as a way to foster transformation toward sustainability, decrease poverty, and increase women's empowerment in Zanzibar, Tanzania. The shell-handicraft project was founded by USAID in 2006 and was introduced as an alternative livelihood to low-paid seaweed farming and invertebrate harvesting activities. The main objective, however, was to not only alleviate poverty and empower women, but also to improve management of coastal resources, and allegedly by doing so, break poverty traps. To analyze the potential benefits of this enterprise, and more specifically whether or not women involved in this project have been empowered, a framework was used that comprises three inter-related dimensions; agency, access to resources, and outcome. Agency includes the process of decision making, negotiation, etc., in which choices are made and put into effect. Access to resources (financial, physical, human, and social) is the medium through which agency is exercised, and outcome can be defined as the result of agency. Simply put, resources and agency make up people's potential for living the lives they want. Semistructured interviews were administered to a group of women (n = 36) involved in shell-handicraft and a group of women not involved in shell-handicraft (n = 36) in five villages located in central/south Zanzibar. The results show that over time, the women engaged in shell-handicraft have improved their access to a range of resources, mainly physical (house, cell phone, freezer, and electricity), human (knowledge in marketing, leadership, and entrepreneurship), and social (organization). This further resulted in reported improved self-confidence and decision-making authority within the household. Regarding financial resources, both savings and income improved for the targeted group, but more research is advised. Positively, the environmental impacts of the activity are seemingly low. Old shells are collected for handicraft and a number of no-take zones, as part of the project, have been established to preserve marine resources, which allowed for women's participation in coastal management. The project has also empowered women and challenged stereotypes, aspects critical for progressive and inclusive management. Although all in all, the women interviewed were satisfied and had increased their standard of living, the discussion problematizes this innovation by addressing scaling up possibilities, market constraints, and the kick-off process having external top-down elements. Even though the recipients of the benefits from the project have been few, this case has valuable elements to learn from and can provide inspiration to drive coastal systems into more sustainable paths.

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• Tuna or Tasi? Fishing for Policy Coherence in Zanzibar’s Small-Scale Fisheries Sector

  2017. Lars Lindström, Maricela de la Torre-Castro. The Small-Scale Fisheries Guidelines, 79-94

  Kapitel

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• Gender analysis for better coastal management - Increasing our understanding of social-ecological seascapes

  2017. Maricela de la Torre-Castro (et al.). Marine Policy 83, 62-74

  Artikel

  Although highly recognized as needed, studies linking gender and coastal/marine management are scarce. This research illustrates the importance of gender analysis in natural resource management by linking gender and coastal management i.e. Marine Spatial Planning. The research was conducted in various Zanzibar seascapes (Unguja Island, Tanzania). Using a typology comprising gender structure, symbolism and identity; the results show a clear gendered division of labor, highly associated with a gender symbolism in which traditional roles of women as responsible for reproduction activities played a major role. Men used the whole seascape for their activities, while women remained in coastal forests and shallow areas collecting wood, invertebrates and farming seaweed. These activities allowed women to combine productive and reproductive work. Ecosystem importance for subsistence decreased with distance from land for both genders, while the importance for income increased with distance for men. Both genders acknowledged seagrasses as very important for income. Income closely followed the universal pattern of men earning more. Identities were defined by traditional ideas like women are housewives, while men identities were strongly associated with fisheries with reinforced masculinity. Livelihood diversity was higher for women also showing a tendency of slow change into other roles. Management was found to be strongly androcentric, revealing a deep gender inequality. The research exemplifies how a gender analysis can be conducted for management enhancement. It also invites replication around the world. If management is found to be androcentric in coastal locations elsewhere, a serious gender inequality can be at hand at global level.

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• The fundamental role of ecological feedback mechanisms for the adaptive management of seagrass ecosystems - a review

  2017. Paul S. Maxwell (et al.). Biological Reviews 92 (3), 1521-1538

  Artikel

  Seagrass meadows are vital ecosystems in coastal zones worldwide, but are also under global threat. One of the major hurdles restricting the success of seagrass conservation and restoration is our limited understanding of ecological feedback mechanisms. In these ecosystems, multiple, self-reinforcing feedbacks can undermine conservation efforts by masking environmental impacts until the decline is precipitous, or alternatively they can inhibit seagrass recovery in spite of restoration efforts. However, no clear framework yet exists for identifying or dealing with feedbacks to improve the management of seagrass ecosystems. Here we review the causes and consequences of multiple feedbacks between seagrass and biotic and/or abiotic processes. We demonstrate how feedbacks have the potential to impose or reinforce regimes of either seagrass dominance or unvegetated substrate, and how the strength and importance of these feedbacks vary across environmental gradients. Although a myriad of feedbacks have now been identified, the co-occurrence and likely interaction among feedbacks has largely been overlooked to date due to difficulties in analysis and detection. Here we take a fundamental step forward by modelling the interactions among two distinct above-and belowground feedbacks to demonstrate that interacting feedbacks are likely to be important for ecosystem resilience. On this basis, we propose a five-step adaptive management plan to address feedback dynamics for effective conservation and restoration strategies. The management plan provides guidance to aid in the identification and prioritisation of likely feedbacks in different seagrass ecosystems.

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• Destructive gear use in a tropical fishery

  2016. Sieglind Wallner-Hahn (et al.). Marine Policy 72, 199-210

  Artikel

  The aim of this study was to empirically assess institutional aspects shaping fishers' behavior leading to unsustainable resource use, by using the example of destructive drag-net fishing in Zanzibar, Tanzania. A broad institutional approach was used to specifically assess institutional factors influencing the fishers' reasons for the current use of destructive drag-nets as well as their willingness- and economic capacity to change to less destructive gears. Different regulative, normative, cultural-cognitive and economic factors (tradition, group-belonging, social acceptance, common practice, identity of drag-net users and weak economic capacity) were identified as critical elements influencing the current use of destructive gears, as well as obstructing changes to other gears. Hence, the importance of addressing all of these factors, matching to the different contexts, rather than focusing on fast-moving regulative measures, is emphasized to increase chances of management success. More promising approaches would be resource allocations to more sustainable fishing gears, well-managed gear exchange programs, as well as alterations of slow-moving normative and cultural factors, e.g. awareness raising on the advantages of more sustainable fishing gears, their traditional and cultural values, information on the actual income they generate, as well as education and an exchange of traditional knowledge on how to use them.

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• Cascade effects and sea-urchin overgrazing

  2015. Sieglind Wallner-Hahn (et al.). Ocean and Coastal Management 107, 16-27

  Artikel

  Marine ecosystems generate a wide variety of goods and services, but are globally deteriorating due to multiple drivers associated with anthropogenic activities. Intense fishing pressure can lead to changes in structure and function of marine food webs. Particularly overfishing of predatory species at high trophic levels can cause cascading effects leading to ecosystem degradation, affecting both marine organisms and people dependent on them. In the Western Indian Ocean region, intensive fishing takes place and degradation of coral reefs and seagrass beds has been documented. One reason behind this degradation is overgrazing by increasing numbers of sea urchins. An essential step towards better management is to thoroughly understand the drivers leading to such changes in ecosystems. Against this background, the general aim of this study was to gain understanding about whether sea urchin predators in the WIO region are fished, and to identify the drivers behind the fishing of these species. The study had four objectives: (i) to document if and how predatory fish eating sea urchins are caught in smallscale fisheries, (ii) to assess if, and if so why, sea urchin predators are targeted species, (iii) to assess if and to what degree local ecological knowledge (LEK) on ecological complexity involving sea urchins and their predators (e.g. trophic cascades) is present among local fishers, and (iv) to identify fishers' suggestions for management that can reduce problems linked to sea urchin overgrazing. The results show that all investigated species of sea urchin predators are fished by local small-scale fishers. Most sea urchin predators are not actively targeted, are not popular local food fish, and have minor use and economic importance for fishers. This stands in sharp contrast to their ecological keystone role by controlling sea urchin populations. The fishers' awareness and LEK were weak and partly lacking. Management suggestions targeted mostly the symptoms of food web changes rather than the drivers behind them.

  Based on the results we suggest that management of degraded ecosystems, as a result of food web changes, should encompass a wide variety of strategies and scales. Specific suggestions for sea urchin predator management are education of local stakeholders on destructive gear effects and food web complexity, further investigations of catch- and release fishing as well as the use of selective gears.

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• Climate change effects on the Baltic Sea borderland between land and sea

  2015. Alma Strandmark (et al.). Ambio 44, s28-S38

  Artikel

  Coastal habitats are situated on the border between land and sea, and ecosystem structure and functioning is influenced by both marine and terrestrial processes. Despite this, most scientific studies and monitoring are conducted either with a terrestrial or an aquatic focus. To address issues concerning climate change impacts in coastal areas, a cross-ecosystem approach is necessary. Since habitats along the Baltic coastlines vary in hydrology, natural geography, and ecology, climate change projections for Baltic shore ecosystems are bound to be highly speculative. Societal responses to climate change in the Baltic coastal ecosystems should have an ecosystem approach and match the biophysical realities of the Baltic Sea area. Knowledge about ecosystem processes and their responses to a changing climate should be integrated within the decision process, both locally and nationally, in order to increase the awareness of, and to prepare for climate change impacts in coastal areas of the Baltic Sea.

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• Promoting Governability in Small-Scale Fisheries in Zanzibar, Tanzania

  2015. Lars Lindström, Maricela de la Torre-Castro. Interactive Governance for Small-Scale Fisheries, 671-686

  Kapitel

  This chapter highlights some governance challenges in small-scale fisheries in the East African region using the case of Chwaka Bay, Zanzibar, Tanzania. In this case, self-governance processes involve strong normative and cultural-cognitive aspects that have underpinned de facto management actions and blocked other options towards sustainability. The conflict level between the villages in the Bay is very high and there is a need to address how the system may move from self-governance and conflict to co-governance and cooperation. The chapter focuses on the governance interactions between the state and the fishing villages as well as the state’s failed attempts to break unsustainable self-governance. It identifies the role that the state has played to promote co-management and participation, as well as highlights changing legislation and conservation in the area. What went wrong with these strategies and why? Who and with what method does the capacity for dynamic, interactive governance develop? Who co-ordinates interactions across different identities, interests, and different spatio-temporal scales, and how? Who establishes a common world view for action, and how? Which institution functions as a court of appeal for disputes arising within and over interactive governance?

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• Seagrass importance for a small-scale fishery in the tropics

  2014. Maricela de la Torre-Castro, Giuseppe Di Carlo, Narriman S. Jiddawi. Marine Pollution Bulletin 83 (2), 398-407

  Artikel

  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.

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• Fish Traders as Key Actors in Fisheries

  2013. Sara Fröcklin (et al.). Ambio 42 (8), 951-962

  Artikel

  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.

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• Governance for sustainability

  2012. Maricela de la Torre-Castro. Coastal Management 40 (6), 612-633

  Artikel

  The last decade has seen a shift in the Natural Resource Management discourse, a shift from management to governance. Governance is held forward as a prime solution to problems associated with the sustainability of natural resources, including fisheries and other marine resources. Several countries in the Western Indian Ocean are framing governance solutions as a response to coastal/marine resource depletion and environmental degradation, but the challenges are huge and success stories remain few. This study provides an analysis of the governance situation in Chwaka Bay, Zanzibar, Tanzania. It presents the governance actors and how governance is expressed in terms of hierarchy (state), heterarchy (self-organized networks of resource users), and anarchy (market). The analysis illustrates the extreme difficulties of using governance approaches to steer human behavior to solve environmental problems and achieve sustainability. The study also provides some insights when considering the use of governance as a tool for the designing and/or steering social-ecological systems in subsistence contexts with weak formal institutions. These include the consideration of governance as an intrinsic part of complex societal processes, the idealization of governance as a template for redressing management failure and broader issues such as the importance of meta-governance.

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• Mobility, Expansion and Management of a Multi-Species Scuba Diving Fishery in East Africa

  2012. Hampus Eriksson, Maricela de la Torre-Castro, Per Olsson. PLoS ONE 7 (4), e35504

  Artikel

  Background: Scuba diving fishing, predominantly targeting sea cucumbers, has been documented to occur in an uncontrolled manner in the Western Indian Ocean and in other tropical regions. Although this type of fishing generally indicates a destructive activity, little attention has been directed towards this category of fishery, a major knowledge gap and barrier to management. 

  Methodology and Principal Findings: With the aim to capture geographic scales, fishing processes and social aspects the scuba diving fishery that operate out of Zanzibar was studied using interviews, discussions, participant observations and catch monitoring. The diving fishery was resilient to resource declines and had expanded to new species, new depths and new fishing grounds, sometimes operating approximately 250 km away from Zanzibar at depths down to 50 meters, as a result of depleted easy-access stock. The diving operations were embedded in a regional and global trade network, and its actors operated in a roving manner on multiple spatial levels, taking advantage of unfair patron-client relationships and of the insufficient management in Zanzibar. Conclusions and

  Significance: This study illustrates that roving dynamics in fisheries, which have been predominantly addressed on a global scale, also take place at a considerably smaller spatial scale. Importantly, while proposed management of the sea cucumber fishery is often generic to a simplified fishery situation, this study illustrates a multifaceted fishery with diverse management requirements. The documented spatial scales and processes in the scuba diving fishery emphasize the need for increased regional governance partnerships to implement management that fit the spatial scales and processes of the operation. 

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• Lessons for resource conservation from two contrasting small-scale fisheries

  2015. Hampus Eriksson (et al.). Ambio 44 (3), 204-213

  Artikel

  Small-scale fisheries present challenges to management due to fishers' dependency on resources and the adaptability of management systems. We compared social-ecological processes in the sea cucumber fisheries of Zanzibar and Mayotte, Western Indian Ocean, to better understand the reasons for resource conservation or collapse. Commercial value of wild stocks was at least 30 times higher in Mayotte than in Zanzibar owing to lower fishing pressure. Zanzibar fishers were financially reliant on the fishery and increased fishing effort as stocks declined. This behavioral response occurred without adaptive management and reinforced an unsustainable fishery. In contrast, resource managers in Mayotte adapted to changing fishing effort and stock abundance by implementing a precautionary fishery closure before crossing critical thresholds. Fishery closure may be a necessary measure in small-scale fisheries to preserve vulnerable resources until reliable management systems are devised. Our comparison highlighted four poignant lessons for managing small-scale fisheries: (1) diagnose the fishery regularly, (2) enable an adaptive management system, (3) constrain exploitation within ecological limits, and (4) share management responsibility.

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• Intertidal Zone Management in the Western Indian Ocean

  2014. Lina Mtwana Nordlund (et al.). Ambio 43 (8), 1006-1019

  Artikel

  This expert opinion study examined the current status of the intertidal zone in the Western Indian Ocean (WIO) and ranked and discussed future management approaches. Information was gathered from scientists, practitioners, and managers active in the WIO region through a questionnaire and a workshop. The experts stated that the productive intertidal environment is highly valuable for reasons such as recreation, erosion protection, and provision of edible invertebrates and fish. Several anthropogenic pressures were identified, including pollution, harbor activities, overexploitation, and climate change. The experts considered the WIO intertidal zone as generally understudied, undermanaged, and with poor or no monitoring. The most important management strategies according to the expert opinions are to develop and involve local people in integrated coastal zone management (ICZM), to increase knowledge on species-environment relationships, and to develop awareness campaigns and education programs. To improve coastal environmental management and conservation, we argue that the intertidal zone should be treated as one organizational management unit within the larger framework of ICZM.

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• Procedural and distributive justice in a community-based managed Marine Park Area in Zanzibar, Tanzania

  2014. Madeleine Gustavsson (et al.). Marine Policy 46, 91-100

  Artikel

  Local participation in governance and management is assumed to lead to something good. But it is rarely explicitly stated who are participating and in what. The study investigates this in the context of a Marine Protected Area (MPA) in Zanzibar, Tanzania, and in particular the Memba Island - Chwaka Bay Marine Conservation Area (MIMCA). This is done by applying Pretty's typology of participation in addressing procedural justice, which is according to Paavola linked to distributive justice, i.e. the just distribution of costs and benefits. How does participation in MIMCA facilitate procedural and distributive justice? To answer this question a number of fishermen, women seaweed farmers, local leaders, and representatives of the private sector were interviewed (n=136) in five villages. Interviews were also made with government officials at relevant departments. The results show that Village Fishermen Committees were participating in the implementation of MIMCA but not in its planning phase. Participation was mainly in the form of manipulative and passive participation. Other local actors did not participate at all. Instead, the government assumed that justice was achieved by distributing equipment, alternative income generating projects, and relying on tourism for local development. However, the distributed equipment and tourism development have created conflict and injustice within and between villages, because of the insufficient resources which did not target those in need. Tourism created problems such as inequality between livelihoods, environmental destruction and local power asymmetries between hotel management and local people. The MIMCA top-down intervention has not increased participation or justice, nor has it achieved sustainable resource use and conflict resolution. It is suggested that interactive participation by all local actors is needed to create just trade-offs. justice needs to be explicitly addressed for integrated conservation and development projects to achieve sustainability.

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• Towards Improved Management of Tropical Invertebrate Fisheries

  2014. Sara Fröcklin (et al.). PLOS ONE 9 (3), e91161

  Artikel

  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.

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• Tracing value chains to understand effects of trade on coral reef fish in Zanzibar, Tanzania

  2013. Matilda Thyresson (et al.). Marine Policy 38, 246-256

  Artikel

  Coral reef fish are an important source of food security and income for human coastal populations. They also underpin ecosystem processes vital for the future ability of coral reefs to generate ecological goods and services. Identifying socio-economic drivers behind the exploitation of fish that uphold these key ecosystem processes and the scales at which they operate is therefore critical for successful management. This study addresses this issue by examining the reef-associated fish value chain in Zanzibar, and how it links to functional groups of fish and maturity stage of fish within these groups. Semi-structured interviews with 188 respondents (fishers, traders and hotel staff) involved in the fisheries and trade with reef-associated fish in Zanzibar and participatory observations were used. The trade with reef fish in Zanzibar is a complex structure involving many different agents and this study shows that these different agents exhibit differential preferences regarding fish functional groups and/or maturity stages within these groups. Consequently, both high and low trophic species, as well as small and large fishes are fished and sold, which leaves no refuge for the fish assemblage to escape fishing. When other market agents than fishers have so much influence and there are few alternative income generating activities, it is not possible to put all burden on fishers. Management measures that extend down the value chain to include all market agents as well as their links to ecosystem processes are thus likely to be needed to reach the target of sustainable fisheries.

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• Confronting Feedbacks of Degraded Marine Ecosystems

  2012. Magnus Nyström (et al.). Ecosystems (New York. Print) 15 (5), 695-710

  Artikel

  In many coastal areas, marine ecosystems have shifted into contrasting states having reduced ecosystem services (hereafter called degraded). Such degraded ecosystems may be slow to revert to their original state due to new ecological feedbacks that reinforce the degraded state. A better understanding of the way human actions influence the strength and direction of feedbacks, how different feedbacks could interact, and at what scales they operate, may be necessary in some cases for successful management of marine ecosystems. Here we synthesize interactions of critical feedbacks of the degraded states from six globally distinct biomes: coral reefs, kelp forests, seagrass beds, shallow soft sediments, oyster reefs, and coastal pelagic food webs. We explore to what extent current management captures these feedbacks and propose strategies for how and when (that is, windows of opportunity) to influence feedbacks in ways to break the resilience of the degraded ecosystem states. We conclude by proposing some challenges for future research that could improve our understanding of these issues and emphasize that management of degraded marine states will require a broad social-ecological approach to succeed.

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• Sea cucumber (Aspidochirotida) community, distribution and habitat utilization on the reefs of Mayotte, Western Indian Ocean

  2012. Hampus Eriksson, Maria Byrne, Maricela de la Torre-Castro. Marine Ecology Progress Series 452, 159-170

  Artikel

  The tropical sea cucumber (Aspidochirotida) fishery for the lucrative Asian dried-seafood trade is a multi-species fishery with little ecological knowledge. To improve ecological understanding of the targeted species, the reefs of Mayotte, Western Indian Ocean, were surveyed to document the distribution, species assemblage and habitat utilization of commercial sea cucumbers. This is one of the few reef areas in the region protected from fishing, thus providing an important and unique opportunity to investigate sea cucumber ecology. Twenty-two species were observed. The medium-value Bohadschia atra and the high-value Holothuria nobilis were the most abundant species. Species distribution varied but the density was generally similar across areas and habitats. Multivariate analysis (ANOSIM) indicated that the community was similar between surveyed areas and reef habitats. Diversity was lower in one of the surveyed areas and in the ocean-facing barrier reef habitat. Habitat complexity was not a significant driver of diversity or abundance. A principal component analysis showed that the 6 most common species (B. atra, Holothuria atra, H. fuscopunctata, H. nobilis and Thelenota ananas) were associated with different substrate types. Clustering these species according to substrate variables indicated both habitat utilization overlap and segregation among species, valuable information for spatial planning of fisheries management and conservation. Although unique species were observed in some areas, the present study shows that, at a large spatial scale, the unfished reefs in Mayotte consist of similar commercial sea cucumber communities, an important baseline finding.

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• Seagrass Meadows in Chwaka Bay

  2012. Martin Gullström (et al.). People, Nature and Research in Chwaka Bay, Zanzibar, Tanzania, 89-110

  Kapitel

  The shallow-water seascape of Chwaka Bay consists of diverse habitats including coral reefs, sand/mud flats, algal belts and mangrove forests, but the embayment is primarily characterized by its widespread and highly productive seagrass beds. The Bay is a unique seagrass diversity “hotspot”, with eleven species observed, from small, fast-growing and thin-leaved “pioneer” species like Halophila ovalis and H. stipulacea to large, slower-growing “climax species” with thick and long leaves like Thalassodendron ciliatum and Enhalus acoroides. Consequently, it is not surprising that the small-scale subsistence fishery of Chwaka Bay can be seen as a seagrass fishery, with catches consisting primarily of species intimately associated with the seagrass meadows (de la Torre-Castro and Rönnbäck 2004; de la Torre-Castro 2006).Seagrasses are a polyphyletic group of marine vascular, rhizomal plants (den Hartog 1970, 12-13), which form stands of varying sizes usually called “beds” or “meadows” in intertidal and subtidal coastal waters across the globe. Seagrass meadows typically occur on nearshore soft bottoms (although some species are found on rocky bottoms) in single- or mixed-species assemblages, with the typical wide range from tropical to boreal margins of coastal waters (Green and Short 2003, 21-22). They form one of the most productive aquatic ecosystems on Earth (Duarte and Chiscano 1999) and in most areas occur intermixed with other large primary producers like macroalgae. Seagrass ecosystems support multiple ecological functions, including nursery grounds, food and refuge for many benthic,

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• Synthesis: Towards an integrative research approach on coastal ecosystems – The example of Chwaka Bay

  2012. Thomas J. Lyimo (et al.). People, Nature and Research in Chwaka Bay, Zanzibar, Tanzania, 17-22

  Kapitel

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• What is this thing called 'community' good for?

  2011. Henrik Angerbrandt, Lars Lindström, Maricela de la Torre-Castro. World Small-Scale Fisheries, 353-366

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• Fishing institutions

  2010. Maricela De la Torre-Castro, Lars Lindström. Marine Policy 34 (1), 77-84

  Artikel

  Institutional approaches in natural resource management in general and in fisheries in particular seldom address cultural aspects or social institutions like kinship. In this study, a broad institutional approach is used to investigate the institutionalization of small-scale fisheries and seaweed farming in a seagrass dominated bay in Zanzibar. Regulative, normative and cultural-cognitive institutions and their rapid/slow moving properties are analyzed. The results show that dynamics of cooperation and conflict between different institutional elements and the balance of forces among actors are crucial to understand fisheries management dynamics. Regulations are, despite their importance, insufficient to promote sound management if they are not backed up by norms and cultural-cognitive institutions. Fisheries management would benefit by broadening the institutional perspective to increase the efficiency of management and to avoid blueprint solutions. The study shows that gaining knowledge about the wide institutional setting takes time but the investment is worth it in the long run.

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• Resource degradation of the sea cucumber fishery in Zanzibar, Tanzania

  2010. Hampus Eriksson (et al.). Aquatic Living Resources 23, 387-398

  Artikel

  This study assessed the Zanzibar sea cucumber fishery using a multidisciplinary approach. Data was collected by (i) interviewing various groups of actors in the fishery and reviewing management documentation and legislation, (ii) by monitoring catches and (iii) through a visual census of coastal sea cucumber populations in areas open and closed to fishing. The fishery showed clear signs of being unsustainable with high fishing effort, and weak formal and informal management institutions. The fishery operation was characterised by an intricate cross-scale structure with both fishers and sea cucumber products being transported across national borders. The visual census of commercial sea cucumber stocks at three sites open to fishing around Zanzibar showed low densities across the range of sea cucumber value groups including low value species. Furthermore, the diversity of commercial sea cucumber species was lower in fished reefs than on a protected reef. The poor status of the sea cucumber populations was confirmed by the perception of an overfished resource by the interviewed actors active in the fishery. This was also depicted by the paucity of high value species, and high representation of low value and newly commercialised species in fishers catch. We conclude that the current state of Zanzibar’s sea cucumber populations is compromising the fisheries self-replenishment and existence and that the fishery is in urgent need of a complete management reform. 

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• Socio-economic features of sea cucumber fisheries in southern coast of Kenya

  2010. Jacob Ochiewo (et al.). Ocean and Coastal Management 53 (4), 192-202

  Artikel

  A socio-economic assessment was conducted at Vanga, Shimoni, Majoreni and Gazi villages in the Kenyan south coast with focus on the sea cucumber fishing patterns, the social and economic characteristics of the fisher communities, the contribution of sea cucumbers to the local livelihoods, and analysis of the management systems. The results indicate that sea cucumber fishers are mainly men. Fishing is done in sub-tidal areas (3-10 m deep) and inter-tidal areas depending on the species being targeted. Those who fish in the sub-tidal areas do skin diving without using SCUBA diving gear. Sea cucumber fishing is heavily done during the northeast monsoon season when the sea is calm and water is clear. About 32% of the sea cucumber fishers also collect other marine products such as octopus. The sea cucumbers are sold fresh from the sea to local first level middlemen who process and sell them to the second level middlemen and exporters in Mombasa. The fishers occasionally borrow money from first level middlemen especially when they fail to catch sea cucumbers but this in turn creates conditions of dependence and possible exploitation. Almost all sea cucumber fishers have stated that they are not willing to make sea cucumbers part of their daily diet. The economic value of the product was substantial; the average monthly revenue for dry sea cucumbers in the area was estimated to US$ 8000. The relative highest profits are derived from juvenile species, thus there is an economic incentive hindering local stocks to reach sexual maturity, which in turn may create a situation in which recruitment success is highly dependent on faraway populations. The present management system falls into general fisheries regulations and was found weak. No specific management plan for sea cucumbers was found.

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• Seagrass importance in food provisioning services: fish stomach content as a link between seagrass meadows and local fisheries

  2008. Maricela De La Torre-Castro (et al.). Western Indian Ocean journal of marine science 7 (1), 95-110

  Artikel

  The links between ecosystem processes and functions and ecosystem services (i.e. the humanbenefits from those) are elusive. In this paper, the food provisioning service of seagrass meadows isoperationalized through the study of the stomach contents of 13 important commercial fish species inChwaka Bay, Zanzibar. Using local fishers’ knowledge on bait, scientific knowledge about the structureof the meadows (associated flora and fauna), stomach content analysis and multivariate statistics, the foodprovisioning service associated with seagrasses and its importance for fish (as important diet component)and for humans (in small-scale artisanal fisheries) are described. The study presents the food items for 13commercial fish species identified at the lowest possible taxonomical level and compares with previousliterature findings. In addition, differences in stomach contents of Siganus sutor and Leptoscarus vaigiensiscaught with both drag-nets and dema basket traps are investigated in order to explore bait presence andindirectly evaluate fishers’ knowledge on bait preference. The results show that most of the items consumedby commercial fishes are associated with seagrass beds and that there are clear indicators that the baittraditionally used seems to be effective. The paper elaborates on the consideration of seagrass ecosystemsin a holistic perspective, the difficulties in valuation of ecosystem services and finally the crucial importanceof these aspects for human well-being and sustainability in coastal communities of the Western IndianOcean.

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• How do seaweed farms influence fishery catches in a seagrass-dominated setting in Chwaka Bay, Zanzibar?

  2006. Johan S. Eklöf (et al.). Aquatic Living Resources 19 (2), 137-147

  Artikel

  Seaweed farming is often depicted as a sustainable form of aquaculture, contributing to poverty reduction and financial revenues in producer countries. However, farms may negatively affect seagrasses and associated organisms (e.g. invertebrate macrofauna) with possible effects on the flow of ecosystem goods and services to coastal societies. The present study investigates the influence of a seaweed farm, and the farmed seaweed Eucheuma denticulatum in particular, on fishery catches using a traditional fishing method ("madema" basket traps) in Chwaka bay (Zanzibar, Tanzania). The results suggest that a seaweed farm, compared to a seagrass bed, had no influence on catch per unit effort (no. of individuals per catch, or catch weight) or no. of species per catch, but significantly affected catch composition (i.e. how much that was caught of which species). The two species contributing most to differences between the sites were two economically important species; the herbivorous seagrass rabbit fish Siganus sutor, which was more common in the seaweed site and is known to graze on the farmed algae; and the benthic invertebrate feeder chloral wrasse Cheilinus chlorourus, more common in the seagrass site. Compared to vegetation-free bottoms, however, the catches were 3-7 times higher, and consisted of a different set of species (ANOSIM global R > 0.4). As traps placed close to the seaweeds fished three times more fish than traps placed on sand patches within the seaweed farm, the overall pattern is attributed to the presence of submerged vegetation, whether seagrass or seaweed, probably as shelter and/or food for fish. However, qualitative differences in terms of spatial and temporal dynamics between seagrass beds with and without seaweed farms, in combination with other factors such as institutional arrangements, indicate that seaweed farms cannot substitute seagrass beds as fishing grounds.

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