he suite of species taken by artisanal fishers targeting tuna often includes species caught in the larger industrial tuna fisheries, leading to concerns that industrial fisheries may reduce local fish availability and consequently impact upon artisanal catch rates. This study provides supporting evidence that industrial purse-seine fisheries may impact upon artisanal and subsistence fishers. A tagged population of skipjack and yellowfin tuna of known size was monitored through time and the probability of recapture was used as a measure of interaction with the industrial purse-seine fisheries. The probability of recapture was positively associated with areas where relative purse-seine fishing effort was higher. The results indicate that skipjack and yellowfin tuna may have longer residency times in nearshore habitats than in open ocean habitats. Lower recapture probabilities in areas currently closed to purse-seine fishing provided empirical evidence that area closures for industrial fisheries may assist with the management of artisanal fisheries. Finally the results suggest that the proximity to industrial purse-seine fishing may also be an important component for decision makers when planning and evaluating the performance of artisanal fisheries in the western Pacific region.
Many multivariate methods have been applied to small-scale fishery data in an attempt to distinguish factors that characterize the fishing activity and influence catch composition. While such approaches are important, they are still incomplete for including the spatial structuring in the analysis, a non-random fundamental and functional component of the ecosystem. This study fills this gap by identifying, describing, and quantifying factors that influence the fleet type of tropical small-scale fisheries using a multivariate spatial approach. The example data came from two Brazilian States where two main fleets, open water canoes and motorized boats, operate. Different complex combinations of fishing, environmental and spatial factors affect the structure of the fish catch composition of each fleet. Motorized boats showed strong spatially-structured species catch composition in comparison with open water canoes. Similar environmental factors, such as type of the seabed and depth, but different fishing variables (gear vs crew size), affected the species catch composition of these vessel categories. Despite some overlap, each fleet focuses on a relatively distinct set of species groups and exploits habitats at different spatial scales. These results suggest that different sets of regulations should be considered for each fleet type within a specific spatial scale. It also shows that multi-species models that aggregate groups of species is a more efficient alternative than single-species assessment models for small-scale fisheries, as these are multi-specific and multi-gear, with scattered landing harbors, features that make such fisheries a complex challenge for management.
People in 114 countries have consumed meat and other products from ~ 87 species of marine mammals since 1990. Nonetheless, assessment of the sustainability of most harvests is very difficult because information on the target populations and harvest numbers is inadequate. Dugongs have been harvested by the indigenous peoples of Torres Strait between Australia and Papua New Guinea, for at least 4000 years; the harvest has been substantial for at least the last 400–500 years. We use several lines of evidence to re-evaluate the sustainability of this harvest in the absence of robust data on the absolute size of this dugong population or the harvest. The evidence suggests that the harvest is sustainable. Dugong relative density was significantly higher in 2013 than in any other survey year and their Area of Occupancy has trended slightly upward since 1987. The proportion of calves in 2013 was the highest recorded. Genetic diversity is high. Dugongs are caught in only 5.0% of the 5268 km2 of very high dugong density habitat as the result of the controls on the harvest and socio-economic factors. Nonetheless, many in the wider Australian community disapprove of this harvest and demand that hunting be banned. Enhancing culturally-appropriate spatial controls may be a more practical approach to managing this harvest than a more data-demanding Total Allowable Catch approach and may also be appropriate for some other indigenous harvests of marine mammals.
Migration is a feature of most small-scale fisheries across the world and has previously been described in spatial and temporal terms. This study assessed spatial and temporal migration patterns of fishers in Kenya, Tanzania, and Mozambique from October 2009 to March 2010 covering important migrant fishers destinations on the coast. The concentrations, fishing destinations, routes, frequency as well as seasonality of migrant fishers in each of the countries were assessed using 192 surveys at 9 sites and 127 semi-structured interviews at 25 sites. Migrations in Kenya and Tanzania were mainly seasonal while in Mozambique circular migrations were common and lasted far longer. Fishers from Pemba, Unguja and Nampula were the most experienced migrant fishers in terms of the numbers involved and their ability to migrate to distant destinations. The region is likely to experience increasing influxes of migrant fishers due to increasing fisher numbers, fisheries governance, and other factors that provide an environment conducive to migration. The small scales of operation of the local co-management structures, the lack of monitoring ability and the limited knowledge about activities of migrant fishers requires a shared regional approach in terms of fisheries management with specific attention to issues concerning migrant fishers.
How social networks support or constrain the transition to co-management of small-scale fisheries and marine reserves is poorly understood. In this paper, we undertake a comparative analysis of the social network structures associated with the transition to co-management in three Jamaican marine reserves. Data from quantitative social relational surveys (n = 380) are integrated with data from semi-structured interviews (n = 63) and focus groups (n = 10) to assess how patterns of relational ties and interactions between and among fishermen and other local level actors (e.g., managers, wardens, NGO staff) support and constrain the transition to co-management. Our research suggests that the transitions to co-management were supported by a combination of three network structure and relational attributes: (i) the presence and position of institutional entrepreneurs; (ii) a dense central core of network actors; and (iii) the prevalence of horizontal ties and vertical linkages held by the community-based organizations formally responsible for the management of the marine reserves. Our findings also show that overall low network cohesion in the three reserves and limited social influence among the wardens may be problematic for sustained collective action that extends beyond the core set of network actors. These findings suggest the importance of strategies to enhance collective action, specifically through attention to the attributes of the corresponding social networks, as a means to contribute to successful transitions to co-management of marine reserves and small-scale fisheries. Our results provide more precise guidance, through social network analysis, on where in the respective networks social capital and leadership may require support or enhancement, and thus on how to target interventions for greatest effect.
The Ecosystem Approach to Fisheries (EAF) has been proposed as a holistic approach for managing fisheries. Although EAF is a widely accepted concept, many challenges remain in its practical implementation, particularly in small-scale fisheries (SSFs) in developing countries. Long-term evaluations of EAF performance in SSFs are scarce and even fewer when considering co-management (Co-M) as the institutionalized governance mode implemented under an EAF scheme (EAF/Co-M). This paper addresses the implementation, development process and performance of an EAF/Co-M in the yellow clam SSF of Uruguay through multiple fishery indicators for the period 2007–2015. EAF/Co-M showed a highly positive response in abundance and biomass of the harvestable stock through time, stabilization in individual sizes above the minimum landing size limit, and a fairly constant exploitation rate at low levels that did not exceed 25%, accompanied by relatively constant CPUE values through time. Temporal variations in unit price and revenues per unit of effort showed higher values after EAF/Co-M implementation. These indicators, taken together, suggest that the enhanced production capacity of the fishery during the EAF/Co-M implementation did not have a negative impact on the stock. The number of fishers involved in the activity has not changed markedly through time, but two remarkable positive changes occurred in the composition of the group: (i) an increasing number of licenses allocated twice in a row through time, which suggests the consolidation of a stable group of fishers; and (ii) a significant increase in the number of women directly involved in the fishing activity. This study provides solid empirical evidences to the idea that EAF, coupled with Co-M as a formal governance mode, could be helpful to address management tasks and to improve social–ecological conditions of SSFs.
The artisanal fisheries of Ecuador operate within one of the most dynamic and productive marine ecosystems of the world. This study investigates the catch composition of the Ecuadorian artisanal fishery for large pelagic fishes, including aspects of its spatio-temporal dynamics. The analyses of this study are based on the most extensive dataset available to date for this fishery: a total of 106,963 trip-landing inspection records collected at its five principal ports during 2008 ‒ 2012. Ecuadorian artisanal fisheries remove a substantial amount of biomass from the upper trophic-level predatory fish community of the eastern tropical Pacific Ocean. It is estimated that at least 135 thousand metric tons (mt) (about 15.5 million fish) were landed in the five principal ports during the study period. The great novelty of Ecuadorian artisanal fisheries is the “oceanic-artisanal” fleet component, which consists of mother-ship (nodriza) boats with their towed fiber-glass skiffs (fibras) operating with pelagic longlines. This fleet has fully expanded into oceanic waters as far offshore as 100°W, west of the Galapagos Archipelago. It is estimated that nodriza operations produce as much as 80% of the total catches of the artisanal fishery. The remainder is produced by independent fibras operating in inshore waters with pelagic longlines and/or surface gillnets. A multivariate regression tree analysis was used to investigate spatio-environmental effects on the nodriza fleet (n = 6,821 trips). The catch species composition of the nodriza fleet is strongly influenced by the northwesterly circulation of the Humboldt Current along the coast of Peru and its associated cold waters masses. The target species and longline gear-type used by nodrizas change seasonally with the incursion of cool waters (< 25°C) from the south and offshore. During this season, dolphinfish (Coryphaena hippurus) dominates the catches. However, in warmer waters, the fishery changes to tuna-billfish-shark longline gear and the catch composition becomes much more diverse.
Monitoring small-scale fisheries (SSFs) is challenging due to the limited information available and their underlying socioeconomic characteristics. This constitutes a serious impediment to assess the compliance level of Aichi Biodiversity Targets (ABT). The European Union has committed itself to include an Ecosystem Approach to Fisheries Management (EAFM) in its Common Fisheries Policy. EAFM depends on suites of indicators that track the pressure exercised, the state of the ecosystem, and the socio-economic consequences of management objectives. Therefore, The Living Planet Index (LPI) is proposed here for describing the performance of SSF towards the ABT. We show that the LPI can be reformulated to track trends in Fishing Effort (LPIFE), trends in Fish Populations (LPIFP), and both the state and trends related to the contribution of fisheries to broader society (LPIDEB). The implementation of the LPI in SSF applies several principles of the EAFM, including decentralization, fishers participation, and consideration of local knowledge. In this paper, we used 10-year daily data from the Cofradía at Palamós port, Catalonia - Spain. This is a multi-species SSF landing ca. 130 species, from which 10.9% are of special interest, being listed by the IUCN or in agreements by regional conventions. We observe a decreasing trend in the LPIFP, the LPIFE, and in the LPIDEB, including 36 species or groups, accounting for 90% of total landings, suggesting an overall decrease in the sustainability of this SSF. We conclude that use of the LPIFP is especially well suited to standardize the reporting of information for multispecies fisheries using a wide array of fishing strategies, and results strongly suggest the feasibility of using the LPI methodology to standardize reporting of any given agreed fisheries indicator in order enhance management towards the ABTs.
Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region’s fisheries in the future.
The literature on commons has established the validity and significance of Elinor Ostrom’s design principles for collective action. Can these principles be used to guide policies and initiatives towards adaptive co-management? We analyze this idea by using two case studies, Piriápolis (Uruguay) and Paraty (Brazil). Both cases are small-scale fisheries, and both have been experiencing a social-ecological crisis in a context of prevailing top-down government management. However, there are signs that government policies are moving towards participatory governance. The objective of this article is to identify opportunities and barriers to adaptive co-management of small-scale fisheries in Uruguay and Brazil using Ostrom’s design principles for guidance. Both case studies partially meet seven of the eleven design principles (as amended by Cox and colleagues), but do not fulfill four. The analysis of the fisheries using Ostrom’s principles sheds light on the opportunities and barriers to adaptive co-management in three categories: resource system, resource users, and governance system. Barriers include long-standing conflicts between small-scale fishers and government agencies, and between small and large-scale fisheries sectors. Nevertheless, recent initiatives involving participatory approaches to research and management show potential to improve compliance with several principles. Two weaknesses of using Ostrom’s principles for the analysis of the cases were a lack of attention to social learning and the exclusion of external drivers.