Summary
The R package TropFishR is a new analysis toolbox compiling single‐species stock assessment methods specifically designed for data‐limited fisheries analysis using length‐frequency data.
It ...includes methods for (i) estimating biological stock characteristics such as growth and mortality parameters, (ii) exploring technical aspects of the fisheries (e.g. exploitation rate and selectivity characteristics), (iii) assessing size and composition of a fish stock by means of virtual population analysis (VPA), and (iv) assessing stock status with yield prediction and production models.
This paper introduces the package and demonstrates the functionality of a selection of its core methods.
TropFishR modernises traditional stock assessment methods by easing application and development and by combining it with advanced statistical approaches.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Marine ecosystem–scale fisheries research and management must include the fishing effort of women and men. Even with growing recognition that women do fish, there remains an imperative to engage in ...more meaningful and relevant gender analysis to improve socio‐ecological approaches to fisheries research and management. The implications of a gender approach to fisheries have been explored in social approaches to fisheries, but the relevance of gender analysis for ecological understandings has yet to be fully elaborated. To examine the importance of gender to the understanding of marine ecology, we identified 106 case studies of small‐scale fisheries from the last 20 years that detail the participation of women in fishing (data on women fishers being the most common limiting factor to gender analysis). We found that beyond gender difference in fishing practices throughout the world, the literature reveals a quantitative data gap in the characterization of gender in small‐scale fisheries. The descriptive details of women's often distinct fishing practices nonetheless provide important ecological information with implications for understanding the human role in marine ecosystems. Finally, we examined why the data gap on women's fishing practices has persisted, detailing several ways in which commonly used research methods may perpetuate biased sampling that overlooks women's fishing. This review sheds light on a new aspect of the application of gender research to fisheries research, with an emphasis on ecological understanding within a broader context of interdisciplinary approaches.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Small‐scale fisheries through the wellbeing lens Weeratunge, Nireka; Béné, Christophe; Siriwardane, Rapti ...
Fish and fisheries (Oxford, England),
June 2014, Volume:
15, Issue:
2
Journal Article
Peer reviewed
Despite longstanding recognition that small‐scale fisheries make multiple contributions to economies, societies and cultures, assessing these contributions and incorporating them into policy and ...decision‐making has suffered from a lack of a comprehensive integrating ‘lens’. This paper focuses on the concept of ‘wellbeing’ as a means to accomplish this integration, thereby unravelling and better assessing complex social and economic issues within the context of fisheries governance. We emphasize the relevance of the three key components of wellbeing – the material, relational and subjective dimensions, each of which is relevant to wellbeing at scales ranging from individual, household, community, fishery to human‐ecological systems as a whole. We review nine major approaches influential in shaping current thinking and practice on wellbeing: the economics of happiness, poverty, capabilities, gender, human rights, sustainable livelihoods, vulnerability, social capital, and social wellbeing. The concept of identity is a thread that runs through the relational and subjective components of social wellbeing, as well as several other approaches and thus emerges as a critical element of small‐scale fisheries that requires explicit recognition in governance analysis. A social wellbeing lens is applied to critically review a global body of literature discussing the social, economic and political dimensions of small‐scale fishing communities, seeking to understand the relevance and value addition of applying wellbeing concepts in small‐scale fisheries.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Local support is important for the longevity of conservation initiatives. The literature suggests that perceptions of ecological effectiveness, social impacts, and good governance will influence ...levels of local support for conservation. This paper examines these relationships using data from a survey of small‐scale fishermen in 11 marine protected areas from six countries in the Mediterranean Sea. The survey queried small‐scale fishermen regarding perceptions and support for conservation. We constructed composite scores for three categories of perceptions—ecological effectiveness, social impacts, and good governance—and tested the relationship with levels of support using ordinal regression models. While all three factors were positively correlated with support for conservation, perceptions of good governance and social impacts were stronger predictors of increasing support. These findings suggest that employing good governance processes and managing social impacts may be more important than ecological effectiveness for maintaining local support for conservation.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Overfishing may seriously impact fish populations and ecosystems. Marine protected areas (MPAs) are key tools for biodiversity conservation and fisheries management, yet the fisheries benefits remain ...debateable. Many MPAs include a fully protected area (FPA), restricting all activities, within a partially protected area (PPA) where potentially sustainable activities are permitted. An effective tool for biodiversity conservation, FPAs, can sustain local fisheries via spillover, that is the outward export of individuals from FPAs. Spillover refers to both: “ecological spillover”: outward net emigration of juveniles, subadults and/or adults from the FPA; and “fishery spillover”: the fraction of ecological spillover that directly benefits fishery yields and revenues through fishable biomass. Yet, how common is spillover remains controversial. We present a meta‐analysis of a unique global database covering 23 FPAs worldwide, using published literature and purposely collected field data, to assess the capacity of FPAs to export biomass and whether this response was mediated by specific FPA features (e.g. size, age) or species characteristics (e.g. mobility, economic value). Results show fish biomass and abundance outside FPAs was higher: (a) in locations close to FPA borders (<200 m) than further away (>200 m); (b) for species with a high commercial value; and (c) in the presence of PPA surrounding the FPA. Spillover was slightly higher in FPAs that were larger and older and for more mobile species. Based on the broadest data set compiled to date on marine species ecological spillover beyond FPAs' borders, our work highlights elements that could guide strategies to enhance local fishery management using MPAs.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Global significance of seagrass fishery activity Nordlund, Lina M; Unsworth, Richard K F; Gullström, Martin ...
Fish and fisheries (Oxford, England),
20/May , Volume:
19, Issue:
3
Journal Article
Peer reviewed
Open access
Seagrass meadows support fisheries through provision of nursery areas and trophic subsidies to adjacent habitats. As shallow coastal habitats, they also provide key fishing grounds; however, the ...nature and extent of such exploitation are poorly understood. These productive meadows are being degraded globally at rapid rates. For degradation to cease, there needs to be better appreciation for the value of these habitats in supporting global fisheries. Here, we provide the first global scale study demonstrating the extent, importance and nature of fisheries exploitation of seagrass meadows. Due to a paucity of available data, the study used a global expert survey to demonstrate the widespread significance of seagrass‐based fishing activity. Our study finds that seagrass‐based fisheries are globally important and present virtually wherever seagrass exists, supporting subsistence, commercial and recreational activity. A wide range of fishing methods and gear is used reflecting the spatial distribution patterns of seagrass meadows, and their depth ranges from intertidal (accessible by foot) to relatively deep water (where commercial trawls can operate). Seagrass meadows are multispecies fishing grounds targeted by fishers for any fish or invertebrate species that can be eaten, sold or used as bait. In the coastal communities of developing countries, the importance of the nearshore seagrass fishery for livelihoods and well‐being is irrefutable. In developed countries, the seagrass fishery is often recreational and/or more target species specific. Regardless of location, this study is the first to highlight collectively the indiscriminate nature and global scale of seagrass fisheries and the diversity of exploitative methods employed to extract seagrass‐associated resources. Evidence presented emphasizes the need for targeted management to support continued viability of seagrass meadows as a global ecosystem service provider.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Small-scale fisheries (SSF) have long been overshadowed by the concerns and perceived importance of the industrial sector in fisheries science and policy. Yet in recent decades, attention to SSF is ...on the rise, marked by a proliferation of scientific publications, the emergence of new global policy tools devoted to the small-scale sector, and concerted efforts to tally the size and impacts of SSF on a global scale. Given the rising tide of interest buoying SSF, it’s pertinent to consider how the underlying definition shapes efforts to enumerate and scale up knowledge on the sector—indicating what dimensions of SSF count and consequently what gets counted. Existing studies assess how national fisheries policies define SSF, but to date, no studies systematically and empirically examine how the definition of SSF has been articulated in science, including whether and how definitions have changed over time. We systematically analyzed how SSF were defined in the peer-reviewed scientific literature drawing on a database of 1,724 articles published between 1960 and 2015. We coded a 25% random sample of articles (n=434) from our database and found that nearly one-quarter did not define SSF. Among those that did proffer a definition, harvest technologies such as fishing boats and gear were the most common characteristics used. Comparing definitions over time, we identified two notable trends over the 65-year time period studied: a decreasing proportion of articles that defined SSF and an increasing reliance on technological dimensions like boats relative to sociocultural characteristics. Our results resonate with findings from similar research on the definition of SSF in national fisheries policies that also heavily rely on boat length. We call attention to several salient issues that are obscured by an overreliance on harvest technologies in definitions of SSF, including dynamics along the wider fisheries value chain and social relations such as gender. We discuss our findings considering new policies and emerging tools that could steer scientists and practitioners toward more encompassing, consistent, and relational means of defining SSF that circumvent some of the limitations of longstanding patterns in science and policy that impinge upon sustainable and just fisheries governance.
Since the 1980s, there has been growing concern in the Mexican Atlantic regarding high catches of neonate and juvenile sharks in small‐scale fisheries. Fishery‐dependent data from 1993 to 1994 and ...2007 to 2017 and fishers' ecological knowledge from 2017 were used to identify nursery areas for scalloped hammerhead, Sphyrna lewini, in the southern Gulf of Mexico. Catch records and fishing areas of neonates, YOYs, juveniles and adults of S. lewini (N = 1885) were obtained from calcareous and terrigenous regions in the western Yucatan Peninsula. The results suggest that a nursery for scalloped hammerhead is found in the terrigenous region, characterized by relatively shallow and turbid waters due to rivers’ discharges. Neonates and YOYs (96% and 86% of their total records, respectively) were commonly found there over the years in May–August in multiple fishing areas identified by fishers, although mainly between isobaths 10–30 m. The enforcement of management measures is necessary because the nursery is located in a region with intense fishing effort.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In the last twenty years, policy prescriptions for addressing the global crisis in fisheries have centred on strengthening fisheries governance through clarifying exclusive individual or community ...rights of access to fishery resources. With a focus on small‐scale developing‐country fisheries in particular, we argue that basing the case for fishery governance reform on assumed economic incentives for resource stewardship is insufficient when there are other sources of insecurity in people’s lives that are unrelated to the state of fishery resources. We argue that more secure, less vulnerable fishers make more effective and motivated fishery managers in the context of participatory or rights‐based fisheries governance, and we further suggest that insecurity among fishers living in poverty can be most effectively addressed by social and political development that invokes the existing legal framework supporting the Universal Declaration of Human Rights. This perspective goes well beyond the widely advocated notion of ‘rights‐based fishing’ and aligns what fishery sector analysts call the ‘rights‐based approach’ with the same terminology used in the context of international development. Embedding the fisheries governance challenge within a broader perspective of human rights enhances the chances of achieving both human development and resource sustainability outcomes in small‐scale fisheries of developing countries.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
The blue octopus (Octopus cyanea) fishery off the southwest coast of Madagascar is important for coastal communities. This fishery is a key economic resource for the local community as blue octopus ...catch is sold by local fishers to international and local export markets. Thus, it is important to monitor and evaluate the status of octopus to ensure its sustainability. One common octopus management approach is through the use of temporary spatial closures. Models can be a useful support tool to evaluate the status of a population and assess different possible management strategies. To better understand the biology and assess the sustainability of blue octopus, we parameterize a Levkovitch population matrix model using existing catch data. We found that the octopus population was experiencing a 1.8% decline per month at the time of data collection in 2006. However, since 2006, a number of management practices, including temporary closures lasting several weeks to several months have been implemented successfully. In line with these efforts, our model indicates that the fishery has likely been sustained since 2006 due to these annual closures. Our model provides support to the idea that temporary closures have restored this population and that temporary closures provide flexibility in management strategies that local communities can tailor to their economic and social needs. In addition, we were able to estimate several important life history metrics, such as time in each stage, stable stage distribution, reproductive value, and per stage survivability, that can be used in future work. Collectively, our study provides insight into the biology of blue octopus as well as demonstrate how temporary closures can be an effective conservation strategy due to the wide range of implementation options.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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