In the intertidal seagrass beds of Zostera noltii of Mira estuary (SW, Portugal) the harvesting practices are frequent. The traditional bivalve harvesting not only affects the target species as the remaining biological assemblages. The main aim of this study was to assess the disturbance caused by sediment digging in the recovery of the seagrass beds habitat, through an experimental fieldwork. The responses of the seagrass plant condition, the sediment microbial activity and the nematode assemblages were investigated after the digging activity in seagrass beds. A total of four experimental plots were randomly demarcated in situ, two plots were subjected to the disturbance - “Digging” - while other two were “Control”; the sampling occurred in five occasions, from May to October: T0–before digging; T1–14 days after digging; T2–45 days; T3–75 days; and T4–175 days. The environmental variables measured in the sediment and the photosynthetic efficiency (α) of the Z. noltii plants in each plot and sampling occasion registered similar values, throughout the experiment. The extracellular enzymatic activity (EEA) clearly presented a temporal pattern, although no significant differences were obtained between digging and control plots. Nematode assemblages registered high densities, revealing the absence of the digging effect: control plots maintained similar density and diversity throughout the experiment, while the density and diversity between digging plots was significantly different at T0 and T4; the trophic composition was similar for both control and digging plots, characterized mainly by non-selective deposit feeders (1B) and epigrowth feeders (2A).Organic matter, nitrate and mean grain size explain a significant amount of the variation in the nematode genera composition. This study demonstrated the capacity of the seagrass habitat to recover under low intensity physical disturbance associated to harvesting.
The goal of food security increasingly serves as an objective and justification for marine conservation in the global south. In the marine conservation literature this potential link is seldom based upon detailed analysis of the socioeconomic pathways between fish and food security, is often based on limited assumptions about increasing the availability of fish stocks, and downplays the role of trade. Yet, the relationship between fish and food security is multi-faceted and complex, with various local contextual factors that mediate between fish and food security. We use data from interviews and food security assessment methods to examine the relationship between fish and food security among fishing households in San Vicente, Palawan province, Philippines. We highlight the local role of income and trade, emphasising the sale of fish to purchase food not easily accessible for fishers, particularly staples. In particular, we show that because rice is the primary staple of food security for these households, fish must be traded with the intent of buying rice. Trade is therefore central to household food security. We argue that the relationship between fish and food security must be considered in greater depth if marine conservation is to engage with food security as an objective.
Antagonistic interaction between Mediterranean marine mammals, including the endangered monk seal (Monachus monachus), and small-scale fisheries is a growing problem in the Aegean Sea. Effective management measures are needed to ensure both the survival of the monk seal population, and its coexistence with the small-scale fisheries. In this study, data from 371 fishing journeys by 8 different boats was collected between March and November 2014. Evidence of depredation by monk seals was recorded in 19.1% of fishing journeys, by cetaceans in 5%, and by other predators in 16.5%. Analysis of landings data showed that gear and depth were the variables most likely to influence the occurrence of depredation. There was a significant decrease in the catch per unit effort (CPUE) of four of the nine targeted fish species when depredation by monk seals occurred. The total cost of monk seal depredation was estimated to be 21.33% of the mean annual income of fishermen in the Aegean Sea. We discuss how the implementation of marine protected areas and the use of specific fishing gear could reduce the frequency of interactions, and thus mitigate the loss experienced by the fisheries as well as contribute to the conservation of an endangered species.
On the Brazilian coast there are many conflicts between Marine Protected Areas (MPAs) and fisher's communities. This research used institutional analysis to integrate studies of sustainable territorial development with coastal fishing in three Brazilian MPAs: the Canavieiras (Bahia) and Itaipu (Rio de Janeiro) Extractive Reserves and the Ecological Station of Tamoios (Rio de Janeiro). Ostrom's Principles (1990) - reviewed by Cox et al. (2010) - were contrasted with the situation of fishing in MPAs in the period of analysis and the fishers' demands for institutional changes. Principles analysis indicated structural weaknesses of the state to promote continuous actions of monitoring resources and users, as well as in the application of graduated sanctions. The design principles most closely associated with the construction of territorial development strategies were related to the rules of appropriation and provision, and nested enterprises. MPAs, as institutional innovations, can act on territorial development dynamics to provide systemic responses capable of preventing the degradation of fisheries resources and marginalisation of users. The sustainable territorial development approach introduces innovative issues for MPAs management, such as territorial identity, integrated production systems and innovation. The perspective on MPAs presented aims to contribute to a quality based fisheries management model, rather than the usual productivity focus.
Territorial Use Rights in Fisheries (TURFs) are gaining renewed attention as a potential tool for sustainable fisheries management in small-scale fisheries. This growing popularity comes despite the fact that there are still unresolved questions about the most effective TURF designs. One of the key questions is the role of TURF size in their efficacy both from ecological and social standpoints. This study explores the expected effects of existing TURF sizes on yields for TURF systems in Chile, México and Japan. The expected effect of larval dispersal and adult movement on yields was simulated for TURFs in each system. The results show that the analyzed TURF systems fall into three main categories: (a) TURFs that are of adequate size to eliminate the expected negative effects of both adult and larval movement, (b) TURFs that are large enough to eliminate the expected negative effects of adult movement, but not the effects of larval dispersal, and c) TURFs that are too small to eliminate the expected impacts on yield of both adult and larval movement. These analyses suggest that either existing models of TURF performance are incomplete or that there is significant scope for improved performance with altered TURF designs. Considering these alternatives, empirical evidence from the TURFs deemed too small suggests that complementary management tools can enhance TURF performance when natural or social constraints prevent the construction of TURFs of optimal size.
Recent coastal planning measures in south-east Portugal (Algarve), where offshore aquaculture developments were set up in fishing areas aiming to maximize expected utility of seafood production activities, raised some discontentment. Public policies created to safeguard offshore aquaculture (OSA) producers and limit small-scale fishing (SSF) activities must be adjusted accordingly in order to maximize income and keep discontentment at a minimum. We collected primary data from stakeholders, fishers (n = 18) and offshore aquaculture operators (n = 3) through participatory workshops and interviews by eliciting problematic issues derived from the offshore area creation and their relative relevance. We used these data to populate conditional probability tables and construct a related influence diagram (Bayesian belief networks) to model the affected system. We selected nine scenarios based on navigability and aquaculture area size with the aim of finding the best expected utility combinations for the OSA – SSF system. The inferred results show that maximizing employment and keep pollution at low levels were the most influential factors to keep the system at a satisfactory level. The best decision was not to enlarge the aquaculture area, but to condition the access to other operational stakeholders, namely SSF operators from nearby areas. The overall results of the Bayesian belief network can be used to recommend coastal planners and decision-makers to deal with the interaction between OSA and SSF activities.
Catch and fishing effort time series are used by managers to safeguard the availability of resources in the future. Fisheries organizations estimate the status of a stock and the levels for sustainable harvest. Based on these indicators, regulations are developed to guarantee the availability of food and sustain economic growth. For example, tuna stocks are important not only in terms of nutrition, but also for the welfare, culture, revenue, and employment of the countries that rely upon them. However, fisheries time-series are the result of many natural and non-natural factors and are usually difficult to predict. Here, we propose a method to aggregate fisheries time series in space and time, to detect hidden periodicities, to predict the time series in the future and to identify the most stressed locations in the fishing area. We apply our method to tuna fisheries data in the Indian Ocean and compare it with respect to other methods. We demonstrate that the method is able to highlight periodic patterns in this high fishing activity area and to forecast the fisheries time series in the future. We use a research e-Infrastructure to comply with modern approaches supporting reproducibility, repeatability, and results sharing.
This thematic series, entitled “Enhancing Stewardship in Latin America and Caribbean Small-Scale Fisheries”, emerged as part of a joint effort to bridge Latin-American scholars interested in networking on small-scale fisheries in the region. Built on results presented at two meetings (‘Too Big to Ignore’ (TBTI) Workshop in Curitiba, Brazil, and the 2nd World Small-Scale Fisheries Congress in Merida, Mexico), this issue combines a unique collection of emergent and pressing issues related to small-scale fisheries in Latin America. It comprises of theoretical, methodological and policy-related aspects across a range of topics such as co-management, biodiversity conservation, governance challenges, and territorial tenure, in seven countries - predominantly from South America. In this Introduction, we provide some background to the similarities and diversity within the Latin America and Caribbean region, and their relevance to small-scale fisheries stewardship. Subsequently, we briefly introduce the contributions that range from cross-scale governance in Chile, cooperativism in Mexico, species introduction in Bolivia, interactive governance in the Galápagos and co-management in Uruguay, Brazil and Colombia, to territorial losses in Brazil. Multiple contexts and processes, theoretical and analytical perspectives (multi-stakeholders, socio-ecological systems, cross-scale issues, territorial approach) are highlighted, as well as the policy challenges to safeguard small-scale fisheries from numerous pressures such as urbanization, industrial expansion, tourism, pollution, and conservation policies. This series aims at inciting further consideration of innovative perspectives to bridge local communities, academics, practitioners and policy makers in joint efforts to promote priority action on issues that require immediate attention and transdisciplinary multidimensional outlooks on that important sector.
Marine protected areas (MPAs) have largely proven to be effective tools for conserving marine ecosystem, while socio-economic benefits generated by MPAs to fisheries are still under debate. Many MPAs embed a no-take zone, aiming to preserve natural populations and ecosystems, within a buffer zone where potentially sustainable activities are allowed. Small-scale fisheries (SSF) within buffer zones can be highly beneficial by promoting local socio-economies. However, guidelines to successfully manage SSFs within MPAs, ensuring both conservation and fisheries goals, and reaching a win-win scenario, are largely unavailable. From the peer-reviewed literature, grey-literature and interviews, we assembled a unique database of ecological, social and economic attributes of SSF in 25 Mediterranean MPAs. Using random forest with Boruta algorithm we identified a set of attributes determining successful SSFs management within MPAs. We show that fish stocks are healthier, fishermen incomes are higher and the social acceptance of management practices is fostered if five attributes are present (i.e. high MPA enforcement, presence of a management plan, fishermen engagement in MPA management, fishermen representative in the MPA board, and promotion of sustainable fishing). These findings are pivotal to Mediterranean coastal communities so they can achieve conservation goals while allowing for profitable exploitation of fisheries resources.
Groupers are highly targeted and vulnerable reef fishes. The effects of fishing pressure on the density of three reef fishes were investigated in 21 islands outside (n=15) and inside (n=6) a Marine Protected Area (MPA) at the Paraty Bay, Brazilian southeastern coast. Two valued groupers (Epinephelus marginatus and Mycteroperca acutirostris) and a non-target grunt (Haemulon aurolineatum) were studied. The total biomass of fish caught in each island was considered as a measure of current fishing pressure, while the island distance from the villages was considered as a measure of past fishing pressure. Fish densities were recordedin number and biomass. The biomass of M. acutirostris was inversely related to current fishing pressure, which did not affect the other two fishes. The density of E. marginatus increased with the island distance from one of the fishing villages, which indicated that past fishing may have had decreased the abundance of E. marginatus. Densities of the three fishes and fishing pressure did not differ between islands inside and outside the MPA. Data on fishing pressure, densities of groupers and coral cover were combined here to assign conservation scores to islands. A redefinition of MPA boundaries to reconcile fish conservation, fishing activities and fishers’ food security was proposed.