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1.
J Environ Manage ; 351: 119735, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38113786

RESUMEN

Understanding and characterizing the spatiotemporal dynamics of fishing fleets is crucial for ecosystem-based fisheries management (EBFM). EBFM must not only account for the sustainability of target species catches, but also for the collateral impacts of fishing operations on habitats and non-target species. Increased rates of large whale entanglements in commercial Dungeness crab fishing gear have made reducing whale-fishery interactions a current and pressing challenge on the U.S. West Coast. While several habitat models exist for different large whale species along the West Coast, less is known about the crab fishery and the degree to which different factors influence the intensity and distribution of aggregate fishing effort. Here, we modeled the spatiotemporal patterns of Dungeness crab fishing effort in Oregon and Washington as a function of environmental, economic, temporal, social, and management related predictor variables using generalized linear mixed effects models. We then assessed the predictive performance of such models and discussed their usefulness in informing fishery management. Our models revealed low between-year variability and consistent spatial and temporal patterns in commercial Dungeness crab fishing effort. However, fishing effort was also responsive to multiple environmental, economic and management cues, which influenced the baseline effort distribution pattern. The best predictive model, chosen through out-of-sample cross-validation, showed moderate predictive performance and relied upon environmental, economic, and social covariates. Our results help fill the current knowledge gap around Dungeness crab fleet dynamics, and support growing calls to integrate fisheries behavioral data into fisheries management and marine spatial planning.


Asunto(s)
Braquiuros , Animales , Ecosistema , Ballenas , Caza , Explotaciones Pesqueras , Conservación de los Recursos Naturales
2.
Ecol Appl ; 31(4): e2307, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33604951

RESUMEN

Natural resources often exhibit large interannual fluctuations in productivity driven by shifting environmental conditions, and this translates to high variability in the revenue resource users earn. However, users can dampen this variability by harvesting a portfolio of resources. In the context of fisheries, this means targeting multiple populations, though the ability to actually build diverse fishing portfolios is often constrained by the costs and availability of fishing permits. These constraints are generally intended to prevent overcapitalization of the fleet and ensure populations are fished sustainably. As linked human-natural systems, both ecological and fishing dynamics influence the specific advantages and disadvantages of increasing the diversity of fishing portfolios. Specifically, a portfolio of synchronous populations with similar responses to environmental drivers should reduce revenue variability less than a portfolio of asynchronous populations with opposite responses. We built a bioeconomic model based on the Dungeness crab (Metacarcinus magister), Chinook salmon (Oncorhynchus tshawytscha), and groundfish fisheries in the California Current, and used it to explore the influence of population synchrony and permit access on income patterns. As expected, synchronous populations reduced revenue variability less than asynchronous populations, but only for portfolios including crab and salmon. Synchrony with the longer-lived groundfish population was not important because environmentally driven changes in groundfish recruitment were mediated by growth and natural mortality over the full population age structure, and overall biomass was relatively stable across years. Thus, building a portfolio of diverse life histories can buffer against the impacts of poor environmental conditions over short time scales. Increasing access to all permits generally led to increased revenue stability and decreased inequality of the fleet, but also resulted in less revenue earned by an individual from a given portfolio because more vessels shared the available biomass. This means managers are faced with a trade-off between the average revenue individuals earn and the risk those individuals accept. These results illustrate the importance of considering connections between social and ecological dynamics when evaluating management options that constrain or facilitate fishers' ability to diversify their fishing.


Asunto(s)
Explotaciones Pesqueras , Recursos Naturales , Animales , Conservación de los Recursos Naturales , Ecosistema , Humanos , Dinámica Poblacional , Salmón
3.
Proc Natl Acad Sci U S A ; 118(9)2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33574042
4.
Harmful Algae ; 98: 101904, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-33129461

RESUMEN

During the 2015/2016 West Coast Dungeness crab (Metacarcinus magister) season, the opening of the fishery in California was delayed almost five months due to high and persistent concentrations of domoic acid in crab following a massive coast-wide Pseudo-nitzschia australis (P. australis) bloom. A hurdle model was used to estimate lost revenues to fishers due to the delay in the opening of the 2015/2016 season, and an input-output model is used to calculate resulting losses in income and employment statewide. The analysis suggests that Dungeness crab revenue was decreased as a result of the season delay, but the reduction was less than was initially estimated when a request for disaster assistance was submitted. However, the analysis also shows that fishers lost out on revenue from other fisheries equal in magnitude to the reduction in crab revenues because the delayed opening led fishers to reduce effort in non-crab fisheries. The research demonstrates the need to consider impacts beyond the revenue losses to directly affected fisheries. Potential management and industry responses that might mitigate future losses if future large scale P. australis blooms threaten fishery delays or closures are discussed along with the research needed to determine whether and how to implement these strategies.


Asunto(s)
Braquiuros , Desastres , Animales , California , Explotaciones Pesqueras , Floraciones de Algas Nocivas
5.
Ambio ; 49(2): 628-639, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31161600

RESUMEN

Fishing is a dangerous and financially risky way to make a living, but it attracts many participants that prefer it to higher paying and safer jobs. Based on a survey of over 1400 U.S. West Coast fishing vessel owners we use factor analysis and structural equation modeling to quantify distinct latent variables representing job satisfaction related to non-monetary versus monetary aspects of fishing and measures of identity and social capital associated with being a fisher. We show that these latent variables have distinct effects on (stated) fishery participation behavior and that higher non-monetary job satisfaction, social capital, and identity, are associated with a willingness to forgo higher income to be a fisher. Understanding how these factors affect and are affected by participation in fisheries could be important to increase benefits from fisheries and to ensure sustainability of management regimes that rely on indirect controls on effort to limit catch.


Asunto(s)
Explotaciones Pesqueras , Satisfacción en el Trabajo , Animales , Renta , Alimentos Marinos
6.
Proc Natl Acad Sci U S A ; 114(35): 9302-9307, 2017 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-28808006

RESUMEN

Many fishers diversify their income by participating in multiple fisheries, which has been shown to significantly reduce year-to-year variation in income. The ability of fishers to diversify has become increasingly constrained in the last few decades, and catch share programs could further reduce diversification as a result of consolidation. This could increase income variation and thus financial risk. However, catch shares can also offer fishers opportunities to enter or increase participation in catch share fisheries by purchasing or leasing quota. Thus, the net effect on diversification is uncertain. We tested whether diversification and variation in fishing revenues changed after implementation of catch shares for 6,782 vessels in 13 US fisheries that account for 20% of US landings revenue. For each of these fisheries, we tested whether diversification levels, trends, and variation in fishing revenues changed after implementation of catch shares, both for fishers that remained in the catch share fishery and for those that exited but remained active in other fisheries. We found that diversification for both groups was nearly always reduced. However, in most cases, we found no significant change in interannual variation of revenues, and, where changes were significant, variation decreased nearly as often as it increased.


Asunto(s)
Explotaciones Pesqueras/economía , Ocupaciones/economía , Animales , Conservación de los Recursos Naturales , Ecosistema , Peces , Humanos , Renta , Ocupaciones/estadística & datos numéricos , Medición de Riesgo , Factores Socioeconómicos , Estados Unidos
7.
PLoS One ; 10(5): e0122809, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25946194

RESUMEN

Pursuit of the triple bottom line of economic, community and ecological sustainability has increased the complexity of fishery management; fisheries assessments require new types of data and analysis to guide science-based policy in addition to traditional biological information and modeling. We introduce the Fishery Performance Indicators (FPIs), a broadly applicable and flexible tool for assessing performance in individual fisheries, and for establishing cross-sectional links between enabling conditions, management strategies and triple bottom line outcomes. Conceptually separating measures of performance, the FPIs use 68 individual outcome metrics--coded on a 1 to 5 scale based on expert assessment to facilitate application to data poor fisheries and sectors--that can be partitioned into sector-based or triple-bottom-line sustainability-based interpretative indicators. Variation among outcomes is explained with 54 similarly structured metrics of inputs, management approaches and enabling conditions. Using 61 initial fishery case studies drawn from industrial and developing countries around the world, we demonstrate the inferential importance of tracking economic and community outcomes, in addition to resource status.


Asunto(s)
Explotaciones Pesqueras/normas , Gestión de la Calidad Total , Explotaciones Pesqueras/economía
8.
Ecol Appl ; 23(7): 1645-58, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24261046

RESUMEN

Fisheries bycatch is driven by both ecological (e.g., area, season) and social (e.g., fisher behavior) factors that are often difficult to disentangle. We demonstrate a method for comparing fishery-dependent bycatch to fishery-independent catch to delineate the influence of ecological and social factors on bycatch and provide insights for bycatch management. We used data from commercial fishing vessels in the U.S. west coast trawl groundfish fishery (fishery-dependent data collected by fisheries observers) and scientific data from the U.S. west coast bottom trawl groundfish survey (fishery-independent data) to compare the relative effects of season, time of day, target group, depth, and latitude on the expected catch of 12 bycatch species of management interest. This comparison highlights two important relationships that help identify drivers of bycatch. First, when the effect of season, time of day, depth, or latitude on bycatch in both the commercial and scientific data is positive, ecological processes are likely strong drivers of bycatch, suggesting technical approaches (e.g., temporal or spatial closures, gear modifications) might effectively control bycatch. Alternatively, when the effects of season, time of day, depth, latitude, or target group appear only in the commercial data (but not in survey data), fisher behavior is likely the stronger driver of bycatch, suggesting a need to strengthen incentives for fishers to change behavior to avoid bycatch (e.g., regulatory quotas). Two other patterns emerge that suggest that fishery bycatch is not associated with temporal, target, or spatial variables, implying that either current incentives to avoid bycatch are working (i.e., when survey expected catch is positively correlated with variables, but fishery catch is not) or bycatch is a product of unstudied or stochastic processes (i.e., variables are not correlated with expected catch in either data set) and continued monitoring is recommended. Our analysis provides managers and fishers with a basic analytical framework to assess bycatch reduction alternatives and methods useful for researchers interested in comparing bycatch before and after a management shift.


Asunto(s)
Ecosistema , Explotaciones Pesqueras , Peces/clasificación , Animales , Océano Pacífico , Estaciones del Año , Especificidad de la Especie , Estados Unidos
9.
Proc Natl Acad Sci U S A ; 110(6): 2076-81, 2013 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-23341621

RESUMEN

Catches and prices from many fisheries exhibit high interannual variability, leading to variability in the income derived by fishery participants. The economic risk posed by this may be mitigated in some cases if individuals participate in several different fisheries, particularly if revenues from those fisheries are uncorrelated or vary asynchronously. We construct indices of gross income diversification from fisheries at the level of individual vessels and find that the income of the current fleet of vessels on the US West Coast and in Alaska is less diverse than at any point in the past 30 y. We also find a dome-shaped relationship between the variability of individuals' income and income diversification, which implies that a small amount of diversification does not reduce income risk but that higher levels of diversification can substantially reduce the variability of income from fishing. Moving from a single fishery strategy to a 50-25-25 split in revenues reduces the expected coefficient of variation of gross revenues between 24% and 65% for the vessels included in this study. The increasing access restrictions in many marine fisheries through license reductions and moratoriums have the potential to limit fishermen's ability to diversify their income risk across multiple fisheries. Catch share programs often result in consolidation initially and may reduce diversification. However, catch share programs also make it feasible for fishermen to build a portfolio of harvest privileges and potentially reduce their income risk. Therefore, catch share programs create both threats and opportunities for fishermen wishing to maintain diversified fishing strategies.

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