The Experts below are selected from a list of 7917 Experts worldwide ranked by ideXlab platform
Deborah R Hart - One of the best experts on this subject based on the ideXlab platform.
-
when do marine reserves increase Fishery Yield
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Deborah R HartAbstract:An age-structured model is developed for analyzing the effects of marine reserves and other long-term closures on Fishery Yield, assuming larvae are well-mixed and that exchange of adults between the open and closed areas is negligible. A number of analytic results are derived, including a formula for the gradient of Yield with respect to fishing mortality and closure fraction. Increasing the closure fraction at equilibrium spawning stock biomass (SSB), B, will increase Yield if and only if s′(B) > 1/b0(0), where s′(B) is the slope of the stockrecruitment curve at B and b0(0) is SSB per recruit at zero fishing mortality. Conditions for the level of closure required to prevent stock collapse are also derived. Applications of the theory to canary rockfish (Sebastes pinniger) and Georges Bank sea scallop (Placopecten magellanicus) illustrate that long-term closures increase Yield only at low SSB associated with fishing mortalities greater than FMSY and with low closure fractions. The theory presented here g...
-
when do marine reserves increase Fishery Yield
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Deborah R HartAbstract:An age-structured model is developed for analyzing the effects of marine reserves and other long-term closures on Fishery Yield, assuming larvae are well-mixed and that exchange of adults between t...
Wilson J White - One of the best experts on this subject based on the ideXlab platform.
-
marine reserve design theory for species with ontogenetic migration
Biology Letters, 2015Co-Authors: Wilson J WhiteAbstract:Models for marine reserve design have been developed primarily with ‘reef fish’ life histories in mind: sedentary adults in patches connected by larval dispersal. However, many fished species undertake ontogenetic migrations, such as from nursery grounds to adult spawning habitats, and current theory does not fully address the range of reserve options posed by that situation. I modelled a generic species with ontogenetic migration to investigate the possible benefits of reserves under three alternative scenarios. First, the Fishery targets adult habitat, and reserves can sustain Yields under high exploitation, unless habitat patches are well connected. Second, the Fishery targets the nursery, and reserves are highly effective, regardless of connectivity patterns. Third, the Fishery targets both habitats, and reserves only succeed if paired on adjacent, well-connected nursery and adult patches. In all cases, reserves can buffer populations against overexploitation but would not enhance Fishery Yield beyond that achievable by management without reserves. These results summarize the general situations in which management using reserves could be useful for ontogenetically migrating species, and the type of connectivity data needed to inform reserve design.
-
decision analysis for designing marine protected areas for multiple species with uncertain Fishery status
Ecological Applications, 2010Co-Authors: Wilson J White, Louis W Botsford, Elizabeth A Moffitt, Douglas T FischerAbstract:Marine protected areas (MPAs) are growing in popularity as a conservation tool, and there are increasing calls for additional MPAs. Meta-analyses indicate that most MPAs successfully meet the minimal goal of increasing biomass inside the MPA, while some do not, leaving open the important question of what makes MPAs successful. An often-overlooked aspect of this problem is that the success of Fishery management outside MPA boundaries (i.e., whether a population is overfished) affects how well MPAs meet both conservation goals (e.g., increased biomass) and economic goals (e.g., minimal negative effects on Fishery Yield). Using a simple example of a system with homogeneous habitat and periodically spaced MPAs, we show that, as area in MPAs increases, (1) conservation value (biomass) may initially be zero, implying no benefit, then at some point increases monotonically; and (2) Fishery Yield may be zero, then increases monotonically to a maximum beyond which further increase in MPA area causes Yield to declin...
Christina C Hicks - One of the best experts on this subject based on the ideXlab platform.
-
harnessing global fisheries to tackle micronutrient deficiencies
Nature, 2019Co-Authors: Christina C Hicks, Philippa J Cohen, Nicholas A J Graham, Kirsty L Nash, Edward H Allison, Coralie DlimaAbstract:Micronutrient deficiencies account for an estimated one million premature deaths annually, and for some nations can reduce gross domestic product1,2 by up to 11%, highlighting the need for food policies that focus on improving nutrition rather than simply increasing the volume of food produced3. People gain nutrients from a varied diet, although fish—which are a rich source of bioavailable micronutrients that are essential to human health4—are often overlooked. A lack of understanding of the nutrient composition of most fish5 and how nutrient Yields vary among fisheries has hindered the policy shifts that are needed to effectively harness the potential of fisheries for food and nutrition security6. Here, using the concentration of 7 nutrients in more than 350 species of marine fish, we estimate how environmental and ecological traits predict nutrient content of marine finfish species. We use this predictive model to quantify the global spatial patterns of the concentrations of nutrients in marine fisheries and compare nutrient Yields to the prevalence of micronutrient deficiencies in human populations. We find that species from tropical thermal regimes contain higher concentrations of calcium, iron and zinc; smaller species contain higher concentrations of calcium, iron and omega-3 fatty acids; and species from cold thermal regimes or those with a pelagic feeding pathway contain higher concentrations of omega-3 fatty acids. There is no relationship between nutrient concentrations and total Fishery Yield, highlighting that the nutrient quality of a Fishery is determined by the species composition. For a number of countries in which nutrient intakes are inadequate, nutrients available in marine finfish catches exceed the dietary requirements for populations that live within 100 km of the coast, and a fraction of current landings could be particularly impactful for children under 5 years of age. Our analyses suggest that fish-based food strategies have the potential to substantially contribute to global food and nutrition security. Nutrient content analyses of marine finfish and current fisheries landings show that fish have the potential to substantially contribute to global food and nutrition security by alleviating micronutrient deficiencies in regions where they are prevalent.
Douglas T Fischer - One of the best experts on this subject based on the ideXlab platform.
-
decision analysis for designing marine protected areas for multiple species with uncertain Fishery status
Ecological Applications, 2010Co-Authors: Wilson J White, Louis W Botsford, Elizabeth A Moffitt, Douglas T FischerAbstract:Marine protected areas (MPAs) are growing in popularity as a conservation tool, and there are increasing calls for additional MPAs. Meta-analyses indicate that most MPAs successfully meet the minimal goal of increasing biomass inside the MPA, while some do not, leaving open the important question of what makes MPAs successful. An often-overlooked aspect of this problem is that the success of Fishery management outside MPA boundaries (i.e., whether a population is overfished) affects how well MPAs meet both conservation goals (e.g., increased biomass) and economic goals (e.g., minimal negative effects on Fishery Yield). Using a simple example of a system with homogeneous habitat and periodically spaced MPAs, we show that, as area in MPAs increases, (1) conservation value (biomass) may initially be zero, implying no benefit, then at some point increases monotonically; and (2) Fishery Yield may be zero, then increases monotonically to a maximum beyond which further increase in MPA area causes Yield to declin...
Coralie Dlima - One of the best experts on this subject based on the ideXlab platform.
-
harnessing global fisheries to tackle micronutrient deficiencies
Nature, 2019Co-Authors: Christina C Hicks, Philippa J Cohen, Nicholas A J Graham, Kirsty L Nash, Edward H Allison, Coralie DlimaAbstract:Micronutrient deficiencies account for an estimated one million premature deaths annually, and for some nations can reduce gross domestic product1,2 by up to 11%, highlighting the need for food policies that focus on improving nutrition rather than simply increasing the volume of food produced3. People gain nutrients from a varied diet, although fish—which are a rich source of bioavailable micronutrients that are essential to human health4—are often overlooked. A lack of understanding of the nutrient composition of most fish5 and how nutrient Yields vary among fisheries has hindered the policy shifts that are needed to effectively harness the potential of fisheries for food and nutrition security6. Here, using the concentration of 7 nutrients in more than 350 species of marine fish, we estimate how environmental and ecological traits predict nutrient content of marine finfish species. We use this predictive model to quantify the global spatial patterns of the concentrations of nutrients in marine fisheries and compare nutrient Yields to the prevalence of micronutrient deficiencies in human populations. We find that species from tropical thermal regimes contain higher concentrations of calcium, iron and zinc; smaller species contain higher concentrations of calcium, iron and omega-3 fatty acids; and species from cold thermal regimes or those with a pelagic feeding pathway contain higher concentrations of omega-3 fatty acids. There is no relationship between nutrient concentrations and total Fishery Yield, highlighting that the nutrient quality of a Fishery is determined by the species composition. For a number of countries in which nutrient intakes are inadequate, nutrients available in marine finfish catches exceed the dietary requirements for populations that live within 100 km of the coast, and a fraction of current landings could be particularly impactful for children under 5 years of age. Our analyses suggest that fish-based food strategies have the potential to substantially contribute to global food and nutrition security. Nutrient content analyses of marine finfish and current fisheries landings show that fish have the potential to substantially contribute to global food and nutrition security by alleviating micronutrient deficiencies in regions where they are prevalent.