Dependence of sustainability on the configuration of marine reserves and larval dispersal distance

2001 ◽  
Vol 4 (2) ◽  
pp. 144-150 ◽  
Author(s):  
Botsford ◽  
Hastings ◽  
Gaines
Keyword(s):  
Larval Dispersal ◽  
Marine Reserves ◽  
Dispersal Distance

Modeling no-take marine reserves in regulated fisheries: assessing the role of larval dispersal

2008 ◽  
Vol 65 (11) ◽  
pp. 2509-2523 ◽  
Author(s):  
Carey R. McGilliard ◽  
Ray Hilborn
Keyword(s):  
Larval Dispersal ◽  
Marine Reserves ◽  
Dispersal Distance ◽  
Maximum Sustainable Yield ◽  
Catch Per Unit Effort ◽  
Long Distance ◽  
Total Allowable Catch ◽  
Dispersal Distances ◽  
The Impact

We explored the effects of larval dispersal distance on the impact of no-take marine reserves (NTMRs) implemented in fisheries with catch regulations. NTMRs exist in many fisheries with harvest regulated by annual catch limits. In these fisheries, catch is taken from outside NTMRs, potentially resulting in reduced abundance outside NTMRs and an overall reduction in catch. We used a spatial model with two life stages (larvae and adults) to evaluate the effects of larval dispersal distance for fisheries managed by a total allowable catch (TAC) and an NTMR. We examined effects of the timing of density-dependent mortality in relation to larval movement. Abundance reached similar values for populations with long and short larval dispersal distances. Catch declined substantially for stocks with short larval dispersal distances. When larval dispersal distances were long, catch declined to values below maximum sustainable yield (MSY), but stabilized. Catch per unit effort (CPUE) declined to 9% of CPUE at MSY for stocks with short distance larval dispersal after the implementation of an NTMR; with long distance larval dispersal, CPUE declined to approximately 50% or less of the CPUE at MSY. The CPUE did not reflect trends in abundance after the implementation of an NTMR.

scholarly journals Designing well-connected marine reserves for climate-change resilience with low socio-economic costs

2018 ◽  
Author(s):  
OCTO
Keyword(s):  
Climate Change ◽  
Larval Dispersal ◽  
Gulf Of California ◽  
Marine Reserves ◽  
Marine Reserve ◽  
Dispersal Distance ◽  
Planktonic Larvae ◽  
Time Of Year ◽  
And Performance

The theory behind networks of marine reserves is that they allow protected pathways for species to grow and maintain populations through their lifecycle - from where individuals begin their lives (typically as planktonic larvae) to where they disperse and live later as adults. Individual reserves - patches of protected habitat - are linked together, often by oceanic currents, with organisms moving between the reserves. Connections between marine reserves in a common area can be explored with graph theory: visualizing ecological networks much like a concept map. The ocean is warming due to climate change. Warming water has effects on larval physiology of at least some species, including shortening the larval development period, and thus shortening larval dispersal distance. These changes could theoretically compromise the connectivity and performance of marine reserve networks, thus requiring adjusting their design to account for ocean warming.The authors used the Midriff Islands Region in the Gulf of California, Mexico as a case study to examine the effects of ocean warming on the ability of planktonic larvae to spread amongst reserves. The Midriff Islands Region features a counter-clockwise gyre in the spring and summer months, which reverses in the fall and winter. As such, larval dispersal changes depending on the time of year and where a reserve is located in relation to the center of the gyre.

scholarly journals Probability of successful larval dispersal declines fivefold over 1 km in a coral reef fish

2011 ◽  
Vol 279 (1735) ◽  
pp. 1883-1888 ◽  
Author(s):  
Peter M. Buston ◽  
Geoffrey P. Jones ◽  
Serge Planes ◽  
Simon R. Thorrold
Keyword(s):  
Larval Dispersal ◽  
Isolation By Distance ◽  
Dispersal Distance ◽  
Population Connectivity ◽  
Marine Ecology ◽  
Sea Anemones ◽  
Marine Population ◽  
Amphiprion Percula ◽  
Distance Distributions ◽  
Dispersal Distances

A central question of marine ecology is, how far do larvae disperse? Coupled biophysical models predict that the probability of successful dispersal declines as a function of distance between populations. Estimates of genetic isolation-by-distance and self-recruitment provide indirect support for this prediction. Here, we conduct the first direct test of this prediction, using data from the well-studied system of clown anemonefish ( Amphiprion percula ) at Kimbe Island, in Papua New Guinea. Amphiprion percula live in small breeding groups that inhabit sea anemones. These groups can be thought of as populations within a metapopulation. We use the x- and y -coordinates of each anemone to determine the expected distribution of dispersal distances (the distribution of distances between each and every population in the metapopulation). We use parentage analyses to trace recruits back to parents and determine the observed distribution of dispersal distances. Then, we employ a logistic model to (i) compare the observed and expected dispersal distance distributions and (ii) determine the relationship between the probability of successful dispersal and the distance between populations. The observed and expected dispersal distance distributions are significantly different ( p < 0.0001). Remarkably, the probability of successful dispersal between populations decreases fivefold over 1 km. This study provides a framework for quantitative investigations of larval dispersal that can be applied to other species. Further, the approach facilitates testing biological and physical hypotheses for the factors influencing larval dispersal in unison, which will advance our understanding of marine population connectivity.

scholarly journals The good, the bad and the ugly of marine reserves for fishery yields

2015 ◽  
Vol 370 (1681) ◽  
pp. 20140276 ◽  
Author(s):  
Giulio A. De Leo ◽  
Fiorenza Micheli
Keyword(s):  
Stochastic Model ◽  
Larval Dispersal ◽  
Environmental Variability ◽  
Marine Reserves ◽  
Maximum Sustainable Yield ◽  
Social Benefits ◽  
Spatially Explicit ◽  
Sustainable Yield ◽  
Population Abundance ◽  
Quota Management

Marine reserves (MRs) are used worldwide as a means of conserving biodiversity and protecting depleted populations. Despite major investments in MRs, their environmental and social benefits have proven difficult to demonstrate and are still debated. Clear expectations of the possible outcomes of MR establishment are needed to guide and strengthen empirical assessments. Previous models show that reserve establishment in overcapitalized, quota-based fisheries can reduce both catch and population abundance, thereby negating fisheries and even conservation benefits. By using a stage-structured, spatially explicit stochastic model, we show that catches under quota-based fisheries that include a network of MRs can exceed maximum sustainable yield (MSY) under conventional quota management if reserves provide protection to old, large spawners that disproportionally contribute to recruitment outside the reserves. Modelling results predict that the net fishery benefit of MRs is lost when gains in fecundity of old, large individuals are small, is highest in the case of sedentary adults with high larval dispersal, and decreases with adult mobility. We also show that environmental variability may mask fishery benefits of reserve implementation and that MRs may buffer against collapse when sustainable catch quotas are exceeded owing to stock overestimation or systematic overfishing.

scholarly journals Estimating dispersal distance in the deep sea: challenges and applications to marine reserves

2015 ◽  
Vol 2 ◽  
Author(s):  
Ana Hilário ◽  
Anna Metaxas ◽  
Sylvie M. Gaudron ◽  
Kerry L. Howell ◽  
Annie Mercier ◽  
...  
Keyword(s):  
Deep Sea ◽  
Marine Reserves ◽  
Dispersal Distance

Population genetic structure in the redefined vermilion rockfish (Sebastes miniatus) indicates limited larval dispersal and reveals natural management units

2009 ◽  
Vol 66 (9) ◽  
pp. 1569-1581 ◽  
Author(s):  
John R. Hyde ◽  
Russell D. Vetter
Keyword(s):  
Larval Dispersal ◽  
Sequence Data ◽  
Isolation By Distance ◽  
Dispersal Distance ◽  
Unintended Consequences ◽  
Management Units ◽  
Distance Analysis ◽  
Mitochondrial Cytochrome B ◽  
Genetic Barriers ◽  
Ecological Province

Recent studies have revealed that the vermilion rockfish Sebastes miniatus is a cryptic species pair. The splitting of this species impacts stock size estimates and draws attention to the unintended consequences of current management policies. Differences in exploitation level between the species necessitated an evaluation of population structure and connectivity among regional management segments of the fishery. Analysis of gene flow and calculations of larval dispersal values were accomplished using 782 bp of DNA sequence data from the mitochondrial cytochrome b gene of 684 vermilion rockfish sampled from 16 sites between Kyuquot Sound, Canada, and San Quintin, Mexico. Significant genetic heterogeneity was found among sample sites (ΦST = 0.0742, p < 0.001 and FST = 0.0899, p < 0.001). Isolation by distance analysis produced a significant correlation, suggesting low average larval dispersal distance. Analysis of molecular variance showed significant partitioning of genetic variance across the biogeographic boundary at Point Conception (ΦCT = 0.0923, p < 0.001 and FCT = 0.0135, p < 0.001) with additional genetic barriers found at Cape Mendocino, Punta Colnett, Santa Monica Bay, and along the coast of Washington. These genetic barriers conform to oceanographic compartments previously proposed for the California Current Ecological Province and suggest natural management units for this species.

scholarly journals Managing mobile species with MPAs: the effects of mobility, larval dispersal, and fishing mortality on closure size

2008 ◽  
Vol 66 (1) ◽  
pp. 122-131 ◽  
Author(s):  
W. J. F. Le Quesne ◽  
Edward A. Codling
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Larval Dispersal ◽  
Population Model ◽  
Marine Reserves ◽  
Spatially Explicit ◽  
Fishing Mortality ◽  
Mobile Species ◽  
Explicit Dynamic ◽  
Dynamic Population

Abstract Le Quesne, W. J. F., and Codling, E. A. 2009. Managing mobile species with MPAs: the effects of mobility, larval dispersal, and fishing mortality on closure size. – ICES Journal of Marine Science, 66: 122–131. The use of closed areas (marine protected areas, marine reserves, no-take zones) has been suggested as a possible solution to the perceived global fisheries crisis. However, to optimize the design and evaluate the effectiveness of closed areas, we need to understand the interaction between larval dispersal, adult mobility, and fishing mortality. In this paper, a simple, spatially explicit dynamic population model was developed to examine the effects of these interacting factors on optimal closure size and resulting yields. The effect of using one large or several smaller closed areas was also examined. Our model confirmed previous results: closed areas do not improve the yield of populations that are optimally managed or underexploited and, as mobility increases, optimum closure size increases. The model also predicted some interesting counter-intuitive results; for overexploited stocks, the greatest benefit from closed areas can be obtained for stocks with highest mobility, although this may require closure of 85% of the total area. For the tested parameter settings, adult spillover had greater potential to improve yield than larval export, and using several small closed areas rather than a single larger one had the same effect as increasing the mobility of the population.

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