Habitat connectivity in reef fish communities and marine reserve design in Old Providence-Santa Catalina, Colombia

On the insular platform of Old Providence/Santa Catalina, Colombia, we compared nearshore lagoonal patch reefs to those on the northern bank distant from the islands to determine the importance of habitat connectivity to fish community structure. Nearshore patch reefs had greater proximity to mangrove, seagrass and rocky shore habitats, and they had significantly more individuals. Nearshore reefs also tended to have a greater total biomass, more species, a higher proportion of predators of mobile invertebrates and small fishes, and a lower proportion of herbivores. Biomass of snappers and grunts at nearshore sites was four times greater compared to bank sites, and was correlated with the amount of seagrass and sand/rubble habitat within 500 m of each patch reef. We also compared length-frequency distributions and abundances of grunts and snappers among all sites (deep and shallow forereefs, patch reefs and deep and shallow leeside slopes). The results were consistent with ontogenetic migrations from shallow sites, primarily seagrass and mangrove habitats, to deeper sites and to those further out on the bank. The evidence suggests that species differed in both distance and direction of dispersal, which may be affected by the abundance and distribution of preferred habitats. Marine reserves near the islands should target nearshore nursery areas and patch reefs harboring species of limited dispersal capability. Reserves on the northern bank would protect spawners of those species showing the greatest dispersal capability

Do Property Rights Lead to Sustainable Catch Increases?

Individual transferable quotas (ITQs) assign property rights in fisheries by granting individual fishers a tradable share of the total allowable catch (TAC). ITQs were originally proposed to enhance profitability and safety, but may also provide incentives for more conservation-minded fishing practices. Indeed, recent empirical evidence shows a reduction in the likelihood of stock collapse and a threefold increase in catches two decades after ITQ implementation. Yet these spectacular catch increases follow modest 20% reductions in reported catches. We used standard fisheries models to analyze whether these catch trends are consistent with the theory underlying conservation benefits from property rights. We find that it appears unlikely that catch increases are attributable to ITQs alone. Improved catch reporting systems are often enacted concurrent with ITQs and may plausibly explain sustained catch increases. The existence of this alternative explanation warrants caution about claims that property rights are the cause of sustainable catch gains

Predicting the Effects of Angler Regulation off Washington and Oregon using Discrete Choice Surveys and Stock Assessments

The effects of regulations on recreational fishers are especially difficult to predict. Data lags typically prevent in-season management, so regulations restrict aspects of individual fishing activity in the hopes of achieving collective catch limits. This study began with discrete choice surveys to elicit angler preferences among various types of fishing trips (including none at all). Trip choices varied in the species composition, number, and size of fish caught, as well as how many could be retained. The results of these surveys allowed us to provide a statistical representation of angler preferences. These preferences were then incorporated into models of fishing behavior in which catch probabilities were modeled using data from actual fishing trips, but potentially constrained by regulation. The model included additional dynamics for selected species by making the probability of catches vary with stock abundance, which in turn varied across years of a model run based on overall fishing pressure. The goal of this angler regulation assessment tool include (a) research to improve our understanding of fishing behavior and (b) operational use to guide managers in setting recreational bag, size, and seasonal limits suitable to achieve recreational catch allocations

The role of marine reserves in achieving sustainable fisheries (One contribution of 15 to a Theme Issue 'Fisheries: a Future?')

Many fishery management tools currently in use have conservation value. They are designed to maintain stocks of commercially important species above target levels. However, their limitations are evident from continuing declines in fish stocks throughout the world. We make the case that to reverse fishery declines, safeguard marine life and sustain ecosystem processes, extensive marine reserves that are off limits to fishing must become part of the management strategy. Marine reserves should be incorporated into modern fishery management because they can achieve many things that conventional tools cannot. Only complete and permanent protection from fishing can protect the most sensitive habitats and vulnerable species. Only reserves will allow the development of natural, extended age structures of target species, maintain their genetic variability and prevent deleterious evolutionary change from the effects of fishing. Species with natural age structures will sustain higher rates of reproduction and will be more resilient to environmental variability. Higher stock levels maintained by reserves will provide insurance against management failure, including risk-prone quota setting, provided the broader conservation role of reserves is firmly established and legislatively protected. Fishery management measures outside protected areas are necessary to complement the protection offered by marine reserves, but cannot substitute for it

The impact of emotional well-being on long-term recovery and survival in physical illness: a meta-analysis

This meta-analysis synthesized studies on emotional well-being as predictor of the prognosis of physical illness, while in addition evaluating the impact of putative moderators, namely constructs of well-being, health-related outcome, year of publication, follow-up time and methodological quality of the included studies. The search in reference lists and electronic databases (Medline and PsycInfo) identified 17 eligible studies examining the impact of general well-being, positive affect and life satisfaction on recovery and survival in physically ill patients. Meta-analytically combining these studies revealed a Likelihood Ratio of 1.14, indicating a small but significant effect. Higher levels of emotional well-being are beneficial for recovery and survival in physically ill patients. The findings show that emotional well-being predicts long-term prognosis of physical illness. This suggests that enhancement of emotional well-being may improve the prognosis of physical illness, which should be investigated by future research

Rapid recovery of genetic diversity of stomatopod populations on Krakatau : temporal and spatial scales of marine larval dispersal

Author Posting. © Royal Society, 2002. This article is posted here by permission of Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society of London B 269 (2002): 1591-1597, doi:10.1098/rspb.2002.2026.Although the recovery of terrestrial communities shattered by the massive eruption of Krakatau in 1883 has been well chronicled, the fate of marine populations has been largely ignored. We examined patterns of genetic diversity in populations of two coral reef-dwelling mantis shrimp, Haptosquilla pulchella and Haptosquilla glyptocercus (Stomatopoda: Protosquillidae) , on the islands of Anak Krakatau and Rakata. Genetic surveys of mitochondrial cytochrome oxidase c (subunit 1) in these populations revealed remarkably high levels of haplotypic and nucleotide diversity that were comparable with undisturbed populations throughout the Indo-Pacific. Recolonization and rapid recovery of genetic diversity in the Krakatau populations indicates that larval dispersal from multiple and diverse source populations contributes substantially to the demographics of local populations over intermediate temporal (tens to hundreds of years) and spatial scales (tens to hundreds of kilometres). Natural experiments such as Krakatau provide an excellent mechanism to investigate marine larval dispersal and connectivity. Results from stomatopods indicate that marine reserves should be spaced no more than 50-100 km apart to facilitate ecological connectivity via larval dispersal.P.H.B. acknowledges support of a NSF Minority Postdoctoral Fellowship. Research was funded by grants to S.R.P. A Putnam grant supported fieldwork

The dynamics of deferred decision

AbstractDecision makers are often unable to choose between the options that they are offered. In these settings they typically defer their decision, that is, delay the decision to a later point in time or avoid the decision altogether. In this paper, we outline eight behavioral findings regarding the causes and consequences of choice deferral that cognitive theories of decision making should be able to capture. We show that these findings can be accounted for by a deferral-based time limit applied to existing sequential sampling models of preferential choice. Our approach to modeling deferral as a time limit in a sequential sampling model also makes a number of novel predictions regarding the interactions between choice probabilities, deferral probabilities, and decision times, and we confirm these predictions in an experiment. Choice deferral is a key feature of everyday decision making, and our paper illustrates how established theoretical approaches can be used to understand the cognitive underpinnings of this important behavioral phenomenon