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    ABSTRACT: The relationship between fish market price and body size has not been explored much in fisheries science. Here, the mean market prices and fish body size were collected in order to examine the hypothesis that large fish, both among- and within-species, are being selectively targeted by fisheries because they may yield greater profit. Trophic levels, vulnerability to fishing and global landings were also collected because these variables may also be related to the market fish price. These relationships were examined using generalized additive models (GAM), which showed that, among species, fish market price was positively dependent on maximum total length (P = 0.0024) and negatively on landings (P = 0.0006), whereas it was independent of trophic level (P > 0.05) and vulnerability to fishing (P > 0.05). When the fish price vs. size relationship was tested within-species, large individuals were consistently attaining higher market prices compared to their medium and small-sized counterparts. We conclude that the selective removal of the larger fish, which is driven by their market price and to a lesser extent by their availability, may contribute to their overfishing.
    Peer J. 10/2014;
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    ABSTRACT: Assessing artisanal fishing effort and catches in remote tropical coastal areas is a continuous challenge for fisheries data collection. This is the first spatio-temporal analysis of the large tidal weir (LTW) fishery operating on intertidal sand banks along the world’s longest mangrove coast, north Brazil. Airborne synthetic-aperture radar (SAR) images and aerial photos were integrated with field sampling to investigate catch and discard compositions of seven LTW during the main fishing season. LTW measurements on the SAR images were used to generate estimates on daily catch, wood extraction, and sand accumulation. In a coastal stretch of 67 km, 793 LTW were identified on SAR images from 2004, including 573 active LTW. The number of active LTW in Taperaçú Bay and Caeté Bay had increased from 87 in 1998 to 132 in 2004 (52% increase), and from 92 to 202 (106% increase), respectively. Sixty-five fish species from 24 families were captured in the LTW. Ariidae, Sciaenidae, Haemulidae, and Carangidae accounted for 45, 20, 10, and 7% of the total sampled catch weight of 3441 kg, respectively. The mean daily catch per LTW was 110 kg ± 9 SE. Total discards in outer estuarine LTW were >3 times higher than in inner estuarine LTW. All Aspredinidae, Belonidae, Tetraodontidae, and Trichiuridae, and >75% of Auchenipteridae, Clupeidae, Engraulidae, Ephippidae, Loricariidae, Scombridae, and Soleidae were discarded. The LTW fishery apparently practices balanced harvesting; however, the massive LTW increase suggests fishing effort reduction to moderate levels. Mangrove wood extraction for LTW construction (22 835 m3 or 855 390 trees) and sand accumulation (144 802 m3) likely have only local scale effects, negligible for the overall ecosystem dynamics. The study highlights the potential of SAR images for use in fisheries data collection and management of tropical coasts, emphasizing the need for integration with ground-truthing field studies.
    ICES Journal of Marine Science 11/2014; · 2.28 Impact Factor
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    ABSTRACT: The emergence of an ecosystem approach to fisheries (EAF) was characterized by the adoption of objectives for maintaining ecosystem health alongside those for fisheries. The EAF was expected to meet some aspirations for biodiversity conservation, but health was principally linked to sustainable use rather than lower levels of human impact. Consequently, while policies including EAF concepts identified objectives for fisheries management and biodiversity conservation, the wording often reflected unresolved societal and political debates about objectives and gave imprecise guidance on addressing inevitable trade-offs. Despite scientific progress in making trade-offs and consequences explicit, there remain substantial differences in interpretations of acceptable impact, responses to uncertainty and risk, and the use of management measures by groups accountable for fisheries management and biodiversity conservation. Within and among nations and regions, these differences are influenced by the contribution of fisheries, aquaculture, farming, and trade to food security, consumers’ options, and other social, economic, and environmental factors. Notwithstanding, mutual understanding of the motivations and norms of fisheries management and biodiversity conservation groups is increasing, and interactions between these groups have likely supported more progress toward meeting their stated objectives than would have otherwise been achievable.
    Annals of the New York Academy of Sciences 07/2014; · 4.38 Impact Factor

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