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Viblanc, V. A., Saraux, C., Malosse, N., & Groscolas, R. (2014). Energetic adjustments in freely breeding-fasting king penguins: does colony density matter? Functional Ecology, .
Résumé: * For seabirds that forage at sea but breed while fasting on land, successful reproduction depends on the effective management of energy stores. Additionally, breeding often means aggregating in dense colonies where social stress may affect energy budgets. * Male king penguins (Aptenodytes patagonicus) fast for remarkably long periods (up to 1·5 months) while courting and incubating ashore. Although their fasting capacities have been well investigated in captivity, we still know very little about the energetics of freely breeding birds. * We monitored heart rate (HR, a proxy to energy expenditure), body temperature and physical activity of male king penguins during their courtship and first incubation shift in a colony of some 24 000 freely breeding pairs. Males were breeding either under low but increasing colony density (early breeders) or at high and stable density (late breeders). * In early breeders, daily mean and resting HR decreased during courtship but increased again 3 days before egg laying and during incubation. In late breeders, HR remained stable throughout this same breeding period. Interestingly, the daily increase in resting HR we observed in early breeders was strongly associated with a marked increase in colony density over time. This finding remained significant even after controlling for climate effects. * In both early and late breeders, courtship and incubation were associated with a progressive decrease in physical activity, whereas core body temperature remained unchanged. * We discuss the roles of decreased physical activity and thermoregulatory strategies in sustaining the long courtship–incubation fast of male king penguins. We also draw attention to a potential role of conspecific density in affecting the energetics of breeding-fasting seabirds, that is, a potential energy cost to coloniality.
Mots-Clés: body temperature; energy expenditure; fasting; heart rate; physical activity; Seabird; social density; Stress
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Avadi, A., Freon, P., & Quispe, I. (2014). Environmental assessment of Peruvian anchoveta food products : is less refined better ? International Journal of Life Cycle Assessment, 19(6), 1276–1293.
Résumé: Life cycle assessments (LCAs) of various anchovy (anchoveta) direct human consumption products processed in Peru were carried out, to evaluate their relative environmental performance as alternative products to enhance nutrition of communities with low access to fish products in the country. LCA was carried out for fresh, frozen, canned, salted and cured anchoveta products, both at plant gate and featuring local and national distribution over non-refrigerated, chilled and fully refrigerated distribution chain. The functional unit used was 1 kg of fish in the final product. Results demonstrate that, in environmental terms, more-refined products (cured and canned anchoveta products) represent a much higher burden than less- refined products (fresh, frozen and salted). Although this is a likely result, the magnitude of this difference (4 to 27 times when expressed as an environmental single score) is higher than expected and had not been quantified before for salted and cured products, as far as we know. This difference is mainly due to differences in energy consumption between types of products. Furthermore, cured and salted products feature larger biotic resource use, when calculated based on the whole fish equivalent, due to higher processing losses/discards. The relevance of taking into account the different transportation and storage needs is highlighted. For those products requiring refrigerated transportation and storage, over a national distribution chain, those activities increase the overall environmental impacts of the products by 55 % (fresh chilled) to 67 % (frozen). However, such an increase does not worsen the environmental performance of fresh and frozen products in comparison to the energy-intensive canned and cured products. It is concluded that a more sustainability-oriented analysis, including the social and economic pillars of sustainability, is required towards decision-making involving promotion of either product for addressing nutritional deficiencies in Peru.
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Freon, P., Avadi, A., Soto, W. M., & Negron, R. (2014). Environmentally extended comparison table of large-versus small- and medium-scale fisheries : the case of the Peruvian anchoveta fleet. Canadian Journal of Fisheries and Aquatic Sciences, 71(10), 1459–1474.
Résumé: Literature on small-scale fisheries usually depicts them as preferable over large-scale-industrial fisheries regarding societal benefits (jobs, jobs per investment) and relative fuel efficiency (e. g., Thomson 1980). We propose an environmentally extended Thomson table for comparing the Peruvian anchoveta (Engraulis ringens) fleets of purse seiners, backed up by methodological information and augmented with life cycle assessment (LCA)-based environmental performance information, as a more comprehensive device for comparing fleets competing for the same resource pool. Findings from LCA and a previous study on the anchoveta steel fleet together allowed characterizing the whole Peruvian anchoveta fishery. These results, along with socioeconomic indicators, are used to build an environmentally extended Thomson table of the fleet's main segments: the steel industrial, the wooden industrial, and the wooden small-and medium-scale (SMS) fleets. In contrast with the world figure, the Peruvian SMS fleets show a fuel performance nearly two times worse than the industrial fleets, due to economies of scale of the latter (although the small-scale segment itself (<10 m(3)) performs similarly to the industrial steel fleet). Furthermore, the absolute number of jobs provided by the industrial fisheries is much larger in Peru than those provided by the SMS fisheries. This is due to the relatively larger development of the industrial fishery, but as in previous studies, the SMS fleets generate more employment per tonne landed than the industrial fleet, as well as more food fish and less discards at sea.
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Merino, G., Barange, M., Fernandes, J. A., Mullon, C., Cheung, W., Trenkel, V., et al. (2014). Estimating the economic loss of recent North Atlantic fisheries management. Progress in Oceanography, , 314–323.
Résumé: It is accepted that world’s fisheries are not generally exploited at their biological or their economic optimum. Most fisheries assessments focus on the biological capacity of fish stocks to respond to harvesting and few have attempted to estimate the economic efficiency at which ecosystems are exploited. The latter is important as fisheries contribute considerably to the economic development of many coastal communities. Here we estimate the overall potential economic rent for the fishing industry in the North Atlantic to be B€ 12.85, compared to current estimated profits of B€ 0.63. The difference between the potential and the net profits obtained from North Atlantic fisheries is therefore B€ 12.22. In order to increase the profits of North Atlantic fisheries to a maximum, total fish biomass would have to be rebuilt to 108 Mt (2.4 times more than present) by reducing current total fishing effort by 53%. Stochastic simulations were undertaken to estimate the uncertainty associated with the aggregate bioeconomic model that we use and we estimate the economic loss NA fisheries in a range of 2.5 and 32 billion of euro. We provide economic justification for maintaining or restoring fish stocks to above their MSY biomass levels. Our conclusions are consistent with similar global scale studies.
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Cuif, M., Keller, F., Chateau, O., Kaplan, D., Labonne, M., Lett, C., et al. (2014). Evaluation of transgenerational isotope labeling of embryonic otoliths in a coral reef damselfish with single and repeated injections of enriched (137)Barium. Journal of Experimental Marine Biology and Ecology, 459, 151–159.
Résumé: Quantifying the larval dispersal component of population connectivity is extremely challenging due to the many difficulties associated with directly observing larvae in their marine environment. Transgenerational isotope labeling is a recent empirical technique that addresses this challenge. It relies on the transmission of an artificially enriched stable isotope (e.g., Ba-137) from gravid females to the embryonic otoliths of their offspring, allowing for mass permanent marking of larvae. Before implementing transgenerational isotope labeling in the wild, it is essential to investigate the transmission longevity of the mark from females to larvae and to assess the potential negative effects on females and their offspring. We injected females of the Humbug damselfish, Dascyllus aruanus, with an enriched Ba-137 solution and reared the resulting progeny to test the marking success and the transmission longevity of the mark, as well as determine potential effects of transgenerational isotope labeling on spawning frequency and size of 1-day eggs and 2-day larvae. Three different single-injection dosages (0.5, 1 and 5 mu g of Ba-137 g(-1) fish weight) were tested, as well as monthly repeated injections of the lowest dosage over a whole reproductive season. We implemented a new method that allows extracting otoliths of newly hatched larvae and analyzing them using laser ablation coupled plasma mass spectrometry (ICP-MS). We showed that for D. aruanus, injection with a low dose (0.5 mu g Ba-137 g(-1), fish weight) produced consistently significantly marked larvae with a half-life for successful enriched Ba mark transmission of approximately 1 month, and that monthly repeated injections of this dose did not negatively impact spawning success or condition of eggs and larvae. Monthly repeated injections of enriched Ba isotope injections at 0.5 mu g Ba-137 g(-1) fish weight will therefore present an effective means of mass marking D. aruanus larvae throughout an entire reproductive season.
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