نتایج جستجو برای: overexploitation
تعداد نتایج: 943 فیلتر نتایج به سال:
The pharmaceutically important anticancer drugs etoposide and teniposide are derived from podophyllotoxin, a natural product isolated from roots of Podophyllum hexandrum growing in the wild. The overexploitation of this endangered plant has led to the search for alternative sources. Metabolic engineering aimed at constructing the pathway in another host cell is very appealing, but for that appr...
The evolutionary stability of mutualisms is enhanced when partners possess mechanisms to prevent overexploitation by one another. In obligate pollination-seed consumption mutualisms, selective abortion of flowers containing excessive eggs represents one such mechanism, but empirical tests have long been limited to the yucca-yucca moth mutualism. We present evidence for selective abortion in the...
Marine protected areas (MPAs) are becoming a favoured management strategy for the conservation of marine biodiversity. We present an analysis of how fishery data from a trawl fishery in northern Australia can contribute to the process of developing a system of candidate MPAs. We investigate ways of using fishing grounds, bioregion and depth information as a means of classifying ecosystems, and ...
A number of experiments all over the world have proven that satellite borne SAR images constitute a valuable tool to monitor oceanic environment, preventing it from overexploitation or pollution matters and it can also help to evaluate the full implications of natural or man made hazards. In fact, thanks to their capability to cover large areas, in all weather conditions, during the day as well...
Overexploitation and climate change are increasingly causing unanticipated changes in marine ecosystems, such as higher variability in fish recruitment and shifts in species dominance. An ecosystem-based approach to fisheries attempts to address these effects by integrating populations, food webs and fish habitats at different scales. Ecosystem models represent indispensable tools to achieve th...
Illegal, Unreported and Unregulated fishing has had a major role in the overexploitation of global fish populations. In response, international regulations have been imposed and many fisheries have been 'eco-certified' by consumer organizations, but methods for independent control of catch certificates and eco-labels are urgently needed. Here we show that, by using gene-associated single nucleo...
Multiple-scale mobility is ubiquitous in nature and has become instrumental for understanding and modeling animal foraging behavior. However, the impact of individual movements on the long-term stability of populations remains largely unexplored. We analyze deterministic and stochastic Lotka-Volterra systems, where mobile predators consume scarce resources (prey) confined in patches. In fragile...
Hymenaea stigonocarpa is a deciduous and monoecious Neotropical tree species pollinated by bats. Due to overexploitation and habitat destruction, the population size has drastically diminished in nature. No previous study has investigated Mendelian inheritance, linkage, and genotypic disequilibrium in the available microsatellite markers in this species. So, our aim was to estimate these parame...
Despite growing concerns about overexploitation of sharks, lack of accurate, species-specific harvest data often hampers quantitative stock assessment. In such cases, trade studies can provide insights into exploitation unavailable from traditional monitoring. We applied Bayesian statistical methods to trade data in combination with genetic identification to estimate by species, the annual numb...
There is general agreement that many, if not most, fisheries subsidies are detrimental to effective resource management. There is not, however, general agreement about subsidies used for decommissioning/buyback purposes. One school of thought argues that such subsidies can have a positive impact upon resource management, by removing excess fleet capacity from the fisheries. An opposing school o...
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