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231.
Developing-world shark fisheries are typically not assessed or actively managed for sustainability; one fundamental obstacle is the lack of species and size-composition catch data. We tested and implemented a new and potentially widely applicable approach for collecting these data: mandatory submission of low-value secondary fins (anal fins) from landed sharks by fishers and use of the fins to reconstruct catch species and size. Visual and low-cost genetic identification were used to determine species composition, and linear regression was applied to total length and anal fin base length for catch-size reconstruction. We tested the feasibility of this approach in Belize, first in a local proof-of-concept study and then scaling it up to the national level for the 2017–2018 shark-fishing season (1,786 fins analyzed). Sixteen species occurred in this fishery. The most common were the Caribbean reef (Carcharhinus perezi), blacktip (C. limbatus), sharpnose (Atlantic [Rhizoprionodon terraenovae] and Caribbean [R. porosus] considered as a group), and bonnethead (Sphyrna cf. tiburo). Sharpnose and bonnethead sharks were landed primarily above size at maturity, whereas Caribbean reef and blacktip sharks were primarily landed below size at maturity. Our approach proved effective in obtaining critical data for managing the shark fishery, and we suggest the tools developed as part of this program could be exported to other nations in this region and applied almost immediately if there were means to communicate with fishers and incentivize them to provide anal fins. Outside the tropical Western Atlantic, we recommend further investigation of the feasibility of sampling of secondary fins, including considerations of time, effort, and cost of species identification from these fins, what secondary fin type to use, and the means with which to communicate with fishers and incentivize participation. This program could be a model for collecting urgently needed data for developing-world shark fisheries globally. Article impact statement: Shark fins collected from fishers yield data critical to shark fisheries management in developing nations.  相似文献   
232.
The brown shrimp Crangon crangon is a key species in the coastal areas of the North Sea. It constitutes a significant food source for fishes. Simultaneously, it is an important predator on a wide range of invertebrates. C. crangon shows a variety of digestive enzymes that allow to utilizing a wide range of food items. The initial step of alimentary protein digestion, that is the degradation into peptides, is facilitated by set of endopeptidases which are expressed by the midgut gland. In crustaceans, these endopeptidases are often dominated by serine proteinases. C. crangon, however, predominantly express cysteine proteinases, while only some specimens show a highly variable pattern of serine proteinases. The composition of these serine endopeptidases was investigated using liquid chromatography, substrate gel electrophoresis and inhibitor assays. Distinctly elevated activities were present only in about 10% of the samples. When activity was detected, two peaks, one with tryptic activity and the other one with chymotryptic activity, could be separated by anionic exchange chromatography. Moreover, specimens with elevated tryptic activities often showed highly polymorphic patterns of endopeptidases after electrophoretic separation. Overall, 30 different bands of endopeptidases were identified. There was no similarity between animals from the same sampling sites, neither between animals of similar size, weight or nutritive state. The polymorphism of proteinase from the midgut gland seems to reflect the high adaptive potential of this species to variable trophic conditions in a continuously changing environment.  相似文献   
233.
The solubilities of acetone, ethanol and acetaldehyde in cold ternary solutions composed of 38.4–75.0 wt% sulfuric acid in water with additional dissolved organic material have been measured over the temperature range 214.4–238.5 K using a Knudsen cell reactor. The solubility of acetaldehyde in H2SO4/H2O is enhanced by an order of magnitude by the presence of ethanol or acetone. The reactive uptake of acetaldehyde is enhanced by the presence of formaldehyde in acid solution. No significant formation of acetals from ethanol with carbonyl partners was observed. The solubility of acetone is unaffected by the presence of ethanol in solution and vice versa. Only polymerization of small aldehydes offers a potentially significant route to the accretion of organic material into acidic particles in the upper troposphere. The acid-catalyzed polymerization of aldehydes, RC(H)O + R′C(H)O, proceeds through the hydrated forms of the aldehydes, is optimized at acidities around 40 wt% H2SO4, and can potentially accumulate significant amounts (>20%) of organic material by mass in upper tropospheric particles.  相似文献   
234.
Reiner JL  Kannan K 《Chemosphere》2006,62(6):867-873
Occurrence of the polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronapthalene (AHTN), in wastewater influent and effluent, as well as in surface waters, has been reported. HHCB and AHTN were also reported to occur in human and wildlife tissues. The major sources for HHCB and AHTN to wastewater are thought to be consumer products such as shampoos, deodorants, laundry detergents, and household surface cleaners. However, the levels of HHCB and AHTN in consumer products are not known. For evaluation of the sources of human and environmental exposures, characterization of levels of HHCB and AHTN in consumer products is needed. In this study, we measured concentrations of HHCB (Galaxolide), AHTN (Tonalide), and HHCB-lactone (Galaxolidone) from a variety of consumer products, including perfumes, body lotions, and deodorants. Concentrations of HHCB, AHTN, and HHCB-lactone in consumer products ranged from <5 ng/g to over 4000 microg/g, <5 ng/g to 451 microg/g, and <5 ng/g to 217 microg/g, respectively. The highest concentrations were found in perfumes, body creams and lotions, and deodorants. The results suggest that a wide variety of source materials exist for HHCB and AHTN, and that these materials are used on a daily basis.  相似文献   
235.
Ambio - A horizon scan was conducted to identify emerging and intensifying issues for biodiversity conservation in South Africa over the next 5–10&nbsp;years. South African biodiversity...  相似文献   
236.
Polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), are used as fragrance ingredients in numerous consumer products such as cleaning agents and personal care products. Studies have reported the widespread occurrence of these musks in surface waters and fish from western European countries. Nevertheless, little is known about their accumulation in humans and wildlife in the United States. In this study, we measured concentrations of HHCB and AHTN in human adipose fat collected from New York City. Furthermore, tissues from marine mammals, water birds, and fish collected from US waters were analyzed to determine the concentrations of HHCB and AHTN. Concentrations of HHCB and AHTN in human adipose fat samples ranged from 12 to 798 and from <5 to 134 ng/g, on a lipid weight basis, respectively. A significant correlation existed between the concentrations of HHCB and AHTN in human adipose fat. Concentrations of HHCB and AHTN were not positively correlated with age or gender of the donors. HHCB was found in tissues of several wildlife species, but not in the livers of polar bear from the Alaskan Arctic. Among wildlife species analyzed, spinner and bottlenose dolphins collected from Florida coastal waters contained measurable concentrations of HHCB.  相似文献   
237.
Assessing the scope and severity of threats is necessary for evaluating impacts on populations to inform conservation planning. Quantitative threat assessment often requires monitoring programs that provide reliable data over relevant spatial and temporal scales, yet such programs can be difficult to justify until there is an apparent stressor. Leveraging efforts of wildlife management agencies to record winter counts of hibernating bats, we collated data for 5 species from over 200 sites across 27 U.S. states and 2 Canadian provinces from 1995 to 2018 to determine the impact of white-nose syndrome (WNS), a deadly disease of hibernating bats. We estimated declines of winter counts of bat colonies at sites where the invasive fungus that causes WNS (Pseudogymnoascus destructans) had been detected to assess the threat impact of WNS. Three species undergoing species status assessment by the U.S. Fish and Wildlife Service (Myotis septentrionalis, Myotis lucifugus, and Perimyotis subflavus) declined by more than 90%, which warrants classifying the severity of the WNS threat as extreme based on criteria used by NatureServe. The scope of the WNS threat as defined by NatureServe criteria was large (36% of Myotis lucifugus range) to pervasive (79% of Myotis septentrionalis range) for these species. Declines for 2 other species (Myotis sodalis and Eptesicus fuscus) were less severe but still qualified as moderate to serious based on NatureServe criteria. Data-sharing across jurisdictions provided a comprehensive evaluation of scope and severity of the threat of WNS and indicated regional differences that can inform response efforts at international, national, and state or provincial jurisdictions. We assessed the threat impact of an emerging infectious disease by uniting monitoring efforts across jurisdictional boundaries and demonstrated the importance of coordinated monitoring programs, such as the North American Bat Monitoring Program (NABat), for data-driven conservation assessments and planning.  相似文献   
238.
In Southeast Asia, elasmobranchs are particularly threatened. We synthesized knowledge from the peer-reviewed and gray literature on elasmobranchs in the region, including their fisheries, status, trade, biology, and management. We found that 59% of assessed species are threatened with extinction and 72.5% are in decline; rays were more threatened than sharks. Research and conservation is complicated by the socioeconomic contexts of the countries, geopolitical issues in the South China Sea, and the overcapacity and multispecies nature of fisheries that incidentally capture elasmobranchs. The general paucity of data, funds, personnel, and enforcement hinders management. Reduced capacity in the general fishery sector and marine protected areas of sufficient size (for elasmobranchs and local enforcement capabilities) are among recommendations to strengthen conservation.  相似文献   
239.
Polychlorinated biphenyl (PCB) congener concentrations and their distributions were determined for the first time in 12 major rivers of eastern China. It was found that the PCB contamination level in those rivers was relatively low compared to the levels reported in most developing countries. Total amount of PCBs in the river sediments ranged from 10 to 22 ng/g dry weight and dichlorodiphenyldichloroethene (DDE) ranged from 0.89 to 7.62 ng/g. The PCB concentrations were basically homogeneous in different rivers; however, they consistently changed with the percent of total organic carbon (TOC). The PCB concentrations and compositions found in the 12 river sediments were very similar, with the tetra‐ and penta‐ groups as the dominants. Given that distributions and contaminant levels in sediments reflect the number of PCBs, the contamination of the 12 major rivers in eastern China is probably due to atmospheric deposition rather than the point source contamination.  相似文献   
240.
The ecological constraints model predicts that daily travel distance and home range size of social animals will increase as group size increases in order to meet the dietary needs of additional group members. This theory has been supported more predominantly by studies of frugivorous primate species than by studies of folivorous species. We examined the ranging patterns of mountain gorillas in Bwindi Impenetrable National Park, Uganda, who include both herbaceous vegetation and fruit in their diet, to determine how ecological, behavioral, and social parameters influence movement patterns. Data were collected from three groups of gorillas with overlapping home ranges at a low-altitude location (1,450–1,800 m) and one group at a high-altitude location (2,100–2,500 m) in Bwindi from September 2001 to August 2002. We analyzed daily travel distance and home range size in relation to group size, while also considering patterns of frugivory, rainfall, and location (proxy for food availability) within the park. Both daily travel distance and home range size were positively related to group size. In addition, the degree of frugivory positively influenced daily travel distance and home range size, while rainfall negatively influenced daily travel distance only. Finally, groups at the low-altitude location, with higher fruit availability, traveled less than the group at the high-altitude location. These results demonstrate that mountain gorillas in Bwindi provide support for the ecological constraints model, but further studies are needed to determine how fine-scale spatial and temporal availability of food resources influence movement patterns. Ranging patterns of Bwindi gorillas are compared to those observed in other gorilla populations in the context of the ecological constraints model.Communicated by D. Watts  相似文献   
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