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1.
Previous estimates of the world-wide input of oil to the marine environment by natural seeps ranged from 0·2 to 6·0 million (metric) tonnes per year with a ‘best estimate’ of 0·6 million tonnes per year. Based on considerations of the availability of oil for seepage from the world's known and assumed oil resources, we believe that the world-wide natural oil seepage over geological time should be revised to about 0·2 million tonnes per year with a range upward or downward of a factor of ten leading to estimates between 0·02 and 2 million tonnes per year. Our estimate of the amount of oil eroding from the land and being transported to the oceans is about 0·05 million tonnes per year with an order of magnitude uncertainty. Therefore, while the uncertainties are large, we estimate that the total amount of oil entering the marine environment by natural, geological processes, is about 0·25 million tonnes per year, and the estimate may range from about 0·25 to 2·5 million tonnes per year.  相似文献   

2.
-On the basis of the data obtained from the surveys in the Bohai Sea during 1982-1983, this paper analysed and discussed the distribution and seasonal variation of primary productivity in the Bohai Sea, and the correlations between the primary productivity and environmental factors. The organic carbon production and prospect of fishery production in the waters of this sea are estimated. It is shown that, there exists production patential in the Bohai Sea, the primary production is 112 gC/ (m2 ?a)the production of organic carbon being 10 million ton per year, the fishery yields 1 million ton and the maximum catch of sea products 0. 5 million ton. The results of the investigation can serve as the basic data for the exploitation, utilization and management of the fishery resources in the Bohai Sea.  相似文献   

3.
This study describes the Thukela Banks crustacean and linefish fisheries and investigates the potential impacts of reduced flow from the Thukela River on the value of these fisheries. Data were obtained from published and unpublished material, key informants and government records. The crustacean fishery employs about 300 people, and comprises an inshore and offshore fishery. Inshore catches and effort are strongly seasonal, peaking in April to June. The probability of fishing in any particular month is positively correlated with catch per unit effort. Average overall annual catch (inshore and offshore) was estimated to be in the region of 700 tonnes for 1992–2002 with a gross output of about R36.7 million per annum, and a gross value added (net output) of R13.8 million (1 US$ = R6.40; 2003). Inshore prawns were estimated to contribute R8.5 million of the gross output. The Thukela Banks was estimated to contribute R4.5 million and R35 million (rand value in 2003) to the gross output of the commercial linefishery and boat-based recreational angling fishery respectively. Freshwater reduction scenarios yielded 0.7–11% reductions in prawn catches, which translated into only a 1–2% drop in the annual value of the fishery. The latter was attributed to the fishery's diversity (predominantly the buffering effect of bycatch) and the fact that the stocks of the species targeted by the offshore component are largely independent of flow. Catches and value of the recreational boat-based linefishery were predicted to remain fairly constant irrespective of any changes in flow. The commercial linefishery was the most responsive, with a 20% decline in total catch and 17% value predicted for the most extreme flow reduction scenario.  相似文献   

4.
The input of river-borne sediments to the New Zealand continental shelf has been calculated for all the major rivers and basins in New Zealand. South Island yields 284 ± 40 × 106 tonnes per year of sediment from a land area of 152 977 km2 and North Island yields 105 ± 9·4 × 106 tonnes per year from a land area of 114 621 km2. Particularly high discharges are noted off the west coast of South Island and east coast of North Island and result in higher offshore sedimentation there. The data are compatible with measured sedimentation rates on the New Zealand continental shelf. The specific sediment yield from South Island is amongst the highest previously recorded.  相似文献   

5.
Tuna purse seining in the Pacific Islands region is the world’s largest tuna fishery. Currently some organizations are publicising the desirability of replacing at least some of the purse seining with pole-and-line fishing—a technique which requires significant quantities of live baitfish. This research was undertaken to determine the quantity of baitfish required to replace purse seining. It is estimated that to catch a million tonnes of tuna annually in the Pacific Islands region (i.e. replace the purse seine fishery) would require about 31,250 t of baitfish per year. Historical catches of baitfish suggest that catches this large may not be possible. There is also some question of the practicality and desirability of a substantial increase in baitfish harvesting in the region.  相似文献   

6.
Bycatch presents a challenge to optimizing yield in commercial fisheries, where bycatch can total more than 1 million mt per year in the United States. Yet the economic impacts of bycatch have rarely been evaluated in the scientific literature. These economic impacts largely occur from the loss of landings through (1) early closure of fisheries when catch limits of bycatch species are reached; and (2) discards of marketable catch due to regulatory requirements in the fishery. This paper illustrates the economic impacts of early closures due to bycatch in U.S. fisheries by describing past case studies, as well as evaluating the economic impacts of discarding fish in U.S. commercial fisheries. Premature closures in the fisheries reviewed resulted in potential losses ranging from $34.4 million to $453.0 million annually. Nationally, bycatch estimates in the form of regulatory discards are annually reducing the potential yield of fisheries by $427.0 million in ex-vessel revenues, and as much as $4.2 billion in seafood-related sales, $1.5 billion in income, and 64,000 jobs. Our review also shows that some of the most promising work to reduce bycatch over the last decade has been the development of gears or gear modifications, termed “conservation engineering.”  相似文献   

7.
A new conservation measure aimed at protecting the larger broodstock (females with a carapace length between 115 and 129 mm, i.e., window‐size females, WSF) to enhance egg production was implemented in 2003 for the American lobster (Homarus americanus) fishery in the southern Gulf of St. Lawrence, Canada. To assess the effectiveness of this new measure, a tagging project was carried out between 2004 and 2007 in the Hillsborough Bay area with the collaboration of local harvesters. Based on a single mark‐recapture Petersen model, the estimated catch rates of WSF not carrying eggs under the abdomen in the study area varied between 40% and 53%. The catch‐per‐unit‐effort (animals per 100 traps) of both berried (egg‐bearing) and non‐berried WSF increased from 0.2 to 0.8 and 1.0 to 1.6, respectively, between 2004 and 2007. Based on the estimated number of non‐berried WSF in the population observed during the spring fishery between 2004 and 2007, the potential total egg production for WSF was estimated at 1.1 billion in the study area. From this total, 515 million eggs would have been produced by WSF directly protected by the conservation measure, i.e., females that would have been harvested if not for the new regulation. Finally, the contribution of berried WSF to the annual egg production in the study area increased from 4% to 23% between 2003 and 2007 based on the at‐sea sampling programme and the fecundity curve. WSF that represented 10% of the total berried female population in 2007 contributed 23% of the annual egg production. Hence, the protection of WSF seems to be an effective conservation measure to increase egg production based on the catch‐per‐unit‐effort and egg production.  相似文献   

8.
Many fish stocks in the world are depleted as a result of overexploitation, which reduces stock productivity and results in loss of potential yields. In this study we analyzed the catch trends and approximate thresholds of sustainable fishing for fished stocks to estimate the potential loss of catch and revenue of global fisheries as a result of overexploitation during the period of 1950–2010 in 14 FAO fishing areas. About 35% of stocks in the global marine ocean have or had suffered from overexploitation at present. The global catch losses amounted to 332.8 million tonnes over 1950–2010, resulting in a direct economic loss of US$298.9 billion(constant 2005 US$).Unsustainable fishing caused substantial potential losses worldwide, especially in the northern hemisphere.Estimated potential losses due to overfishing for different groups of resources showed that the low-value but abundant small-medium pelagics made the largest contribution to the global catch loss, with a weight of 265.0 million tonnes. The geographic expansion of overfishing not only showed serial depletion of world's fishery resources, but also reflected how recent trends towards sustainability can stabilize or reverse catch losses.Reduction of global fishing capacity and changes in fishery management systems are necessary if the long-term sustainability of marine fisheries in the world is to be achieved.  相似文献   

9.
The southern rock lobster, Jasus edwardsii, is South Australia's most valuable fisheries resource, with an annual landed value of c. AU$100 million. Approximately 80% of this revenue comes from the southern zone (SZ) rock lobster fishery, which has been managed under an individual transferable quota system since 1993. The total allowable commercial catch is currently set at 1900 tonnes. Long‐term spatial trends in catch and effort were analysed over the period 1970–2005 to investigate possible changes in the spatial dynamics of the fleets as a result of quota introduction. Data indicate that the fishery contracted into three main Marine Fishing Areas (MFAs) after 1993. In particular, the long‐term catch average in MFA 51 decreased from 185.4 tonnes pre‐quota to 59.8 tonnes post quota. This MFA is located in the northern region of the SZ and is one of the furthest MFAs from the main fishing ports in the region. The fishery is also spatially contracted within MFAs. Approximately 80% of the annual catch comes from <60m depth despite catch rates being 2–3 times greater in offshore sites as evidenced from both fishery‐dependent and independent sources. Such trends appear driven by recent market preferences that select for small (<1 kg), red‐coloured lobster that are primarily located on inshore grounds. As a result, fishers now target inshore sites to maximise returns under the quota‐based system. The observed shift in the spatial dynamics of the SZ has clear implications for the biological performance indicators on which the fishery is managed. Specifically, the results highlight the need for a fishery‐independent assessment of the resource that provides estimates of catch rate and biomass independent of current harvest strategies. Preliminary results from a trial survey undertaken in 2005/06 and 2006/07 show higher lobster abundance in lowly exploited offshore sites compared with inshore areas. These trends highlight the need for refined spatial management of the resource, which is the focus of the new management plan for the fishery.  相似文献   

10.
A preliminary mass-balance trophic model was constructed to determine the flow of energy in a community of fish and invertebrates on the continental shelf of the south-western Gulf of Mexico. Input parameters were taken from the literature, except for the biomass of fish groups which was obtained from trawl surveys in the study area. The model consists of 12 fish groups, five invertebrate groups, phytoplankton and detritus. Results indicate an imbalance between primary production and consumption, with only about 10% of primary production being consumed in the water column. Most of the primary production is exported to detritus which forms the basis of the food-web, with a detritivory/herbivory ratio of 2·5. Benthic invertebrates play a significant role in transferring energy from detritus to higher trophic levels. Eight discrete trophic levels were found, with very reduced flow at levels higher than the fifth. The highest fractional trophic level is 4·3, and consists of sharks. Analysis of mixed trophic impacts showed that detritus and lower trophic levels have a significant positive impact on other groups in the system. Mean transfer efficiency is 9·2%. Some whole system properties are also given. Of net primary production, 6·7% is required to sustain current catch levels, suggesting that the resources in this area are fully exploited.  相似文献   

11.
The dynamics of benthic primary production and community respiration in a shallow oligotrophic, marine lagoon (Fællestrand, Denmark) was followed for 1·5 years. The shape of the annual primary production cycle was explained primarily by seasonal changes in temperature (r2 = 0·67-0·72) and daylength (r2 = 0·63), whereas temperature almost explained all variation in benthic community respiration (r2 = 0·83-0·87). On a daily basis the benthic system was autotrophic during spring and summer supplied by 'new' and 'regenerated' nitrogen and predominantly heterotrophic during fall and winter caused by light and nutrient limitation. The linear depth-relationship between porewater alkalinity and ammonium indicated that the C:N ratio of mineralized organic matter is low in spring and summer (3-6) and high in fall and winter (9-16). This is inversely related to net primary production and thus the input of labile, nitrogen-rich algal cells. Accordingly, mineralization occurred predominantly in the upper 2-5 cm of the sediment. The pool of reactive material (microalgal cells) was estimated to account for 12% of total organic carbon in the upper 3 cm, and had an average turnover time of less than 1 month in summer. Assimilation of organic carbon by benthic animals was equivalent to about 30% of the annual gross primary production. Grazing reduced chlorophyll a concentration in the sediment during summer and spring to values 30-40% lower than in winter, but maintained a 3-4 times higher specific microalgal productivity. The rapid turnover of organic carbon and nitrogen, and important role of benthic microalgae showed that the benthic community in this oligotrophic lagoon is of a very dynamic nature.  相似文献   

12.
Bangladesh's hilsa shad (Tenulosa ilisha) comprises the largest single-species fishery in the country, constituting 11 per cent of the total catch and employing 2.5 million people directly or indirectly. Since 2003, following a sharp decline in catch figures, the hilsa fish has been the subject of a government conservation programme offering fishers economic incentives or payments for ecosystem services (PES). While PES schemes are widely used to conserve natural resources such as forests and watersheds, Bangladesh's programme is a rare example of PES for sustainable fishery management. Catch figures have improved since the programme was introduced; but concerns remain about fishers’ socioeconomic conditions and the long-term sustainability of Bangladesh's hilsa fishery. This paper analyses the conservation scheme's legal and institutional frameworks, identifying challenges to its design and implementation, and makes recommendations to overcome them.  相似文献   

13.
St Lucia is one of the largest estuarine systems in Africa, and attracts thousands of anglers each year. Catchcard data from the National Marine Linefish System for the years 1986–1999 were analysed to determine catch composition, catch per unit effort (cpue) and seasonality of catches by recreational anglers. Because not all anglers completed catch cards, estimates of total catch were made using additional data on the number of private boat outings, the number of boat trailers at boat slipways and the number of boats recorded entering the campsite gates during 1992 and 1993. In all, 27 fish families, constituting 55 species, were recorded by recreational anglers. Dusky kob Argyrosomus japonicus, spotted grunter Pomadasys commersonnii, perch Acanthopagrus berda, Natal stumpnose Rhabdosargus sarba, springer Elops machnata and mini-kob Johnius dorsalis were the most prominent species caught in terms of numbers and mass. Catch rates expressed numerically (fish angler?1 h?1) peaked during the summer and early winter. However, in terms of mass, catch rates peaked during late winter and spring, when there were increased landings of large dusky kob. Fluctuations in cpue were linked to salinity and estuary mouth conditions (i.e. mouth closure). Despite annual fluctuations in cpue, regression analysis revealed an overall downward trend for the dominant species (dusky kob and spotted grunter) and a gradual increase for stumpnose, perch and springer, but with the exception of stumpnose, these trends were not significant. Socio-economic aspects of the fishery were also investigated by conducting an independent boat-angler survey. The value of the recreational fishery, in terms of accommodation and direct angler expenditure, was estimated to be in the region of R9 million during 1992. Angler attitudes towards fishing regulations were positive and anglers generally had a good knowledge of the regulations for target species. Based on this assessment, a number of suggestions are made regarding the future management of the recreational fishery at St Lucia.  相似文献   

14.
White stumpnose Rhabdosargus globiceps is the main target of the linefishery in Saldanha Bay. Increased fishing pressure over the last three decades, particularly by the recreational sector, has led to concerns regarding sustainability of the local white stumpnose stock. The fishery was exceptionally productive between 2006 and 2008, with an estimated annual catch of 141.2 tonnes (t). Only 3% of boat outings surveyed were commercial boats targeting white stumpnose, yet this sector accounted for 39.3 t (31%) of the average annual catch. The recreational boat sector accounted for most of the catch (70.0 t), and the recreational shore sector the least (31.9 t). Commercial boat catch per unit effort (CPUE; 3.7 fish angler–1 h–1) was more than 10 times that of recreational boats (0.3 fish angler–1 h–1). White stumpnose catch length-frequency differed significantly (p < 0.01) between the fishing sectors, with the commercial sector retaining larger fish (34.7 cm [SD 5.9]) than the recreational boat (33.9 cm [SD 5.9]) and shore (30.4 cm [SD 5.8]) sectors. A decline in commercial CPUE (2000–2015) of approximately 40% and a concomitant severe decline (>95%) in survey data for juvenile white stumpnose CPUE (2007–2016) indicate that the current rate of exploitation is not sustainable. Recovery of the white stumpnose stock will require a decrease in fishing mortality. Possible management regulations include sector-specific effort limitations, extending the ‘no take’ marine protected area, reducing the recreational-sector bag limit to 5 fish person–1 day–1, implementing a commercial-sector bag limit, and increasing the minimum size limit to 30 cm TL.  相似文献   

15.
The predatory fish community and their prey in the Norman Rivere estuary, Gulf of Carpentaria Australia, are compared with the communities of other tropical inshore areas, to investigate patterns of predation in tropical inshore areas particularly in relation to penaeid prawns. Abiotic factors (turbidity, freshwater input) and diversity of habitat types affect the composition of both prey and predator communities, resulting in large differences in the communities of tropical inshore waters. The stomach contents of 2059 predatory fish from the Norman River estuary were analysed over four sampling trips in the wet and dry seasons. The stomachs of 61% (1255 fish) of 54 species contained a total of 676·2 g (dry weight) of food, while 39% (804 fish) were empty. Teleosts were the main component of the diet (by dry weight) of 13 of the 22 species analysed, followed by annelids for two species. Five species had only teleosts in their stomachs. Most predator species ate benthic or bentho-pelagic prey, while three species—Rhizoprionodon taylori, Scomberoides commersonianusandLeptobrama mulleri—ate mainly pelagic prey. Although 19 species ate some penaeids, onlyPolydactylus sheridaniate little else. This species,Lates calcariferandEleutheronema tetradactylumate 94·5% of all the penaeid prey and 97·9% of all the commercially important penaeid prey recorded in the study. Penaeid predation indices (calculated from gillnet catch rates, proportion of penaeids in the diet and a consumption rate of 3% body weight per day) were 0·23 g of penaeid per net-metre per day forP. sheridani, 0·15 forL. calcariferand 0·03 forE. tetradactylum. Commercially important penaeid predation indices were 0·11, 0·13 and 0·01, respectively. These values are intermediate between those previously recorded for the main penaeid predators in other inshore areas of the Gulf of Carpentaria (Embley River estuary and Groote Eylandt).  相似文献   

16.
The Caeté Estuary lies within the world's second largest mangrove region, 200 km south-east of the Amazon delta. It has an extension of about 220 km2and is subjected to a considerable human impact through intensive harvest of mangrove crabs (Ucides cordatus) and logging of mangroves. In order to integrate available information on biomass, catches, food spectrum and dynamics of the main species populations of the system, a trophic steady state model of 19 compartments was constructed using the ECOPATH II software (Christensen & Pauly, 1992). Ninety-nine percent of total system biomass is made up by mangroves (Rhizophora mangle, Avicennia germinans andLaguncularia racemosa ), which are assumed to cover about 45% of the total area and contribute about 60% to the system's primary production. The remaining biomass (132 g m−2) is distributed between the pelagic and benthic domains in proportions of 10% and 90% respectively. Through litter fall, mangroves inject the main primary food source into the system, which is either consumed directly by herbivores (principally land crabs, Ucides cordatus) or, when already metabolized by bacteria, by detritivors (principally fiddler crabs, Uca spp.). These two groups are prominent in terms of biomass (80 g and 14·5 g m−2), and food intake (1120 g m−2 yr−1and 1378 g m−2 yr−1respectively). According to the model estimates, energy flow through the fish and shrimp compartments is of relatively low importance for the energy cycling within the system, a finding which is contrary to the situation in other mangrove estuaries reported in the literature. The dominance of mangrove epibenthos is attributed to the fact that a large part of the system's production remains within the mangrove forest as material export to the estuary is restricted to spring tides, when the forest is completely indundated. This is also the reason for the low abundance of suspension feeders, which are restricted to a small belt along the Caeté River and the small creeks which are watered daily. Phytoplankton, temporarily refloating benthic diatoms, neritic zooplankton and small pelagic fish dominate the (low) pelagic biomass. Total system throughput (10 559 g m−2 yr−1) and mean transfer efficiency between trophic levels (9·8%) calculated by the model fit well into the range reported for other tropical coastal ecosystems. The very high gross efficiency of the fishery (catch/net primary production) of 8·6% and its low trophic level (2·1) is explained by a high harvesting rate of mangroves and the fact that the main animal resource in the system are the mangrove crabs (Ucides cordatus), which feed at the first trophic level. The model was balanced asuming a turnover rate for the land crabs of P/B=0·25 (P/B: production per unit of biomass) which is possibly too high. If this value was replaced by a (possibly more realistic) lower value, the model would not balance, suggesting a situation in which more biomass is being harvested than produced, which hints to an overexploitation of this resource A ranking of the various system components in terms of their contribution to the system function (ascendency sensu Ulanowicz, 1997) revealed that detritus and associated bacteria contribute 34%, mangroves 19%, fiddler crabs 13%, phytoplankton and microphytobenthos 10%, mangrove crabs 10%, and the remaining 14 groups 14% to the total ascendency. Summary statistics of the model are given and compared with those of other coastal ecosystems.  相似文献   

17.
A total of 248 roving creel surveys along the length of the Berg River Estuary, in the Western Cape, South Africa, recorded 626 shore-angler and 88 boat-angler outings over the period December 2002–November 2005. Catch-and-effort information was obtained from catch inspections with 360 handline and 246 rod-anglers. Average total annual linefishing effort was estimated at 449 ± 29 (mean ± SE) boat-angler days, 1 299 ± 118 recreational shore-angler days and 1 394 ± 57 subsistence (handline) shore-angler days. The estimated total shore-based linefish catch (excluding boat-based catches) from the estuary for the years 2004 and 2005 was 37 231 ± 1 326 fish and 26 938 ± 706 fish (approximately 8 t and 7 t) respectively. Compared with other estuaries along the South African east coast where angler catches have been surveyed, species diversity in catches from the cool-temperate Berg River Estuary was low, with only 15 species caught, of which three, elf Pomatomus saltatrix (56%), harder Liza richardsonii (31%) and carp Cyprinius carpio (11%), dominated the catch. Average linefish catch per unit effort of most species increased significantly in the two years subsequent to the closure of the long-existing commercial gillnet fishery in March 2003. Length frequency distributions revealed significant increases in the average size and an increased contribution of larger size class elf and harder to the linefish catch over the monitoring period, suggesting a degree of recovery of the estuarine icthyofauna after more than a century of intensive gillnet fishing.  相似文献   

18.
Midsummer (1 August) population estimates of about 2 million O-group plaice (Pleuronectes platessa L.) were derived for sandy bays around the Firth of Forth in 1979–1980. This is an order of magnitude less than similar estimates made for the Clyde Sea Area in 1973–1974. Autumn population estimates of 0·4–1·0 million fish were comparable to estimates by the Ministry of Agriculture, Fisheries and Food for the area between the Scottish border and Flamborough Head (2·3 million for 1970 and 1973) which represented 4·8% (1973) to 5·3% (1970) of the total number of O-group fish on the English east coast.Largo Bay was the most important nursery area holding 25% of the total population. It is particularly well situated to receive newly metamorphosed plaice carried in water currents along the north side of the Forth from the spawning ground off Fife Ness. Plaice in the Forth are mainly distributed on fine to medium sandy beaches (186–480 μm), the mean number per haul in midsummer (D) being correlated with the median diameter (m.d. in μm) of the low water sediments by the equation: D=−45·7666+0·2327 m.d. (n=11,r=0·68,P<0·02 but>0·01).The shallow inshore water in sandy bays in the outer Firth was well mixed and more marine than estuarine (27·7–35·0‰). The correlation coefficient between fish density and water temperature was low, while that with salinity (S‰) was: D=6·1618+0·2238S (n=23,r=0·62,P<0·005).Regression analysis demonstrated that the relationship between the instantaneous mortality rate (Z) and the initial population density (Dp) was: Z×100=0·7480+0·0546dp (n=12,r=0·87,P<0·001).The mean mortality rate for the O-group plaice in the Forth nursery areas was 53% month−1.  相似文献   

19.
Fish stocks associated with seamounts may be particularly susceptible to overexploitation. From January to July 2001, the Spanish Oceanographic Institute (IEO) conducted an experimental fishing survey entitled ‘Palguinea-2001’ on the seamounts of the Sierra Leone Rise. Beryx splendens (commonly called alfonsino) is the main commercial demersal fish associated with this area. The aim of this study was to investigate the effects of a demersal longline fishery targeting B. splendens on the previously unexploited small Machucambo Seamount over a short time-scale, and also to consider trends in pooled catch rate at another four seamounts. During 110 fishing days at Machucambo, a total catch of 207 tonnes of B. splendens was taken with a fishing effort of 1 309 070 hooks. A spectral analysis and red-noise spectra procedure (REDFIT) algorithm was used to identify the red-noise spectrum from the gaps in the observed time-series of catch per unit effort by weight. Our results show the potential impact of longline fishing pressure on an unexploited ecosystem – after approximately 50 fishing days, the stock appeared to decline substantially, as reflected by a marked drop in catch per unit effort. The apparent rapid decline of the stock might be related to the small size and the virgin state of the Sierra Leone seamounts. The results could be extrapolated to similar small seamounts elsewhere.  相似文献   

20.
Sea turtles can be incidentally caught in pelagic longline fishing gear targeting tuna and swordfish. Bycatch to fish catch (B/C) ratios can differentiate seafood based on sea turtle impacts. This study demonstrates the use of B/C ratios indexed to the weight of fish catch: (1) to report on the significant progress in reducing sea turtle bycatch in Hawaii's swordfish longline sector and (2) to compare Hawaii and other Pacific longline fisheries by number of sea turtle interactions per weight of catch. Hawaii's longline tuna fishery sets the benchmark of 1 sea turtle interaction per 190,000 kg of tuna caught.  相似文献   

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