| Antarctic krill, usually refers to is the Euphausia superba. Dana,50%of the greataccounting for the number of Antarctic waters zooplankton biomass of the species inthe number of absolute advantages can be used as the indicator of Antarctic waters.Then it is the main species of Antarctic biological resources development andutilization of the main fishing object. Fishing of Antarctic krill trawls and cold-based,production vessels are generally large tail slide trawl factory ship.Antarctic krill living away from the Southern Ocean near Antarctica (south of50°S), was the Central Antarctic distribution-intensive areas often appeared in the edge ofthe continental shelf, the ice edge and islands around. Involved in the Antarctic krilltraditional fishing grounds, including: the South Islands Shetland (48.1area)surrounding waters, Antarctic krill are mainly gathered in the coastal waters; SouthOrkney Islands (48.2area) is one of the former major Antarctic krill fishing groundsof Soviet Union.The paper based on Antarctic Marine Living Resources Development andUtilization Project Ministry of Agriculture in2010-2011.the measured data areexploratory fishing boat ‘KaiLi’&‘KaiXin’ from Shanghai KAICHUANG fishingCo., Ltd..The ‘KaiLi’ boat fishing locations in the South Shetland Islands waters (48.1area), from December14to December30,2010. The ‘KaiXin’ boat round the mainplace of fishing waters in the northwest of the South Orkney Islands (48.2area),2011March5to April20. The two ships survey,832four single capsule trawl.Actual fishery data at sea, including: catches, position, drag the depth and dragspeed, the measured environmental data: light intensity, temperature, pressure. Seasurface temperature SST data downloaded from Oceanwatch site, the resolution (0.1°×0.2°), the time interval of7days. Through the calculation of the nominal amountof catch per unit effort (CPUE) of fisheries data and draw maps of CPUE and relativeresources index RAI. CPUE and each factor, the statistical analysis include: thecorrelation analysis between the different factors, the use of the generalized additive model GAM analysis of different factors on CPUE impact weight. The same time, thesite collection in the Antarctic krill living holding the water column under artificialconditions to observe the impact of water temperature on the individual behavior ofAntarctic krill. Come to the effects of environmental factors on the temporal andspatial distribution of Antarctic phosphorus fisheries, The main results are asfollows:(1) Distribution of fishing groundSouth set Shetland Islands in the northern waters (61°S～61°30’S,57°W～59°30’W), the values of CPUE is ranged for (12.5kg/min～400kg/min)and anaverage of209.65kg/min. CPUE changes with relatively stable CPUE of small pointsconcentrated in the west. Waters in the northwest of the South Orkney Islands (60°S～61°S,46°30’W to47°W), the CPUE of the value range (8.7kg/min～1400kg/min), an average of336.46kg/min. CPUE changes in the distribution ofnon-obvious law, the CPUE of the value of the point distribution is more concentrated.According to operating the water layer obtained krill distribution of the water layerfrom5m to90m,25m interval of four water layer, the CPUE of the mean fromshallow to deep into from shallow to deep the368.58kg/min、303.05kg/min、318.11kg/min、216.13kg/min. With the depth increases, the mean of the CPUE of adecreases.(2) environmental factors on CPUEGAM model is obtained: in the horizontal direction, the weight of each factor onthe impact of CPUE descending were: time, latitude, sea surface temperature SST,longitude, air pressure, air temperature; in the vertical direction, the depth is greaterthan the impact of illumination on CPUE. The depth and illumination by a variety ofcurve fitting, linear fit to the highest degree, we can see with the enhancement of theillumination of the krill distribution of the water layer on a downward trend. Thedistribution of shrimp group depth in March most up to100m, in April only about60m.(3) sea surface temperature SST changes on the CPUEAccording to overlay between CPUE and SST data, in the South ShetlandIslands, SST within the scope of (0.3℃～2.0℃)，the number of nets graduallyincreased, over time, gradually increasing CPUE of value. The larger the CPUE maindistribution in the area of SST from1.3℃to1.7℃. In the waters northwest of theSouth Orkney Islands, the SST range is-0.3℃to2.0℃, the CPUE of a downward trend, the waters of the fishing operations to move northwest from the east, the largerthe CPUE distribution in the within the region of SST (1.0℃～2.0℃).(4) the impact of temperature on the Antarctic krill individualsThe observations show that: water temperature range of0℃to5℃, the krill areable to maintain its vitality and normal swimming. Water temperature exceeds5℃,krill is not suited to the phenomenon. The krill death occurred when watertemperature is higher than7℃,7℃can be regarded as minimum temperature todeath. The molting of krill occurred mainly in the water that temperature ranged of (3℃～7℃). Therefore, the Antarctic krill under artificial conditions can adapt to thenormal water temperature range of (0℃～5℃), tolerance limit water temperature was7℃.(5) the characteristics of the Antarctic krill fishery(a) remove the outside time and space factors on the horizontal distribution of seasurface temperature SST resources of Antarctic krill distribution and abundance of thegreatest impact, resource abundance a large fishing ground area in the SST region of(1℃～2℃).(b) the inter-linkages between the depth of the illumination, illuminanceincrease is a direct result of the Antarctic krill population distribution of waterdropping.(c) Antarctic krill individuals as the water temperature ranged of (0℃～5℃), krill in the range of normal survival; krill ability to adapt to temperature change isweak.(d) the northern Antarctic Peninsula, krill fisheries are good fishing grounds oftemperature change, Antarctic krill can’t by the temperature gradient of thethermocline.(e) Through the analysis of SST, we could find the center of theAntarctic krill fishery. |
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