南海中南部主要经济种类渔业资源声学评估

Fishery resources acoustic assessment of major economic species in south-central of the South China Sea

2012年9~10月(秋季)和2013年3~4月(春季),利用科学探鱼仪(Simrad EY60)结合灯光罩网对南海中南部(5°00'N^16°00'N)渔业资源进行了声学调查与评估。通过分析渔业声学数据,并结合渔业资源采样和生物学测定数据,对鸢乌贼(Symplectoteuthis oualaniensis)、鲭科(鲣Katsuwonus pelamis、圆舵鲣Auxis rochei、扁舵鲣Auxis thazard)、鲹科(长体圆鲹Decapterus macrosoma、颌圆鲹Decapterus lajang和无斑圆鲹Decapterus kurroides等)和金枪鱼属(黄鳍金枪鱼Thunnus albacores和大眼金枪鱼Thunnus obesus)等4类大宗经济鱼类的资源尾数和生物量做了初步评估与分析。结果表明,2012年秋季调查海域上述4类经济种类的资源尾数依次为3.67×10^(10)、2.28×10~9、8.78×10~9、0.80×10~9 ind,合计为4.86×10^(10) ind;生物量依次为2.07×10~6、8.62×10~5、1.78×10~5、2.70×10~5t,合计为3.38×10~6t。2013年春季的资源尾数依次为2.98×10^(10)、1.39×10~9、4.40×10~9、0.65×10~9 ind,合计为3.62×10^(10) ind;生物量依次为2.44×10~6、2.68×10~5、2.44×10~5、1.88×10~5t,合计为3.14×10~6t。秋季渔业资源密度较高的海域位于10°00'N^16°00'N、110°00'E^118°00'E;春季渔业资源密度较高的海域位于8°00'N^9°00'N、110°00'E^118°00'E和10°00'N^16°00'N、110°00'E^118°00'E。

From September to October in 2012 and from March to April in 2013, the scientific sounder （Simrad EY60） combined with light cover net sampling method was employed to evaluate the acoustic survey and fishery resources in the central and southern part of the South China Sea （5°00＇N -16°00＇N）. The acoustic data were collected according to the pre-set survey route by the dual split beam Simrad EY60 portable scientific sounder （70 kHz and 120 kHz） and the analysis processing was mainly done through Echoview （ version 5.3 ） software. The aqueous layer was from 10 to 200 m and the basic unit of integral voyage was set to 5 nmi. Biological samples collected by a light cover net, each station worked one network, depth was from surface to 100 m. The time to light to lure the fish was 19：00 and buckle cover trapped fish after 2 h . After each hauling, catches were randomly sampled by proportion of category on the deck, all catches were classified and counted, and then measured and recorded by body length （ mantle length or fork length ）, weight, gender, gonad maturity and feeding level of catches. Through the analysis of fisheries acoustic data, and combined with the fishery resources sampling and determination of biological data, the abundance and biomass of Symplectoteuthis oualaniensis, Scombridae （Katsuwonus pelamis, Auxis rochei, Auxis thazard ）, Carangidae （Decapterus macrosoma, Decapterus lajang and Decapterus kurroides etc. ）and Thunnus （Thunnus albacores and Thunnus obesus ）and other large economic fish resources were assessed and analyzed preliminarily. In the two surveys, their proportion of total catch weight was 87. 94% and 83. 39% respectively, and the proportion of total catches mantissa was 87.01% and 82.55% respectively,which were the dominant and major economic species in the South China Sea. Therefore, it＇ s representative that this paper was based on the evaluation and analysis of these four categories, it can also reflect the present situation of fishery resources in major economic species ：in the central and southern South China Sea. The accurate assessment of biomass and application to guide fishery production and management had important practical significance which was aimed at providing scientific reference for the development, utilization and management of fisheries resources in this sea area . The results showed that in the autumn of 2012, the abundance of four kinds of economic types in the survey sea was 3.67 ×1010, 2.28× 109, 8. 78 ×109, 0. 80× 109 ind, and total of them was 4.86 × 1010 ind; and the biomass was 2.07× 106, 8.62 × 105, 1.78 × 105, 2.70 × 105 t, respectively, and total of them was 3.38 ×106 t. In the spring of 2013 ,the abundance was 2.98 × 1010, 1.39 × 109, 4.40 × 109, 0.65 × 109 ind, respectively, and total of them was 3.62 × 1010 ind ; the biomass was 2. 44 × 106, 2.68 × 105, 2.44 × 105, 1. 88 ×105 t, respectively, and total of them was 31.40× 105t. The distribution of fishery resources in the autumn was nearly located from 10°00＇N to 16°00＇N , 110°00＇E to 118°00＇E. The distribution of fishery resources in the spring was nearly located from 8°00＇N to 9°00＇N, 110°00＇E to 118°00＇E and 10°00＇N to 16°00＇N, 110°00＇E to 118°00＇E.