不同捕捞方式下南海北部海域鲹类渔场的时空分布

Temporal and Spatial Distribution of Carangidae in the North of South China Sea under Different Fishing Methods

【目的】分析南海鲹科鱼类在单拖、双拖和围网三种捕捞方式下的渔获率,探究南海北部海域鲹科渔场的时空分布。【方法】计算三种捕捞方式的年均、月均和季节性渔获率,并对三种捕捞方式的时空分布进行双因素方差分析。【结果与结论】单拖在2016年渔获率达到最高为1.44 kg·kW^(-1)·d^(-1),双拖在2009年渔获率达到最高为4.65 kg·kW^(-1)·d^(-1),围网渔获率最高为2014年的3.8 kg·kW^(-1)·d^(-1),年均渔获率受产量和渔场分布的影响较大。三种捕捞方式的渔获率随作业功率增加呈先增大后减小的趋势,单拖最高渔获率为3.12 kg·kW^(-1)·d^(-1)(功率为262 kW);双拖最高渔获率为10.81 kg·kW^(-1)·d^(-1)(功率为313 kW);围网最高渔获率为8.97 kg·kW^(-1)·d^(-1)(功率为405 kW)。夏季渔获率相比其他季节达到最高,单拖、双拖和围网的渔获率分别为1.21、2.74、3.62 kg·kW^(-1)·d^(-1),三种捕捞方式的渔获率在时间变化都有极显著差异(P<0.01)。双拖和围网的渔获率在空间变化上都具有极显著差异(P<0.01);单拖在110°15′E-111°45′E和117°45′E-118°45′E之间的渔场存在较高渔获率,但渔场之间无明显差异;双拖在112°45′E-114°45′E左右的渔场存在高值渔获率;围网在109°45′E-110°45′E和115°45′E-117°45′E的渔场都出现高值渔获率,因此鲹科鱼类的渔场主要分布在粤西、珠江口及海南岛东部海域。

【Objective】To analyze the CPUE(Catch Per Unit Effort)of Carangidae under the three fishing methods of otter trawl,twin trawl and seine,and explore the temporal and spatial distribution of fishing grounds in the north of South China Sea.【Method】The annual,monthly and seasonal distribution of CPUE under the three fishing methods of otter trawl and twin trawl and seine were calculated,and the temporal and spatial distribution of the three fishing methods was analyzed by two-way analysis of variance.【Result and conclusion】The results showed that the highest CPUE of otter trawl was 1.44 kg·kW^(-1)·d^(-1) in 2016;and the highest CPUE of twin trawl was 4.65 kg·kW^(-1)·d^(-1) in 2009;the highest CPUE of seine was 3.8 kg·kW^(-1)·d^(-1) in 2014,the average annual CPUE was greatly affected by the yield and the distribution of fishing grounds.With the increasing of the power,the corresponding CPUE of three fishing modes showed a trend of increasing first and then decreasing,and the highest CPUE of otter trawl was 3.12 kg·kW^(-1)·d^(-1) (Power is 262 kW),of twin trawl was 10.81 kg·kW^(-1)·d^(-1) (Power is 313 kW),of seine was 3.12 kg·kW^(-1)·d^(-1) (Power is 405 kW).The CPUE in Summer was the highest compared with other seasons,and CPUE of the three fishing methods were 1.21,2.74 and 3.62 kg·kW^(-1)·d^(-1) respectively.The CPUE of three fishing methods varied significantly in temporal(P<0.01),and the CPUE of twin trawl and seine were significantly different in spatial(P<0.01).Fishing grounds with otter trawl between 110°15′E to 111°45′E and 117°45′E to 118°45′E showed high CPUE,but there was no significant difference between fishing grounds;there was high CPUE in the fishing grounds with twin trawl around 112°45′E to 114°45′E;the high CPUE with seine were found in 109°45′E to 110°45′E and 115°45′E to 117°45′E fishing grounds.The fishing grounds were mainly distributed in the west of Guangdong,the outer part of the Pearl River estuary and the eastern area of Hainan Island.