闽南-台湾浅滩渔场二长棘鲷群体景观多样性

根据1998年7月到2000年6月闽南-台湾浅滩渔场开展二长棘鲷资源的专项调查资料,以各个渔区CPUE(Catch Per Unit Effort)及其到渔场重心距离为参数,构建基于渔场重心动能的景观要素,运用景观多样性,并结合因子分析,分析了二长棘鲷群体景观多样性的空间格局及其与海洋环境因子之间的关系,探究了种群空间分布格局与生态过程之间的相互作用关系,旨在揭示闽南-台湾浅滩渔场二长棘鲷的生态境况及空间变异特征,为从生态水平上合理综合利用二长棘鲷渔业资源提供新的依据。结果表明:(1)不同月份鱼群的分布特征差别明显,8月鱼群分布范围最广,11月鱼群分布最为均匀,2月和12月鱼群分布最集中,而9月鱼群占据渔场空间能力最强;(2)不同群体之间具有不同分布特征,生殖群体分布范围最小,且最集中,其占据渔场空间能力最弱,幼鱼群体分布范围小,且相对均匀,其占据渔场空间能力强,索饵群体分布范围最广,且较均匀,鱼群分散索饵,其占据渔场空间能力最强,而9—11月群体平均分布范围较广,且最均匀,其占据渔场空间能力较弱;(3)鱼群综合景观指数是具空间结构的CPUE指数,从生态水平上反映了鱼群CPUE,其排名依次为8月、6月、7月、9月、10月、11月、5月、1月、4月、3月、2月、12月;(4)多样性指数、均匀度指数和优势度指数指示的生态学意义分别为鱼群的分布范围、均匀程度和鱼群空间竞争能力,其中多样性指数和均匀度指数呈正相关;(5)水温是影响鱼群景观均匀度的主要因子,索饵是增加鱼群景观多样性和优势度的主要因子,而生殖因子则降低鱼群景观多样性和优势度,水温、索饵和生殖是二长棘鲷群体景观格局变化的主要驱动因素。

Landscape diversity of Paerargyrops edita Tanaka stock in Minnan-Taiwan Bank Fishing Ground

The landscape elements with barycenter of fishing ground of kinetic energy were established based on the parameters of catch per unit effort (CPUE) of each fishing area and the distance between fishing center and each area from the special survey data of Paerargyrops edita Tanaka in Minnan-Taiwan Bank Fishing Ground during July 1998 to June 2000. Using landscape diversity index and factor analysis, we studied the space structure of Parargrops edita Tanaka's landscape diversity and its relationship with marine environment factors. We also explored the interaction relationship between spatial distribution pattern and ecological processes, which revealed the ecological condition and spacial variability characteristics of Paerargyrops edita Tanaka in Minnan-Taiwan Bank Fishing Ground. Results are listed as follows: (1) The distribution characteristics of fish population differed obviously in months: the fish population distributed most extensively in August, most equably in November, and most concentrated in February and December, while the fish population had the strongest ability in occupying fishing ground in September. (2) Different populations had various distribution characteristics: The reproductive population had the smallest distribution range and reproduced concentratedly; however, this population had weakest ability to occupy fishing ground. Juvenile fish had the smallest average distribution range and was well-distributed; however, they had the strongest ability to occupy fishing ground. Feeding stock distributed widely and uniformly and foraged dispersedly; they also had the strongest ability to occupy fishing ground; while during September to November fish group's average distribution range became smaller, and fish group concentrated gradually with weak ability to occupy fishing ground. (3) The fish comprehensive landscape index referred to CPUE index with space structure, which reflected the CPUE of fish population from ecological levels; and the ranking was as follows: August, June, July, September, October, November, May, January, April, March, February and December. (4) Diversity index, evenness index and dominance index indicated the distribution range, uniformity coefficient and space competitiveness of fish population, respectively. We observed a positive association between diversity index and evenness index. (5) Water temperature was the main factor that affected the landscape uniformity; foraging was the major factor for enlarging fish population's landscape diversity and dominance, while reproduction factor was the important factor for reducing fish population's landscape diversity and dominance. Water temperature, foraging and reproduction were the main factors for the variations of landscape pattern of Paerargyrops edita Tanaka.