厦门东海域鱼类的群落结构及种类多样性研究

A study on fish species diversity and community structure in eastern waters of Xiamen

2003年7月至2006年6月对厦门东部海域用定置网和流刺网渔获鱼类进行周年逐月采样分析。结果表明,该海域鱼类至少有287种,录属于21目87科164属,以鲈形目最多,有151种,占总种数的52.6%。渔获物组成以近岸小型鱼类为主,底层鱼类和中下层鱼类合计有235种,占81.88%;中上层鱼类仅52种,占18.12%。鱼类的亚热带动物区系特征明显,暖水性种类达221种,占77%,暖温性种类66种,占23%,未出现冷温性种类及冷水性种类。鱼类种类存在明显的季节更替现象,月更替率大多在30%以上,最高达72.1%。定置网渔获鱼类年平均数量为277尾.网-1,年平均产量为1.93kg.网-1,平均数量和平均产量均以夏季大于秋季大于春季大于冬季;月平均数量和月平均产量均以8月最高,分别为700尾.网-1和5.0kg.网-1,2月最低,分别仅为55尾.网-1和0.38kg.网-1。种类丰度及数量变化与海域水温变化总体呈正相关关系。Shannon-Wiener种类多样性指数的月变化在1.555—4.337之间,多数月份的指数值在3以上,多样性水平较高。渔获鱼类中经济种类占比例较大,但绝大多数个体都比较小,年平均尾重仅6.97g。根据营养动态法估算潜在资源量为1133.30t.年-1,目前厦门东海域鱼类总渔获量已超过最大可捕量一倍以上,应加强资源的管理和保护。

The authors analyzed monthly fish samples from set nets and drift nets in the eastern waters of Xiamen taken from July 2003 to June 2006. There are total 287 species identified, which belong to 164 genus, 87 families and 21 orders, and of which 151 species are in the order of Percifromes, accounting for 52.6% of the total species. Among the catches that are mainly composed of small-size coastal species, 235 species are benthic and mid-bottom species, accounting for 81.88% of the total, and 52 are pelagic species, accounting for 18.12%. The samples show distinct subtropical features, as there are 221 tropical species, accounting for 77%, 66 warm water species, accounting for 23%, and no cold warm or cold species. There exist distinct seasonal changes in fish composition, with a monthly rate over 30% and maximum 72.1%. The average catch by set nets is 277 heads and 1.93kg per net for a year, and in the order of summer, autumn, spring, and winter for the four seasons in terms of catch from high to low, with the highest in August （700 heads per net and 5.0 kg per net） and the lowest in February （55 heads per net and 0. 38 kg per net）. In general, the changes of species abundance and quantity are positively correlated with water temperature. Shannon-Wiener species indexes are relatively high, ranging from 1. 555 to 4. 337, above 3 in most months. Commercial species have a higher proportion in the catches although most of them are of small size, with an annual-average weight of only 6.97 g per head. The total allowable capture （TAC） estimate based on nutrient dynamics indicates that the potential fish yield is 1 133.30t per year. At present,the catch from the waters has exceeded the TAC value, and fishery resource management and protection should be strengthened immediately for the sake of sustainability.