大亚湾鱼卵、仔稚鱼种群特征与环境因子的相关关系

为了解大亚湾鱼卵、稚仔鱼种群动态变化及其与环境因子的关系, 2015年采用浅水I型浮游生物拖网对大亚湾鱼卵、仔稚鱼进行了4个季度的调查,结果表明,4个季度共采获鱼卵31361粒,仔稚鱼244尾。经鉴定分析共有27种,其中鱼卵19种,隶属于6目16科18属;仔稚鱼18种,隶属于5目15科16属;鱼卵、仔稚鱼共有种11个。鱼卵平均丰度为614.55 ind/1000 m^3,稚仔鱼的平均丰度为3.69 ind/1000 m^3。鱼卵丰度季节变化由高到低依次为夏季、春季、冬季、秋季;空间分布显示,丰度由高到低依次为中央列岛、人工鱼礁区、湾口东岸。鱼卵多样性指数(H￠)范围为0.05～2.26,平均值为0.86,稚仔鱼多样性指数(H?)范围为0～2.53,平均值丰度0.82;鱼卵均匀度指数(J)范围为0.02～0.99,平均值为0.50;稚仔鱼均匀度指数(J)范围为0～1.00,平均值为0.52。根据Pearson相关性结果分析表明,与种群关系最密切的环境因子为温度和溶解氧(P<0.01)。研究结果显示,春夏季是大亚湾海域鱼类产卵的重要时期,中央列岛海域是大亚湾鱼类繁殖的关键区域。

Population characteristics of fish eggs and larvae and their relationship with environmental factors in Daya Bay

This study aimed to evaluate the relationship between the dynamic changes in the abundance of fish eggs and larvae with respect to the environmental factors in Daya Bay. In the fourth quarter of 2015, 31361 eggs and 244 larvae were collected, including eggs from 19 species, belonging to 6 orders, 16 families, and 18 genera. There were fish larvae from 18 species, belonging to 5 orders, 15 families and 16 genera; 11 fish species were common between the eggs and larvae collected. The eggs and larvae of Perciformes accounted for 57.9% and 73.6% of the total collection, respectively. Fish eggs belonged to 3 dominant species:Sillago sp., and Callionymus sp, and species of the family Sparidae. The average abundance of fish eggs and larvae were 614.55 individuals/1000 m³ and 3.69 individuals/1000 m³, respectively. Horizontal distribution of abundances revealed that in general, the abundance in the central islands of Daya Bay was the highest, followed by that in the artificial reefs of Daya Bay. The value of Shannon-Wiener index (H'') for fish eggs in the investigated area ranged from 0.05-2.26, with an average value of 0.86, while that for larvae ranged from 0-2.53, with an average value of 0.86. The value of Pielou''s evenness index (J) for fish eggs ranged from 0.02-0.99, with an average value of 0.5, while that for larvae ranged from 0-1.00, with an average value of 0.52. The results of Pearson correlation analysis showed the environmental factors that were most correlated with the population were temperature and dissolved oxygen (P<0.01). Low temperature and low dissolved oxygen, within their respective suitable ranges, were more beneficial to the growth and development of juvenile fish. The spring and summer were important periods for fishes to spawn, and the central islands were the key areas for the reproduction of fish in Daya Bay.