Development of the method for dynamic detection and analysis of environmental pollutants based on the study of feeding ecology of coastal fishes with high degree of environmental sensitivity

为了验证新济湖夏季大群死鱼是否由二恶英污染所致，我们用定置渔网采集了小圆头鱼。6月份，由于大规模死亡，在东部定置渔网附近也收集到了漂浮的死鱼。所有6月份的样品都是漂浮的死鱼。去年12月，在西部布设渔网捕获了5条鱼。随着马尾藻的生长，它会积累更多的二恶英。然而，无论是体长还是总体重都没有显著的相关性。4月份的一些样品和6月份的漂浮鱼类显示出比12月份收集的相同大小的鱼更多的TEQ。这可能支持上述假设。受二恶英污染较多的鱼类可能会对环境压力变得脆弱，并在夏季死亡。GSI表示因产卵而耗尽的程度。GSI=性腺重量(G)/总重量(G)x10^2 6月份浮游死鱼的GSI并不比4月份的样本小很多。另外，我们还采集了37条死鱼和35条三岁活鱼，比较了体长、体重、性腺重量、GSI和F(F=体重/(体长)^3×10^6)。未配对的t检验表明，死鱼和活鱼之间的差异不大。这可能表明，受二恶英污染较多的鱼类在产卵后很容易死亡。

To examine if the mass mortality of Konoisirus punkutatus at Lake Shinji in summer is caused by contamination of dioxin, we collected Konoisirus punkutatu using set nets. Dead floating fishes due to mass mortality were also collected near the east set nets in June. All the June samples were floating dead fishes. Five fishes were collected at the west set nets in December. As K. punctatus grows, it would accumulate more dioxins. However, neither body length nor total weight showed significant correlation. Some April samples and floating fishes in June showed more TEQ than the same size fishes collected in December. This may support the above hypothesis. Fishes more contaminated by dioxins may become weak to environmental stress and die off in summer. GSI expresses the degree of exhaustion due to spawning. It is calculated as follows.GSI=Gonad weight (g)/Total weight (g)x10^2The GSI of floating dead fishes in June were not considerably smaller than the samples in April. We additionally sampled 37 dead fishes and 35 live fishes of three years old, and compared the body length, body weight, gonad weight, GSI, and F (F=body weight/(body length)^3x10^6). Unpaired t-test suggested that they are not different between dead and live fishes. This may suggest that fishes more contaminated dioxins are easily dead after the spawning.