摘要：There are two genera and four species of icefishes in Nanyi Lake, which have been commercially exploited in the past two decades. As result, icefish yield decreased over the years, from the peak of 260 metric tons to 15 metric tons, and this change was highly correlated (t =—3.95, df = 1, p = 0.001) with increased fishing effort. Meanwhile, the size composition of the icefish assemblage dramatically changed, with significantly increased relative abundance of the small icefish category (from 0.06 to 0.91). Furthermore, sampling during the 2001 fishing season was characterized by a progressive decrease in CPUE (by 3.14 times) and an increase in relative abundance (from 0.83 to 0.97) of the smallest icefish, giving direct evidence of the stocks decline and size diminution of icefishes in relation to the commercial fishing effort. Both the historical records and the 2001 seasonal changes of the icefish stocks indicated that this resource in Nanyi Lake has been overfished and illustrated that small fishes can also be overfished to degradation when they are commercially exploited.
