参考答案：错

解析：[听力原文]Cheliean sea bass is a snow-white, flaky delicacy in restaurants in the United States, Japan and Europe. Environmentalists have warned that over-fishing and poaching could cause it to vanish from the coasts of Antarctica.

[分析]： 语法理解。 通过原文“over-fishing”可判断Cheliean sea bass可能是鱼类，且原文提出对该物种的过度和非法捕捞“could cause it to vanish”与题干“might have already become extinct”意思不能吻合，前者表示对未来预测的一种可能性，而后者则表示对已发生情况的判断。因此，题干的说法是错误的。[解题关键] 正确理解语法概念。