Marine biologists differ on the extent of the decline.Some argue that stocks of many large oceangoing fish have fallen by 80 to 90 percent, while others say the declines have been less steep.

• 海洋生物学家在数量减少的程度上仍有分歧，有的争论说许多大洋鱼类的数量降低了百分之八十到九十，而另一些人则说降幅应该更小一点。