Other threats include hunting and invasive species .

此外，猎杀和外来物种入侵也威胁着这些物种。

The tourists are partly responsible for invasive species that threaten endemic wildlife .

游客对于那些危害本地野生物种的入侵物种负有一定的责任。

Invasive species can decrease biodiversity and drive resident species to the brink of extinction .

入侵的物种能减少物种的多样性，并将寄主物种逼到濒临灭绝的边缘。

California has spent millions of dollars trying to get rid of the worst invasive species .

加利福尼亚州已经花费了数百万美元试图清除掉最麻烦的入侵物种。

Because at least one kind of invasive shrimp is an even bigger pest when it has a parasite on board .

因为当船上有寄生物时，至少有一种入侵的虾类是一种更大的害虫。