Alaska natives are not limited by federal law in the number that can be harvested providing the harvest is not wasteful.
* 主句：Alaska natives are not limited by federal law 阿拉斯加当地人不受联邦法律的限制
* 程度状语：in the number that…在…的数量方面
其中——定语从句：that can be harvested 可以被捕捞的（数量）
* 条件状语：providing the harvest is not wasteful 如果捕捞是不划算的
翻译：如果捕捞是不合算的,阿拉斯加当地人在可以捕捞的数量方面不受联邦法律的限制.