You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Marshall_Islands

Context:
In October 2011, the government declared that an area covering nearly 2,000,000 square kilometres (772,000 sq mi) of ocean shall be reserved as a shark sanctuary. This is the world's largest shark sanctuary, extending the worldwide ocean area in which sharks are protected from 2,700,000 to 4,600,000 square kilometres (1,042,000 to 1,776,000 sq mi). In protected waters, all shark fishing is banned and all by-catch must be released. However, some have questioned the ability of the Marshall Islands to enforce this zone.

Question:
What is forbidden in shark sanctuaries?

shark fishing