The main purpose of this legislation is to strengthen the United States' ability to combat illegal, unreported, and unregulated (IUU) fishing by expanding the criteria used to identify nations that are involved in such activities. The law aims to protect U.S. fishers and promote sustainable fishing practices by holding foreign nations accountable for their fishing regulations. Key provisions of the law include allowing the Secretary of Commerce to consider nations with open registries when identifying those that engage in or endorse IUU fishing.