Fishing means using any vessel, vehicle, aircraft or hovercraft for any of the following activities, or attempting to do so:
(1) Searching for, catching, taking, or harvesting fish;
(2) Engaging in any other activity which can reasonably be expected to result in the locating, catching, taking, or harvesting of fish for any purpose;
(3) Placing, searching for, or recovering fish aggregating devices or associated electronic equipment such as radio beacons;
(4) Engaging in any operations at sea directly in support of, or in preparation for, any of the activities previously described in paragraphs (1) through (3) of this definition, including, but not limited to, bunkering;
(5) Engaging in transshipment at sea, either unloading or loading fish.
50 CFR § 300.211
In addition to the terms defined in 300.2 and those in the Act and in the Convention on the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean, with Annexes (WCPF Convention), which was adopted at Honolulu, Hawaii, on September 5, 2000, by the Multilateral High-Level Conference on Highly Migratory Fish Stocks in the Western and Central Pacific Ocean, the terms used in this subpart have the following meanings.