Fishing, or to fish means any activity, other than scientific research conducted by a scientific research vessel, that involves:
(1) The catching, taking, or harvesting of fish;
(2) The attempted catching, taking, or harvesting of fish;
(3) Any other activity that can reasonably be expected to result in the catching, taking, or harvesting of fish; or
(4) Any operations at sea in support of, or in preparation for, any activity described in paragraphs (1), (2), or (3) of this definition.
50 CFR § 600.10
Unless defined otherwise in other parts of Chapter VI, the terms in this chapter have the following meanings: