(a) Four methods of harvesting fish are: (i) The use of Nets: This involves the use of various types of nets like gill net, trawl net which have been woven into various sizes and thickness and are thrown into water for fish haulage. (ii) Use of Traps: These are gears made from ropes woven into various models of enclosures for capturing fishes. (iii) Draining of ponds: Draining off pond water and using net to catch large fish. (iv) The use of Hooks and Line: The use of hooks which are baited and tied to strings and set across the water to catch fish.
(b) Four fishery regulations are: (i) No vessel (except canoes) shall fish within the first two nautical miles of the waters of the Nigerian continental shelf (ii) Catch quota is a form of control in which a fisherman is allowed to catch a specific quantity or regulating the number of fishermen by issuing them fishing permits at a specified amount. (iii) The use of any explosive substances is prohibited. (iv) The use of noxious or poisonous materials is prohibited as this can kill virtually all categories of fishes in the water.