This Act amends and extends Fisheries Acts 1956 to 1976. A person guilty, of an offence under any section of the Fisheries (Consolidation) Act, 1959, specified in Table 1 to section 2 of this Act shall be liable on conviction on indictment, to the fine specified in column (3) of Table 1 to that section at the reference number at which that section is specified and to the forfeiture specified in column (4) of that Table at that reference number. Section 5 redefines restrictions on foreign sea-fishing boats entering exclusive fishery limits of the Irish State, whereas section 6 contains provisions in relation to expediency and good order of foreign sea-fishing boats lawfully entering exclusive fishery limits of State. The Minister may from time to time by bye-law prohibit or restrict the use of any boat or any boat of a specified class, or of any method of fishing (including trawling, seining and fishing by means of any kind of net hauled along the bottom of the sea whether by a moving boat or by any mechanical appliance in an anchored boat) and different bye-laws may be made in respect of different classes of boats and different methods of fishing (sect. 8). The Minister may by order prescribe and adopt such measures of conservation of fish stocks and rational exploitation of fisheries as the Minister thinks proper (sect. 9) or provision by regulations for the purpose of carrying out the Convention on the Conduct of Fishing Operations in the North Atlantic (sect. 10). The definition of "fish" is amended in section 16 so as to include all marine invertebrates, and the definition of net in section 17. Other provisions deal with measures of enforcement.