By way of derogation from Article 1, during a period of three years from the date of accession, vessels flying the flag of Finland, Norway or Sweden shall be authorized, provided that such fishery does not entail risks of irreversible ecological damage, to engage in direct fishing for herring for purposes other than human consumption, under the same conditions as before accession, taking into account market outlets and subject to a monitoring system for by-catches supervised by the Commission.