Jersey's politicians have thrown out plans to create a National Marine Park.
Had they been approved, the proposals would have seen 30% of the island's territorial waters covered as part of an initiative by the Global Ocean Alliance.
The bid by Jersey's Deputy Chief Minister, Senator Lyndon Farnham, was rejected by States members during the debate on the Bridging Island Plan.
Senator Farnham had submitted the proposals as an amendment to a separate amendment by Environment Minister, Deputy John Young.
Deputy Young said Senator Farnham's amendment was not supported by the local fishing industry, describing it as 'inappropriate and ineffectual'.
He added that because Jersey is bound by the post-Brexit trade agreement between the UK and EU, any marine conservation measures - such as those involved in creating a Marine Park - would need to be thoroughly examined by both Jersey's government and the European Union.
Deputy Young's original amendment, which was ultimately voted through by the Assembly, will create a 'marine spatial plan' to develop a 'network of marine protected areas'.
He says the move would enable the island how best to approach developing sustainable fisheries in the islands waters, following a long-running row with French fishers on the issue.
Politicians also approved a move to create a new planning zone called the 'Protected Coastal Area', which will include the Coastal National Park in its current boundaries.