The change has implications for wind and wave power
The Scottish Government has been given responsibility for all planning and nature conservation matters at sea up to 200 miles from the Scottish coast.
The move came after talks between the UK Government and other devolved administrations aimed at allowing each country to manage its own seas.
Until now, Holyrood's responsibility only stretched to a 12-mile limit.
The change has implications for the offshore industry, wind and wave power and to a lesser extent, fishing.
Environment Secretary Richard Lochhead told MSPs agreement had been reached to give Holyrood responsibility up to the 200-mile international limit.
The responsibility for fishing quotas remains an EU issue.
Mr Lochhead said: "This is excellent news for Scotland and for Scotland's economy. We will now be responsible for planning and conservation up to 200 nautical miles out to sea from our shores.
"Further devolution of powers on the marine environment will help us safeguard our seas for generations to come."
Mick Borwell, environmental issues manager with Oil and Gas UK, said: "Oil and Gas UK has always made the case for consistency and coherence between the UK and Scottish marine bills.
"Although oil and gas licensing and permitting will remain a reserved matter, our operations are influenced by marine planning and nature conservation and hence we welcome this new joined up and integrated approach to marine management."
Lloyd Austin, head of conservation policy at RSPB Scotland, said: "We have long argued for marine legislation with the environment at its heart, and it is the marine environment that wins from this announcement.
"The challenge now is to make certain that both parliaments adopt a truly visionary approach, and deliver marine bills that restore our seas for people, wildlife, and future generations who want to be able to profit from them, but in a long-term, sustainable way that enhances their precious wildlife."
And Scottish Fishermen's Federation (SFF) chief executive Bertie Armstrong said: "For Scotland, this aligns the responsibility for specific practical matters of marine nature conservation with that for fisheries management - which was always out to 200 miles.
"We strongly support this because dealing with the two issues separately was disjointed.
"More broadly, we welcome also the commitment of all the UK administrations to join up marine management across the board; this is essential for coherence - in most matters of consequence in marine planning and management, political boundaries are false."