Campaigners have stepped up calls for radical reform to protect the marine environment around Scotland.
Many Scottish communities rely on the sea
The move marks the close of the Scottish Executive's three-month public consultation on the future management of the seas.
The Joint Marine Programme (JMP) wildlife body has warned that problems from pollution and falling fish stocks could become insurmountable.
It wants to see a Marine Act for Scotland and a clear marine strategy.
The JMP is a partnership between WWF Scotland and the Scottish Wildlife Trust (SWT).
The organisation's Dr Rebecca Boyd said the future of the marine environment was a matter of genuine concern for the people of Scotland.
Dr Boyd said: "If we don't act now with some radical solutions we may be forever fighting a losing battle against dwindling fish stocks, plummeting marine wildlife, polluted waters and increasing conflicts between marine users.
"We challenge the Scottish Executive to deliver a clear mechanism that will solve these problems - a Marine Act that will enable the coasts and seas to be protected and managed for future generations of coastal communities and wildlife."
The campaign is backed by the Hebridean Partnership, the Association of Scottish Shellfish Growers and the Fair Isle Committee and Community Association.
Helen McLachlan, marine policy officer for WWF Scotland, stressed the need for action.
Climate change may be depleting the plankton on which fish live
"Our seas and coasts contribute many millions to the Scottish economy and yet are suffering from diverse pressures, mismanagement and inadequate legislation," she said.
"We have some of the most incredibly rich and biologically diverse seas in the world containing an estimated 8,000 species, yet they are poorly protected by fragmented laws."
At present, 13 UK bodies have marine responsibilities and 85 acts of parliament apply in coastal areas.
JMP estimates that the value of Scotland's coastline and estuaries is about £10bn, with coastal tourism contributing £375m to the economy.