Divers' observations will complement the project's underwater footage
Marine biologists are surveying the Firth of Clyde in the hope of confirming the presence of Scotland's most important underwater wildlife.
Scientists are searching for priority marine features (PMFs) - species and habitats of conservation importance.
These include horse mussels, flame shell beds and rare creatures such as the fireworks anemone.
The survey forms part of the Scottish Marine Protected Areas Project, investigating Scotland's seas.
Scottish Natural Heritage (SNH), Marine Scotland, Historic Scotland and the Joint Nature Conservation Committee are involved in the project.
Underwater footage will be captured by a drop-down video camera and divers will add detailed observations to complement the video imagery.
A greater understanding of marine habitats should be revealed
The survey area ranges from Loch Fyne to the Clyde Estuary covering Campbeltown Loch, the waters around Arran, Irvine Bay, Great Cumbrae and Bute.
Laura Clark, SNH Firth of Clyde project manager said: "These surveys are about building a greater understanding of the distribution and extent of species and habitats that are particularly important to the diverse ecosystems in Scottish waters.
"The findings will give us valuable information on the status of marine priority features and will help us advise Government on marine conservation and development."
Environment Minister Roseanna Cunningham said the sea around Scotland provided habitats for some of the world's most precious wildlife.
She said: "This includes internationally important species and that is why efforts to increase our knowledge, such as those being undertaken in the Firth of Clyde, are so important.
Rare species such as the fireworks anemone may be discovered
"This work will help identify the tremendous national underwater assets we have and enable us to get the careful balance between the growth of important new marine industries and our conservation commitments right."
Other areas in the project survey include the Sound of Canna and Ullapool Approaches. Marine Scotland will also survey Fair Isle and Rockall in 2010. The survey is expected to finish in September with results published next spring.