The Dumfries and Galloway coastline has a wide range of habitats and is astonishingly rich in both abundance and diversity of wildlife. The majority of the coastline forms the northern edge of the Solway Firth which extends from the Mull of Galloway round to St Bees Head on the Cumbrian coast. Deeper waters extend along the Rhinns coastline which lead in to the sea loch of Loch Ryan.
The Solway Firth can be viewed as two distinct areas. The Inner Solway is a large estuary, characterised by extensive areas of intertidal mudflat, fringed by salt marsh at the top of the shore, along with highly mobile sand banks and scar ground (coarse sediment such as pebbles, cobbles and boulders slightly raised above the level of the surrounding sediments). A significant proportion of Scotland's saltmarsh habitat is on the Dumfries and Galloway coast, with major concentrations around the Inner Solway and Wigtown Bay. This part of the Solway is rich in invertebrates and crustaceans, which in turn support nationally and internationally important numbers of overwintering waterbirds, including the entire Svalbard Barnacle Goose Branta leucopsis population during wintertime. It is also the most northerly site for Natterjack Toad Epidalea calamita supporting 10% of the UK's population.
The Outer Solway consists of shallow open sea areas and numerous inlets and enclosed bays flanked by shingle, dunes and maritime cliffs. The seagrass Zostera beds (e.g. at Auchencairn Bay and Wigtown Bay) are composed of three nationally scarce species and are an important nursery for flat fish, shrimp and other marine species. The largest of the region's sand dune systems can be found at Torrs Warren. This area is of European importance and supports a mosaic of habitats from mobile sand to flower-rich grassland and heathland. The maritime cliffs and slopes of Kirkcudbrightshire and Wigtownshire, cover approximately 150km of coastline, along with a further 100km of vegetated slope. This habitat supports rare plants such as Sticky Catchfly Lychnis viscaria, is home to several colonies of seabirds which in turn support a healthy breeding Peregrine Falco peregrinus population. Reptiles such as Adders Vipera berus are common and widespread. Some cliff nesting House Martin Delichon urbica colonies still remain (e.g. Cruggleton) and the maritime heathland supports small numbers of breeding Twite Carduelis flavirostris.
The deeper open sea that begins around the Mull of Galloway and extends off the Rhinns coast also supports a variety of species, from microscopic plankton to large mammals and fish. The headlands and points provide good watchpoints for whales and dolphins, or the Basking Sharks Cetorhinus maximus which feed on the plankton blooms in the summer months.
The Local Biodiversity Action Plan identifies ten priority coastal and marine habitats:
- Subtidal Rock
- Subtidal Sands and Gravels
- Intertidal Sand and Mud Flats
- Seagrass Beds
- Intertidal Rocky Shores
- Honeycomb Worm Reefs
- Coastal Shingle Beaches
- Coastal Sand Dunes
- Coastal Saltmarshes (Merse)
- Coastal Cliffs and Slopes