Herdísarvík

Herdísarvík Nature Reserve protects approximately 2,400 hectares of coastal wetlands, beaches, and low-lying grasslands along the southern Icelandic coast between Selfoss and Eyrarbakki, serving as important habitat for breeding and migratory shorebirds. The reserve encompasses the Herdísarvík bay area with its intertidal flats, coastal marshes, and adjacent farmed grasslands that collectively support significant bird populations along the East Atlantic Flyway. The site's combination of sheltered coastal waters, productive mudflats, and undisturbed nesting habitat makes it one of southern Iceland's key ornithological areas. The reserve demonstrates the importance of Iceland's southern lowland coast for both breeding and passage wading birds.

The intertidal flats and coastal marshes support breeding populations of redshank, oystercatcher, ringed plover, and dunlin, while the wet meadows host whimbrel, black-tailed godwit, and snipe. Eider ducks breed along the coastline, with their down historically harvested by farmers. The mudflats attract significant numbers of migratory waders during spring and autumn passage, including turnstones, sanderlings, and knot moving between Arctic breeding grounds and European wintering areas. Grey seals are regularly observed in the bay, while common seals haul out on coastal rocks.

Salt marsh vegetation dominated by thrift, sea plantain, and various saltmarsh grasses occupies the intertidal zone, transitioning to wet meadow communities inland. The coastal grasslands support sedge and grass species adapted to periodic salt spray and winter flooding, with the vegetation maintained in an open condition by the maritime exposure. Seashore species including scurvy grass, sea sandwort, and lyme grass colonize the upper beach and dune margins. The limited scrub development due to wind exposure ensures the open habitat structure required by ground-nesting shorebirds.

The coastal lowland consists of Holocene marine and alluvial sediments accumulated since sea levels stabilized following the last glacial period. The intertidal flats comprise fine sediments — silts and clays — deposited in the sheltered bay by tidal and wave action. Storm beaches of volcanic sand and rounded pebbles form the seaward margin, with material derived from the erosion of basaltic coastal cliffs and offshore volcanic deposits. The low-lying terrain reflects both geological youth and ongoing subsidence of Iceland's southern coast relative to post-glacial isostatic adjustments elsewhere.

The southern coastal location provides Iceland's mildest climate, with average temperatures from 1 degree in January to 11 degrees in July and minimal snow persistence at sea level. Annual precipitation exceeds 1,200 millimeters with frequent rainfall year-round. The coast is fully exposed to North Atlantic storms from the south and southwest, with salt spray affecting vegetation well inland during severe weather. The mild maritime conditions allow early spring arrival of migratory birds and extend the autumn feeding period before departure for wintering grounds.

The coastal area has been utilized for farming since Norse settlement, with the salt marshes providing traditional sheep grazing and the bay supporting small-scale fishing. Eider duck farming — protecting nesting colonies in exchange for harvesting the valuable down — has been practiced along this coastline for centuries. The adjacent village of Eyrarbakki served as one of Iceland's principal trading ports from medieval times through the 19th century. Traditional land management practices maintained the open grassland character that supports current bird populations.

Nature reserve designation recognized the area's ornithological importance, protecting the breeding and feeding habitat from development and disturbance that could reduce bird populations. The reserve's establishment reflected growing awareness of Iceland's international responsibility for migratory shorebird populations that depend on Icelandic breeding sites. Management coordinates with local farmers to maintain agricultural practices compatible with bird conservation, particularly regarding grazing intensity and timing of hay cutting. The site's inclusion in international Important Bird Area networks emphasizes its significance within the East Atlantic Flyway.

Birdwatching is the primary visitor activity, with the coast and wetlands accessible from several points allowing observation of diverse shorebird assemblages without entering sensitive nesting areas. The coastal walk between Eyrarbakki and Stokkseyri passes adjacent to the reserve with views across the wetlands. Spring migration periods (April-May) and autumn passage (August-September) provide the highest species diversity. The nearby Flói reserve offers complementary inland wetland birdwatching, allowing visitors to experience both coastal and freshwater bird communities in a single trip.

The reserve is located approximately 50 kilometers from Reykjavik near the villages of Eyrarbakki and Stokkseyri, accessible by paved road in under an hour. No formal visitor facilities exist within the reserve, though the adjacent villages provide restaurants, accommodation, and the Húsið museum. Viewing is possible from roads and designated access points around the reserve perimeter. The site is accessible year-round, with the breeding season (May-July) and migration periods providing peak birdwatching interest.

Protection of ground-nesting birds from disturbance during the May-July breeding season requires limiting human access and controlling dog walking in sensitive areas. Coastal development pressure from the expanding Reykjavik commuter belt threatens the buffer zone surrounding the reserve. Sea level rise and increased storm frequency associated with climate change may alter the coastline and affect intertidal feeding habitat. Maintaining appropriate farming practices within and adjacent to the reserve ensures the open habitat character required by breeding waders.