The ocean quahog (Arctica islandica) is an economically important species across much of its range. This should not be confused with the quahog (Mercenaria mercenaria) which is smaller and is the primary clam used in the famous soup called clam chowder in New England in the USA. While the quahog lives in the intertidal zone and can be dug up at low tide, the ocean quahog found in Iceland only lives well below the beach and is fished by dredging.

Ocean quahogs are found all around Iceland and the population is estimated at over one million tons.  It is therefore a common species and is found down to a depth of about 100 m.

Artisanal fisherman in Iceland have long used the ocean quahog as bait and more recently, the animal has been harvested as a food product. Fishing of these clams has been sporadic, but began in 1995. The largest annual catch since fishing began was nearly 10,000 tons.

Ocean quahog is an infaunal species that burrows into the sediment, stretching its two siphons up out of the mud. One siphon is used to suck in nutrient-rich water and the other is for exhaling the water out again. Because the clams burrow vertically, their assemblages can be quite dense with 88 shells per square meter.

The ocean quahog also has the honour of being the oldest living animal (besides sponges) in the world. The record holder was a more than 500 year old individual found north of Iceland.