Common whelk (Buccinum undatum)

Fishery

The fishery for common whelk has expanded significantly in the past decade in Manx waters, in the Irish Sea region as a whole, and northwest Europe generally. The increase in effort and landings is a response to the emerging market for common whelk in Southeast Asia, before which the primary market for common whelk was in France. The whelk fishery includes significant landings from within the Isle of Man territorial sea by UK registered vessels.
To participate in the Isle of Man fishery a vessel must have a whelk fishing licence. Each licence has a maximum pot limit of 1000 pots, of which. no more than 400 can be set within the 0-3 nautical mile zone. The current minimum conservation reference size is 75 mm total shell length, which is approximate to the estimated size at functional maturity observed in the population.

Life Cycle

The common whelk is a large neo-gastropod mollusc, which can grow up to 16 cm high and 6 cm wide. The shell is usually a pale colour, but can vary geographically, and has 7-8 whorls.
Common whelks are active predators that mostly feed on live polychaete worms and bivalves. They extract the flesh of bivalves by either using their own shell to pry open the bivalve shell or by drilling holes into the shell.
This species reaches sexual maturity at 5-7 years and breeding takes place in late autumn and through winter in Manx waters. The eggs produced are attached to hard substrate such as rocks, shells and stones in protective capsules. Each capsule contains as many as 1000 eggs, and many female’s egg capsules can be grouped together in groups of over 2000. After several months, crawling young emerge from the capsules. Common whelks are believed to live for 10 years.

Habitat & Distribution

Common whelk are found on sand, sandy mud or stony bottoms from below the tide line to a depth of 100 m.