By Sarah Ward
Living Seas Officer
When we think of nests, our thoughts immediately go to birds, building intricate shelters in which to lay their eggs and rear their newborns. However, a number of fishes also create nests, one of which does so right on our doorstep.
The black sea bream, Spondyliosoma cantharus, sometimes known as a ‘porgy’, is a large, silvery fish which can be found around the west and south coasts of the UK. Like most of the species in its family (Sparidae), black sea bream are hermaphrodites. More specifically, they are protogynous, meaning that they are born female and change to male after maturity.
During the black bream breeding season, these mature males will seek out specific types of seabed on which to spawn. There are a few different habitats which are known to be used by this species, all of which consist of a thin layer, or veneer, of mobile gravel covering a hard surface. Here in Sussex, we have the perfect habitat for them which is protected within the Kingmere Marine Conservation Zone (MCZ).
Thousands of black bream will arrive in the MCZ in the spring to spawn. The males will excavate a nest by moving the gravel around to create a crater in which a female can lay her eggs. The females will inspect a potential nest for suitability before laying her eggs, which attach to the hard rock surface where the male fertilises them. He will then guard the eggs to keep them free of sediment, using his tail as a fan, and protect them from any predators, such as other fish, crabs and whelks.
The eggs hatch after 10-15 days and the juvenile fish will remain around the nest for a few weeks.
The Kingmere MCZ specifically protects black sea bream as one of its features; there is a byelaw in place which protects the bream from all fishing activity, including recreational angling, throughout their breeding season. For further information, please visit the Sussex IFCA website.