Black coral

Photo: terence zahner · CC BY-NC

Black corals are not true reef-building corals but colonial cnidarians that produce a dark, chitinous skeleton — the structure prized historically for jewellery, causing severe population declines. On the River Taw they have colonised at unusual shallowness, typically being deep-water specialists, suggesting the shade and current conditions of the wreck mimic deep-reef environments. Colonies support diverse communities of shrimp, gobies, and pygmy seahorses. Their slow growth rate — as little as 5cm per year — means the large specimens on this wreck represent decades of recovery and carry significant ecological value.