Anglerfish  (Lophius piscatorius)

The biology of deep-water fish such as the anglerfish is still relatively unknown and with deep-water fishing largely unregulated, it has proved difficult to assess whether populations of these fish are being adversely affected. Another problem associated with many deep-water species is their late maturity, meaning that there is a greater risk of them being caught before reaching reproductive age.

When these deep-water fish are caught accidentally (bycatch) as often happens with indiscriminate trawling, they are unable to survive being hauled up to the surface, and are already dead before they are returned to the sea.

These large predatory fish are thought to be top of the food chain within the ecosystem they inhabit, and there are fears that commercial overfishing of their food, and subsequent damage to their habitat by weighted trawl nets, could have an adverse effect on populations.

The anglerfish is listed in the UK Biodiversity Grouped Species Action Plan for deep-water fish. The European Union (EU) has regulatory powers over commercial sea fishing for member countries but allows individual nations some flexibility in the application of the EU rules.

The commercial exploitation of anglerfish is governed by the total allowable catch (TAC) regulations. Catches in the North Sea and west of Scotland, areas monitored by the International Council for the Exploration of the Sea (ICES), are covered by precautionary TACs. However, the fishing industry has been lobbying for an increase, and permission to extend the catching of anglerfish into deeper waters. ICES has suggested that commercial deep-sea fishing could pose a serious threat to many species as numbers are below safe biological limits. For other species, we simply do not know the size of their populations. ICES has recommended that unsustainable commercial deep-sea fishing should therefore be reduced, and better records kept of fishing activities so catches can be equated to known fish population sizes. At the present time, anglerfish are being overfished, and there are no management plans for its conservation.

The deep-sea ecosystem is still largely unexplored and understudied. However, we do know that it is a fragile system. Unregulated, unsustainable commercial harvesting of fish stocks risks wrecking this fascinating habitat before we have learned of its importance and value to the ocean as a whole.