Entanglement is the biggest identified cause of death due to human activity for minke and humpback whales, and the extent of the issue has not been well understood.

Whales and other marine animals can become entangled in fishing equipment, including the ropes linking creels (also known as pots), which are set around Scotland’s coasts to catch prawns, crabs and lobsters.  There is now a legal obligation in Scotland for fishers to report entanglements.

A study involving the Scottish Entanglement Alliance (SEA), the Scottish Government, and academics, estimated that in Scottish waters, approximately six humpback whales and 30 minke whales become entangled in creel fishing ropes each year. Other marine species such as basking sharks and dolphins were also recorded to have been entangled.

Commercial creel fishermen from all around the Scottish coast were interviewed and their contribution allowed the researchers to better understand the nature and extent of entanglements in Scotland’s waters.

Study findings

The study showed that a high proportion of entangled whales had become caught in the groundline, the rope that links creels together on the seabed. As groundline is usually made from rope which floats, it can form arches in the water between creels in which basking sharks or whales can get caught by their mouths, flippers or tails.  If the groundline is made of rope which sinks rather than floats, it will lie on the seabed, and will not pose an entanglement risk.

This has shown the way for a new plan to trial sinking groundlines in the Scottish fishing industry.

Russell Leaper, from the International Fund for Animal Welfare, lead author on paper, said: “Our current understanding of the extent of entanglements in Scottish waters only became apparent through this study and the valuable contribution made by the fishermen who participated.

Susannah Calderan, a research fellow at the Scottish Association for Marine Science (SAMS) in Oban and report co-author, said: “This wouldn’t be possible without different organisations including the creel fishing industry working together, and I’m optimistic that we can progress solutions in this fishery, which otherwise has a relatively low environmental impact.”

Bally Philp from the Scottish Creel Fisherman’s Federation (SCFF), a SEA partner, added: “It’s great to see Scotland’s fishermen are at the forefront of understanding and addressing the issue of marine animal entanglement.”

The news story in the Press and Journal can be read here and the piece in the Herald can be read here. The full journal paper can be read here.