New study identifies solution to prevent whale entanglements in fishing gear

A ground-breaking new study in Scotland investigating the nature and extent of whale entanglements in fishing gear has identified ways to prevent them and the harm they cause, in the future.

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. If whales become entangled they often cannot escape, which can lead to injury and even death. Entanglement is known to be the largest identified cause of death due to human activity for minke and humpback whales in Scottish waters. However, the extent of the issue was not previously well understood.

The findings have been published in the Journal Endangered Species Research. The study estimated that in Scottish waters approximately six humpback whales and 30 minke whales become entangled in creel fishing ropes each year. The collaborative project behind the study also identified possible ways to address the problem.

WDC has been working with the Scottish Entanglement Alliance (SEA), which brings together government, academia, NGOs and the fishing industry. During the project, commercial creel fishermen from all around the Scottish coast were interviewed and their valuable contribution allowed the researchers to better understand the nature and extent of entanglements in Scotland’s waters. This work is an excellent example of successful collaboration between fishers, NGOs, and academia to understand the entanglements in Scottish waters.

The addition of data from the Scottish Entanglement Alliance and WDC’s citizen science Shorewatch programme has allowed the number of humpback and minke whales entangled in the Scottish pot (creel) fishery to be estimated. As well as the number of entanglements taking place, the study also 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.

This study’s findings have led to a possible way forward in addressing this problem. 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.

Not all entanglements are fatal. Even those entanglements which are not can potentially pose a serious welfare problem. The 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.

This collaborative approach means that we now understand so much more about how entanglements occur, which has led us to be able to develop strategies for how to reduce entanglements in the future.

Bally Philp from the Scottish Creel Fisherman’s Federation (SCFF), a SEA partner, said: ‘It’s great to see Scotland’s fishermen are at the forefront of understanding and addressing the issue of marine animal entanglement and we hope to continue the collaborative approach in partnership with government, NGOs and researchers. We really want to trial solutions, and look forward to the next stage in this work.’

WDC has now received funding from the Scottish Government’s Nature Restoration Fund, managed by NatureScot, for trials of sinking groundline in Scottish creel fisheries. This will help inform how they might be implemented in a way that’s practical for fishers and beneficial for the marine environment.

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