So-called “ghost nets” pose a deadly threat to fish and many other marine animals. There are now guidelines that are intended to prevent or at least curb the intentional and unintentional disposal of fishing gear. But the example of the Baltic Sea shows that so far these measures have had little effect. Marine researchers have now examined in more detail why this is.
The problem has been known for a long time and endangers animals in almost all oceans. Remains of fishing nets, fishing lines or other fishing equipment floating in the water can become a death trap for fish, seabirds and marine mammals: They get caught in them and starve or drown. It is estimated that almost two percent of all fishing gear used in the sea is lost and becomes such “ghost nets”. Because these utensils are mostly made of plastic, they also contribute significantly to plastic pollution in the oceans.
In order to better protect the marine environment and its inhabitants, the European Union has issued relevant directives years ago, including the Marine Strategy Framework Directive and the Single-Use Plastics Directive. They are intended to help curb the entry of plastic waste and ghost nets into the oceans.
Unclear responsibilities and lack of involvement
But despite such European and regional measures, there has been little progress so far. This can also be seen, especially in the Baltic Sea: “There is agreement that the entry of further plastic waste of this type must be prevented, but how this should be done is controversial,” explain Ben Boteler from the Research Institute for Sustainability in Potsdam and his colleagues. The researchers have now examined in more detail the reasons for the slow implementation of the protective measures. Their work is based on interviews with representatives from politics, industry, non-governmental organizations and research.
It became clear that a core problem is unclear responsibilities. “The inadequate and unclear distribution of roles results in a power vacuum: responsibility is too diffusely distributed for one actor to take the lead and, for example, initiate a large-scale recovery of lost fishing gear,” says Boteler. There is also the problem, especially in the Baltic Sea, that many different countries and organizations have to work together there. Not only do different policy areas and national responsibilities intertwine, the economic interests of the fishing industry and the equipment manufacturers also play a role.
However, according to the study, these actors – in particular fishing gear manufacturers and importers – are not sufficiently involved in the implementation of agreed measures. This makes it more difficult to develop joint solutions, such as deposit return systems or improved identification systems for fishing gear, explain Boteler and his colleagues.
The role of the fishermen
Another problem: the extent to which fishing nets end up in the Baltic Sea is still unclear. Because of fear of punishment, lost fishing gear is often not reported or only reported incompletely. Fishermen actually have strong economic incentives not to lose their equipment because fishing gear is expensive. However, this can happen again and again due to storms, strong currents or ice. Nets and fishing lines can also be lost when fishing methods interfere or ships collide. But because the recovery of these utensils is complex, dangerous and not economically viable, it is usually not done. And because fishermen fear punishment or other negative consequences, they often do not report the loss.
Environmental organizations have tried to close gaps by mapping lost fishing gear and raising public awareness. But without stronger coordination and clearer mandates, progress will likely only be made gradually, the researchers say. “To understand the full extent of the challenge, all stakeholders must build trust and develop an action plan together,” says Boteler.
What can be done?
The researchers recommend establishing joint work programs between fisheries, waste and environmental authorities for the Baltic Sea. Regional data sharing platforms could help improve communication between stakeholders. In addition, cooperation with fishing gear manufacturers should be strengthened and voluntary guidelines or pilot projects for the recovery of fishing gear should be developed. According to Boteler and his team, the Baltic Sea offers an important lesson when it comes to the ghost network problem: even where awareness is high and institutions are in place, aligning interests remains a formidable challenge.
Source: Research Institute for Sustainability Helmholtz Center Potsdam; Specialist article: Maritime studies, doi: 10.1007/s40152-026-00479-8