Dolly Ropes – Material protection instead of environmental protection?

If you enjoy spending time on the German North Sea coast, you are familiar with the weather, wind and waves. Another sight will also be familiar to you: small plastic threads, usually orange or blue, that have been washed up on the beach. These are so-called “dolly ropes” or “chafing threads”. They were developed to protect fishing nets, but they endanger the environment. What can we do about it?

If you enjoy spending time on the German North Sea coast, you are familiar with the weather, wind and waves. Another sight is also certainly familiar to you: small plastic threads, usually orange or blue, that have been washed up on the beach. These are so-called "dolly ropes", which are used to protect fishing nets that are dragged across the seabed. Many of these threads get lost and drift through the seas or onto the beach as plastic waste. But what exactly are dolly ropes? How come so many of them break and what do they mean for the environment?

Have you ever seen such plastic threads on the beach?

We answer these questions for you in this blog post and also explore what approaches already exist to reduce their contribution to ocean litter. Small spoiler: We also have a few ideas on how we can upcycle salvaged dolly ropes or abrasion protection threads - for example into earrings or bracelets! But more on that at the end.

First: How do dolly ropes work?

Dolly Ropes are especially used in bottom trawling In Europe, it is mainly used to catch sole and crabs. Huge, funnel-shaped nets are dragged across the seabed, where they stir up entire ecosystems and catch everything that comes into their funnel. This extremely destructive form of fishing also takes its toll on the nets themselves: they rub against the bottom or break off if they get caught on rocky ground, for example.

To protect their expensive nets, fisheries have developed a chafe protection device - the dolly ropes. These are many small plastic threads made of polyethylene, usually around 1-2 meters long. These dolly ropes are put together in bundles and attached to the underside of trawl nets in the middle of the bundle. When the nets are dragged along the bottom during fishing, the threads in the bundles spread out and form a protective layer between the seabed and the fishing net. Where the bottom previously clogged the nets, the dolly ropes now take the abrasion caused by the uneven seabed. That's why they are also called "chafing threads".

This picture shows particularly well the small bundles in which dolly ropes are attached to fishing nets.

How do the scouring threads get into the environment?

Dolly ropes are exposed to harsh conditions due to their function as abrasive threads. They are subject to wear and tear: they rub off, get tangled, knotted and matted. Sometimes they even break. According to the Thünen Institute, a federal research institute for fisheries, 10 to 25% of all dolly ropes are lost during their first two weeks of use . This means that they have to be regularly maintained and replaced. This creates a never-ending cycle in which dolly ropes are lost every day and pollute the environment. And that's not all. Due to poor waste management on many fishing boats Just as many dolly ropes end up in the sea if they are not disposed of properly during maintenance work . This means that around 20 to 50% of all dolly ropes end up in the sea.

What do dolly ropes mean for the environment?

Dolly ropes are part of a particularly destructive fishing practice. Bottom trawling destroys the seabed irreparably and has an extremely high bycatch rate. In our eyes, dolly ropes do not mean anything good. However, we are not going to discuss the fishing industry itself here - some of the problems of fishing and the fact that even fish labels are only partially meaningful, we have already discussed here. Instead, we now focus only on dolly ropes that end up in the environment.

danger to animals

When plastic gets into the environment, the danger for wildlife is not far away. Many animals confuse plastic with natural materials and dolly ropes are no exception. We can see this as an example on Heligoland. The birds from Germany's only northern gannet colony collect dolly ropes to build or reinforce their nests. Many birds become entangled in the nets and cannot free themselves, so they suffer a slow and painful death.

Nesting gannets on Heligoland – can you see the dolly ropes between the nests?

Plastic waste and microplastics in our oceans

Have you ever heard of Great Pacific Garbage Patch This huge garbage patch in the North Pacific is about four and a half times the size of Germany and consists of huge amounts of plastic waste that we as humans have produced. What hardly anyone knows: 46% of it consists of former fishing equipment How ghost nets and dolly ropes. In fact, it takes It takes 400 to 600 years for such net parts to decompose in the oceans - and even then only to microplastics. These are tiny plastic particles that irreversibly pollute the sea water and are consumed by many marine animals as supposed food. With dolly ropes, marine pollution is inevitable: this harmful microplastic is created simply by abrasion on the seabed.

Dolly ropes are a threat to the environment, which is why it is so important that we remove them from the oceans with organizations like Healthy Seas and Ghost Diving.

What can we do about this problem?

Dolly ropes are designed to protect valuable material. This is of course a good goal - but not at the expense of the environment. That is why we need alternative solutions to end this form of pollution. What could that look like?

• end bottom trawling
  This demand sounds drastic. But there are reasons for it, because bottom trawling is not only damaging to the environment because of dolly ropes. Federal Agency for Nature Conservation With reference to the North Sea, the use of bottom trawling causes severe damage to the seabed and results in particularly high levels of bycatch, both of which have long-term consequences for ecosystems and species conservation.
• Use alternative materials
  As long as bottom trawling continues, other materials could mitigate the negative environmental impacts of dolly ropes. The Dollyropefree project in the Netherlands is testing alternatives that are either more resistant to abrasion on the seabed or are biodegradable. Solutions made of wood, hemp or leather are possible, for example. seawater biodegradable dolly ropes developed – however, there are some reasons that speak against bioplastics speak.
• Improved network designs
  Even better would be methods that make dolly ropes completely unnecessary - for example, new net designs that prevent any contact with the ground and thus make chafing protection unnecessary. The Thünen Institute is currently developing such modifications , for example by cutting the nets or using buoyancy aids.
• Better waste management from fisheries
  Finally, there is one thing that fisheries can implement without major changes or additional costs: the way they deal with waste. Raising awareness among fishing crews about the negative environmental impact of dolly ropes and how to dispose of them properly could ensure that up to 50% less ends up in the seas and on our beaches.

Upcycling – reusing the scouring threads

These proposed solutions all look to the future and want to prevent more dolly ropes from ending up in the oceans. But what about those that are already there? The answer is as simple as it is complex: we have to collect them. Then we can return them to the material cycle and recycle them. In the past, we have also worked on an idea of ​​how we can upcycle them. For example, into earrings and bracelets.

Be sure to stop by when we have them back in stock.