Ghost fishing is what happens when lost or discarded fishing gear continues to kill sea animals long after the end of its intended use. Ghost fishing nets and discarded longlines are a well-known entanglement risk for many deep ocean species, like sea turtles, sharks and whales, but what about the effects of lost fishing line from shore-based recreational and subsistence fishermen? The Strandloper Project and its founder Mark Dixon are working to answer that question - and their initial results are rather shocking!
The Strandloper Project
Mark Dixon has lived on the shores of the Western Cape's iconic Garden Route for much of his life, and feels an incredible link to the coastline that helped shape the person he is today.
A turning point for Mark came when he went snorkelling off a stretch of coast near Sedgefield, which also happened to be a popular fishing site. While below the waves, Mark was shocked at the huge amount of lost fishing gear he encountered - hooks, lines, sinkers and more littered the beautiful reef. Mark decided to return to this site a while later with a team of volunteers to carry out an underwater cleanup of the area.
But, the real shock came a month later when this group of volunteers decided to return to the site for a second cleanup to see how much new fishing gear had accumulated in that month - they collected almost the same amount of gear from this spot!
It was as if there was a "perpetual replenishment of trash" created by the fishing community!
Being scientific about ghost fishing gear
We asked Mark how the Strandloper Project qualifies the amount of fishing gear that they find during these cleanups. A notable difficulty is that you cannot simply count the number of pieces of fishing line found - this can break up underwater, and counting hooks is also not perfectly reliable, as fishermen sometimes have tackle configurations with multiple hooks. Instead, the Strandloper Project looks at the number of sinkers. When conducting a cleanup, the Strandloper Project focusses on a 100m transect and quantifies the types of tackle found discarded in each 1m section.
The Strandloper Project also takes the time to separate the fishing gear it finds, which enables them to work out the "type" of fisherman that may be responsible for each individual item found.
- Subsistence fishermen, or entry-level recreational fishermen, tend to use thinner line and have a more traditional tackle configuration where the hook is on the end of the line, with the sinker attached further back. When these lines "snag", the hooks tend to get caught on rocks or shellfish and become embedded, not generally resulting in ghost fishing. This configuration tends to be the same whether or not the fishing is legal or not, and by hand or with a rod.
- Recreational fishermen who target larger fish tend to have configurations with the sinker on the end of the line and the baited hook further up, held in the water column by a float. A subset of these recreational fishermen, and sometimes shark-finners, are those specifically trying to catch large trophy fish, such as sharks, who use more expensive braided line to attach their hooks, in addition to "normal" monofilament line. When these types of tackle snag, it is usually the sinker that snags, and this often allows the hook and float to continue drifting in the water column and ghost fishing until the hook eventually rusts away.
The impact of ghost fishing
In the short time that the Strandloper Project has been in operation, five species of fish have already been observed as victims of ghost fishing, meaning that they got caught on the hooks attached to abandoned fishing tackle. These were pyjama catsharks, white musselcrackers, kob, blacktail and sea catfish.
Some of these fish are caught on hooks that are attached to pieces of line as long at 12m - which means they are swimming around frantically, stressing out and eventually starving to death or being predated on. As they decompose and their bodies disintegrate, the rotting fish heads are often left attached to the hook - serving as bait to catch another animal.
The Strandloper message
This initiative was named "Strandloper Project" as a nod towards the coastal heritage of some of South Africa's inhabitants, and the lesson that they teach us: Sustainable use of the ocean's resources does not need to compromise its biodiversity.
Mark points out that South Africa has 3 000km of coastline - that's about 5cm of coastline for every South African person, not even enough for us to line up on. If we are going to share the ocean's resources, then it is up to those of us that have the privilege of being able to make use of our coast to remember that it is part of something that we share with all South Africans - including those who will come after us.
When we asked Mark Dixon what message he'd like fishermen to know about this lost gear, his offered solution was simple - if you know a fishing spot is prone to snagging, either fish in a different spot or learn to retrieve your line.
Not everyone has the equipment or skills needed to clean up ghost tackle, but everyone can help prevent it.