There’s a big problem with the catch of the day, it literally catches everything! The very common gillnet, which floats vertical in the water like a floating spider web, is used to catching large amounts of fish and also catches large amounts of everything else including birds and mammals.
These unintended victims of the nets are called “bycatch.” Gillnettting is a method of fishing used most often on commercial boats, where large nets are dragged across large areas of water, entangling everything in its path. A new report estimates 400,000 seabirds alone are killed by gillnets every year.
The report suggests that 148 different seabird species are at risk of being caught in gillnets. However, Ramunas Zydelis, co-author of the new report, told Mongabay, “Bird bycatch in gillnets is not type-specific and species-specific. Not all the nets are equally dangerous. Nets set deep in waters are less likely to catch birds than nets in shallow places or drifting at the surface.”
The birds at most risk tend to be ones that dive deep into the water for food — this even includes some penguins, especially those living off South America. Although it seems like not much can be done about this issue, there are many solutions to lower and prevent bycatches in fishing nets. It’s the planning and implementation that needs to be worked on.
One success story is in California where restrictions to gillnets depth were implemented in 2000. Starting in the 1980s, fisherman in California began to use monofilament gillnets, which are basically invisible when submerged, to catch halibut. Unfortunately, these invisible nets also were catching on average 13,000 guillimots (a seabird found along the Pacific coast) every year. After California placed restrictions on the the depth of the nets, there has only been one reported guillimot death.
There has been many other solutions suggested to find the balance between still allowing fisherman to use gillnets and preventing bycatch. One solution is to make the nets more visible. A study conducted in 1999, in the Puget Sound, found a 45 percent decrease in bird bycatch due to more visible nets, however, it did not help at night time. Others suggest using sound to deter birds from the fishing nets, which has been proven to reduce bird bycatch by 50 percent! However in scaring away the birds, the noise unfortunately attracted more mammals to the nets.
The study suggests the solution that may make the most difference is “spatiotemporal closures.” This approach would limit gillnet fishing to specific ecosystems and times of the year in order to allow for migration of species like birds, mammals, and even some fish to go undisturbed.
Ultimately, what we need to do is mediate a solution using the government, the fishing industry and people to prevent and hopefully stop the tidal wave of death that are gillnets.
Image Source: Ingrid Taylor/Flickr