GHOST GEAR AND ITS IMPACTS
"ghost gear,” is any discarded, lost, or abandoned, fishing gear in the marine environment. Often linked to Illegal, Unregulated or Unreported fishing (IUU), and the use of poor-quality fishing gear, ghost fishing is often composed of plastics that last for hundreds of years, drifting for long periods in the open ocean. Besides being a hazard to navigators and scuba divers, it entangles marine mammals, sharks, turtles and seabirds. It can also transport persistent toxic compounds and invasive species. There are lots of different types of ghost gear.
These are “Fish Aggregating Devices”, known as FADs. The use of FADs as a fishing tool is a common practice worldwide, but the type we encounter are homemade, rudimentary artefacts that can be as simple as several plastic bottles tied up to a mass of twine and rope. They easily become lost and can remain adrift for several years.
In 2019, we estimated that over 40.000 of such ghost FADs were drifting in the South West Mediterranean. In 2020, after only 6 weeks at sea, we retrieved 68 ghost FADs just around the waters of Cabrera National Park. These drifting FADs are absolute death traps for loggerhead turtles, who tend to find themselves in the same oceanographic features that transport and aggregate drifting ghost gear.
In the Balearic Islands, Sicily, Malta and Tunisia, one of the most ancient Mediterranean fisheries is that of anchored FADs for fishing dolphin fish (Coryphaena hippurus). The use of poor-quality plastic line results in the FADs breaking loose. Bundles of this plastic line end up entangling sea turtles and other species, either on the surface or along the sea bed.
OCEANIC GHOST FADs
In the open ocean, the most ravaging form of FAD ghost fishing has its source in the tropical tuna fleet that deploys tens of thousands of FADs every year in the Indian, Pacific and Atlantic Oceans. In the case of some fleets, there has been some progress in developing FADs of better materials to mitigate the risk of entanglement, as well as the integration of “intelligent buoys” that allow the fishing vessel to monitor and track their FADs for more efficient and selective sets. Such “intelligent buoys” also have the advantage of facilitating the “rescue” of lost FADs before they destroy vulnerable reefs.
ILLEGAL PELAGIC DRIFTNETS
Pelagic drift nets were introduced in the Mediterranean by Italy and France for fishing swordfish and tuna in the 1980s. In only a few years, the fishery had already heavily depleted fish stocks and impacted vulnerable species like the sperm whale.
In 1987, when the first driftnets appeared in Spain, the Spanish longlining fleet teamed up with Greenpeace to block the port of Cartagena and force the government to ban drift nets. Pelagic driftnets were banned in 2001, but some fleets have continued to use them ever since.
In 2003, a study presented the death toll of this fishery at the ICCAT meeting in Reykjavik, totalling tens of thousands of sharks and thousands of cetaceans and sea turtles. As a result, the US and EU invested 15.000.000 Euros for converting this fleet. In 2013, the conversion programme seemed to be finally successful, but in 2014 the nets appeared again in Algeria. Nobody said anything, the EU imported the illegal catch, and in 2015 there were still over 1.000 boats using theses nets.
Drifting longlines are one of the greatest threats to marine life. Longlines are normally made from practically invisible monofilament and a line can be anything from 1km to 100km long. While the main line is kept afloat by buoys vertical lines are dropped down into the sea with baited hooks to attract various species of fish, over 100 million of these baited hooks are dropped into the seas and oceans every year.
Unfortunately very few of these lines actually catch the intended species an have a high by-catch rate including sea turtles, dolphins and more. Longlines are without doubt responsible for the vast decline in shark numbers in our oceans.