Destructive Fishing Techniques and Discards
The more fish stocks decrease, the more extreme the fishing techniques become.
When we talk about destructive fishing techniques, we refer to the devastation of the seabed caused by trawling, bycatches, the use of poisons and explosives and ghost fishing.
For techniques universally recognized as destructive, there is no other solution than the prohibition. Those who use them must be severely punished. National laws have identified and prohibited many of these practices. However, for industrial vessels that generate huge profits and small fishermen who have to cope with dwindling fish stocks, the temptation to break the law is very strong.
It is clear that the larger and more powerful the vessels are, the more devastating the impact of illegal fishing techniques.
Trawling
One of the most harmful techniques is trawling, an industrial method based on the use of huge nets ballasted by heavy loads and equipped with metal wheels, which scrape the seabed, raking (and destroying) everything they find along their path, from fish to centenary corals.
Many species, even in danger of extinction, are collected without reason and then thrown back into the sea, often already dead. These “collateral” losses ( bycatch) reach, in some cases, 80% or even 90% of the catch. Furthermore, large surfaces on the ocean floor, which constitute the habitat where fish find food and protection, are crushed and destroyed. The largest nets used in trawling have a “mouth” the size of a rugby field and leave marine scars over 4 km long. The wounds inflicted on the ecosystem can be permanent. Furthermore, trawling leaves sediments (sometimes toxic) in suspension, responsible for a turbidity of the water unfavorable to life. This kind of fishing cancels the natural characteristics of the environment which in normal conditions allow marine animals to live, rest and hide.
Often used by industrial vessels in (open) high seas, sometimes regulated in territorial waters, this practice, accused of having strongly contributed to overfishing, clearly demonstrates that there is a lack of global management of the sector.
The ecosystems of the large sea beds are characterized by exceptional biodiversity. The scientific studies of the last twenty-five years have made it possible to identify very rich marine environments beyond 400 meters, up to 2000 meters and more in depth. Despite the almost total absence of light, strong pressure and very weak currents, many species are found in deep waters. These fish, which live in extreme conditions, have a very slow growth, a very long life expectancy and a late reproductive age; they are particularly vulnerable to disturbances in their environment. The marine ecosystems at risk are not only those of the high seas: trawling on underwater mountains and on the steep slopes of the continental margin, on the edge of the shelf, also causes serious damage.
The scientific community and many NGOs are calling for an international moratorium to protect the seabed of the high seas from trawling. At present, the efforts of governments in this regard are insignificant.
Fishing With Dynamite
The Discards ( bycatch )
One of the most important and scandalous aspects of the degradation of the oceans.
Discards are all forms of marine life caught other than intentional prey. They are “waste”, they include specimens of the sought species whose size does not conform, plus other species that are not eaten or have no market, prohibited or endangered species, such as certain birds, turtles and marine mammals. Some fish are rejected solely because the vessel does not have a license to take them ashore, because there is no space on the boat, or because they are not the species the captain has chosen to catch. All of them, and we are talking about MILLION TONS of fish, are thrown back into the sea, dead or injured.
A recent WWF report estimates that discards are 40% of the total catch and specifies that in many cases they are young specimens. It is easy to understand the dramatic consequences on the ability of species to reproduce and regenerate stocks.
Beyond the pressure on the species, this is a huge waste of food, both for human consumption and for that of marine predators.
Furthermore, specialists point out that while industrial fishing vessels discard MILLIONS OF TONS of unwanted fish each year, artisanal fishing discards very little.
Poisons and explosives
The use of poisons to kill or stun fish is widespread, in the sea as well as in fresh water, including coastal lagoons and coral reefs. Cyanide fishing, for example, is practiced from the decimated and devastated reefs of the Philippines – where it is estimated that 65 tons of cyanide are spilled annually – to isolated ones east of Indonesia and other Western Pacific countries. In many places the use of poisons in fishing is a traditional technique, but the negative effects have been accentuated since chemical pesticides have replaced substances of plant origin. The poisons kill all organisms in the ecosystem, including the coral that forms the reefs.
The use of explosives has also been around for centuries and is expanding. The explosions can produce very large craters, which devastate 10 to 20 m 2 of the seabed. They not only kill the sought after fish, but also the surrounding fauna and flora. In coral reefs, rebuilding damaged habitats takes decades. Explosives are readily available and cheap. They often come from the mining or construction industry. In many regions, explosives are extracted from old ammunition recovered from past wars or ongoing conflicts. Elsewhere, fishermen get them through illegal arms trafficking.
Ghost Fishing
Ghost fishing means the abandonment in water, usually accidental (but sometimes voluntary), of nets and other material, which continue to unnecessarily capture fish, molluscs, but also large marine mammals that die of exhaustion after hours of struggle to rise to the surface to breathe. The problem of abandoned or lost gear is amplified by the intensification of fishing operations and the introduction of equipment produced with resistant synthetic materials.