Meet the victims of illegal driftnets
Saturday 14 january, 2012, 22:00, by
The use of illegal driftnets in the Mediterranean Sea is causing the deaths of hundreds of thousands of animals each year, including whales, dolphins, turtles, sharks, swordfish and tuna. But which species are most at risk? As The Black Fish prepares for its campaign to end the use of these destructive nets, we look at the victims of this criminal fishing activity.
Thousands of endangered fin whales die on Mediterranean driftnets each year
The majority of driftnets in the Mediterranean Sea are set out to catch swordfish and tuna. However, research indicates that up to 100.000 cetaceans (dolphins and whales) and up to 100.000 sharks are also caught 'accidentally' in the nets each year in the Mediterranean region alone. Numbers show that on average only 15% of the catch of driftnets is the actual targeted species, with over 85% of the catch thrown dead overboard as unwanted by-catch.
Meet some of the most common victims:
Sperm whales
For sperm whales an encounter with a driftnet will mean almost instant entanglement because of their particular head shape. Sperm whale deaths have increased dramatically along with the growth of driftnet fishing in the Mediterranean Sea, with many recorded strandings along the coasts of Spain, France and Italy in the last three decades. Very little is known about the Mediterranean Sea population of this species but it is believed that the sudden sharp decline of strandings in recent years indicates that the population is increasingly endangered. Some researchers believe that the total amount of Mediterranean sperm whales is now in the low hundreds.
Fin whales
Fin whales are regularly found stranded with marks of driftnet entanglement. The continued illegal use of the fishing nets are directly linked to the declining number of fin whales in the region. The fin whale is the second longest animal on earth and one of the most endangered species of cetacean. Fin whales are found in the central and western parts of the Mediterranean Sea and live most commonly in the deeper parts of the sea. Some research indicates that the fin whale population in the Mediterranean Sea is resident, meaning they stay in this region and might not mingle with the North Atlantic population as much as previously thought, making them more vulnerable to the impacts of human activity in the relatively busy Mediterranean Sea. Other species of whales regularly caught in driftnets include the Cuvier’s beaked whale and long-finned pilot whale.
Common dolphins
By-catches of dolphins in driftnets have been so common in the past decades that in case of the Spanish driftnet fleet (which operated in the Alboran Sea until the mid-1990's) one dolphin used to be caught for every 10km of net set out during a single fishing operation. Common dolphins used to be found in most areas of the Mediterranean Sea, hence their given name. However, in last 40 years the combined effects of pollution, habitat loss and industrial fishing has caused the species to face a bleak future.
In the last 20 years the Moroccan driftnet fleet has greatly expanded in size and can be found fishing in the Alboran Sea where between 1500-2000 common dolphins are estimated to be killed every year. The animal is now rarely found in other area's of the Mediterranean Sea where they used to be abundant.
A pod of sperm whales entangled in a driftnet off the Italian coast
Striped dolphins
Although the striped dolphin is categorized as being at 'lower risk', the Mediterranean population of this species is known to be severely under threat from driftnets. Many of these animals continue to be found along Italian beaches during the height of the driftnet season, bearing the marks of driftnets. The striped dolphin is one of the most commonly caught species in driftnets in the region, with the illegal driftnet fishing fleets from Italy, Morocco and Turkey being responsible for most deaths. Another dolphin species regularly found in driftnets is the bottlenose dolphin.
Sharks
Sharks are slow producing species, meaning that they are considerably more at risk from fishing operations. For this reason driftnets can be pointed out as one of the major activities responsible for the declining number of sharks in the Mediterranean Sea. Shark species most commonly at risk are the blue shark, thresher and shortfin mako shark.
Basking sharks have also been known to get caught in Italian driftnets, while overall it is Morocco which is the largest culprit when it comes to shark by-catches, numbering in the tens of thousands annually. Pelagic stingrays and the endangered giant devil ray are shark related species regularly caught. The latter is a huge plankton feeding animal which is slow-reproducing, meaning the continued use of illegal driftnets is forming a major hazard to its survival.
To give you an idea about the numbers involved: even if we just look at the Moroccan driftnet fishing fleet operating around the Strait of Gibraltar, they are estimated to catch between 60.000 and 90.000 sharks as by-catch every 12 months in this area alone. Adding to this the impact of all the other driftnet fleets the scientifically accepted estimate of 100.000 sharks as by-catch in driftnets a year suddenly seems like quite a conservative one.
Sea turtles
All species of sea turtles in the Mediterranean Sea are endangered. Their survival is literally on the line with various types of obstructive fishing gear used in their habitats. It is believed that fishing practices are responsible for 60.000 turtle deaths in the Mediterranean Sea annually. The four sea turtle species in the region that are classed as either critically endangered or endangered are the loggerhead, green, leatherback and hawksbill turtle. For the French 'thonaille' (driftnet) fishing fleet, loggerhead turtles are the second most common caught animal after the striped dolphin.
Sea turtle trapped in abandoned driftnet. Photo by Eric Leong/Marine Photobank.
Fish
Swordfish and tuna are the targeted species of most driftnet fishing activity in the Mediterranean Sea. Other fish species caught as unwanted by-catch include the Atlantic bonito and frigate mackerel. While by-catch is often the deciding factor which makes a fishing technique destructive, we can't ignore the problems which exist even with the targeted catch itself. Morocco for example catches many swordfish that are much smaller than the minimum 125cm as set out by the International Commission for the Conservation of Atlantic Tuna (ICCAT), which is supposed to manage the fishery.
Due to the increased catches of juveniles in the Alboran Sea, the swordfish fishery in this region is a direct threat to the survival of the local swordfish population. In a report to ICCAT in 2006, the Moroccan government confirmed that 90% of the swordfish caught by the country's driftnet fleet in the Alboran Sea, were in fact juvenile fish. Many juveline bluefin tuna fish are also thought to be discarded by fishermen from the Moroccan, Italian and Turkish fleets.
Support The Black Fish in ending the use of driftnets
Stopping the illegal use of driftnets in the Mediterranean Sea is a top priority for The Black Fish. The Mediterranean Sea is one of the most unique yet fragile marine eco-systems in the world. A place where illegal driftnets simply don't belong. Keep an eye on our website, Facebook and Twitter for the latest updates and consider supporting us in this important campaign.
For more detailed information on the Mediterranean driftnets, see NGO reports [1] [2] [3] [4]
