Ghost nets: a deadly trap for marine life

Lost at sea, forgotten by fishermen but still killing indiscriminately, discarded fishing nets continue to haunt marine life along the country's coastline.

Two rare olive ridley sea turtles recently fell victim to the underwater menace near Guns, a coastal settlement close to Jiwani in Balochistan. The turtles, trapped in a strong nylon net, were rescued by fishermen who freed them and returned them to the open sea.

The incident has once again drawn attention to the threat posed by so-called ghost nets - abandoned, discarded or accidentally lost fishing gear that continues to ensnare marine creatures long after it has been left behind.

The latest rescue was the 37th reported incident of olive ridley turtles becoming entangled in fishing nets along the coast over the past 15 years, according to Muhammad Moazzam Khan, technical adviser at the World Wide Fund for Nature-Pakistan (WWF-Pakistan).

Thirty-six such incidents had been documented previously, with the number of turtles trapped ranging from one or two to four in a single incident, Khan said.

He explained that the drifting nets involved in the latest incident were not used in Pakistan. However, changing wind patterns carry large numbers of such nets into the region, where they drift across the sea and threaten marine life.

Between October and December, winds shift from east to west, transporting the nets from one area to another and increasing the risk of entanglement along different stretches of the coast, he added.

Fishing nets can become damaged or unusable over time. While some are accidentally lost at sea, others are deliberately discarded by fishermen instead of being stored on boats or brought ashore for proper disposal. Once abandoned, the nets continue to catch marine animals, earning them the name ghost nets.

Marine creatures trapped in the nets often become more entangled as they struggle to escape. Their movement becomes restricted, leaving them vulnerable to injury and death.

Sea turtles face a particularly grave danger because they must periodically surface to breathe. When entangled in a net, they may be unable to reach the water's surface, eventually drowning.

The threat extends beyond turtles to fish, crabs and other marine organisms, including marine mammals. Ghost nets can remain in the sea for long periods, adding to plastic pollution and damaging the marine ecosystem.

Their movement also makes them difficult to track and retrieve. Ocean currents, waves and winds carry the discarded gear across different locations, exposing marine life in multiple coastal areas to the same danger.

Olive ridley turtles are an important component of the marine ecosystem. Compared with some other sea turtle species, they spend relatively more time near the surface, making them especially vulnerable to floating nets.

Khan said olive ridley turtles had not been visiting the Karachi and Balochistan coasts for breeding for a long time. However, their numbers in the Arabian Sea remain higher than those of green sea turtles.