Environment

Picking out silent ghosts in the deep

Ghost nets can kill marine wildlife, including vulnerable species.

Ghost nets can kill marine wildlife, including vulnerable species.  

It’s a lazy Sunday morning, but not for Suneha Jagannathan. With over 3 kg of diving gear, she is out on a mission — to collect ‘ghost nets’.

Diving to depths of 30-50 m, Ms. Jagannathan, CEO of Puducherry-based Temple Reef Foundation (TRF), helps contain a growing and insufficiently studied threat to marine ecosystems.

Ghost nets are classified under Abandoned, Lost or otherwise Discarded Fishing Gear (ALDFG), which includes lines, traps, hooks, dredges and buoys.

Ghost nets can kill marine wildlife, including vulnerable species, and destroy the benthic ecosystems that exist at the lowest level of a body of water. The problem has been worsening with the global expansion in fishing operations, and the availability of more durable gear.

High quality synthetic nets can last in the oceans for centuries, and lead to micro-plastic ingestion by aquatic life.

A 2010 Marine Fisheries Census by the Central Marine Fisheries Research Institute (CMFRI) said there were about 1,30,000 gillnets and drift nets in operation in India.

Research needed

The United Nations Environment Programme (UNEP), in a 2009 study titled ‘Abandoned, Lost or Otherwise Discarded Fishing Gear’, states that almost 6,40,000 tonnes of all fishing gear (approximately 10% of the total usage) is lost or discarded in our oceans annually, in bad weather or when nets get stuck to the rocky bottom.

Additionally, “the economic impacts of ALDFG are complex and have not been estimated systematically but include incremental costs associated with fishing operations, compliance, accidents at sea, search and rescue and recovery,” says a 2016 submission on ‘Marine Debris, Plastics and Microplastics’ by the Food and Agriculture Organisation (FAO) to the the UN Secretary General. The report also states, “Likewise, the impacts on biodiversity have not been addressed systematically.”

Report submitted

“We studied four different locations with the help of fishermen from Gujarat, Andhra Pradesh, Kerala and Tamil Nadu, and submitted a report to the FAO in April 2018,” said Dr. Saly N. Thomas, Principal Scientist, Department of Fishing Technology, Indian Council of Agricultural Research-Central Institute of Fisheries Technology, Kochi.

The results of this research have not been made public yet. “The government is also in the process of preparing a national ghost net management policy,” Dr. Thomas added.

Temple Adventures, a recreational scuba diving operator, has been conducting ghost net removal programmes since its inception in 2008, and with support from the Wildlife Trust of India since February 2018.

Dive against debris

“We usually find ghost nets about 12 km off the coast of Puducherry, at depths of about 50 m. They are also washed to shallower sites at a depth of about 18 m, about 5 km off the shoreline,” said Ms. Jagannathan. TRF organises ‘Dive against Debris’ sessions, where certified divers volunteer for underwater clean-ups.

Similarly, a retrieval drive in March by Thiruvananthapuram-based NGO Friends of Marine Life collected 400 kg of ghost nets in 90 minutes from several places off the coast of the Kerala capital. “Identifying and removing ghost nets, especially in rocky sections and coral reefs, is a tough, labour-intensive task,” said Robert Panipilla of Friends of Marine Life.

The Maharashtra Tourism Development Corporation’s Indian Institute of Scuba Diving and Aquatic Sports (IISDAS) has also begun retrieving ghost nets along the coast of Sindhudurg, in collaboration with the UNDP-Global Environment Facility, training youth from coastal communities in scuba diving.

Big loss

“Nets covering an area of 0.2 sq km were removed from the bottom of the sea near Sindhudurg, after about 800 hours of scuba diving,” said Dr. Sarang Kulkarni, Marine Biologist and Chief Instructor, IISDAS.

“Even if 1 kg of fish is tangled per year per square kilometre, it [the loss of aquatic life to ghost nets] can reach over 200 tonnes annually. To address the issue of ghost fishing nets, India needs to put an in situ action plan in place.”

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Printable version | Sep 17, 2020 2:47:26 PM | https://www.thehindu.com/sci-tech/energy-and-environment/picking-out-silent-ghosts-in-the-deep/article25146517.ece

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