Aimed at reducing the diesel consumption in fishing trawlers, the Central Institute of Fisheries Technology (CIFT) has introduced a new innovative model of V-form double-slotted otter boards.

It will help in considerably reducing the burden of ever-increasing fuel prices, carbon emission and improve the economic performance of the trawling sector.

Otter boards are gear accessories used for keeping the mouth of the trawl net open horizontally. 

The new V-form double-slotted otter boards has slots that permits water to flow through it, thereby reducing the resistance significantly compared to conventional otter boards.

Field trials of the new otter boards fitted to a CIFT research vessel revealed that, on an average, three litres of diesel can be saved per hour for trawling in comparison with a non-slotted V-form otter boards of the same size and weight. The new otter boards also reduce the RPM requirement without affecting the required trawling speed.

High fuel consumption

In India, trawling constitutes about 50 per cent of the marine fish landings and is also one of the most energy-intensive fishing activities.

A CIFT study found that about 165 million litre of diesel are consumed annually by 3,678 trawlers in Kerala. The hydrodynamic drag of the trawl net and the accessories is the major factor responsible for high fuel consumption. A pair of otter boards account for 20 per cent of the trawl drag.

Wooden rectangular otter boards and the V-form steel otter boards, introduced first by CIFT in the 1970s, are presently used for trawling in India.

Aiming for net-zero carbon emissions

Leela Edwin, Director of the institute, said there are about 35,228 trawler boats in India and its diesel consumption varies from 15-45 litre/hour depending on the size of the vessel, horsepower of the engine, type of gear and accessories, the skill of the operator, water currents, sea, and atmospheric conditions, etc.

Usually, a trawler operates for 7-8 hours in a day, and the total diesel savings by using the new otter board is approximately 21-24 litres per day.

A multiday trawler engaged in 20 days of fishing can save up to 480 litre of diesel in a month. Thus, if 80 per cent of the trawlers adopt the V-form double-slotted otter boards, more than 30 million litres of diesel can be conserved annually on average in India alone.

The new otter board model, if implemented widely, will also help accelerate India towards achieving net-zero carbon emissions by 2070, as pledged in the COP26 climate meeting held in 2021 at Glasgow, the Director said.

The technology has been very well accepted by the trawlers in Kerala, Karnataka, and Tamil Nadu. CIFT has already started to popularise this technology in all the maritime States across India.