Sea of plastic: Fisherfolk cannot manage fishing-related litter without disposal sites and technology, says Manju Lekshmi

Fishing contributes a smaller share of marine plastic than land-based waste, but abandoned gear and discarded fibre-reinforced plastic boats can cause serious harm to marine ecosystems, says Manju Lekshmi, senior scientist at Indian Council of Agricultural Research (ICAR)-Central Institute of Fisheries Technology.

In this interview with Down To Earth, she explains how lost nets can lead to ghost fishing, why old FRP boats are difficult to dispose of or recycle, and why India needs harbour-level waste units, incentives for fisherfolk and clear guidelines to manage marine litter from fishing activities.

Akshit Sangomla (AS): What are the major sources of marine litter from fishing activities?

Manju Lekshmi (ML): The first major source of marine litter from fishing activities is abandoned, lost or otherwise discarded fishing gear (ALDFG). Our focus is on ALDFG because it causes damage to sensitive marine organisms and ecosystems. These organisms include species such as marine turtles and mammals such as whales. When fishing nets, along with other debris, entangle organisms, the phenomenon is known as ghost fishing, which could lead to their deaths.

Another major marine litter item from fishing activities is fibre-reinforced plastic (FRP) boats. FRP is a good material for constructing fishing boats because it is economically viable and easy to use. Therefore, many traditional wooden boats were converted into FRP boats, mainly in the small-scale fishing sector, where boats are 15-20 metres long.

There are two types of FRP boats. The first is sheathed boats, where FRP is coated over wood, and the second is full FRP boats. The lifespan of a full FRP boat is more than 30 years, while the lifespan of a sheathed boat is less than 10 years. When FRP boats break, the only option is to abandon them somewhere, mostly along beaches. There is currently no proper disposal mechanism for abandoned FRP boats.

AS: How do these two types of fishing-related marine litter affect the coastal environment?

ML: When there are extreme weather events in coastal areas, such as cyclones or other storms, abandoned fishing nets and FRP boats get washed into the sea. Nobody is generally fully aware of the impacts of FRP boats on the marine ecosystem.

We conducted a toxicity study in which we fed FRP to fish under controlled conditions and found that microplastics derived from FRP caused problems for the reproductive behaviour of fish.

AS: What do fisherfolk do with FRP boats that are no longer functional?

ML: As fisherfolk have no other choice, they sometimes burn FRP boats that are no longer functional, because otherwise they can cause navigational and safety issues.

We conducted another study on the issues arising from the burning of FRP boats in the coastal environment. We found that different persistent organic pollutants, or POPs, are emitted during the burning of FRP boats.

The other option for fisherfolk is to dispose of the boat in a landfill, but there the chemicals from the boats can leach into the ground.

AS: What is the scale of the FRP boat and other marine litter problem?

ML: There is no common database on marine litter, which makes it challenging to know whether the problem is reducing or increasing, and by how much. But coastal fisherfolk are telling us that the amount of litter has reduced from before.

We have observed that 80 per cent of marine plastic is land-based, mainly from households, and only 20 per cent is from fishing and shipping. To control marine litter, we have to first control land-based solid waste. The sources of land-based plastic can be identified more easily than sea-based plastics.

In India, we have a multi-species, multi-gear fishing system. Therefore, there is a huge diversity of fishing nets made of different materials and of different sizes. This makes the management of fishing gear difficult.

In our studies, we found that monofilament polyamide, or nylon, gillnet is one of the major problematic types of gear. This is because it is cheaper than other fishing nets. Fisherfolk often throw it on beaches, and it reaches the sea. Most fishing gear is manufactured in small-scale industries, where proper standards are not maintained.

We have done our studies in Kerala, but we know that the problem is true not just for other coastal states in India, but also in other Asian countries such as Sri Lanka.

AS: What could be a solution for FRP boats and other marine litter?

ML: The Kerala government is working on a model in the harbours. What I would suggest is that there should be a unit in every harbour where sorting, shredding, pulverisation and baling of all kinds of marine litter can be carried out.

Fisherfolk could be given incentives to bring back plastic from the sea, which can then be managed in the harbour. In Kerala, environmental units such as Haritha Karma Sena can be involved in the collection of litter in harbours. The final material from marine litter can be reused for composite materials and other purposes.

In the Munambam area, Chinese dip-net fisherfolk are collecting plastic that comes into their nets. We are working with the fisherfolk and a non-profit called Plan@Earth, which collects the retrieved plastic from fisherfolk and takes it for recycling, after we have weighed and quantified the litter.

We also provide litter booths from CIFT in many harbours for the disposal of solid waste items. Many fisherfolk are voluntarily working with us without any incentives. Many are becoming aware, but we have to further increase awareness about these issues.

FRP is a thermosetting plastic that uses two kinds of resin and glass fibre. One is polyester and the other is epoxy resin. Because of its composition, it is extremely difficult to recycle. For sheathed FRP boats, the removal of FRP material coated on the boats is a difficult task.

First, we clean it, shred it and pulverise it. Based on the quality, we can then use it for different products. This material can be mixed with cement and used for construction. We can also make cementitious composites, which can be used for making different products such as furniture and architectural structures.

The ultimate aim is to use recycled ALDFG materials for producing textiles. The next challenge is commercialising these products. There must be stakeholder linkage. Companies will not go to beaches to collect the litter.

AS: What are some of the challenges of managing marine litter?

ML: Marine litter is not on the list of the Central Pollution Control Board, so responsibility for its collection and disposal is not fixed.

One of the major challenges of managing marine litter is retrieval from the sea. Only 60 per cent of plastic can be seen as floating plastic; the rest is beneath the surface. Whatever we are able to retrieve is floating plastic. The microplastics coming from litter beneath the sea surface remain a question mark.

The retrieval mechanism for floating plastic can be through fisherfolk themselves. In other countries, people specifically fish for plastic. In India, this is not possible. So whenever fisherfolk get plastic, they can retrieve it.

Fisherfolk do ask the question: most plastic is coming from land, so why should they be the ones retrieving it? To resolve these questions, we have suggested an incentive mechanism. Some people have also said that if incentive mechanisms are stopped, fisherfolk will not bring back plastic. Therefore, some behavioural change should also come about.

After retrieval, we do not know the percentage degradation of the retrieved plastic material. This is important for knowing whether the material is suitable for recycling and secondary products.

A lot of work on marine litter management is happening in patches, and all of it should come together for it to be more efficient. This could be done through a common platform for the reduction and management of marine litter.

Currently, there is no technology, mechanism or guideline for the disposal of ALDFG or FRP boats. So how can we tell fisherfolk to manage the litter on their own? Beaches and harbours are their working areas, so they will keep the gear and boats there until we give them an alternative.

First, we need to provide disposal sites. Then there has to be some kind of technology for the management of litter generated by fishing activities.