THE Philippines is no longer the third largest contributor of marine plastics in the world.

It is in the fifth spot - after Indonesia, India, the US, Thailand and Brazil.

(From futureocean.org/ozeanwissen/topics/plastic_en_php 2020)

It is, however, still on the Top 10 list of contributors, producing 1.01 million metric tons of mismanaged plastics annually. Of this, 0.28-0.75 MMT/year leak to the oceans.

Plastic management is the main problem, specifically on single-use plastics. These are hard to recuperate, use only once and do not degrade/decompose causing havoc in other ecosystems.

Twenty percent of plastics in the marine environment come from ships, tourism cruise lines, and fishing vessels. But 80 percent come from land-based sources.

Sixty-five percent of mismanaged wastes come from illegal dumpsites and the remaining 35 percent are from sanitary landfills.

We account for only the managed but not the mismanaged plastics.

There was an average 427,050 MT of plastic waste generated by eight cities in Metro Manila in 2014. These are Malabon, Navotas, Manila, Parañaque City, Quezon City, Marikina, Pasig and Taguig.

Waste collection increased from 8,907 MT in 2014 to 9,286 MT per day in 2018.

Use of single-use plastics continues to increase despite the imposition of a plastics ban by LGUs.

The main contributors of marine plastics are the rivers near Manila Bay - Macabebe, Tullahan and Pasig rivers (the top three polluters in terms of riverine input).

Floating plastics in Manila Bay - 40,000 pieces per square kilometer in Manila Bay.

The highest accumulation of marine plastic from Manila ended up in Las Piñas-Parañaque Critical Habitat and Ecotourism Area (LPPCHEA), then Baseco and Noveleta.

Mangroves act as a natural filtering mechanism, preventing plastics from going into the ocean.

The main types of plastics that end up in the oceans are plastic bags and caps - PET and polypropylene.

The Spratly, Pagasa Island, Kalayaan Island have piles and piles of plastics from Malaysia, Indonesia, Thailand and the Philippines.

The seagull sanctuary in Lawak Island in Kalayaan Island Group (2021 expedition) is already inundated by marine plastics. Some birds have already died. This is a direct threat to the biodiversity in the area.

Ghost nets contribute to the degradation of the coral reefs.

Plastics were found deep in the ocean floor during the March 2021 expedition in the Philippine Trench.

Plastics are not staying on the surface. Buoyancy of the material changes and these eventually go down the sea. Plastics were found 10,400 meters below the surface, affecting the ecosystems in the deepest parts of the sea.

Plastics can also be found floating around the air in the form of microplastics - found even in protected areas.

Fate of plastics in the ocean

Stages:

– Plastic falls in the ocean and microorganisms attach to it and form biofilm

– The plastics and transported and dispersed through air and waves

– The plastics fragment and bio-deteriorate forming microplastics

– Microplastics get ingested by marine creatures

– Biomagnification happens as concentration of toxins increases from ingested microplastics

– Microorganisms are eaten by fishes and other economically important seafood

– Seafood is eaten by humans

Plastics that have sunk in the ocean release gases like carbon dioxide are seen to contribute to greenhouse gas emissions.

Plastics impact not just dolphins and whales but cut across all trophic levels, even zooplanktons.

Plastisphere

Plastics are becoming a new environment where microorganisms attach to. The type of organisms that attach to plastics - microbial communities on floating plastics - include prokaryotes, protists and heterotrophs. These make up an environment very unique inside the plastic compared with the surrounding environment.

Many organisms attached to the plastisphere are toxic. For instance, red tide causative organisms like dinoflagellates are known to attach to plastics and could get dispersed to areas where there are no known red-tide causing organisms. This is a direct health risk.

How much plastic is produced worldwide

A 2021 study showed that the US produces the greatest number of plastics.

The Philippines is one of the top importers of waste - mostly not recyclable and toxic.

What can we do:

1. Reduce and manage wastes - DENR is leading the crafting of a National Plan of Action on Marine Litter

2. Hold more clean-up initiatives

3. Monitor (generate baseline to look at efficacy of interventions; assess extent and gravity; quantify and visualize the problem; and determine the efficacy of interventions)

4. Calamities - plastics used to distribute aid/assistance; agencies should adopt more environment-friendly policy (need for research and innovation and incentives for adoption of these policies)

5. Evidence-based policy

PlastiCOUNT Pilipinas project - with the help of NGOs (including Oceana), marine scientists in the Philippines are making the plastics problem visible with the use of technologies using drones and artificial intelligence.

Plastics are everywhere - go up the food web; go to far places; go deep in the oceans and go down as rain.

Our actions are strongly connected to the organisms and environments in the ocean. There is connectivity in the marine environment.

The author is a marine scientist at the Marine Science Institute, University of the Philippines-Diliman.