UN-backed research ship scours Indian Ocean for plastic waste

An estimated 5 trillion pieces of plastic currently float in the world's oceans, up from none in 1950 and posing a question about their potential impact on a food supply chain that stretches from plankton – which have been filmed eating plastic pellets – up through shellfish, salmon, tuna and eventually humans, not to mention whales.

With these troubling facts in mind, the UN Food and Agriculture Organization (FAO) issupporting the efforts of the Dr Fridtjof Nansen, which is plying the waves of the southern Indian Ocean, trawling for trash.

The research vessel, operated by the Norwegian Institute of Marine Research (IMR) in collaboration with FAO, has since 1975 plied the world’s oceans to collect information on marine resources and the health of the marine ecosystems and to help train scientists from around the world.

Some 18 scientists from eight countries and crew are aboard now, in the second of two seasonal missions.

Researchers typically measure ocean temperatures, oxygen levels, chlorophyll and biological processes like plankton production and fish distribution, but there are two particular additional goals this year: to assess the scale and nature of industrial rubbish in remote parts of the southern Indian Ocean, and to study how the local Gyre, a cyclical vortex of currents, operates to spread plankton and tiny fish.

“We have found some plastic particles in almost all the stations we sampled,” said Reidar Toresen of IMR, cruise leader of the first leg. IMR is providing scientific services to the FAO EAF-Nansen Project financed by the Norwegian Agency for Development Cooperation (Norad).

Ocean-borne plastic trash can be ingested by wildlife – some sea creatures have even been seen to prefer beads of a particular colour – causing harm.

Even tiny plankton have also been observed consuming plastic beads.

Such menu choices can have tragic outcomes; sea turtles that eat plastic bags, for example, often die of dehydration and sunburn as their digestion is paralyzed and decomposing food turns into gas that forces the animals to float.

According to FAO, huge floating islands of trash twice the size of Texas have recently been located in both the Atlantic and Pacific Oceans, but the southern Indian Ocean is relatively unexplored.

The Trans-Indian Ocean Survey will yield critical information to scientists concerned about the extent and impact of so-called plastic beads in the ocean.

On the current mission, the crew is also launching new, high-technology sinking sensors to measure levels of a range of deepwater biological elements.

Provided by Australia with help from India, these robotic sensors are a step beyond the floating robots already in use to monitor ocean temperatures and salinity, as they are programmed to dive down as deep as 2,000 meters to sample oceanic health indicators.

When they resurface, these diving devices gather data at various depths, then resurface and transmit the data to scientists by satellite.

The sensors will collect data on levels of chlorophyll, an indicator both of trends in the ocean's carbon storage capacity as well as in the basic food supply that plankton and the fish that eat them can rely on.

Promoting sustainable oceans and fishing practices is a priority for FAO as capture fishery production is the source of 80 million tonnes of nutritious food each year.

Together with aquaculture, the world's capture fisheries provide nearly 3 billion people with 20 percent of their protein intake, as well as almost 60 million jobs.

Photo: UN Photo/Martine Perret