Racing against the microplastics tide

Complex tides and constantly shifting weather make circumnavigating Britain a tough job. It needs good navigation skills as well as experience of coastal sea conditions. If you are rowing against the clock in a non-stop race in which competitors won’t set foot on dry land until it is over, you need to back up this expertise with the strength, stamina and determination that go with being an elite athlete.

This is the GB Row Challenge, the prestigious Annual Around Great Britain Rowing Race. This year, three teams - Albatross, All Systems Row and Sea Legs - will form up at the start/finish line on 12 June at London’s Tower Bridge on the Thames. As well as competing against each other, they will be aiming to beat the Guinness World Record race time of 26 days, set in 2013 by a four-man crew called the Islanders. According to GB Row founders Will de Laszlo and Jim Bastin, the race is “the toughest rowing challenge in the world”. Their vision for the race has gone beyond that of establishing a sporting tradition that now spans two decades.

The founders wanted to provide “a powerful sustainable purpose to the event, to leave a legacy in the sport of ocean rowing for our environment and the next generation”. When the three GB Row crews battle their way unsupported around the gruelling 3,500km course, they will undertake the largest-ever collection of marine biology data of its kind in the UK.

“The race is a great opportunity to spend huge amounts of time at sea monitoring microplastics pollution and the eDNA [environmental DNA] that’s in the water,” says Ben Green, spokesperson for GB Row Challenge sponsor Portsmouth-based Harwin, which is supplying custom hardware for the microplastics sampling technology built into the race boats. “It provides us with a chance to benchmark this data, to record it annually, to see what the changes are over time.” The sampling systems have been designed by Harwin’s technical support engineer Alex Mair and will supply data to a research project at the University of Portsmouth led by Dr Fay Couceiro, reader in biogeochemistry and environmental pollution in the university’s School of Civil Engineering and Surveying.

Couceiro says that the monitoring of microplastics, underwater noise pollution and eDNA has so far not been undertaken in British waters on the scale offered by the GB Row Challenge boats: “We don’t yet know our impact as humans in the oceans. There is no complete map for the UK concentrations of microplastics in the coastal waters.” The closest we have to such a map, says Couceiro, comes from the UK government agency CEFAS (Centre for Environment, Fisheries and Aquaculture Sciences). “But there are still areas where no data has been collected. How concentrations change over time is also yet to be explored. Data collected during the annual GB Row Challenge will significantly improve our understanding of the changing numbers of microplastics in our waters.”

Whatever the data from GB Row uncovers, it is unlikely to be good news. Figures from the sustainability consultant Eunomia state that plastic enters the sea at a rate of 12.2 million tonnes per year, the equivalent to one rubbish truck full of plastic every minute - and it can take centuries to biodegrade (see box below). This contamination causes problems not just for marine animals but the entire ecosystem. Larger fragments are an injury and choking risk to mammals such as dolphins and whales, as well as birds, turtles and fish, while fragments act as a carrier for harmful bacteria, moving it to places where it had previously not existed. Smaller sub-5mm pieces of microplastic enter the food chain, and when eaten by fish, crustaceans and crabs can cause irreparable damage. Many of these microplastics are also covered with bacteria that can be harmful to animal and human health.

Harwin’s technology has been a departure from the type of engineering applications the company routinely addresses. Mair says that designing the sampling system has included materials selection considerations, with 316 steel preferred to plastics as a build material, due to reported instances of plastic equipment used in field research in Antarctica contaminating its own findings. “Precision engineering for harsh environments is our speciality. Seawater is one of the harshest there is.

“This has been a different kind of challenge,” continues Mair. “The pump and filters process large volumes of water and must be ultra-efficient to keep within the 100Ah power budget allocated to scientific equipment.”

There were other aspects to factor into the design, too. “As well as being a sustainability project,” says Mair, “the GB Row Challenge is a race, so size and weight are critical. In addition, the whole system must be as quiet as possible because the athletes will be living and sleeping very close to the technology.”

Green says that Harwin is sponsoring two of the three boats in this year’s GB Row Challenge. While this might look like a bit of an each-way bet, the purpose of the support is not so much to back a race winner, but to align Harwin’s corporate social responsibility outreach with the work being done in academic environmental research. “It’s more about contributing to the sustainability cause. That’s why we got involved with the project.”