Measuring Marine Litter on Rossall Beach

The Rossall Beach Group has gained insight into what litter is and where it might have come from – but never had any firm evidence to back these theories up. But Coast Watchers citizen science project has been measuring marine litter on Rossall Beach and changed that.

Marine litter is a big problem. It’s reported that there are 5.25 billion (and counting!) individual plastic items alone in our world’s oceans. There’s so much plastic in the oceans that the marine ecosystem may be termed a ‘plastisphere’, and that’s before we start accounting for all the other waste materials in the oceans.

This waste poses risks of entanglement, drowning and starvation to marine life. Plastic also doesn’t biodegrade, it breaks down into ever smaller fragments called microplastics. Chemicals and pollutants can bind to microplastics, which, when ingested by marine life, can travel through cell membranes, accumulate inside their bodies, and ultimately travel up the food chain.

Tackling the problem demands global efforts to both prevent the input of waste into our oceans and increase our clean up efforts. Locally, the Rossall Beach Buddies have been doing an incredible job to clean waste from Rossall Beach every month since 2008. Through the Coast Watchers citizen science project, we were able to add a monitoring component to these monthly beach cleans, so that we can better understand the types of waste of the beach, how much is there, and why it might be there.

Monitoring litter on Rossall Beach

Come rain or shine, our fantastic Coast Watchers volunteers were on Rossall Beach every month for one year between August 2021 and July 2022 collecting and surveying the types and amounts of litter on the beach. We marked out a dedicated 150-metre-wide sample area of the beach where we repeated our surveys, asking other beach cleaners to avoid cleaning in that area to allow litter to accumulate naturally between each survey.

Coast Watchers volunteers enjoying the blue, and braving the grey skies, to collect and survey litter on Rossall Beach.

Plastic dominates

Over the year, Coast Watchers volunteers surveyed and cleaned over 22,500 items of litter from our sample area. On average across the twelve months, we found 1248 litter items for every 100m of beach, three times more litter than the average amount collected nationally during 2022 Great British Beach Clean.

In terms of materials collected, plastic waste unsurprisingly dominated the surveys, accounting for over 77%, or 17000 items, of total waste removed. Plastic fragments and food packaging comprised the bulk of this waste, although interestingly we found over 1300 more plastic bottle caps than plastic bottles! Where on earth do the plastic bottles go?

Sanitary waste, including everything from wet wipes to nappies, was the second most numerous category, with over 1900 individual items collected. Fishing related waste, encompassing all wire, netting and rope, followed closely behind as the third most numerous litter type. Various other materials, including glass, metals and textiles, were also found on the beach, but in substantially fewer numbers.

Winter waves and ‘grot’ spots

The amount of litter collected per month varied substantially over the year, with the greatest loads found over the winter months, and the least found over the summer. We recorded the greatest amount of litter in February 2022, when we surveyed over 3600 items, almost five times the amount we collected in July.

Perhaps the dominant driver of this variation in litter quantity was the seasonal wave climate, with larger, more energetic winter waves appearing to wash ashore much greater amounts of litter than the smaller summer waves.

Heavily littered ‘grot’ spots were also found on the beach, with litter tending to accumulate in specific areas across our sample area. These ‘grot’ spots tended to appear in sheltered locations which favoured the accumulation of strand line material, including sea weed and dead vegetation, with the litter becoming both tangled within and trapped on the surface of such material. As a result, not only did we find that the amount of litter on the beach varied across the year, the location of it within our sample area was also highly variable.

Waste from direct littering or the sea?

The vast majority of litter did not come from beach users. Instead, most litter came from the sea, evidenced by its discoloured and fragmented state, suggestive of litter which has spent a considerable time exposed to chemical and physical decay processes in the sea. The fact that most litter was found over winter, when beach usage was at lowest compared with the busy summer, is further evidence that most litter was sourced offshore, and not from direct littering onto the beach.

Few freshly dropped items were also found. For instance, the number of cigarette ends, good indicators of direct littering from beach users, remained low, with just 57 found over the whole study period, an insignificant amount when compared with the quantity of predominantly sea-borne plastic fragments (5000+). Whilst humans are still responsible for the litter entering the sea in the first place, the fact that so few directly littered items were found reflects well on the good waste practices of Rossall Beach users.

A litter type not associated with direct littering are sanitary items, which are likely sourced from combined sewer overflows (CSO), when excess untreated sewage is discharged directly into the sea. Yet, on Rossall, we found no correlation between the timing of reported CSO discharges and the presence of abundant sanitary waste. For instance, the ‘explosion’ of sanitary waste in February 2022, when almost 700 items were collected from the beach, came after a three-month period without any locally reported CSO events. Although untested in this study, water quality may still be affected by such waste though, typified by the media and public focus on the impact of CSO events on bathing water safety over summer 2023.

A cleaner beach for all

The insights that we’ve gained from one year of litter monitoring would not have been possible without our fantastic group of highly dedicated Coast Watchers. We’ve certainly helped to confirm anecdotal, and reveal new, knowledge about the types, amounts and sources of litter found on Rossall Beach. The work has also raised plenty of new questions and unknowns, particularly regarding the source location and transport pathways of such sea-borne litter.

Locally, we’ll never remove all 5.25 billion plastic items, but it is with the fantastic collective efforts of people engaging in beach cleans and citizen science that we can certainly make Rossall Beach a cleaner and more pleasant environment for people to visit, enjoy and benefit from.

September 2023

Joseph Earl
j.earl@lancaster.ac.uk

Read More: Litter in the Ocean: Litter on the Beach