Seabirds and marine plastic debris

Plastic Gannet nest Iceland HWSRecently I have been involved in a project, as part of Circular Ocean, to establish what we currently know about seabirds and marine plastic in the northeastern Atlantic.

Marine plastic pollution is huge global environmental issue, which can pose a major threat to all marine species from mussels and fish to dolphins and seals. Seabirds are particularly affected by marine plastic as they can ingest it, become entangled in it and / or incorporate it into their nests, all of which can have negative consequences on an individual’s breeding success and survival.

circular ocean screen shot seabirds plastic

In the northeastern Atlantic, an area of international importance for seabirds, there has been little effort to better understand how marine plastic affects different seabird species over time and regionally. Therefore, we actually know very little about the current prevalence of plastic ingestion and nest incorporation for most species.

In order to highlight what we do and don’t know about seabirds and plastic in this region we collated data from all known studies reporting instances of plastic ingestion and nest incorporation in seabirds around northern Europe, Scandinavia, Russia, Greenland, Svalbard, the Faroes and Iceland.

imm hg rubber ball
Immature Herring Gull trying to eat a rubber football on Thurso beach (I confiscated it!)

One of the first notable things we discovered was that only 49% of the 69 species  commonly occurring in the region have been investigated for plastic ingestion within the northeastern Atlantic Ocean.  This means that for the remaining 51% of species we have no idea if they have ingested plastic as no one has looked – or at least not recorded it if they have.  Of the 34 seabird species that have been examined, 74% were found to have ingested plastic – highlighting that this is an issue for many species! However, many of the studies included had small sample sizes, with only 16% of species having data on plastic ingestion from multiple countries and years. Furthermore, the majority of data collected by studies was prior to 2000, so we don’t have an up to date understanding of plastic ingestion by most species.

Graphicla Abstract 3

Similar to other studies elsewhere, surface feeding seabirds such as Fulmar and shearwaters had the highest prevalence of ingested plastic, as they likely mistake floating plastic for food. Diving species, such as the auks and seaducks, were less likely to have ingested plastic, although Puffins have been found with elastic in their stomachs in Scotland and Norway.

In order to better understand how ingesting plastic impacts seabirds we need data on the amount (ideally the mean mass) and type of plastic ingested . However, very few studies have recorded this type of information so far.  Ensuring this type of information is collected in a standardised way, and recorded appropriately, is therefore of high priority for future studies.

EPseabirdsplastic

What we know about nest incorporation of plastic by seabirds is even less.  Although several species are known to incorporate plastic into their nests, as a Google search will highlight, we found only three studies documenting quantifiable data on nest incorporation, for two species in two countries – the Northern Gannet in Wales and Black-legged Kittiwake in Denmark.  Therefore, determining how nest incorporation can be monitored in a standardised way and the collection of baseline data is what we are looking to focus on next.

puffin plastic Shiants
Puffin carrying plastic string back to its nest on the Shiants (c) Rob Hughes
Shag nest with fishing netting
Plastic was seen incorporated into the nests of several Shags on Stroma this year.

The amount of plastic entering the oceans each year continues to rise so this issue is not going to go away without action from individuals, industry and governments! The properties that make plastics desirable are the very things which make it problematic. Due to its low cost, approximately half of all plastic items are produced for single-use. Plastic never breaks down, it only breaks up, into smaller fragments which remain in the environment and, as its density varies, it can be found throughout the water column, increasing the number of species which come into contact with it.

This research highlights the need for multi-jurisdictional, coordinated and collaborative efforts to gain a more comprehensive and current understanding of marine plastic pollution across the northeastern Atlantic. In response to the publishing of this research a motion has been lodged in the Scottish Government by Richard Lochhead MSP, which is great especially after the recent announcement of a deposit return system in Scotland for drinks containers.

Another important action, in my mind, is to ban balloon releases.  Plastic balloons, even those that state they are natural and biodegradable, can be ingested by many species, not just seabirds, whilst the attached string can entangle individuals. These releases are unnecessary and are directly littering our environment.

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Razorbill entangled in balloon string

This research was carried out with two colleagues at ERI, Neil James and Elizabeth Masden, and Alex Bond from the RSPB Centre for Conservation Science. The paper “Assessing the impact of marine plastic on seabirds in northern Europe and Arctic: A synthesis and recommendations for monitoring and research” was recently published in the journal Environmental Pollution.

 

 

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