We’ve all seen it at one time or another… The stray plastic bag, pirouetting towards a bird’s nest before taking flight in its aspirational journey to the great Pacific garbage patch. A journey which defies any poetic and artistically visceral connotations and instead breaks down the already objective beauty of nature into a synthetic wasteland. Such is the sight that has become so commonplace that people have begun to accept this waste debris as part of the landscape and whilst it isn’t fair to assume everyone avoids the responsibility of cleaning up, its consistent presence points towards neglectful and apathetic communities.
I’m sure, as you are reading this that you too are unsettled by the amount of litter surrounding your local area or perhaps as a concerned individual you dare to care about how litter is affecting the ecosystem. This article will touch upon how our waste is contributing to existing and potential ecological issues and ways in which you as an individual can help create instantaneous change to better the environment.
So how does litter affect the ecosystem?
Litter often enters the river ecosystem through wind-blown processes and dumping from human activity. This is a huge problem as the movement of water allows it to be carried further downstream. As the litter is carried – due to the brittle nature of plastic it begins to break apart into smaller pieces as it is dragged along rocks, gravel and other debris. Smaller and smaller plastic pieces are produced over time and become microscopic. These microplastics are easily ingested by invertebrates which in turn are eaten by predators which digest the invertebrates and plastic. This is a process called bio-accumulation and poses a threat to all species within the food web. As a result of bio-accumulation invertebrates ingest less nutrients and may cause development problems (deformities etc…). This can lead to crashes in populations of prey and predators alike.
Something we’ve noticed whilst surveying the river is that litter accumulates in areas where there are both natural obstructions, such as large woody materials, and engineered river features, particularly during flood events. Figure 1 illustrates the scale of the litter hot spots on just 1 km stretch of catchment after surveys conducted in 2019.
The data recorded during these surveys will help us target sections of the river that are particularly bad so we can focus on river clean ups and other actions to help prevent and stop these hot spots occurring.
As the environment changes so too does the behavior of the species which inhabit it. In this context when litter is added to the environment, foraging habits of species and the construction and establishment of habitats will change. It is also highly likely that the distribution of wildlife in affected areas will change depending on the extent of waste within a defined community. This inevitably leads to changes in food webs and the relationship between all forms of life, which only takes the loss or addition of one individual species to upset an ecosystem.
On land another example could be the hibernation and estivation (dormancy during dry or hot period) habits of terrestrial snails in rural grasslands/woodland. Typically, snails try and establish a safe place to retreat such as underneath a tree trunk or leaves, however when confronted with a foreign construction such as a crisp packet or plastic bag, their rare concealing structure among a sea of trees and grass make them ideal and will appeal to a weary mollusc. This poses two ecological consequences, in particular predation. Snails are secondary producers meaning that they eat primary producers (vegetation) and are prey to mammals whose populations are dwindling such as hedgehogs and some species of birds. Plastics are a potential hazard to hedgehogs in search of food and due to their fragility can be easily ingested which can cause asphyxiation. Not only that, plastics such as six pack rings can entangle larger mammals and birds which can lead to untimely death if not removed and has been a growing problem over the years.
The second consequence is speculative because it is still too early to know for certain as to whether acquired behavioral characteristics and traits can be passed on to offspring, however evidence is mounting and could prove fatal for species who are forced to adapt and depend on unpredictable human activity. If animals are indeed adapting to unnatural phenomena such as littering, then it is possible for a dependency to form which could lessen instinctual behavior. Such dependencies can be observed in birds who rely on the location of bird feeders to feed their young in rural areas. This is a potentially new fundamental problem for conservationists and although an inevitable consequence due to human activity, it is a harrowing reminder of our impact on the planet.
How can I help?
Luckily there is one thing we can all do to have an immediate impact on our local environment and that is litter picking. If one person can potentially destroy the balance of an ecosystem by discarding their waste, one person can restore that balance by removing it. It is really that simple. It can take as little or as long as you want and it is something that will have a positive outcome regardless of the amount you collect.
For people new to litter picking it can be a great way of learning first hand just how much our activity is affecting the planet. Even at a local scale – if you project and imagine the amount of litter you pick up in your region over that of Earth’s populated regions the picture soon comes into focus.
River Holme Connections regularly host litter picking activities in and around the river catchment. Check out our “What’s On” page to find the next volunteer day and get involved with making the river a healthier and cleaner place!