Can seagulls pollute the sea? Yes, but it’s very unlikely

Posters in Scotland have conservationists all of a flutter. They claim that seagulls pollute the sea. The answer to the question: ‘Can seagulls pollute the sea?’ is, yes, in theory. However, if they did, they would have gone extinct a long time ago. It doesn’t mean it can’t happen in the short term but to understand the consequence we need to think in term of ecosystems and animal impact. We are always too quick to jump to conclusions about the impact of wildlife being negative. This puts our future at risk.

Can any animal pollute the environment?

Yes. We pollute the environment and we are an animal. In a steady stable-state ecosystem though, this is kept under control. But what do we mean when we say ‘pollution’? What we mean is something called surplus free energy. Most energy-containing molecules are based on carbon or nitrogen. For example, ammonium, nitrate, faeces or the bodies of dead animals even. When these are in excess they cause the surrounding environment to collapse. Pollution is most often the consequence of some species becoming too abundant and upsetting the shape of the food pyramid. However, it tends to involve organisms lower down the food chain. Plants are actually the biggest potential sources of pollution as they fix the world’s carbon using powerful sunlight.

The impact of animals is positive even when it’s not

Humans tend to think of impacts as negative but the impact of larger animals like seagulls is usually positive, even when it’s not. When there is an excess of food – including, for example, chips – birds can become more abundant. The chips are also a source of pollution. The seagulls are actually cleaning up another source of waste. But as I discussed in this article, it’s a messy process. Just like on a building site, it takes time to reorganise waste into something useful. Animals are often seen as the harbingers of chaos, pollution and inconvenience. The short-term impact might be positive even when it’s not seen that way. What they are really doing is cleaning up our mess! If we have too many gulls, it’s either because we are too abundant, or we are too wasteful. Blaming the gulls won’t make the problem go away.

What good do seabirds actually do?

Seabirds have an enormous impact on nutrients and weather.

• It’s been shown that areas adjacent to breeding seabirds have significantly more fish life.
• Seabirds transfer and amplify nutrients, creating the basis for coastal health and fisheries.
• The ammonia from seabird poo, when combined with algae on the sea surface, seed clouds and create rainfall on an epic scale.
• Entire cultures and some of the wealthiest places on Earth were built on seabird guano (the other name for seabird poo).

As when it comes to all animals, in order to create our own survival, we have to start respecting the function of wildlife. Our own biased perspective tends to contradict the reality, which is that animals are essential for our survival. When we treat them as pests, we risk creating an obstacle to progress, in rebuilding the systems needed for our own futures.