We all know Gary the meowing snail from Spongebob. A list of things that he likes probably include: Spongebob, crawling, and eating. What about a list of things that Gary doesn’t like? I bet you didn’t know that Gary doesn’t like copper.
As it turns out, no snails like copper. And it’s not just snails, it’s probably all the sea critters that live in Bikini Bottom too- sponges, sea stars, octopuses, crabs. Copper is a common marine pollutant that harms many animals. The most common source of copper pollution in the water is from antifouling paints that are applied to boats to stop animals from growing and settling on the boat. Copper is especially good at preventing the growth of animals so it’s used in antifouling paints as a biocide.
Knowing that copper is harmful to many marine organisms, I did an experiment to see what copper does to snails. I wanted to find out what copper concentration was deadly for snails and how copper could affect their feeding and response to a predator. I predicted the rate of snail deaths would be greater at higher concentrations of copper and that feeding and a response to a predator would be reduced. I placed common periwinkles in different containers of seawater that contained various concentrations of copper. After being exposed in copper water for 3 days, I counted the number of dead snails and with the ones that survived, I tested their feeding and predator response behaviours. I gave the snails sea lettuce to see if they would eat it. To test the snails’ predator response, I would touch a sea star’s arm to the snail and record their crawling speed. In short: I found that copper does not do any good for snails. The more copper there was in the water, the more snail died, the less they fed, and they did not crawl away when there was a sea star predator. This has big implications for the toxic effects copper has on snails. Being exposed to copper pollution can prevent snails from eating, growing, reproducing, and escaping predators. Ultimately, at high enough concentrations, it kills them.
These results shed some light on the negative impacts copper has on snails, and probably other marine animals as well. Areas where there are a lot of boats, in harbours and marinas, there is bound to be marine pollution. Animals that live around these areas may be harmed as pollutants such as copper are present in the environment. If copper can kill snails, decrease their feeding, and make them unable to escape predators, continued pollution may cause these animals to disappear. And the toxic effects of copper extend beyond snails, they effect other organisms in the habitat that they’re present in as well. We could see changes in marine ecosystems as the abundances of animals decrease from the continual exposure to marine pollution.