Microplastics are being eaten by the endangered Galapagos penguin
Microplastics have been seen rapidly accumulating in the diet of the endangered Galapagos penguin. For such a remote, fragile ecosystem, this brings concerns to environmentalists.
Microplastics have a size from 1-5 millimetres so are mostly only visible by microscopy, and hidden to the human eye, but they are more pervasive than we realise. Microplastics have already been found nearly everywhere we can imagine, from the human placenta, to the top of Mount Everest and even clouds.
The microscopic form of plastics may be the most concerning form of plastic pollution when they are widely distributed in the ocean. Recent evidence shows they may be causing changes to the marine food web.
Plastic particles found in the diet of the endangered Galapos penguin
Researchers recently discovered that microplastics are present in the prey of endangered Galapos penguins (Spheniscus mendiculus), meaning that a large part of their food web may be plastic.
The research, published in PLOS ONE, was carried out in a collaboration by researchers from Galapagos and the ESPOL Polytechnic School (Guayaquil, Ecuador), with University of British Columbia UBC’s Institute for the Oceans and Fisheries scientists.
Together, they observed the bioaccumulation of microplastics around Santa Cruz Island, to find out how the pollution is impacting the endangered Galapagos penguin. Seawater collected around the human-populated island showed a presence of microplastics, but researchers wanted to zone in on the specific food web of the endangered species for answers.
Ethical analytical approaches
The team used models that focused on the penguin’s diet, comprising sardines, herring, salema, anchovy and barracuda. Data was also collected from surface seawater near their colonies, which included zooplankton.
The scat of penguins were analysed to find out what they were eating, as an ethical alternative to lethal sampling of the tissues and gut contents of animals. Instead, the team combined empirical data they collected with from prey and feces, which were fed into statistical computer model methods.
Their unique food web model was created using system modelling tools called Ecopath and Ecosim to track the bioaccumulation. For wider context and comparison, they also incorporated a wider model for the penguin’s wider habitat and for the Boliver Channel Ecosystem.
Rapidly increasing plastic particles in penguin's prey
Using their model predictions, they identified rapidly increasing plastic particle accumulations and contaminations in the prey and in the Galapagos penguin's gut. First author Karly McMullen explained: “The model predictions highlight the accumulation behaviour and residence time of microplastics in the gut.”
This is not only a small-scale problem to these islands of Ecuador, as microplastics affect wider ecological regions. “With microplastics emerging as a prominent ocean pollutant, entering the environment every day, there is a growing concern for marine fauna and coastal wildlife, particularly if this anthropogenic threat is reaching even the most remote and protected areas such as the Galápagos Archipelago,” McMullen adds.
Protecting "at risk" marine habitats
The result of bioaccumulation modelling in the food web of the Galapagos penguin supports the risk management of plastic pollution, and ultimately, to cut down on microplastics in the marine environment. This is particularly the place for fragile habitats and isolated UNESCO Heritage Sites like the Galapagos Islands.
Senior co-author Dr. Juan Jose Alava hit this home, after having mentioned: “It is imperative that we are prioritising efforts to reduce the input of microplastics into vulnerable ecosystems and food webs, particularly such as that of the endangered Galapagos penguin.”
The scientific findings are concerning for endangered wildlife, but on a more positive note, marine science research like this helps to inform key decision makers about marine policy and conservation management. As a result, vulnerable species such as the endemic seabirds of Galapagos’ marine reserve can become better protected when the right decisions made.