National Marine Week is a time for celebrating and appreciating all things marine. From our coastlines to the open oceans, seabirds play an important part in ecosystems around the world. Here are just a few of the ways our feathered friends help preserve our marine spaces:
Birds as predators
It sometimes feels weird to think of birds as a top predator because they seem like such gentle and passive animals. We usually think of predators as fierce looking beasts with large teeth but in many marine environments birds sit at the top of food chains and help to control populations of their prey. From fish catching seabirds like the gannet, to shellfish cracking waders at the beach, to birds who eat other birds! For example, take a local Solent predator, the Great Black Backed Gull (GBB gull); this very large gull with dark upper wings can be seen in many locations around the Solent coast. The small picture on this page from Marcus Ward shows a GBB gull predating a black headed gull near Lymington. Predators are so important to maintain balance in ecosystems, by taking weak and injured birds GBB gulls actually reduce the competition between other black headed gulls for food and space increasing the surviving birds’ chances of survival. Without birds in the marine ecosystem some species, currently kept in check, would out-compete others and take over, reducing the biodiversity of the shoreline.
Birds as ecosystem engineers
One study carried out in the Wadden sea found that the action of brent geese, wigeon and pintail moving and feeding on seagrass beds was important for the survival of this habitat. Over the winter period, the birds would trample and uproot the seagrass which led to unstable sediment that was washed away by tidal currents. During the summer, seagrass habitat naturally helped sediment accumulate on the shore. This seasonal variability in sediment movement led to a balance which ensured the height of the seabed stayed the same over the years. If the seabed continuously rose, which would occur without the birds presence in the winter, seagrass would not be able to survive as it requires water cover at high tide. The birds, without even knowing it, were helping seagrass survive! I wonder if this might be the case around the Solent too…
Birds as bioindicators
Seabirds are also really good for conservationists working in marine environments as they act as bioindicators. This means they can tell us a lot about the health of an environment from their position in different food chains. Here’s a great article explaining why birds are awesome for conservationists.
To wrap it all up, birds are so important to the marine world and it wouldn’t be the same without them. Happy National Marine Week from all of us at Bird Aware.
Ranger Lizzie
