When you go down to a yacht club or marina anywhere on the coast in Vancouver, you are likely to miss a lot of animals if you don’t know what to look for. What you may not realize is all the marine life that you are missing is actually right underneath your feet on the docks and pilings you are walking along when at a marina or yacht club.
Fouling communities are communities of animals that establish on manmade structures. Often, in marinas, these communities consist primarily of invertebrate animals and algae species. Invertebrate animals are generally considered animals with simple body plans that lack a backbone at all stages of development. These include animals like sea stars, insects, snails, sand dollars and many others.
New manmade structures will often seem pretty bare, however structures that have existed for a while will be abundant with these fouling communities.
If you look down while wandering among the boats you will probably see a sight like this:
In this image is algae, a sea star, mussels, and just a short distance away (just out of the image frame) was a Northern Feather Duster Worm. Many more animals than you probably would have thought.
If you get really lucky while looking down you may even see a nudibranch wandering along some of these manmade structures and materials. These are sea slugs, and there are a many different kinds, all of which are beautiful!
One thing to consider about the fouling communities you may encounter and many other ecological communities is that not all organisms present were originally from that community. A community may be composed of native, non-native, and invasive species. The difference between non-native and invasive species is that invasive species are actually having an effect on the community they have entered or been introduced to. One of the primary methods of new species entering communities is via humans. This can be through methods such as ballast water, or the release of live organisms that were originally intended for food.
Fouling communities are particularly vulnerable to invasive species due to boats moving back and forth between marinas around the world and carrying organisms with them. One invasive species that can be found in the fouling communities around Vancouver is an invasive tunicate, Botryllus schlosseri. This tunicate is quite different from our native tunicate, Corella inflata.
What we were interested in was investigating whether there were effects of light, yearly salinity patterns, and the presence of native species on the abundance of the invasive tunicate. By establishing one-meter transects we conducted a survey of the number of native species and invasive tunicate colonies that were present. Initial analysis indicated that neither light, nor the presence of native species had an effect on the number of invasive tunicate colonies. However, further analysis is needed to confirm this and examine the effects of yearly salinity patterns.
For more information on tunicates, check out:
For more information about invasive species and fouling communities, check out the Marine Invasions Research Lab at the Smithsonian Environmental Research Centre:
So next time you are out and about, wandering around a marina or yacht club, watch out for all the animal life, both native and not, that you may have been missing before!