We have all walked past a yacht club in Vancouver on our way to the beach and thought of the city’s most affluent citizens. Rows upon rows of luxurious boats locked behind fences, successfully separating you from the elite community. Unless you are lucky enough to be a part of this community, chances are you have never stepped into the club and roamed the docks. Well we did, and let me tell you: it may look ostentatious from the outside, but the inside is just like any other dirty old fishing dock.
This past Monday, we set out to examine fouling communities, which are communities of ocean critters that establish on manmade structures like boats, piers, and yes, even the dock at your local yacht club. Half of the group visited the Coal Harbor Yacht Club in downtown Vancouver, and the other half set out to explore the Jericho Yacht Club. After walking past rows of boats that could easily pay for my tuition, we picked a nice dry spot, laid across the dock, and poked our heads under to count and collect the animals that were living there. We didn’t see seastars made out of gold or oysters laden with pearls, but the same invertebrates we have been seeing for the last two weeks in the intertidal and along seawalls. In fact, there were so many mussels living on the underside of the docks that it looked like a campus library during midterm season.
After collecting chunks of the fouling community and bringing them back to the lab, we found some cool invertebrates living among the multitude of mussels. Caprellids (Caprella mutica), more commonly known as “Japanese Skeleton Shrimp”, were one of these invertebrates. As the name suggests, they are invasive to our local waters here in B.C. Check out the gif from the lab and watch them work out their abs while they wave through the water column looking for food. The Obelia that they are latched onto look like algae, but they are actually a colony of tiny animals called hydrozoans (you can think of them like soft, stringy corals). We also found two species of tunicates, one invasive and one non-invasive.
Have you noticed a pattern? Fouling communities, like the ones living under these docks, are quite susceptible to invasive species. One of the major reasons are that manmade structures are often associated with other manmade structures (i.e. boats and piers), and boats are one of the major contributors to the dispersal of invasive species from other areas. You can learn more about the basics of invasive species with this quick TedEd talk on youtube: https://www.youtube.com/watch?v=spTWwqVP_2s.
So think about that next time you head to the beach and pass a yacht club: not only do their docks look just like anyone else’s, but they also harbour some of the least desirable species in our area.