“Go collect handfuls of diverse things”, they said. “Alright”. We agreed, but time was tight, and downtown congestion is horrendous at any time of day. In order to beat the impeding rush hour traffic, our class trip to Coal Harbour had to be kept short, and perhaps more salty than sweet.
So how do you find diversity in a fouling community? After looking at mussels upon mussels (pun intended) of animals too far down for us to reach, our answer came to us by accident when we noticed a rope hanging off the side of the dock. Lifting it up, we found a variety of tunicates (clear: native, orange: invasive and colonial) also known as sea squirts, sponges, shrimp, barnacles, polychaete worms, nematodes, anemones, and many more mussels.
Ropes, of course! Seafood farmers have increased their mussel populations in this fashion for years. Young mussels attach themselves to exposed substrate to grow and a rope, being suspended in the water, allows for a much greater volume of water to flow through the filter feeders as opposed to when substrate dependent organisms attach themselves to the side of a stationary part of floating dock.
Not just mussels, but other amazing invertebrates such as the jellyfish we love and adore at our local Vancouver Aquarium are also dependent on finding a substrate for growth during their polyp stages.
These fouling communities rely on our human made structures to survive. Our docks create an accidental, but very suitable habitat for them to grow and prosper. These unexpected populations are beautiful once you take the time to investigate and learn about them. Filter feeders are often the first type of organism to be impacted by pollutants in water. This is why it is important to understand how we can promote their growth to ensure their vibrancy thrives in our waters for as long as possible.