Dumping garbage in the ocean is usually considered a bad thing – unless you are a member of the Artificial Reef Society of British Columbia (ARSBC). In this case, by garbage we mean the massive retired naval ships or small planes that you see lying derelict in the wreck-yards. These ships are stripped, filled with explosives, and sunk in locations along the southern BC coastline to provide a useful habitat for fish, and a playground for divers looking for an adrenaline rush. Aside from divers and some finfish looking for a place to hang out, what impacts are these “artificial reefs” having on our local environment and economy? Well, it might not be as banging as it’s made out to be (plus the ship-sinking isn’t exactly Titanic-worthy. There are regulations. Sorry.).
Artificial reefs are a great idea in theory – you sink a structure that can substitute for a real reef that was destroyed by human related impacts like shipping, fishing, pollution… the list goes on. And on. (We suck). By sinking a stand-in reef in an unproductive area (read: nothing considered important to humans lives there anymore), the hope is that the reef will be colonized again by all levels of ocean life, thus turning the area back into a productive ocean habitat that can be enjoyed by divers. The problem lies here: we don’t actually know what the habitat was like before we destroyed it. Without long term monitoring before and after reef introduction, scientists have an unclear picture as to how much good these habitats actually do for the coastline. Some have gone so far to say that artificial reefs primarily act as “fish attraction devices”, meaning that less fish live in the area than anticipated, and they are simply leaving their old homes to find new shelter in the artificial reef. This is great for divers, who are there to explore an abandoned wreck, but poor for biodiversity and habitat reconstruction.
Donna Gibbs at the Vancouver Aquarium is attempting to change this monitoring problem. She is working alongside the ARSBC on a biodiversity survey on their most recently sunk reef: the HMCS Annapolis (The Annapolis Biodiversity Study, ABIS). Gibbs’ team works with the local dive community to perform individual counts of animals present on the reef over time. At the end of the five year study (currently in it’s second year), they hope to have an idea of how the reef was colonized and what species are calling it home. This is great in practice, but the fact of the matter is that five years just isn’t a very long time. Like every summer when there is a forest fire and everyone freaks out because it’s gonna take forever for the trees to grow back? Yeah. Same scenario here. In order to know how truly successful these reefs are at improving biodiversity, we are going to need to think of a way to extend monitoring programs to assess reef colonization and habitation.
HCMS Annapolis (c) CBC
Pushing monitoring aside, the second half of the matter is management. With their crevices and holes, artificial reefs are excellent at luring in fish, and thus have an impact on our local fisheries. Yet, we don’t know how to incorporate them into any sort of fishery management plan. Are the reefs making fish more vulnerable to catches by gathering them in one area? Or are they providing more breeding and survival ground where existing habitat is sparse? Fortunately for invertebrates, like the Spiny Lobster, the answer seems to be the latter. For other animals, however, we still don’t know. You’d think after decades of implementing artificial reefs as fishing devices, and organizing periodic worldwide conferences on their use in sustainability, we’d have a pretty good understanding of how beneficial they can be. But we don’t.
One thing that is apparent, is the success of colonization on these reefs. It’s been just enough that it sparks the interest of the international dive community; already there are tons of neat species accumulating on the HMCS Annapolis, including wrinkled dogwinkle and opalescent nudibranch. Diving shipwrecks filled with fish is, well, pretty cool.
In fact, so cool that our own ARSBC has sparked international tourism attention. Eventually, money came in between the founding members of the society which caused them to split into two: the non-profit ARSBC and the for-profit Canadian Artificial Reef Consulting (CARC). Nowadays, ARSBC is working locally, and CARC is working internationally to establish artificial reefs to increase the tourism commercial gain in places like Portugal. In British Columbia alone, we bring in an estimated 1.75 million dollars annually from dive tourism, thanks to the draw of these artificial reefs.
So with that 1.75 million dollars in mind, you may think to yourself, “great, these artificial reefs are helping our economy, and providing habitat to cool fish species! What’s the issue?” Even though these benefits are great, we still have to think about this critically. The issue of these reefs keeps circling back to the very real problem of no long-term studies; while we know that species are accumulating on these artificial reefs, what will the structures look like 10 years down the line? 20? And, also importantly, what did the area look like in terms of biodiversity before the artificial reef was sunk? So, while the socioeconomic implications are clear, we need to understand what we are doing to our environment, and we need to take care of it. Artificial reefs are a start to a very good idea, however we need to prioritize the biodiversity implications over socioeconomic gains if we as British Columbians want to have a success story with them.
HCMS Saskatchewan (c) Quiroga
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