What does a pile of construction rubble have to do with fish? When old concrete gets put on the ocean floor, it goes from trash to habitat. Workers did just that to an artificial reef two miles off the coast of Yarmouth last week; they dumped pieces of granite and concrete to expand a reef that was built in the 1970s. WCAI's Kathryn Eident talked with biologist Mark Rousseau of the state's Division of Marine Fisheries (DMF)about how his office manages artificial reefs like this one.
Eident Work was being done recently on the reef that already exists off Yarmouth and you were out there taking some pictures. Can you explain what was going on?
Rousseau Sure. We are received some funding to do a deployment on previously permitted site. The site was initially developed back in 1978. It's 125 acres in size and the DMF went out in 2011 or 2012 and surveyed the area and found 75 percent of the site to be still available for being able to accept additional materials. So we reopened the permit to allow for that activity to happen there.
Eident Explain what an artificial reef is and what it's made of.
Rousseau An artificial reef is a man-made fish habitat. It can be made of many things. In Massachusetts, we like to focus building artificial reefs on what we call repurposed stone material or natural stone material. We typically try and obtain materials at no cost to the Commonwealth. So, what we typically use are concrete and granite that has been donated. We do have specific criteria that we're looking for for the materials. We want to make sure that they're clean and they don't have any paint or any other toxicants on the material that can leach into the environment.
Eident Is this Yarmouth reef, was it originally made out of tires?
Rousseau It was, yes.
Eident Would you put tires down there now? I would imagine those would break down and have chemicals in them over time.
Rousseau So we would not utilize tires anymore. Tires--well, they were misused back in the 80s in several other locations along the Atlantic Coast. There are proper ways of deploying tires to make them effective reef units. And then there were improper ways of doing so. In Yarmouth, there was a concerted effort to make sure that the units themselves were ballasted and strapped together. And in fact, in our survey in 2011, we found that they haven't moved in 40 years and it's still a very popular recreational fishing spot and it attracts a lot of fish.
Eident And, is that the main purpose of an artificial reef, not necessarily to dispose of material, but to actually create new habitat?
Rousseau That's correct. It's to create habitat for structure-oriented fish in areas that we would consider to be structure-limited. So, Nantucket Sound is a prime example of that. It's a primarily a sandy bottom habitat. And there are a lot of structure-oriented fish like Scup and Black Sea bass and Tautog that are in the area that utilize structured habitats. And there are they're also very popular commercial and recreational fish species.
Eident There's only a few reefs in Massachusetts, I want to say maybe five reefs.
Rousseau That's correct.
Eident Is that right? And, there's one a newer one in Harwich, built for similar reasons. And what's the status of that one?
Rousseau We built our reef in 2016. It's a 10-acre site. So, it's much smaller than Yarmouth. There's still capacity to receive additional materials. We just haven't had the opportunity yet to deploy more materials to the site. But the initial deployment occurred in February of 2016 and we saw legal sized recreational fish on the reef that May. So, its function as a fish habitat was almost immediate.
Eident Wow, that's amazing. I was going to ask how long it might take for different organisms to, you know, make it "home".
Rousseau Sure. So, for some other organisms, it can take years and even decades. So, there is a sort of a succession process that occurs on these reefs. So, some species will initially colonize the reef and over time, other species will move in. And so, early on in the colonization of the reef itself, we'll see things like barnacles. Later on, we'll see some tunicates. But sometimes it can take decades to see things like sponges and other commonly-occurring invertebrates and macro algae and other marine species.
Eident Well, thank you so much for talking with us. Mark, we really appreciate it.
This conversation was lightly edited for grammar and clarity.