An underwater marine survey completed at West Mabou Beach in Port Hood has yielded some interesting results that shed new light on what species dwell in Nova Scotian harbours.
The survey was completed by the Canadian Parks and Wilderness Society, and their findings were released at a public meeting in the Cape Breton community of Mabou on Monday evening.
Information Morning Cape Breton host Steve Sutherland spoke with Hunter Stevens, a biologist with the group, who co-ordinated the survey and was one of the divers involved.
Their conversation has been edited for length and clarity.
LISTEN | What species are hiding underwater at West Mabou Beach:
Information Morning – Cape Breton9:49Under the sea: marine wildlife survey off West Mabou
We find out what some divers with the Canadian Parks and Wilderness Society saw under the water at West Mabou Beach as part of a recent marine survey.
What prompted you guys to do a marine survey?
The short answer is that we knew it would be cool. We’d done previous work on the land and surrounding area, and we’d found all these rare species, and we knew it was an ecological hotspot, but we’d never made it down into the water, and so we were really curious about what we would see and what sort of critters we’d find.
What made you think offshore West Mabou Beach would be any different than anywhere else offshore Cape Breton?
It’s just got a unique geography with the harbour and the channel, and it’s just interestingly placed close to people, and we knew that this is a shared space between people and nature, and we just wanted to see what people were sharing it with.
Where did you go?
We actually spent one week in Mabou doing these surveys, so we did approximately two surveys per day just inside the harbour, just inside the breakwater there, and just sort of outside on the beach on the other side of the dunes.
Walk us through some of what you found.
One of our favourites is the northern pipefish and we found a couple of those. Northern pipefish is pretty much Nova Scotia’s answer to the seahorse. It’s a seahorse cousin and it looks like if you sort of took a seahorse and stretched it out like a noodle and they’re really quite camouflaged and hard to spot, but always really fun to see.
They’re interesting because the males actually take care of the young. The females will transfer the eggs over to the male, and the male will gestate them and then give birth to them.
One of the other really cool features that we found was actually this oyster bed. So what this is, is that successive generations of oysters are starting to sort of grow on top of each other, and what this does is form a structure known as an oyster reef.
And as the name implies, that actually is analogous to a coral reef where you’ve got these organisms building on the dead skeletons of the previous generation. This creates a lot of interesting 3D habitats for all sorts of different creatures.
Is that in the harbour?
Yeah, this was just inside the harbour, along with some really healthy eel grass patches, which is another thing that we’re really interested in and there’s other researchers in Nova Scotia interested in this.
Now, deeper in the harbour, people actually commercially harvest oysters, so was there anything surprising or unusual about that oyster bed?
In all honesty, it was just surprising to see it. We’ve done a lot of these snorkeling surveys across the province and we’d never found the amount of oysters that we did in Mabou Harbour just naturally growing there.
What else did you see that might have been out of the ordinary?
One of my personal little favourites was this fish called an Atlantic poacher, and they’re just sort of a long skinny, in all honesty, they almost look like little dragons. They’re kind of scaly as well, and got some horns on them.
But this is a fish that’s really kind of rare. It’s only ever pulled up in trawl surveys offshore, and I believe actually we found out in the presentation last night, there’s another group that had been doing some beach sand surveying for a couple years, and they’d never pulled up one of these fish, and we observed one of those swimming around during our survey, so that was a really interesting observation for us.
One of our other favourites is flatfish. We saw two species: the common winter flounder and then a little bit more uncommon, the windowpane flounder, and they’re always really fun just because they’re a very unique fish.
They’re flat when they’re young, they look like a normal fish, they have an eye on either side of their body, but when they get a little bit older about five to six weeks old, one of those eyes actually just completely switches over to the other side of their face, and then they lay down and spend their lives on either the left or right side of their body, depending on the species.
And you spotted a couple of interesting jellyfish specimens?
Oh yes, we were contending with quite a few lion’s mane jellyfish that week.
So lion’s mane jellyfish are a cold-water jellyfish. They like the North Pole, but in the early spring and summer months when the water is still cold, we get them down here and they get to be pretty big. Up in the poles, they can actually have a bell — which is like the main part of the jellyfish — that’s one metre across, and there have been individuals with tentacles over 100 feet long, so that is a pretty big animal.
The sting isn’t too medically significant unless you’re allergic to it, so it’s not actually something that’s dangerous to us, but it’s still a little bit unnerving because when we’re doing these snorkeling surveys in the harbour, when the tide changes, you get current within the harbour and you’ll be looking down at something interesting or trying to take a photograph, and then you look up and you’ve got this big cannonball-sized jellyfish floating right into your face, so you’ve got to take some quick action to avoid it.
They’re obviously common in Cape Breton. Anything less so?
There was one species of jellyfish there that we found, and I love jellyfish, so it’s always fun to find a new one. And it’s also really fun because a lot of times these animals, they’ll only spend like a day or two or a week in a form that we can actually readily see in the water.
Jellyfish, they alternate between a polyp form, which is kind of like a small anemone, and a medusa form, which is the swimming, typical jellyfish that you think of when you hear the word jellyfish.
On our first couple days while we were there, we found a new species to us, which didn’t really actually have a common name so we’ve been calling it the honey jelly.
But the scientific name for it is Melicertum octocostatum. It’s a really small jellyfish, about the size of a thimble, but the interior of it was just a bright yellow, you couldn’t miss it in the water, so that was very interesting to see.
It’s always a joy to see something new on these surveys.
What’s the value of the survey you guys did?
A lot of ecological data for the marine environment is taken from offshore trawling surveys or other methods that happen way offshore, so there’s actually a pretty big data gap in just general pictures of what marine life you can really expect to find in the intertidal zone, like immediately offshore of Nova Scotia.
And we really just wanted to, and continue to do, is shed light and sort of provide snapshots of what you might find at a given time of year around the coast of Nova Scotia.
