Researcher hopes work on invasive species will make a difference

Cory Hurley
Published on April 23, 2014

Scott Caines has been studying the waters of the Bay of Islands for invasive species, and he has found reason for concern.

There are seven species recognized as invasive in Newfoundland and Labrador waters and three of these have been introduced to the west coast of island. Globalization is being credited with the exponential increase in introduction through the voyages along oceanic vessels — with aquaculture and the aquarium trade recognized as contributers.

These boats often carry foreign species, which could have the ability to survive here.

Of the seven species, Caines said four have particular interest to the west coast — the golden star tunicate, the violet tunicate, the green crab, and the coffin box (membranipora).

The instructional assistant at Grenfell Campus, Memorial University of Newfoundland — in collaboration with Humber Arm ACAP and the Department of Fisheries and Oceans — has been researching three particular species in the past year. He has set up various traps for each invasive species at designated areas throughout the Bay of Islands.

The most commonly known is the green crab, which has created concern among fishermen and industry representatives for its impact on native aquatic flora and fauna. The aggressive species has been known to have devastating impacts in areas it has taken over once introduced.

In the Bay of Islands, 2,655 green crab, of which a large number were male, especially earlier in the summer were removed, the majority of which were located in  Lark Harbour and Pleasant Cove.

“When green crab gets well established, it reaches a population level where you are going to see drastic decreases in eel grass abundance,” Caines said. “Once that happens you will start seeing a shift from areas that were 100 per cent covered in eel grass to just a sandy habitat.

“When you lose that habitat you lose coastal productivity. Eel grass provides a food source to herbivores, it provides structure for fish and other individuals to hide within.”

The impacts can be large scale, both directly and indirectly, and expand to commercially significant species such as salmon. Caines said the green crab would be direct competition for native crab and other shellfish.

Meanwhile, lesser known invasive species such as the tunicates and coffin box  could have significant impact on the coastal habitat.

Tunicates are a particular concern in areas where there is mussel aquaculture, he said.

“Once they get in and establish themselves ... unless you effectively attack them, you are not getting rid of them,” he said.

The coffin box causes a concern for flora such as kelp. These type of impacts create a trickle effect along the food chain, Caines said.

While there is obvious signs of invasive species in the Bay of Islands, the nature of the area and its fish industry creates opportunity for more.

“The invasion of the Bay of Islands is inevitable,” he said. “The Bay of Islands acts as a staging ground for a lot of pelagic fisheries — herring, caplin, mackerel — and a lot of fish harvesters come from other sites along the west coast.”

Caines hopes the research is educational for fishermen. By creating awareness of foreign species, Caines hopes fishermen will help destroy these species rather than throw them back in the water.

“The fact we hopefully have an established, long-term monitoring program allows us to detect these species and hopefully establish better mitigation or management strategies for the Bay of Islands,” he said.