Aquatic Invasive Species

What are aquatic invasive species and why are they a concern?

An aquatic invader is a non-native species whose introduction will likely cause damage to the host ecosystem and its indigenous plants or aquatic life. Invasive species thrive in the absence of their native predators and have the potential to drastically alter habitat, rendering it inhospitable for existing species.

In ports that host seaborne trade, prevention is key. Vectors for the introduction of invasive species can include hydrographic processes, foreign waterborne debris, and recreational and port-related vessel traffic. In particular, PRPA works closely with Transport Canada to ensure that commercial vessels manage their ballast water (sea water pumped into vessels for the purpose of stabilization) according to international convention, including mid-ocean ballast exchange programs. Successful management limits the transfer of alien species from one region to another. In addition to PlateWatch and also in collaboration with CMC and DFO, PRPA also monitors for European Green Crab adults using traps and conducts quarterly zooplankton sampling using a plankton tow net to look for their larval stages.

Aquatic invasive species have already been responsible for significant devastation of some native fish species and fisheries in Canada. There are a number of species of specific interest to the waters surrounding Prince Rupert, including Didemnum Vexillum which spreads rapidly to overgrow many other species including shellfish. Also of concern is the European Green Crab, a potentially harmful invasive species only recently introduced to the West Coast.

How are aquatic invasive species monitored?

In 2012, the Port Authority began a partnership with Coast Mountain College and the Invasive Tunicate Network’s Plate Watch program to launch one of only a handful of aquatic invasive species monitoring programs on the BC coastline. With support from Fisheries and Oceans Canada, the local program reports its findings to the coast-wide network of experts and contributes to an early detection system for invasive species not previously present in the northwest of the Pacific.

The program utilizes the simple device of a clean, flat PVC plate tied to a brick, which is then deployed from a pier or floating dock. The plate is secured approximately one metre underwater where the largest percentage of target species can be found and allowed to collect samples for up to six months before they are pulled up and investigated. Together with Coast Mountain College’s Applied Coastal Ecology program, PRPA monitors a total of 40 plates at four different waterfront sites.

The Plate Watch program is a collective of researchers and volunteers from various marine science groups that stretch from California to Alaska, some of whom have been collecting data since 1994. Since its formal launch in 2007, Plate Watch has created an online network to share information across the broad network of participating sites.

Through this unique monitoring program, PRPA is working collaboratively with partners in Prince Rupert and across the west coast of North America to better understand how we can collectively keep our coastline healthy and free from potentially harmful organisms.

What determines a threat from an invasive species?

In addition to establishing critical baseline data and a registry of species in the region, participation in the Plate Watch program provides access to a larger view of the arrival and spread of invasive species along the north Pacific coast. The network also allows for participation in a greater mobilization of management strategies.

So far, no invasive species have been detected in the Prince Rupert Harbour, while a few have been found in the general area of BC’s north coast and the Alaskan southeast coast.