Our healthy harbour

Researchers from Canadian Rivers Institute identify 26 varieties of fish during study

A group of University of New Brunswick/Canadian Rivers Institute researchers (Allen Curry, Heather Hunt and Karen Kidd) have concluded a three-year study[1] on the Saint John Harbour, and the results were very positive.

The main motivations for conducting this study were to establish a long-term environmental monitoring process for the entire harbour, and to collect data to establish a baseline we can use to compare future findings.

The process and baseline are tools that will empower stakeholders ensure the health and protection of all the species that call the Saint John Harbour home, and act as a reference for other ports in Canada and around the world. This global data pool will ensure all ports are held to the highest environmental standards.

There were two projects included in this study.Saint John Harbour

  • Project one developed a method to monitor pollutants found in the sediment on the harbour floor. The method the researchers used is elegantly simple: they chose two “sentinel species” to watch.A sentinel species is a creature that is sensitive to disturbances in their habitat, including the presence of pollutants. These species can provide useful insights into the environmental health of the area in which they live.  The sentinel species the researchers selected for our harbour are the Atlantic Nut Clam, and the Catworm.  Over the course of the study (2012 – 2015) the researchers monitored the size of individual clams and worms as well as their population size. They found that the clams and worms were reproducing and growing well, when compared to data from other harbours – which is great news.  The information collected for this project will form a baseline for comparison in future years, so we can assess long-term changes to these species and monitor pollutants on an ongoing basis.
  • Project two developed a method to monitor the diversity and population size of various species found in the Harbour including ichthyoplankton, fish communities, sand shrimp and caged mussels.

We were really pleased to learn that even though the Harbour has been an industrial site for more than two centuries, it remains a nursery for a wide variety of fish.

The researchers found 26 varieties of fish, including 5 that had not previously been recorded.

In collaboration with Port Saint John, the researchers conducted a catch-and-release sample process in both dredged and un-dredged areas of the harbour, counting both the number of species and the quantity of fish caught in each sample.

Species richness and abundance was found to be slightly higher in un-dredged areas but statistical analyses showed no significant difference between the two types of sites, indicating that our harbour is dredged responsibly, with no significant impact on the species that call it home.

The research team at UNB is currently finalizing their recommendations for long-term monitoring to assess the effects of current and future environmental stressors.

We are excited to have a plan in place and such great news to report from this study. We look forward to continuing responsible growth in our Port, ensuring the long-term health of our harbour’s ecosystem.

[1] Designing a long-term environmental monitoring program for the Saint John Harbour. Allen Curry, Heather Hunt, Karen Kidd – University of New Brunswick.


This post is also available in: French