Toxic bloom-forming cyanobacteria inhabit lakes in New Brunswick, Canada

The frequency and intensity of cyanobacterial blooms have been increasing around the world, mainly as consequence of eutrophication and climate change.

These blooms can negatively impact humans, fisheries, and wildlife, as some species of bloom-forming cyanobacteria have the potential to produce toxins (called cyanotoxins).

Canada, with more than one million lakes and innumerable ponds, is not an exception to this trend.

Read the open access article on the FACETS website.

In the province of New Brunswick, which is located in Atlantic Canada, the frequency of cyanobacterial blooms has increased considerably in the last decade, but unlike the large inland waters in other regions of Canada, waterbodies in this region remain poorly studied.

Washademoak and Harvey lakes are mesotrophic and oligotrophic lakes, respectively, located in New Brunswick.

We collected water samples from each lake bi-weekly and applied genetic tools to determine the identity of the bloom-forming cyanobacteria that were present as well as their potential to produce microcystin (hepatotoxin) and anatoxin-a (neurotoxin).

We sequenced total DNA to determine the identity of, and to further characterize, bloom-associated microorganisms.

We identified the potential for microcystin and anatoxin-a production in cyanobacteria inhabiting both lakes during most of the sampling dates, even when blooms were not evident.

We recovered the genome of the cyanobacteria Microcystis aeruginosa from a bloom in Washademoak lake. The genome contained the genes required to produce microcystin, as well as for producing other compounds that have relevance for human health and microbial ecology.

The genome is very similar to those recovered from lakes in eastern Canada, suggesting they are closely related.

Our study establishes an important baseline for future studies of Atlantic Canadian lakes.

Read the article — Amplicon-based and metagenomic approaches provide insights into toxigenic potential in understudied Atlantic Canadian lakes by Cecilio Valadez-Cano, Kristen Hawkes, Rossella Calvaruso, Adrian Reyes-Prieto, and Janice Lawrence