An unusual plankton bloom event witnessed by Inuit in the western Canadian Arctic

What is it about?

We summarize observations and experiential knowledge from western Canadian Inuit (Inuvialuit) harvesters combined with a scientific assessment of an unusual account of a high density bloom of gelatinous plankton during summer 2019 in the eastern Amundsen Gulf, Northwest Territories. The plankton were primarily pelagic tunicates (appendicularian larvaceans, Oikopleura spp.) and their gelatinous “houses” and were observed within 3–5 km of the marine coast, from ∼1–2 m below the surface and to depths of ∼30 m with an underwater camera. These organisms have rarely been documented in this region and, to our knowledge, this was the first time they had been noted by the people of Ulukhaktok, NT. The organisms clogged subsistence fishing nets and Inuvialuit harvesters were concerned about negative impacts to the marine mammals and fish they depend on.

Featured Image

Photo by Sangga Rima Roman Selia on Unsplash

Photo by Sangga Rima Roman Selia on Unsplash

Why is it important?

Blooms of these small animals have a unique and important role in ocean ecosystems due to the structures they make. They use their gelatinous structures called "houses" to filter the water for very small plant-like particles (plankton). The material is an important food source for other marine animals, but during bloom events they can clog fishing nets and they could compete with more energy rich Arctic species like copepods. They could also attract other sub-Arctic species that feed on them. Inuit Elders’ highlighted some other potential impacts such as ringed seals limiting their diving during the bloom to avoid the small stinging organisms that could affect their eyes.