Recently, divers have noticed plumose anemones (Metridium spp.) detaching from rocks and dying at rocky reef sites in British Columbia. This project aims to track the geographic occurrence and trends related to this phenomenon.
Location: Howe Sound and elsewhere in British Columbia
Description: The purpose of this project is to track observations of unusual morbidity or mortality of plumose anemones (Metridium spp.).
Background: Divers have noticed plumose anemones (mostly Metridium giganteum, but possibly also Metridium senile ) detaching from rocks and dying. Visible circles of bare rock on walls and boulders indicate where anemones were previously attached, and in some cases, detached anemones can be found lying at the base of the rock slopes. Some dislodged anemones have been observed being eaten by large aggregations of shag-rug nudibranchs (Aeolidia papillosa), and others have been found lying loose or deteriorating on the bottom. In addition, some of the anemones that are still attached may appear to have 'skinny' columns with a ring of bare rock visible around the base, indicating movement or a decrease in size.
Funding: Open invitation
Observing Guidance: Observers are asked to record observations of apparent morbidity or mortality of plumose anemones (Metridium spp.). This could include evidence of recently detached anemones (circles of bare rock in anemone beds), dislodged or sick-looking anemones, and estimates of the extent or severity of impact. Detailed photos of the site, substrate, and individual anemones are encouraged in addition to information about the precise location of the specimens or observations.
Source Data: LEO Network posts; observations submitted to the Vancouver Aquarium
Outputs: Contributed data will be added to LEO regional map and to timeline trends. Contributed data will potentially be used in published reports or papers.
Project Updates: Project updates may be provided in forthcoming LEO BC newsletters, regional ocean health reports, and through direct collaboration with project contributors.
Resources: Divers interested in participating in more involved surveys are encouraged to use the following protocols for subtidal surveys: https://issuu.com/jessica.schultz/docs/plumose_anemone_survey_protocols. The purpose of these transects is to conduct quantitative surveys at the same sites through time to build a picture of mortality rates and trends over time. Please contact Jessica Schultz before initiating a new survey.
A black ring of bare rock at the base of an anemone, indicating a decrease in size or movement. Photo by Jessica Schultz
Dislodged anemones at the base of a wall. Photo by Jessica Schultz
Evidence of detached anemones at Whytecliff Park in September, 2016. Photo by Vlad Chernavsky
Evidence of dislodged anemones at Bird Islet, Howe Sound. Photo by Jessica Schultz
Fallen anemone being eaten by Aeolid nudibranchs. Photo by Jessica Schultz