Green Sea Urchins might be ‘dime a dozen’ in the Discovery Passage, but that doesn’t mean they aren’t worth a closer look! Urchin biology is fascinating, and we hope that after watching this video you agree with us! Scroll down to the end of this blog post for our drawing and photography activities!
Fun facts about Green Sea Urchins:
Where can I find Green Sea Urchins?
In Campbell River and the Discovery Passage, Green Sea Urchins are everywhere. From the tip of Tyee Spit to Shelter Point, these urchins can be found during just about any low tide. The best spot to see Green Urchins in Campbell River would be at the tip of Willow Point Reef. In some areas on the reef, they are so many that you can’t even walk without stepping on them, so be careful!
How many kinds of urchins are there in British Columbia?
In B.C., there are four common species of sea urchins. There are the Red Urchins, Purple Urchins, Green Urchins, and White Urchins. At a first glance, each species is readily distinguished by their colour, however Green Urchins can sometimes be red, and Red Urchins can sometimes be purple! When biologists are uncertain, they will measure the length of the urchin’s spines to determine the species, as the spines of each species have a different length.
Who are the Green Sea Urchin’s predators?
As this species is so plentiful, many animals have learned how to get through an urchin’s spines for a tasty meal. Green Urchins are eaten by Red Rock Crabs, Leather Stars, Sunflower Stars, Wolf Eels, crows, Sea Otters, and sea gulls!
Why are there so many Green Sea Urchins out there?!
There are a lot more urchins in local waters than there used to be! There is one main reason for the explosion of Green Sea Urchin populations, and this is the disappearance of one major predator: the Sunflower Star. In 2013, a virus which caused an illness known as ‘Sea Star Wasting Syndrome’ appeared. This syndrome affects at least 20 species of sea stars, however the species most heavily hit was the Sunflower Star. Populations of Sunflower Stars across their range were decimated; between 95% and 100% of individuals had died from the disease depending on the area.
Sunflower Stars have been very slow to recover. In the Discovery Passage they are regularly seen, but are still affected by Sea Star Wasting Syndrome every summer.
Another significant Green Sea Urchin predator is the Leather Star. Leather Stars haven’t been as heavily affected by Sea Star Wasting Syndrome, but they don’t eat nearly as many urchins as Sunflower Stars do. Some naturalists are reporting that Leather Star populations are on the rise, however this observation has yet to be formally studied by biologists.
Are Green Sea Urchins dangerous?
As long as you handle them gently, local urchin species pose no threat to humans. Visitors to the Discovery Passage Aquarium often assume that our species are venomous, however spines of local urchins are relatively blunt and carry no venom.
If urchins were in any way dangerous, we would not have them in our touch tanks!
Weekly Video Series Activities!
Green Sea Urchin Drawing and Photography Activities:
Send us your drawing or photograph of a Green Sea Urchin this week and we will feature it on our Facebook page and Instagram accounts! Attached is a PDF worksheet to help younger participants with their drawings. For the artistic folks out there, any medium is encouraged! Whiteboard art, painting, sculptures, you name it! The tides are great this week so head down to your local tide pooling spot and see if you can find some urchins!
Send us your drawing or photo by email at: info@DiscoveryPassageAquarium.ca
Or tag us in your Instagram Post: @DPAquarium #DPAquarium
Or send it to us in a message on Facebook: DiscoveryPassageAquarium
Be sure to do so before 10:00AM, Monday, April 20th so we can feature you on our Monday social media posts!