As July comes to a close, our awesome volunteer Crab Teams are wrapping up their third set of European green crab monitoring at multiple sites around Átl’ka7tsem/Howe Sound. Thankfully we haven’t caught any invasive crabs yet!
However, this doesn’t mean we can be 100% certain that European green crabs aren’t present somewhere in the Sound. At a minimum, it does indicate that populations haven’t become established at our priority monitoring sites such as important estuaries and freshwater-influenced intertidal habitats. This is great news!
Searching for Absent Crabs
Monitoring marine life at Furry Creek.
You might be wondering why we’re searching so thoroughly for something that doesn’t seem to be here. The reason lies in the concept of Early Detection Rapid Response (EDRR), which is a crucial principle in managing invasive species for both plants and animals.
Early Detection Rapid Response underscores the importance of detecting invasive species soon after they arrive in a new area, when only a few individuals or small populations are present.
Early detection allows for a rapid response, quickly removing early invaders before they’re able to establish a larger, more destructive population.
Monitoring marine life at Porteau Cove.
Under the Sea = Tricky to Track
Early Detection and Rapid Response is key to preventing new infestations of invasive species, because once a population is established, a variety of factors make it much more difficult to address.
Actively practicing EDRR is particularly important when it comes to invasive marine animals like the European green crab.
First off, crabs live in the ocean, which makes them quite difficult for us to see! Secondly, European green crabs reproduce quickly; a single female can release up to 185,000 eggs twice a year. Considering both these factors, it would be very possible for large populations of green crabs to become established long before anyone (on land) even notices.
Actively monitoring (i.e., setting traps in the intertidal zone, like our Crab Team volunteers have been doing), dramatically increases the likelihood of catching invasions early.
Monitoring marine life at Porteau Cove.
The time the crabs took over
This short video from the Coastal Restoration Society illustrates the difficulties of addressing a well-established EGC population in Clayoquot Sound (traditional Ahousaht territory, western Vancouver Island).
The video shows how completely European green crabs can take over intertidal ecosystems. We hope that our Crab Teams can help prevent a situation like this Átl’ka7tsem/Howe Sound!
Have we ‘pinched’ your interest?
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