Crustacean Examination

After successfully deploying 23 pit traps in the last week (one went missing), on the 7th we were able to check them after being open for 24 hours. The results were pleasing to see, as we did in fact have crabs of multiple species in all of our traps. Many sculpin were caught as well and were noted. The number of Hemigrapsus crabs seemed to increase as we got closer to shore and the number of Dungeness was less and more randomly distributed. We also found two strange looking crabs that turned out to be Pea crabs. As planned the size selection method worked in a fairly smooth manner. I say fairly, because the majority of the traps caught small crabs, but a few actually caught large crabs that we are unsure of as to how they managed to get in. (while molted soft enough to squeeze??). This will be repeated several more times as the summer continues on.

Here is a video of the Dungeness Crab GoPro footage that was shot a few weeks back. We believe the crab is exhibiting this behavior because he (it is a male) is trying to crack his own shell open so that he may begin molting. The video is sped up from 30fps to 120fps.

Pit trap in action

Removing the zip ties on a trap to access the catch.

Staghorn sculpins that were caught in the traps


The panoramic camera work is taking a bit longer than expected, mostly because some equipment we were thought to of had by now, has not arrived so that testing our design is not possible yet. I have been working with a few video editing softwares that allow panoramas to be made via stitching.

This weekend a trip up to The Gorge is being made. Will post pictures!

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2 thoughts on “Crustacean Examination

  1. I can’t watch your video because I’m not a member of your FB group, I think.. :-(

    But great photos from the field! Pea crabs are one of my favorite benthic critters. How will your team deal with fouling on the traps?

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