— Written by Gabbie Baillargeon
Walking along Stern’s Wharf, accompanied by the bustling crowd of downtown Santa Barbara tourists and locals alike, signs proudly boasting the sale of delicious rock crabs seem to line the boardwalk. Similar to their more famous and tasty cousin, the Dungeness crab, rock crabs are a group of crab that comprise a productive and lucrative fishery along the coast of Southern California and the Northwestern Pacific states. Three distinct species of rock crab are found off the shores of California: Yellow (Cancer anthonyi), Red (Cancer producutus), and Brown (Cancer antennarius) rock crabs. All three species are available to purchase as seafood, though red rock crabs have the highest demand due to their larger size and sweeter meat. For the amount of recreational and commercial fishing that surrounds Rock Crabs, shockingly little research has been dedicated to studying them and even less information is available to shed light on how these crabs operate in the unique environmental conditions of Santa Barbara.
Two yellow rock cabs inside a cinderblock, a favorite resting spot.
My research project investigates how changing fishing pressures on rock crab populations alters their foraging behavior. In order to mimic fishery pressure, different densities of rock crabs will be put in controlled environments and fed different densities of California mussels (Mytilus californianus) to measure their predation rates in each case. The goal of this project is to determine if changing the number of rock crab competitors of a single species will affect how they forage. In an effort to better understand how fishing plays a role in shaping the nearshore marine environment, the potential consequences of varied foraging behavior in response to population shifts on the larger ecosystem will be analyzed.
A Brown rock crab being measured and tagged after collection from Stern’s Wharf.
In the early stages of the project, plenty of challenges quickly multiplied when working with the rock crabs or “little monsters” as we fondly like to think of them. The rock crabs have earned this nickname as they seem to have a bit of a angst-ridden destructive streak in them, especially when it comes to following some basic tank rules. After only 24 hours, the crabs had deftly removed their identifying leg bands – I’m sure they planned this operation carefully and helped each other out. Then, instead of being happy with their buffet of mussels and clean tank to play in, some crabs decided that they simply must explore what was on the other side of the tank barrier and crawl into their neighbor’s tank. The mussels are bluer on the other side, right? Lastly, although the names red, yellow, and brown rock crab seem to indicate that it would be simple to distinguish between the three species, I painfully came to find out that could not be farther from the truth. Despite the roadblocks, learning to care for the crabs and become excited over little things such as a crab finally deciding to eat mussels, has all been a part of the learning curve and given me invaluable skills of patience, problem-solving, and a lightning-fast reaction to a feisty crab claw.