Red Rock Bait Talk

By Bowen Grace Davies
Elementary Category (Grades 4-6)
Experiment | Biology

In British Columbia, it is illegal to harvest female Red Rock crabs in an effort to protect the species from overfishing and extinction. This experiment looks at whether a certain type of bait will affect the likelihood of catching a male instead of a female crab, reducing the risk of female crabs being harvested or harmed accidentally. Three different types of crab bait were tested: raw bacon, raw salmon, and vegetable matter, and placed in three identical traps, in identical conditions. My hypothesis was that raw bacon with its high caloric value will attract more male crabs than female crabs locally, if female crabs are given plant matter as a choice of bait. This is because research from Japan shows that Sasarmia intermedia female crabs are more specialized in their food preference to plant matter, while males are more generalized to their food choice, but are attracted to foods with a higher caloric value. The experimental results were inconclusive because I did not catch any female crabs in the 10 pulls completed during my experiment. If I tried this experiment again when the female crabs are in shallower water and could be caught, and tried repeating the experiment year round, I might be able to catch female crabs to see if there is a bait preference for female as well as male crabs. The most male crabs were caught with salmon, not bacon with the highest caloric value, so that part of my hypothesis was incorrect. I’m wondering if it is a high protein content, rather than a high caloric value, that the crabs are attracted to. In the future, I might try the experiment again with high protein foods, and see if more males are attracted to those foods.

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