I can’t believe it’s already August! I wish I had more time to do so much more with my research project. I started by running trials that standardized for prey carapace length, then conducted trials that matched prey weight, and have now started to trials to see just how much smaller the green crabs need to be compared to the Dungeness to present an easy meal by predation from the red rock. As I have gotten to know the system more fully, I see many ways that could expand and carry forward my research concept. Of course, it is difficult to get a lot done in 9 weeks, and I think I would always want to do more, no matter how much time I was given. One thing I started this week was using game cameras to catch a predation event on film. I mentioned last week that it could give good insight into the crab interactions, and it would be nice to have the evidence on camera. The cameras I am using are equipped with IR to film at night, as the crabs appear nocturnal and commit most predation events overnight. Unfortunately, the cameras do not appear to be sensitive enough to pick up on the crab movement under water. I am trying to troubleshoot this, so hopefully next week I will have a better report. I have also come to realize the difficulties with working with live specimens. Most weeks I have had trouble catching enough of all three species. I usually have to trap at different sites to get abundant specimens in order to sift through and find enough male crabs with no missing limbs in the correct size. Early in the season I needed more red rock crabs, and have done extra trapping with crab rings off of docks to supplement. This week, I caught plenty of red rocks in the traps and crab rings, and have struggled to find Dungeness in the correct size class. Those that I bring back from the field have a slightly larger carapace width, missing limbs, or are not hard enough when I feel under their chelipeds, or claws, indicating that they may have recently molted. This means I am not able to run all 16 trials at the same time, leading to fewer results On the subject of molting and carapace hardness, I have determined that a factor in the weight difference between green crab and Dungeness of the same carapace width could be the hardness or thickness of the shell. Green crabs appear to be much better defended with a thick outer carapace. I am hoping to develop a method to measure and quantify this difference, which would indicate another factor that favors green crab survival and dominance. In other news, I got to go tide pooling on Friday! It was an early morning, but a beautiful low tide which allowed us to get out to Qochyax island, an island just off the coast near Sunset Bay. Because the tide was low enough, we crossed an exposed land bridge and explored the island. There was a tunnel through rock in the middle of the island, and many ridges and pools on the far side that were rich in invertebrates and algae. I was so happy I got to go and feel lucky to be in such an amazing place this summer. Being so busy with work, I sometimes forget the incredible sights that exist all around me, and wish I could take some time to just explore like this more often. Megan, Hannah, and I also participated in a women's surf clinic. What an awesome opportunity and we had the best time!!
0 Comments
Leave a Reply. |
AuthorHi! My name is Renee and I am a rising junior at Muhlenberg College in Pennsylvania. I am a double major, studying Biology and Dance. I am so excited to be a part of the Oregon Institute of Marine Biology’s summer REU program and to work with Shon Schooler and the South Slough National Estuarine Research Reserve. Archives
August 2019
Categories |
Proudly powered by Weebly