Week 2: Dungeness Crab in the Lab

Week 2 has ended and I have to say that Oregon is becoming more and more homely. Friends are being made and new experiences are occurring. Early in the week, core samples were taken in order to capture mud shrimp. A core sample, to those of you unaware of what that is, is where you take a large metal tube and press it completely into the ground and then proceed to dig all of the sediment out and sift through it while for mud shrimp. To get the core into the ground you must stand on top of it and do the “shrimp dance” which consists of wobbling motions. Once the mud shrimp were captured we measured the carapace length, sexed them, and checked for the infestation of parasites. The parasites are definitely not the most appealing creatures to look at, but they are still very interesting.

The mudflats show no mercy to those who science.

Mid-week many bucket lids were purchased (24 total). The reasoning for this is that we began to build experimental pit traps that would be size selective for the capture of small Dungeness crabs. We made two different designs, one with a larger whole and steeper funnel, and the other with a smaller hole and more gradual funneling. To set these traps, you basically just dig a hole in the ground and place the bucket in and wait for the crabs to fall in. Some people around here call them the “Dodos of the sea”. This is not due to having a resemblance with birds, but because of their ease of capture. After setting the traps we decided to place GoPro cameras onto two of the traps to capture some footage and observe the crab’s interactions with the traps. I’ve taken a brief look at the footage and there is some interesting behavior to note. I will definitely be including some of the video in my next blog entry. Several crabs were captured overnight, as well as a few Staghorn Sculpins, and a lone jellyfish. The next step will be to build 24 traps in total, and set them out in various locations. I’m really looking forward to see how things will play out with the implementation of our traps.

Young Dungeness crab captured in the pit traps

It’s been only two weeks and I already feel like I’ve learned quite a lot. Being from a freshwater background, marine and estuarine has offered a new perspective. 8 more weeks to go!

From Cornfields to Coastal Mudflats

It has been roughly 12 days since I departed on my 4 day cross-country road trip from Indiana to the coast of Oregon. Many sites were seen like Medicine Bow, Winnemucca Mountain, and Crater Lake. Taking the time to see such colossal structures really made me realize how small we are in the vastness of our own country, let alone the planet.
It took 35+ hours to get to Oregon, and I’ve only been here for roughly a week, but I already feel a sense of home here. For the next 9 weeks, to my understanding, I will be working with integrating different pit trap methods for the capture of juvenile Dungeness crabs (Cancer magister) as well as the utility of using underwater video to get quality quantitative data on fish and invertebrate use of US West Coast intertidal estuarine habitats. Working this week with the USDA under my mentors, I have been very fortunate to already be getting out into the field.

 

Dungeness Crab (Cancer magister) caught from pit trap

This week we drove 60 miles north to Netarts, OR and checked shell bags for colonization by shellfish. We also took water quality in areas that were bare (lacked vegetation) and areas with seagrass present. Closer by (Yaquina Bay), pit traps were set up for the capture of Dungeness crabs to quantify their morphometrics to create more accurate size selection in the future. To our delight, we managed to catch several crabs, along with a few mud shrimp.

Mud shrimp that was dug up with the traps

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There is no doubt that the next 9 weeks will pass by quickly, a lot will be learned and a lot of great memories are to be made. With that I hope you continue to enjoy my blogging as the weeks go by. I’m lucky to call this beautiful city and state my home for the summer. Follow me on here or via twitter @Prechtelguy93