Sorry for the lack of posts from the Channel Island crew! Augie and I went on a whirlwind tour of the Bay Area last week, and were too busy to keep up on our blogging. But here’s a recap!
The Lagemann boys! (minus Alex, plus Kristen) From left: Peter, Augie, Gian, and Kristen. Thanks to the Lagemanns for letting me stay at their gorgeous home!
Last Tuesday Augie and I loaded into our trusty suburban (with significantly less gear than last time) to go to PRBO Conservation Science in Petaluma, where we would learn techniques of identifying the krill in our net tow samples! It was a long drive, but the radio kept us entertained. We stayed the night at Augie’s house in Saratoga, CA- his parents were very nice and generous and made us a delicious dinner. I also got to meet all three of Augie’s brothers- even Alex, who goes to Berkeley, came home for a surprise visit.
I was super excited about crossing the Golden Gate Bridge. It was nothing exciting for my Bay-Area-Bred lab partner.
The next day, we woke up early to beat the traffic on the way through San Francisco to the PRBO headquarters in Petaluma. There we met Meredith Elliot, who was also very sweet and lent us all her equipment and lab space for two whole days. She also (very patiently) explained all her techniques for identifying net tow samples. She mostly works with Tucker Trawls, with which you can get a more exact depth than our hoops nets. Also, in Northern California, they get a lot more krill and a lot fewer copepods in their samples. So, we focused on our krill, though they were all zoea (larval), so they were very tiny. Adult krill often migrate diurnally, meaning during the day they sink to deeper waters and they ride the currents up to the surface at night, so our samples probably just weren’t deep enough to collect adults. We’ll try to put up some pictures of our samples later…
Augie brings our samples and identification guides into PRBO. Hooray for being out of the car!
Not only can the hulk knock over buildings, he also helped us keep track of how many times we split our sample.
In order to get a manageable number of krill to identify, we use a plankton splitter, which is this simple, but rather ingenious piece of equipment that cuts every sample in half, and then half again, and then half again, etc., etc. On our samples, we often did seven splits- so our final sample was 2^7 or 128 times smaller than the original! We split until we had approximately 100 krill to ID. From there, it was a lot of microscope work- lots of staring at tiny carapaces and denticles (little hooks on the carapace) and telsons (part of the tail).We had three main species—Euphausia pacifica, Nematoscelis difficilis and Thysanoessa spinifera. At first, I was sure I would never ever be able to tell them apart. But, thanks to Meredith and her list of minute differences, I think I can ID them pretty well. Not only do we have krill and copepods in our samples, but also decapods, which grow up to be crabs, lobsters, etc., and mysids, which are shrimp-like and easily confused with krill. phew!
Augie funnels our krill into the plankton splitter.
Kristen separates the krill from the rest of the sample before counting and IDing the different krill species.
Augie and I explored Petaluma that night. We also explored the “strange, new worlds†alongside Kirk and Spock as we watched the new Star Trek movie. It was great! (this was after I threw my movie ticket into the Petaluma River. Ooops!)
Fun Fact of the Day: Petaluma is the former home of the World Arm-Wrestling Championships! Fortunately, the World’s Ugliest Dog Contest still calls Petaluma home.
Thanks again to Meredith, who helped us out SO MUCH, and all of the PRBO staff (especially for the pizza and oreos!)
Tags: Augie, krill, Kristen, Meredith, net, Petaluma, PRBO, zooplankton