One of the goals of the Baikal Dimensions project is to uncover patterns of long-term change in Lake Baikal plankton communities that might be related to lake warming. Why have we decided to focus on plankton communities? The short answer is that they are important members of the aquatic food web. Phytoplankton (plant plankton) are primary producers that provide energy near the base of the food web, while zooplankton (animal plankton) transfer energy from phytoplankton up to higher trophic levels (e.g. fish). For a more exciting and inspiring explanation about the awesomeness of plankton see the post by Dr. Marianne Moore.
During the recent visit of one of our Russian collaborators, Dr. Lyubov Izmest’eva, we were able to discuss two interesting patterns uncovered using the amazing long-term Izmest’eva plankton and temperature data set. First, there appears to be changes in the depth distribution of important zooplankton groups through time. For example, juvenile copepods are shifting to a shallower position in the water column during the summer months (July, August, September). This change is likely a response to more intense thermal stratification caused by warming surface waters.
Another interesting pattern found in the long-term data is the increasing richness of zooplankton through time. For example, the number of species sampled at the monitoring site during the winter months (January, February, March) seems to be increasing. The sampling methodology has remained consistent through time and two well-trained taxonomists have been counting the monitoring samples. We are currently exploring the potential reasons for these changes in diversity.
These results are just a quick preview of things to come. I will be presenting some of the results from our Baikal plankton depth work at the upcoming meeting of the Association for the Sciences of Limnology and Oceanography in New Orleans.