Week 8: The End of the Snails!

Week 8 of my internship was really exciting as I reached a day I never thought would come- the end of sediment core dissections! As I've mentioned before in my blogs, core dissections involve sawing at frozen mud in the CMOP cold room- so while it yields some really interesting and valuable results, it can be a bit of a tiring (and messy!) process. It felt good to be free of the cold room, and it felt even better to have a complete picture of the snail abundance in our various sites throughout the summer months. With the conclusion of my last sediment core dissection, I had P. antipodarum (New Zealand mud snail) abundance counts for every site visited in May, June and July. I summed all of the snails found at each site per month, and made a cohesive table to look for any patterns. I found that there were no obvious patterns, and each site instead showed great temporal variability. Each site showed a peak in snail density during one month, and it would fall off in the other months. This may speak to aspects of the P. antipodarum life cycle, in that population densities can change drastically in just four weeks. For example, the Young's Bay Back site had 9 snails in May, and then dropped to 0 in June and only 2 in July. Another interesting trend that we noticed was the high densities of snails found at Baker Bay sites. All of the previous literature said that there were very few to no P.antipodarum present in Baker Bay, while we found our highest overall densities at Baker Bay Boat launch and Baker Bay Chinook sites. Clearly the mud snails, which are an invasive species, are continuing their colonization of the estuary by establishing themselves in Baker Bay. Furthermore, we think this may speak to the invasive strategy of these snails. Both BBB and BBC are home to marinas with lots of boat movement and human involvement, and we know that P.antipodarum can be introduced to new areas by riding on the bottoms of boats. Therefore, it is easiest for them to reach these sites, and we think they may be slowly working their way towards the more inner Baker Bay sites, such as BBA and BBI, where we found them in much lower densities. 

Once I finished with the core dissections, I worked on DNA extractions and qPCR to get a final, analytical picture of whats been going on at these bays. By Week 9, I expect that I will have all of the DNA extracted and Kiley and I will have the qPCRs run, so we will be able to see whether there has been a correlation between P. antipodarum abundance and archaeal amoA abundance in Youngs Bay and Baker Bay throughout the summer.