The Effects of Ocean Warming and Acidification on the American lobster Homarus americanus
By: Darcia Gonzalez, REU intern
The American lobster is regarded as one of the most abundant sources of income in the Northern England areas of the United States. In fact, there has even been a recent boom in the amount of lobster landings within the last few years. It has been observed that the American lobster has shifted its geographic location about 43 miles northward into the Gulf of Maine, which pretty much explains this recent boom. This isn’t necessarily a good thing and may actually be a red flag to definitely be concerned about.
In our study, we are testing how changing oceanic pCO₂ and warming water will affect the growth and development of the four pre-juvenile planktonic stages of the American lobster (Homarus americanus). We have been hard at work testing respiration, swimming speed, recording carapace lengths and mortality rates throughout this experiment. Ovigerous lobsters are known to have a hatching period that last from late May to early June – which meant this project took off as soon as my plane landed here to join this REU.
The differing levels of pCO₂ that were used in this experiment correspond to what the IPCC has investigated in regards to the atmospheric conditions our earth will experience within this coming century. We are raising them under the pCO2 and temperature that they are experiencing today as well as the pCO2 and temperature that is predicted to occur at the end of the century.
Preparation for this experiment required “all hands on deck!” We planned to have duplicated experimental treatments which meant we needed to prepare 24 buckets of filtered seawater in a temperature controlled chamber. We also made the trip out to the Darling Marine Center where our goal was to carefully transfer over 3000 stage 1 lobster larvae in order to place them in their corresponding experimental tanks.
Lobster larvae are known to climb straight through all four stages within only 28 days. In this experiment we began observing a few stage 4 lobster larvae within only a matter of 16 days, therefore, data needed to be collected quickly yet thoroughly.
This experiment is definitely crucial for fisheries in northern New England and even parts of Nova Scotia. Knowing how our changing oceans are affecting the development and physiology of the American lobster is crucial to the livelihood of lobstermen in and around the Gulf of Maine. The effects observed within this experiment will provide commercial fisheries with the data necessary to be able to make important decisions with how they will manage lobster stock, and prioritize landings in the coming years.
About the Blogger:
Darcy Gonzalez is a summer REU intern at Bigelow Laboratory for Ocean Sciences. Darcy is a biology major at the University of Texas – Rio Grande Valley and is originally from McAllen, Texas. Her research interests include microbial ecology, photosynthesizing bacteria, seaweeds, and terrestrial plant life and the role they play in ecosystems.