As their name suggests, cold-water lobsters are a category of lobster that prefer colder climates. They can be found in a wide variety of coastal areas, including the coasts of New England, Australia, Canada, and New Zealand. All of these areas have water temperatures in the 55 to 65 degree range, which is ideal for cold-water lobster species. Some scientists predict that at the rate we are going, ocean waters will warm 2-3 degrees by the end of the century. This will put a lot of coastal areas currently inhabited by cold-water lobsters over the temperature threshold they need to thrive.

An American Lobster in it’s natural habitat (https://gmgi.org/research/fisheries-aquaculture/genomics-and-genetics-of-fish-and-shellfish/american-lobster-genome/)

The article “Increased temperature and acidification elevate the risk of starvation in American lobster larvae” (Niemisto, Contreras, Wahle, Fields et al., 2025) explains a study on how the larvae of a cold-water lobster species are negatively affected by ocean warming and acidification due to increased atmospheric CO₂. The experiments were conducted at the University of Maine’s Darling Marine Center. During these experiments, researchers recorded the behavior of lobster larvae in water with different temperatures and pH levels. Newly hatched lobsters from the Gulf of Maine were captured and separated into tanks with four different conditions: normal Gulf of Maine temperature (16 degrees Celsius) and normal pH (8.1), normal temperature and lowered pH (7.7), warmed temperature (19 degrees Celsius) and normal pH, and warmed temperature and lowered pH. Each experiment was done multiple times with hundreds of different larvae to make sure that a trend could be found in the data. The experiments lasted two weeks, and some lobsters were fed a normal diet, while others were not fed as much so the researchers could see how larvae react under stress in the different environments. The researchers found that warming and acidification had a big effect on the survival and growth rates of the larvae. In the warmed water, Niemisto and his colleagues found that there was a 5-27% increase in the larvae’s metabolic rate, which means that the larvae are spending more energy to get the same amount of nutrients as they would in ideal temperatures (16 degrees Celsius). They explained, “Our data suggest that elevated temperatures drive higher metabolic demands in larvae from cool-sourced populations than those from warmer regions over the critical first 2 days after hatching. This effect is likely to exacerbate the bottleneck of larval survival.” (Niemisto, Contreras, Wahle, Fields et al., 2025). This, among other factors, dropped the survival rate of the larvae from a 78-80% survival rate in ideal conditions to a 42-45% survival rate in warmed waters with lowered pH. With only a lowered pH, the larvae had a 68% chance of survival, and with only warmed waters, they had a 61% chance of survival.

American Lobster larvae (0.3-0.5 inches long) (https://seagrant.umaine.edu/2021/11/22/what-baby-lobsters-eat-and-why-it-matters/)

The cause of both warming waters and lowered pH in the ocean is increased levels of CO₂ in the atmosphere, which means that as the water warms, the pH will also be lowered. This means that with these hypothetical conditions, lobsters in the Gulf of Maine will only have a 42-45% chance of survival to survive the first two weeks of their lives. As temperatures increase and pH levels decrease in the Gulf, we have already seen lobsters moving further north, and they will continue to do so as ocean conditions become less ideal. This could lead to serious consequences for cold-water lobster fisheries and the health of the Gulf of Maine ecosystem.