2023 CEQ Annual Report


Piping Plovers               Raptors               Forest Birds                State-Listed Species

Lobster and Fishes of Long Island Sound

Climate Change Indicator

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Long Island Sound’s species are trending towards animals that prefer warm water, and lobster landings decline to an all-time low.

Lobster, which thrive in cold water, have become less common in Connecticut waters. Lobster landings in the state have declined dramatically from a high of over 3.7 million pounds in 1998 to a low of 88,654 pounds in 2022 (most recent data available). Lobster landings in 2022 decreased by 40 percent from 2021 levels and decreased by 45 percent from the previous ten-year average.52

Researchers have investigated several possible causes for the dramatic downturn in lobster populations since 1998 including disease, changes in water quality, changes in climatic conditions and other human impacts to Long Island Sound, such as the presence of pesticides. The increase in water temperature may not negatively affect the availability of thermally suitable habitat; however, warmer temperature has been linked to the increased prevalence of epizootic shell disease, caused by bacteria.53

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The decline in lobsters was also confirmed by the Department of Energy and Environmental Protection’s (DEEP) spring and fall trawl surveys, which recorded a geometric mean of approximately 0.01 lobsters per tow (fall) in 2023.

The chart above shows the mean number of fish species caught during the spring and fall surveys combined. The trends show that the average number of warm-adapted species increased while the average number of cold-adapted species decreased over time. The difference is particularly evident in the fall when water temperatures are highest. Although overall finfish diversity in the Sound remains high, the composition of the finfish community is changing in favor of species tolerant of warmer temperatures.54


Technical Note: *Data from 2010 and 2020 are missing for the marine species chart because no fall and/or spring surveys were conducted those years. Finfish species captured in the Connecticut DEEP Long Island Sound Trawl Survey were divided into adaptation groups based on their temperature tolerance and seasonal spawning habits.


52  NOAA, Annual commercial landing statistics, 1970-2022, accessed January 2024; www.fisheries.noaa.gov/national/sustainable-fisheries/commercial-fisheries-landings.
Kisei R. Tanaka, Michael P. Torre et al., “An ensemble high-resolution projection of changes in the future habitat of American lobster and sea scallop in the Northeast US continental shelf”; April 27, 2020; doi.org/10.1111/ddi.13069.
DEEP, Division of Marine Fisheries; personal communication from K. Gottschall February 22, 2024..