Photos of the Long Island Sound

Research & Monitoring

Status and Trends: LISS Environmental Indicators

Game Fish

CTDEEP Long Island Sound Trawl Survey * Data for 2010 unavailable for Bluefish, Scup, Summer Flounder and Weakfish. see note below.

CTDEEP Long Island Sound Trawl Survey * Data for 2010 unavailable for Bluefish, Scup, Summer Flounder and Weakfish. see note below.

CTDEEP Long Island Sound Trawl Survey

CTDEEP Long Island Sound Trawl Survey * Data for 2010 unavailable for Bluefish, Scup, Summer Flounder and Weakfish. see note below.

CTDEEP Long Island Sound Trawl Survey

CTDEEP Long Island Sound Trawl Survey * Data for 2010 unavailable for Bluefish, Scup, Summer Flounder and Weakfish. see note below.

CTDEEP Long Island Sound Trawl Survey

Game Fish Count Per Tow
Scup Striped Bass Summer Flounder Tautog Weak-
Winter Flounder
1984 23.41 10.72 0.02 0.99 2.86 1.55 110.75
1985 18.16  30.97 0 1.19 1.49 6.35 67.6
1986 13.64  25.76 0 1.72 1.5 13.57 61.55
1987 14.29  18.54 0.05 1.4 0.71 0.73 67.94
1988 15.51  39.7 0.04 1.42 0.65 3.54 100.98
1989 26.25  65.09 0.06 0.14 1.09 8.69 135.22
1990 23.9  69.48 0.16 0.87 1 5.71 170.05
1991 33.43 311.57 0.15 1.26 0.92 12.11 118.98
1992 25.22 83.73 0.22 1.02 0.82 3.22 54.31
1993 18.92  77.06 0.27 1.11 0.42 4.18 53.33
1994 32.06  92.54 0.3 0.55 0.44 11.21 74.01
1995 24.46   59.14 0.59 0.54 0.15 5.64 48.11
1996 20.8   61.46 0.63 2.19 0.49 15.49 93.05
1997 37.9   41.28 0.85 2.5 0.4 12.93 57.41
1998 31.41 103.27 0.97 1.72 0.42 5.28 59.38
1999 45.31 537.68 1.1 2.68 0.4 31.36 32.8
2000 20.57 521.1 0.84 1.91 0.57 63.42 33.7
2001 24.24 177.64 0.61 4.42 0.7 40.51 46.4
2002 18.75 348.7 1.3 6.12 0.91 41.45 25.5
2003 28.53 152.23 0.87 3.38 0.52 49.46 21.22
2004 29.1 291.5 0.56 1.96 0.54 59.07 16.5
2005 18.89 424.06 1.17 2.41 0.57 26 17.41
2006 15.7 116.8 0.61 1.4 0.64  1.50   7.5
2007 30.66 475.29 1.02 1.89 0.48 63.96 20.58
2008 14.28 303.26 0.57 3.09 0.5   9.11 22.34
2009 18.11 139.38 0.60 3.12 0.4   6.65 19.98
2010 N/A* N/A* 0.40 N/A* 0.25 N/A* 20.88
2011 11.10 198.23  .48 2.56   .38 12.27 16.68
2012 15.06 223.52  .43 3.74  .44 22.27 12.02
2013   9.71   40.68  .67 3.07  .43   7.50   6.35
2014 18.61 182.58  .41 1.71  .51 41.56   4.1
2015   8.42 422.23  .20 2.03  .47 31.05  3.93


Game fish are those species prized by anglers for their size and strength which make fishing for them an exciting sport. All of these fish are also harvested commercially and are managed by regulations restricting minimum harvest size, number, and season in order to keep their abundance stable. In addition, state health departments monitor many of these species for contamination by toxic substances such as mercury and issue consumption advisories when needed.

The Long Island Sound Trawl Survey (LISTS), conducted by the Connecticut Department of Energy and Environmental Protection since 1984, has provided independent monitoring of important recreational species in Long Island Sound. Seven of these species are identified in this chart—bluefish (Pomatomus saltatrix), scup (Stenotomus chrysops), striped bass (Roccus saxatillis); summer flounder (Paralichthys dentatus), or fluke, tautog, (Tautogo onitis), or blackfish, weakfish (Cynoscion regalis), and winter flounder (Pseudopleuronetes americanus).  These abundance indices are used by fishery managers for local and regional assessment of stock condition, and to provide a more complete annual inventory of LIS fishery resources.


The abundance of game fish is a reflection of the productivity of Long Island Sound and the effectiveness of coast-wide fishery management plans that seek to stabilize populations while maximizing harvest opportunities.


In general, the population of boreal game fish (e.g. Winter Flounder) is stable or declining while the abundance of temperate species (weakfish & summer flounder) is increasing.  The aggregate average is roughly stable, but highly variable :

  •  Bluefish: The abundance of adult bluefish has remained relatively stable over the last 27 years, and the population is thought to be doing well.  Relatively low abundance in the trawl survey is not reflective of true abundance, as this type of fishing gear does not always catch this species when present.
  • Scup: Recent numbers of adult scup from the Long Island Sound fall trawl survey remain high relative to observations made between 1984 and 1998. The 2008 fall index of scup two years and older was the fifth highest in the 27 year time series. Coast-wide management using annual quotas has helped improve the health of the fishery.  Scup typically have a boom and bust population cycle and the occurrence of several strong years recently is a good sign of overall health in the coast-wide population. Due to this abundance, Connecticut and New York extended the season to fish scup by three months in 2011.
  • Striped bass: Abundance has been above average for the past 14 years. The striped bass fishery was historically overfished and was the first species to be targeted for stock rebuilding in 1984. Restrictive harvest limits over the last 16 years allowed the stock to grow to unprecedented levels. In 1995 the striped bass stock was declared “officially recovered.” In recent years fishing regulations have been liberalized. New York and Connecticut lowered the minimum size restriction for striped bass to 28 inches and have added special harvest opportunities in response to the positive recovery of this species. Relatively low abundance in the trawl survey is not reflective of true abundance, as this type of fishing gear does not sample this species well.
  • Summer flounder: This species is considered a management success; it has been under very tight management regulations and the population seems to have responded.  Abundance has increased since the mid-1990s, showing particularly high abundance since 2008.
  • Tautog: Spring survey indices for this species have remained low and below the time-series average for the past 16 years except for a short-lived increase in abundance recorded in 2002.  This species is one of the few warm temperate species that has not increased in abundance over the last 25 years. In an effort to rebuild stock, the NYSDEC and CTDEEP have recently instituted more restrictive fishing regulations.
  • Weakfish: Abundance indices have been highly variable over the last few years, but over the last decade have been generally higher than in the 1980s and 1990s.  Most of the weakfish caught in the LIS Trawl Survey are small, young fish, suggesting that the Sound primarily functions as a nursery area for this species.  Both overfishing and increased predation (by other fish such as striped bass) have been implicated in the low relative abundance of adult fish.  Weakfish are a major component of the gill-net, pound-net, haul-seine, and trawl fisheries along the coast.
  • Winter flounder: At one time, winter flounder supported a thriving commercial fishery, but over the past 10 years winter flounder springtime abundance indices have been the lowest on record.  This species does well in very cold winters, but may be experiencing increased competition and/or predation by mid-Atlantic finfish predators, as well as cormorants and seals.


  • The above graph depicts data from CTDEEP’s spring and fall  trawl surveys. For this chart, the season in which abundance is greatest is used for each species. In fall 2010, sampling for bluefish, scup, summer flounder, and tautog was cancelled because the CTDEEP’s research vessel was out of service due to repairs.
  • The survey uses geometric mean instead of arithmetic mean to find the most frequently observed  number of  fish collected per tow. In a natural environment such as Long Island Sound  fish have a “patchy” distribution, i.e. some areas will have a very high abundance of fish, and other areas very low abundance or no fish at all. An arithmetic mean can be easily biased by unusually high or low values so that it doesn’t reflect the true center of a data set. The geometric mean minimizes the effects of very high or low values using a log transformation and is a better average for this type of biological data. For further information see: A Study of Marine Recreational Fisheries in Connecticut: March 1, 2009-Feb. 28, 2010, CTDEEP Fishing Publications Web site

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Bluefish are present in the Sound from April until October. The juvenile Bluefish, or “snapper”, run occurs in late summer and early fall. Photo by Bob Bachand.

Scup, also known as porgy, are a small migratory fish that travel in schools and are plentiful around piers, rocks, offshore ledges, jetties, and mussel beds. In the summer scup move inshore and into shallow estuaries, then during the winter tend to migrate to deeper waters offshore. Photo of scup at Mason Island by Robert DeGoursey, UConn.

Striped bass are a migratory fish that spawn in fresh water. Photo by Richard Howard/Long Island Sound Fish Trawl Survey.

Summer flounder, or fluke, are a migratory fish that move into the Sound as temperatures warm up around June and migrate out in the late fall as temperatures drop. Photo by Richard Howard/Long Island Sound Fish Trawl Survey.

Tautog, or blackfish, live in shallow coastal waters, usually at depths of less than 60 feet. The rocks and boulders left by glacial deposition in the Sound make it an ideal “reef” habitat. Tautog are the only important recreational fish species that live year round in the Sound. Photo by Richard Howard/Long Island Sound Fish Trawl Survey.

Weakfish are most abundant in shallow coastal waters over sand and mud. Estuaries such as Long Island Sound are typically used by this species for summer feeding and nursery grounds. Photo by Richard Howard/Long Island Sound Fish Trawl Survey

Winter flounder are a cold-temperate species that ranges from Labrador to the Chesapeake Bay. In Long Island Sound many juveniles leave their estuarine spawning grounds during summer months and enter the freshwater sources that drain into Long island Sound. Photo of flounder in an eelgrass habitat at Mulford Point, LI by Chris Pickerell.

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