Summer Flounder

Life History

Summer flounder (Paralichthys dentatus) are found in inshore and offshore waters from Nova Scotia, Canada to the east coast of Florida. In the U.S., they are most abundant in the Mid-Atlantic region from Cape Cod, Massachusetts to Cape Fear, North Carolina.

Summer flounder usually begin to spawn at age two or three, at lengths of about 10 inches. Spawning occurs in the fall while the fish are moving offshore. Spawning migration is linked to sexual maturity, with the oldest and largest fish migrating first. As in their seasonal migrations, spawning summer flounder in the northern portion of the geographic range spawn and move offshore (depths of 120 to 600 feet) earlier than those in the southern part of the range. Larvae migrate to inshore coastal and estuarine areas from October to May. The larvae, or fry, move to bottom waters upon reaching the coast and spend their first year in bays and other inshore areas. At the end of their first year, some juveniles join the adult offshore migration.

Adults spend most of their life on or near the sea bottom burrowing in the sandy substrate. Flounder lie in ambush and wait for their prey. They are quick and efficient predators with well-developed teeth allowing them to capture small fish, squid, sea worms, shrimp, and other crustaceans.

Commercial & Recreational Fisheries

Sumer Flounder

Summer flounder are one of the most sought after commercial and recreational fish along the Atlantic coast, with total landings at approximately 19.2 million pounds in 2020. Using baseline data from 1980 to 1989, the current plan allocates the summer flounder quota on a 60/40 percent basis to commercial and recreational fisheries, respectively.

Two major commercial trawl fisheries exist — a winter offshore and a summer inshore. Summer flounder are also taken by pound nets and gillnets in estuarine waters. Throughout the 1980s, commercial landings ranged from 17.9 to 37.7 million pounds. In 1993, the coastwide quota was implemented for the first time. Commercial landings (which are limited by the quota) have ranged from 5.9 million pounds to 18.17 million pounds since 1993. Commercial landings reached a time series low of 5.9 million pounds in 2017, but have since increased to 9.1 million pounds in 2020. Commercial discard losses in the otter trawl and scallop dredge fisheries are estimated from observer data, and an 80% commercial discard mortality rate is assumed.

Summer flounder are also highly prized in the recreational fishery. Anglers catch summer flounder from the shore, piers, and boats with hook and line. From 1981 through 2004, recreational landings varied widely from a high of 36.7 million pounds in 1983 to a low of 5.7 million pounds in 1989. Starting in 1993, harvest limits were implemented for the recreational fishery. Recreational harvest in 2020 was 10.06 million pounds, a significant increase from the prior year's harvest of 7.80 million pounds.

It is worth noting that the pandemic caused some significant challenges in data collection for both the commercial and recreational fisheries. NOAA Fisheries waived the requirement for vessels with Greater Atlantic fishing permits to carry a fishery observer from March until August. The 2020 commercial discard estimates will be affected by the missing observer data. In addition, the Access Point Angler Intercept Survey (APAIS) was suspended for several months in the spring and summer of 2020. APAIS is crucial for calculating estimates of recreational catch.

Stock Status

Sumer Flounder

The 2021 management track stock assessment indicates that summer flounder is not overfished nor experiencing overfishing. Spawning stock biomass (SSB) is estimated at 104 million pounds, approximately 86% of the SSB target of 122 million pounds. Fishing mortality is estimated to be 0.340, below the fishing mortality threshold of 0.422. Recruitment was estimated at 49 million fish at age 0, below the time series average of 53 million fish at age 0.

Data analyzed by the Northeast Fisheries Science Center for the assessment indicate an expanded age structure relative to the stock observed in the 1980s and 1990s. However, the data also indicate that recruitment has remained generally below average this past decade, and the reason is not known. Additionally, the last benchmark stock assessment found the spatial distribution of the resource is continuing to shift northward and eastward.

Atlantic Coastal Management

Sumer Flounder

Recreational angler with summer flounder. Photo credit: Mark Terceiro, NMFS NEFSC.

The Commission approved the first Fishery Management Plan (FMP) for Summer Flounder in 1982, followed by a similar FMP approved by the MAFMC in 1988. Since then, both agencies have made significant revisions to the plan, increasing the protection of juvenile fish and ensuring the maintenance of an adequate spawning population. This increased protection has been implemented through larger minimum size limits across all sectors, increased mesh sizes, and decreased recreational possession limits. Cumulatively, these changes have contributed to conserving the resource while maintaining important commercial and recreational fisheries. This is not to say that challenges in managing this species do not still exist. Issues related to sector allocation and annual harvest levels persist.

In December 2018, the Board approved Addenda XXXI and XXXII to the FMP. Addendum XXXI adds to the suite of tools available for management, with particular focus on enhancing the compatibility of state and federal regulations, by allowing the use of conservation equivalency for recreational management starting in 2020. Conservation equivalency allows recreational management measures in federal waters measures to be waived, and instead requires recreational anglers to abide by the measures of the state in which they land their catch. The Board and Council will annually decide whether to enact conservation equivalency.

Addendum XXXII establishes an annual specifications process for developing recreational management measures. The Board will approve regional measures in early spring each year, based on technical committee analysis of stock status, resource availability, and harvest estimates. Public input on specifications will be gathered by states through their individual public comment processes. The specifications process will provide the Board more flexibility in adjusting measures, if necessary, to constrain harvest to the annual coastwide RHL. Further, the process will enable the Board to consider a host of factors, including: regional equity; regulatory stability; species abundance and distribution; and late-breaking recreational harvest estimates.

Based on the 2018 stock assessment findings, the Board and MAFMC revised the 2019 specifications and set new specifications for 2020 and 2021, with the intent to maintain regulatory stability. For the 2019-2021 fishing seasons, the commercial quota is set at 11.53 million pounds and the recreational harvest limit (RHL) is set at 7.69 million pounds. The revised commercial quota was approximately a 49% increase over the previously set 2019 quota. While the revised 2019 RHL represents an approximate 49% increase over the previously set 2019 RHL, the Board chose to maintain status quo recreational measures, which are projected to achieve a harvest level close to the revised RHL based on the calibrated MRIP recreational harvest data.

Upcoming Actions

Summer Flounder, Scup, and Black Sea Bass Commercial/Recreational Allocations Amendment

The Board and MAFMC developed a joint amendment to consider an adjustment to the allocations between the commercial and recreational fisheries for summer flounder, scup and black sea bass. The commercial and recreational allocations for all three species are currently based on historical proportions of landings (for summer flounder and black sea bass) or catch (for scup) for each sector. Recent changes in how recreational harvest is estimated have resulted in a discrepancy between the current levels of estimated recreational harvest and the allocations of summer flounder, scup and black sea bass to the recreational sector. Some changes have also been made to commercial catch data since the allocations were established. This amendment considers whether modifications to the allocations are needed in light of these and other changes in the fisheries. The amendment also considers options that would allow a portion of landings to be transferred between the commercial and recreational sectors each year, in either direction, based on the needs of each sector. At the April 2021 meeting of the Board and MAFMC, final action was postponed to allow for further development of the Recreational Reform Initiative. The Council and Board are now scheduled to take final action on the commercial/recreational allocation amendment at a joint meeting in December 2021. Additional information and updates on this amendment are available at: https://www.mafmc.org/actions/sfsbsb-allocation-amendment.

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