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

Summer flounder are one of the most sought after commercial and recreational fish along the Atlantic coast, with total landings at approximately 17.2 million pounds in 2021. 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 10.5 million pounds in 2021. 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 2021 was 6.8 million pounds, a decrease from the prior year's harvest of 10.1 million pounds.

Stock Status

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

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 Mid-Atlantic Fishery Management Council (Council) 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.

Recreational management has garnered a lot of attention in recent years. Under the current process, the Board and Council annually determines whether to implement coastwide measures or enact conservation equivalency. 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. In 2018, the Board approved Addendum XXXII which established an annual specifications process for developing recreational management measures under the conservation equivalency process. The Board 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 is gathered by states through their individual public comment processes. The specifications process provides the Board more flexibility in adjusting measures, if necessary, to constrain harvest to the annual coastwide recreational harvest limit (RHL). Further, the process enables the Board to consider a host of factors, including: regional equity; regulatory stability; species abundance and distribution; and late-breaking recreational harvest estimates.

In 2019, the Board and the Council jointly approved the Summer Flounder Commercial Issues Amendment. The Amendment revises the management program's goals and objectives specific to summer flounder and implements new state-specific commercial allocations. The revised management program's goals and objectives focus on ensuring biological sustainability of the resource, supporting and enhancing development of effective management measures, and optimizing social and economic benefits from the resource. These revisions were made to reflect current priorities in sustainably managing the resource.

In 2021, the Board and Council jointly approved changes to the commercial and recreational allocations of summer flounder, scup, and black sea bass. These changes are intended to better reflect the current understanding of the historic proportions of catch and landings from the commercial and recreational sectors. The Board and Council developed this amendment in response to recent changes in how recreational catch is estimated by the Marine Recreational Information Program (MRIP), which resulted in a revised time series of recreational data going back to the 1980s. This created a mismatch between the data that were used to set the allocations and the data currently used in management for setting catch limits. Additional information about this amendment is available at https://www.mafmc.org/actions/sfsbsb-allocationamendment.

The Board and Council has set new specifications for 2023 with a commercial quota of 15.27 million pounds and an RHL of 10.6 million pounds.

Harvest Control Rule

In June 2022, the Commission’s Interstate Fisheries Management Program Policy Board (Policy Board) and MAFMC approved changes to the recreational fisheries management programs for summer flounder, scup, black sea bass, and bluefish. The changes include a new process for setting recreational measures (bag, size, and season limits) and modifications to the recreational accountability measures. The Policy Board and MAFMC recommended these changes through a framework action, and the Policy Board adopted the new process through Addendum XXXIV to the Summer Flounder, Scup, and Black Sea Bass Fishery Management Plan (FMP) and Addendum II to the Bluefish FMP. Approval of this new process is part of a broader long-term effort by both the Commission and MAFMC to improve recreational management of these four species. The new management program aims to provide greater stability and predictability in recreational measures from year-to-year while accounting for uncertainty in recreational catch estimates.

The Policy Board and MAFMC considered a range of management options and ultimately selected one referred to as the “Percent Change Approach,” with an agreement to continue development of several other options for possible implementation by 2026. Under the selected approach, managers will consider two factors when determining whether recreational measures should be restricted, liberalized, or remain unchanged for the next two years. First, they will look at how recreational harvest limits (RHLs) for the next two years compare to recent estimates of recreational harvest. This gives an indication of whether recreational harvest is likely to exceed the RHL if management measures remain unchanged. Next, managers will consider the most recent estimate of stock size relative to the target stock size. These two factors, in combination, will be used to determine the percentage change in harvest that management measures should aim to achieve.

Under the new process, when recent harvest estimates are close to the future RHL, management measures will either remain unchanged or be reduced or liberalized by 10%, depending on stock size relative to the target. In cases where the RHL is substantially above or below recent harvest estimates, the specific reduction or liberalization will vary based on stock size and will either be fixed at 10% or will be based on the difference between recent harvest and the RHL but capped at 20% or 40% (see table on page 11 for additional details). The Policy Board and MAFMC selected this option because it uses currently available data and gives additional consideration to stock status when making management decisions. Under this approach, changes will be considered every other year when new scientific information about the stock is available.

While the Percent Change Approach is similar in some ways to the current process for setting recreational measures, there are several key differences. To account for uncertainty in recreational data, future RHLs will be evaluated relative to the confidence intervals around recent recreational harvest estimates. A confidence interval indicates the range of possible values given the statistical uncertainties around the estimate. The new process also places greater emphasis on stock status, potentially reducing the magnitude of restrictions in measures when the stock status is healthy. Finally, the new process will provide greater stability, as measures will be set for two years at a time instead of every year.

The Policy Board and MAFMC acknowledged this approach will not solve all recreational fisheries management challenges. With this in mind, they agreed to continue refinement of the Percent Change Approach as well as two other options considered within the Draft Framework/Addenda, with particular emphasis on using improved statistical models to develop measures. Use of the approved Percent Change Approach will sunset no later than the end of 2025 with a goal of implementing a new and improved approach to managing the recreational fisheries by the beginning of 2026.

The Policy Board and MAFMC also revised the recreational accountability measures for all four species. Specifically, when biomass is between the target and threshold levels, the requirement of paying back recreational catch limit overages will account for whether those overages contributed to overfishing based on the most recent stock assessment information.

The Policy Board and MAFMC considered but did not recommend an option to set constraints around the use of the Commission’s conservation equivalency policy as applied to the recreational fisheries for these four species. They decided to maintain the current policy to allow individual states the flexibility to tailor management measures to meet the needs of their fisheries.

The Framework/Addenda’s changes to the recreational management program are final for state waters (0-3 miles from shore) and will be used to develop 2023 recreational measures for summer flounder, scup, and black sea bass. The new process will not be used for bluefish until the stock is declared rebuilt. The Council has submitted the framework to NOAA Fisheries for review, approval, and implementation.