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 17.4 million pounds in 2014. 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 21 to 38 million pounds. By 1990, landings reached a low of nine million pounds and have since fluctuated between nine and 17 million pounds. In 1993, the coastwide quota was implemented for the first time, setting a commercial landings limit of 12.35 million pounds. Commercial quotas have since ranged from 9.46 to 18.18 million pounds. Commercial landings (which are limited by the quota) have ranged from 8.81 million pounds to 18.17 million pounds since 1993. Over the past five years, commercial landings have been on the decline, in part due to annual quota limits, dropping from 10.6 million pounds in 2015 to 5.8 million pounds in 2018.

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 1980 through 2004, recreational landings varied widely from a high of 38 million pounds in 1980 to a low of three million pounds in 1989. Starting in 1993, harvest limits were implemented for the recreational fishery. Recreational harvest from 2005 to present has also shown a steady decline, in part due to declines in the coastwide recreational harvest limit (RHL). In 2017, recreational anglers harvested 3.2 million pounds of summer flounder.

Although reported landings have equaled or only slightly exceeded commercial quotas and recreational harvest limits in recent years, there is evidence of substantial illegal harvest in the form of unreported, underreported, or misreported landings. In 2013 and 2014, two separate investigations revealed that large quantities of summer flounder were being taken illegally under the guise of quota acquired through the Council’s Research Set-Aside (RSA) program (the Council subsequently suspended the program in order to consider alternative cooperative research options). There may also be substantial non-RSA related illegal/unreported landings, although fewer details are available on the extent of unreported landings outside of the RSA program.  While the exact amount of illegally harvested summer flounder is not known, the effect may have resulted in substantial overages of the fishery’s annual catch limits (ACLs).

Stock Status

Sumer Flounder

The 2018 benchmark stock assessment and peer review indicate that summer flounder is not overfished nor experiencing overfishing. Spawning stock biomass (SSB) is estimated at 98 million pounds, approximately 78% of the SSB target of 126 million pounds. Fishing mortality is estimated to be 0.334, below the fishing mortality threshold of 0.448. Recruitment was estimated at 42 million fish at age 0, below the time series average of 53 million fish at age 0. Recruitment has been below average since 2011.

Data analyzed by the Northeast Fisheries Science Center for the assessment indicate increasing relative abundance of older fish and an expanding age structure. However, the data also indicate a decrease in relative total abundance since the late 2000s, as well as decreasing trends in average lengths and weights at age for both sexes, suggesting slower growth and delayed maturity which impacts the biological reference points. The assessment shows current mortality from all sources is greater than recent recruitment inputs to the stock, which has resulted in a declining stock trend. Additionally, the assessment found the spatial distribution of the resource is continuing to shift northward and eastward.

A key attribute of the assessment is the incorporation of revised recreational catch data. In July 2018, MRIP revised the previous recreational catch estimates with a calibrated 1982-2017 time series that corresponds to the new MRIP survey methods. For comparison with the previous estimates, the revised estimates of 2017 recreational landings and discards are over three times the previous estimates. The revised recreational catch estimates increased the 1982-2017 total annual catch by an average of 29%, ranging from 11% increase in 1989 to 43 percent increase in 2017. The increase in estimated removals resulted in an increased population estimate compared to previous assessments.

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 MAMFC 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.

In March 2019, the Board and MAFMC 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 summer flounder resource, supporting and enhancing development of effective management measures, and optimizing social and economic benefits from the resource.

The new state commercial allocations are based upon a 9.55 million pound trigger point. When the annual coastwide commercial quota is at or below 9.55 million pounds, the formula for allocating the quota to the states will remain the same state-specific percentages that have been in effect since 1993. When the annual coastwide quota exceeds 9.55 million pounds, additional quota above 9.55 million pounds will be distributed as follows: 0.333% to the states of Maine, New Hampshire and Delaware, and 12.375% to the remaining states. As a result, state allocations will vary over time based on overall stock status and the resulting coastwide commercial quotas. Depending on the timing of final rule-making by NOAA Fisheries, new state allocations will likely go into effect for the 2021 fishing season. The final Amendment document will be available later in 2019. 

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