Alexandria, VA – The Commission’s South Atlantic State/Federal Fisheries Management Board has approved Addendum I to Amendment I to the Interstate Fishery Management Plan for Atlantic Croaker. The Addendum changes the management unit to one region (New Jersey through the east coast of Florida) and modifies the biological reference points used to assess stock condition.
Both measures stem from the recommendations of the 2010 benchmark assessment, which indicates that Atlantic croaker is not experiencing overfishing. Based on the findings of the assessment, Atlantic croaker is now considered to be a single stock on the Atlantic coast. The previous stock assessment, which formed the basis of Amendment 1, divided the stock into Mid-Atlantic and South Atlantic regions and assessed the resource separately in the two regions due to difficulty assessing the resource as a single unit. The 2010 assessment used data from both regions to produce a single, coastwide assessment.
Addendum I also modifies the biological reference points (BRPs) used to assess stock condition since the results of the 2010 assessment cannot be compared to the Amendment 1 BRPs, which are specific to the Mid-Atlantic region only. Addendum I’s BRPs are very similar to those in Amendment 1. They use the same definitions for the targets and thresholds (e.g., fishing mortality rate threshold = FMSY), but they differ in that absolute estimates of spawning stock biomass (SSB) and fishing mortality (F) are not estimated. Estimates are not given because of uncertainty in the assessment resulting from inadequate data on the magnitude of croaker discards in the South Atlantic shrimp trawl fishery. The determination of stock status is thus based on the ratios of F and SSB to their respective target and threshold, which are compared to one.
The new targets and thresholds are:
- F target = 0.75*FMSY
- SSB target = SSBMSY
- F threshold = FMSY
- SSB threshold = 0.70*SSBMSY
If F/FMSY is greater than 1, then overfishing is occurring. If SSB/(0.70*SSBMSY) is less than 1, the stock is overfished (see Figures 1 and 2). In other words, F must be lower than its threshold, and SSB must be higher than its threshold, or the stock will be considered to be experiencing overfishing or be in an overfished condition, respectively. The targets would still represent the levels that management measures are designed to achieve.
Copies of Addendum I will be available on the Commission’s website at www.asmfc.org under Breaking News by the end of March. For more information, please contact Danielle Brzezinski, Fishery Management Plan Coordinator, at dbrzezinski@asmfc.org or 703.842.0740.