2. STATUS OF THE STOCKS The

thresholds used to determine the status of Atlantic HMS are presented in Figure 2.1. They are fully described in Chapter 3 of the 1999 Tunas, Swordfish, and Shark FMP (1999 FMP) and in Amendment 1 to the Billfish FMP. These thresholds were carried over in full in the 2006 Consolidated HMS FMP and are based upon the thresholds described in a paper providing the technical guidance for implementing NS 1 of the Magnuson-Stevens Act (Restrepo et al., 1998). Figure 2.1 Illustration of the Status Determination Criteria and Rebuilding Terms In summary, a species is considered overfished when the current biomass (B) is less than the minimum stock size threshold (B < BMSST). The minimum stock size threshold (MSST) is determined based on the natural mortality of the stock and the biomass at maximum sustainable yield (BMSY). Maximum sustainable yield (MSY) is the maximum long-term average yield that can be produced by a stock on a continuing basis. The biomass can be lower than BMSY, and the stock not be declared overfished as long as the biomass is above BMSST. It is important to note that other bodies, such as ICCAT, use different thresholds for stock status determination. For instance, the ICCAT Convention defines an overfished status as B/BMSY < 1.0, not Byear/BMSY < MSST. Overfishing may be occurring on a species if the current fishing mortality (F) is greater than the fishing mortality at MSY (FMSY) (F> FMSY). In the case of F, the maximum fishing mortality threshold is FMSY. Thus, if F exceeds FMSY, the stock is experiencing overfishing. If a species is declared overfished or overfishing is occurring, action to rebuild the stock and/or prevent further overfishing is required by law. A species is considered rebuilt when B is greater than BMSY and F is less than FMSY. A species is considered healthy when B is greater than or equal to the biomass at optimum yield (BOY) and F is less than or equal to the fishing mortality at optimum yield (FOY)