The risk policy shall be used by the SSC in conjunction with the ABC control rules in §648.20(a) through (d) to ensure the MAFMC's preferred tolerance for the risk of overfishing is addressed in the ABC development and recommendation process.

(a) Stocks under a rebuilding plan. The probability of not exceeding the F necessary to rebuild the stock within the specified time frame (rebuilding F or FREBUILD) must be at least 50 percent, unless the default level is modified to a higher probability for not exceeding the rebuilding F through the formal stock rebuilding plan. A higher probability of not exceeding the rebuilding F would be expressed as a value greater than 50 percent (e.g., 75-percent probability of not exceeding rebuilding F, which corresponds to a 25-percent probability of exceeding rebuilding F).

(b) Stocks not subject to a rebuilding plan.

(1) For stocks determined by the SSC to have an atypical life history, the maximum probability of overfishing as informed by the OFL distribution will be 35 percent for stocks with a ratio of biomass (B) to biomass at MSY (BMSY) of 1.0 or higher (i.e., the stock is at BMSY or higher). The maximum probability of overfishing shall decrease linearly from the maximum value of 35 percent as the B/BMSY ratio becomes less than 1.0 (i.e., the stock biomass less than BMSY) until the probability of overfishing becomes zero at a B/BMSY ratio of 0.10. An atypical life history is generally defined as one that has greater vulnerability to exploitation and whose characteristics have not been fully addressed through the stock assessment and biological reference point development process.

(2) For stocks determined by the SSC to have a typical life history, the maximum probability of overfishing as informed by the OFL distribution will be 40 percent for stocks with a ratio of B to BMSY of 1.0 or higher (i.e., the stock is at BMSY or higher). The maximum probability of overfishing shall decrease linearly from the maximum value of 40 percent as the B/BMSY ratio becomes less 1.0 (stock biomass less than BMSY) until the probability of overfishing becomes zero at a B/BMSY ratio of 0.10. Stocks with typical life history are those not meeting the criteria in paragraph (b)(1) of this section.

(c) Most restrictive ABC recommendation.

(1) Unless otherwise allowed in paragraph (c)(2) of this section, for instances in which the application of the risk policy approaches in either paragraph (b)(1) or (2) of this section using OFL distribution, as applicable given life history determination, results in a more restrictive ABC recommendation than the calculation of ABC derived from the use of FREBUILD at the MAFMC-specified overfishing risk level as outlined in paragraph (a) of this section, the SSC shall recommend to the MAFMC the lower of the ABC values.

(2) The SSC may specify higher 2019-2023 ABCs for Atlantic mackerel based on FREBUILD instead of the methods outlined in paragraph (a) of this section to implement a rebuilding program that would rebuild this stock by 2023.

(d) Stock without an OFL or OFL proxy.

(1) If an OFL cannot be determined from the stock assessment, or if a proxy is not provided by the SSC during the ABC recommendation process, ABC levels may not be increased until such time that an OFL has been identified.

(2) The SSC may deviate from paragraph (d)(1) of this section, provided that the following two criteria are met: Biomass-based reference points indicate that the stock is greater than BMSY and stock biomass is stable or increasing, or if biomass based reference points are not available, best available science indicates that stock biomass is stable or increasing; and the SSC provides a determination that, based on best available science, the recommended increase to the ABC is not expected to result in overfishing. Any such deviation must include a description of why the increase is warranted, description of the methods used to derive the alternative ABC, and a certification that the ABC is not likely to result in overfishing on the stock.

[76 FR 60616, Sept. 29, 2011, as amended at 77 FR 51857, Aug. 27, 2012; 84 FR 58058, Oct. 30, 2019]