Legalese on rebuilding fish stocks that are "overfished"
Distribution Courtesy of Southeastern Fisheries Association from fax received 9/17/97

MEMO FOR: Wayne Swingle, GMFMC

FROM: GCSE B. Michael McLemore

DATE: September 2, 1997

SUBJECT: Rebuilding levels

You inquired about the appropriate level to which overfished stocks must be rebuilt under the Magnuson Stevens Act, and whether rebuilding programs must be geared toward maximum sustainable yield (MSY) or optimum yield (OY).

Of course, national standard one requires that conservation and management measures in a fishery management plan prevent overfishing while achieving, on a continuing basis, the optimum yield ¹ from a fishery. 16 U.S.C. 1851 (a) (1). The Act's definitions of "optimum" and "overfished," and the proposed rule ² to revise the guidelines for national standard one are instructive on the question. The former explicitly states that the optimum yield for an overfished fishery is the level consistent with producing MSY. See Notes 1 and 3, infra. The latter acknowledges the Act's implicit rebuilding target as equal to the MSY stock size as a minimum standard, and states that in general rebuilding should be consistent with the goal of achieving an average stock size associated with OY. (62 F.R. 41910).

The proposed guidelines would require consideration of more than stock size to overcome overfished conditions or overfishing, however. ³ Subsection 600.310 (d) (2) would require an FMP to contain a specification of two status determination criteria to enable the Council and Secretary to monitor a stock to determine whether a stock was in an overfished condition and whether overfishing was occurring. The first criterion is a maximum fishing mortality threshold or reasonable proxy thereof; the second criterion is a minimum stock size threshold or reasonable proxy thereof. These criteria are both tied to MSY. The maximum fishing mortality threshold may not exceed the fishing mortality rate or level associated with the relevant MSY control rule.

The minimum stock size threshold is the greater of 1) one-half the MSY stock size or 2) the minimum stock size at which rebuilding to the MSY level would be expected to occur within 10 years if the stock were exploited at the specified maximum fishing mortality threshold. A stock would be considered overfished if the size in a given year fell below that threshold.

Some may find the parameters in the act and guidelines a bit circular in attempting to apply them to a particular set of facts. However, MSY does seem to be the parameter Congress used in refocusing the Act on sustainability. Interestingly, the Act does not define the term MSY nor the term "sustainable." The guidelines define MSY as the largest long-term average catch or yield that can be taken from a stock or stock complex under prevailing ecological and environmental conditions. 600.310 [c] (1) (I), 62 F.R. 411913. One comment regarding NMFS' recent disapproval of a proposed overfishing definition seemed to focus on a distinction between specification of an overfishing threshold based on MSY, as opposed to a specification based on the capacity to product MSY. It seems logical that in order to be able to produce MSY, an MSY stock size would be necessary, and I have not seen any explanation of how MSY could be produced from less than an MSY stock size. The focus on "capacity" may imply an incorrect treatment of the fact that MSY is a long term average. While the concept of an average implies some fluctuation between high and low reference points, over-emphasizing a low reference point or using a low reference point as a target would not be consistent with the requirement to use the average. MSY, even when identified as a range, is defined as an average over some time frame.

CC: NMFS

GCF

GCSE-Joy; Smit-Brunello

Footnotes

1. The term "optimum", with respect to the yield from a fishery, means the amount of fish which-

(A) will provide the greatest overall benefit to the Nation, particularly with respect to food production and recreational opportunities, and taking into account the protection of the marine ecosystems;

(B) is prescribed as such on a basis of the maximum sustainable yield from the fishery, as reduced by any relevant economic, social, or ecological factor, and

(C) in the case of an overfished fishery, provides for rebuilding to a level consistent with producing the maximum sustainable yield in such fishery. 16 U.S.C. 1802(28).

2. 62 F.R. 41907-41920, 8/4/97-

The terms "overfish" and "overfished" mean a rate or level of fishing mortality that jeopardizes the capacity of a fishery to produce the maximum sustainable yield on a continuing basis.

3. 16 U.S.C. 1802(29).