Since 1996, NOAA Fisheries has reported on the status of U.S. fisheries, as required by the Magnuson-Stevens Fishery Conservation and Management Act. Reporting on the status of fish stocks provides fisheries managers and the public with an account of how well current fisheries management measures are working. A scientific analysis of the abundance and composition of a fish stock (stock assessment) evaluates the stock against reference points. Stock assessments use the best information available, which may include data from fisheries landings, scientific surveys, and biological studies. NOAA Fisheries uses the stock assessment and reference points to determine whether the stock is subject to overfishing or overfished. Information from the stock assessment is used by the regional fishery management council to recommend the annual catch limit for the stock.
NOAA Fisheries’ Office of Sustainable Fisheries updates the status of fish stocks managed under federal fishery management plans quarterly based on stock assessments completed during that quarter. Stock status definitions include:
Overfishing – The annual rate of catch is too high.
Overfished – The population size is too small.
Rebuilt – A previously overfished stock that has increased in abundance to the target population size that supports its maximum sustainable yield.
These data also help NOAA Fisheries calculate its Fish Stock Sustainability Index (FSSI), which measures the performance of U.S. fish stocks selected for their importance to commercial and recreational fisheries.
NOAA Fisheries measures the performance of U.S. federal fisheries through the Fish Stock Sustainability Index (FSSI). First implemented in 2005, the FSSI is a quarterly index that currently includes 199 fish stocks selected because of their importance to commercial and recreational fisheries. The FSSI measures the performance of these important fish stocks, which represent 85 percent of total catch.
The FSSI increases when NOAA Fisheries determines the status of a stock and when a stock's status improves (either no longer subject to overfishing, no longer overfished, biomass increases to at least 80 percent of target, or is rebuilt). The number of stocks in the index may be revised as new fisheries develop and stocks are assessed.
Since 2000, increases in the FSSI show significant progress in sustainably managing U.S. fisheries. The graph below illustrates the growth in the FSSI from 2000 to the end of 2016. For details on the current status, visit the Stock Status Updates page.
The original FSSI reported on 230 stocks managed under federal fishery management plans (FMPs), including domestic stocks we manage solely within the U.S. Exclusive Economic Zone and international stocks we manage jointly under international agreements. We reported the original FSSI on a scale of 920 possible points which required a constant 230 stocks in the index. Over time, as fishery science and management evolved and stocks were both added to and removed from FMPs, maintaining exactly 230 stocks in the FSSI became an increasing challenge.
Beginning in 2015, we revised the FSSI so that the maximum possible FSSI score is 1,000, even if the number of stocks reported in the FSSI changes. This will allow the FSSI to accommodate future additions or removals of stocks to and from FMPs. We also removed international stocks from the FSSI. International stocks are subject to different management requirements than domestic stocks, and the impact of U.S. fisheries management to control overfishing or rebuild these stocks is often small or indirect. By focusing on domestic stocks, the FSSI is a stronger performance measure for U.S. fishery management. We will continue to track the overfished and overfishing status of international stocks separately from FSSI.
We have developed a historical summary (PDF, 9 pages) of all the stocks that have been included in FSSI over time.
Each quarter, NOAA Fisheries calculates an FSSI score, incorporating information from new stock assessments and stock status determinations. The FSSI is calculated on a 1,000 point scale using the following methodology:
Step 1: Assign weighted criteria points for each stock based on the following:
* Stocks rebuilding from a previously overfished condition are not awarded the fourth point until they reach BMSY, as mandated by the Magnuson-Stevens Act. After they have been fully rebuilt, they may fluctuate within the 80% parameter and retain the score of 4 like the other non-rebuilding stocks. This point is in addition to the point awarded for being above the “overfished” level.
Step 2: Calculate the sum of criteria points for all FSSI stocks.
Step 3: Calculate maximum criteria points possible: multiply number of FSSI stocks (199) x maximum criteria points per stock (4 points).
Step 4: Calculate a raw total point score: divide sum of criteria points / maximum criteria points possible.
Step 5: Convert raw total point score to a 1,000 point scale: total raw point score*1,000.
The Magnuson-Stevens Fishery Conservation and Management Act requires that a fishery management plan specify objective and measurable criteria, or reference points, for determining when a stock is subject to overfishing or overfished. A scientific analysis of the abundance and composition of a fish stock (stock assessment) evaluates the stock against its reference points.
Stock assessments use the best information available, which may include data from fishery landings, scientific surveys, and biological and ecological studies. A stock assessment typically undergoes peer review by independent scientists before it is accepted as the best scientific information available.
Generally, NOAA Fisheries uses the stock assessment and the reference points to determine whether the stock is subject to overfishing or overfished. Information from the stock assessment is used by the regional fishery management council to recommend the annual catch limit for the stock.
NOAA Fisheries’ stock assessments are key to sustainable fisheries management. A number of NOAA Fisheries resources can help you learn more.
Learn more about the science behind stock assessments.
When NOAA Fisheries determines that a stock is overfished, the relevant regional fishery management council (council) must implement a plan to rebuild it to the level that can support maximum sustainable yield (MSY). A typical rebuilding plan allows fishing to continue, but at a reduced level so that the stock will increase to the target level that supports MSY.
The graph below helps illustrate the concept of a rebuilding stock. A stock that is declared overfished—with a population size below the blue line—must have a rebuilding plan in place. The goal of that plan is to grow the stock to its target size—the orange line. The time between when the rebuilding plan goes in place and reaching the orange line is the stock’s rebuilding period. The time to achieve a rebuilt status will vary, depending on the individual stock.
In 2016, we rebuilt two stocks—barndoor skate and North Atlantic albacore—for a total of 41 rebuilt stocks since 2000. Successful rebuilding plans for both stocks included a variety of management measures.
For barndoor skate, fishery managers have prohibited catch since 2003. As a result of being rebuilt, managers may consider allowing catch of barndoor skate in the future.
For North Atlantic albacore, NOAA Fisheries worked successfully with the International Commission for the Conservation of Atlantic Tunas (ICCAT) to successfully negotiate reduced catches by other countries. Read more in the 2016 Report to Congress.
Overfished Stocks/Stocks in Rebuilding Plans (PDF, 2 pages)