Note that the data published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution. For the most recent data, purchase the 2008 Report from Island Press.

The Data

Data Source: The National Oceanographic and Atmospheric Administration’s (NOAA) National Marine Fisheries Service (NMFS) Research Centers in Woods Hole, Massachusetts; Miami, Florida; La Jolla, California; and Seattle, Washington (two centers). Natural Resources Consultants, Inc., analyzed the data under contract for The Heinz Center.

Data Manipulations: As reported by NMFS in the recent publication Our Living Oceans, there are 203 stocks within federal jurisdiction. Excluded from these analyses are near-shore stocks, many of which are under state management jurisdiction, and anadromous salmon stocks from the Pacific Northwest.

For 158 of these stocks, data are adequate to consider reporting on their status; the remaining 45 stocks constitute a small fraction (2.5%) of recent landings. Analyses presented in this report were limited to those stocks for which at least 10 years of data were available over the 1981–1999 time period. Both spawning stock biomass and total exploitable stock biomass figures were used to track stock trends. This restriction (i.e., 10 years of data) meant that only 49 of the 158 stocks having status data could be used (these 49 stocks represent about 75% of the weight of fish caught in U.S. waters). It should be noted that requiring spawning stock biomass or total exploitable stock biomass figures certainly restricted the number of trackable stocks; other means exist (e.g., catch per unit effort, relative abundance, indices that combine several stocks) to track stocks that were not included in this analysis.

Biomass refers to the total weight of fish, and can change either because there are more or fewer fish or because, on average, fish are larger or smaller, although changes in biomass are generally described as changes in population size. Stock trends (i.e., “increasing,” “decreasing” or “no trend”) were determined by linear regression. Trends were determined for four overlapping 10-year periods (1981–1990, 1984–1993, 1987–1996, 1990–1999), which reduced the likelihood that normal year-to-year fluctuations would influence the results. (This is analogous to the effect of using a running average.) Two conditions were necessary for a trend to be reported: the regression line had to have a correlation coefficient (R) indicating at least 95% confidence that the slope was different than zero; and the regression line had to indicate a minimum 25% change over the 10-year period (increasing or decreasing). Trends for the following 49 stocks were studied:

• North/Mid-Atlantic: Atlantic menhaden, Georges Bank cod, Georges Bank haddock, Georges Bank yellowtail flounder, southern northeast yellowtail flounder, mid-Atlantic summer flounder, Gulf of Maine red fish, Gulf of Maine cod, Gulf of Maine–Georges Bank plaice, Gulf of Maine–Georges Bank witch, Georges Bank winter flounder, and southern New England winter flounder.
• Gulf of Mexico: Brown shrimp, white shrimp, and pink shrimp.
• Southern California: Mackerel and sardine.
• Pacific Northwest: Dark blotched rockfish, lingcod (northern), lingcod (southern), widow rockfish, yellowtail rockfish, bacaccio rockfish, canary rockfish, cow rockfish, Pacific hake, petrale sole, chilipepper rockfish, sablefish, Dover sale, and longspine thorny rockfish.
• Alaska Region: West & central Alaska pink salmon, west & central Alaska sockeye salmon, west & central chum salmon, west & central Alaska Chinook salmon, west & central Alaska Coho salmon, Bering Sea pollock, Bering Sea Pacific cod, Bering Sea yellow fin sole, Bering Sea rock sole, Bering Sea sablefish, Gulf of Alaska pollock, Gulf of Alaska sablefish, Pacific halibut, red king crab, blue king crab–Pribilofs, blue king crab–St. Matthews, Tanner crab, and snow crab.

Data Quality/The Remaining Data Gap: Currently, we are able to evaluate trends on only about 25% of the commercially important stocks found in U.S. waters.

Data Access: Stock biomass data are available by contacting the NMFS research centers noted above in “Data Source.”