National Oceanic and Atmospheric Administration NOAA National Marine Fisheries Service El Niño Related Research

The warming of the tropical Pacific Ocean has significant impact on marine life. NOAA’s National Marine Fisheries Service (NMFS) is studying the effect of El Niño and other climate events on the marine environment. The NMFS Southwest Fisheries Science Center is working with Scripps Institution of Oceanography and NOAA’s Office of Oceanic and Atmospheric Research to study California offshore waters in order to expand current information about the impact of El Niño on marine fisheries and the ocean environment.

The Alaska Fisheries Science Center hosted a workshop on October 28, 1997 to discuss potential research projects over the coming year to investigate impacts of the current El Niño on the fishery resources of the north Pacific Ocean.

The Alaska Fisheries Science Center’s National Marine Mammal Laboratory (NMML) conducts assessments of pinniped and cetacean populations in Oregon, Washington and Alaska coastal and offshore waters. NMML also conducts long-term studies of pinniped population biology at the Pribilof islands, on islands in the Eastern Aleutians and Gulf of Alaska and on San Miguel Island in the California Channel Islands. On San Miguel island over 25 sequential years of population data on northern fur seals and California sea lions have been collected which have documented impacts on these populations from El Niño events in 1983 and 1992. The California Channel Islands represent a unique location to study effects of El Niño and long term oceanographic warming. The islands are occupied by the largest populations of four species of pinnipeds anywhere along the west coast outside of the Pribilof Islands in the Bering Sea, and because of the islands southern geographic location, the modification of biological and physical oceanographic conditions during El Niños have been observed to be most extreme recorded along the U.S. west coast. The pinnipeds in the California Channel Islands have shown dramatic impacts of previous El Niño events and may be good indicator species of effects of long-term global warming.

NMFS’ Northwest Fisheries Science Center scientists have several ongoing research projects that will contribute to the greater understanding of how El Niño events impact anadromous and marine resources. For example, beginning in 1996, Northwest Fisheries Science Center scientists at the Newport Field Station (central Oregon coast) initiated studies to investigate relationships among coastal upwelling, ocean conditions, zooplankton production, and the growth and survival of coho salmon. Although this project was not specifically designed to focus on the impacts of El Niño, the timely start of this work (particularly the oceanographic sampling) prior to the onset of the 1997 El Niño and continued monitoring during and after the event should provide important information on the impacts of El Niño on coastal productivity.

As part of the NMFS Northwest Fisheries Science Center's ongoing stock assessments for west coast groundfish, staff will continue annual fishery monitoring and periodic surveys to estimate the new generations of young fish in this commercially important species group. These data form a time series that can be used to explore relationships of species abundance before, during, and after the 1997 El Niño. Further, in response to El Niño, the 1998 summer survey for Pacific whiting will be adjusted to account for more northerly migration.

As part the long-term investigation of salmon predator/prey interactions in the nearshore ocean, NMFS Northwest Fisheries Science Center scientists are conducting annual surveys of zooplankton distribution from Grays Harbor, Wash., to Cape Blanco, Ore. A primary focus of research is to quantify the abundance and distribution of northern anchovy (using an egg production index) and relate this to salmonid productivity. The time-series of zooplankton composition and distribution over this large coastal area will provide an important data set for prospective analyses of the impacts of El Niño.

NMFS Northwest Fisheries Science Center researchers also are investigating environmental factors affecting the location, size, and dynamics of toxic algal blooms and the elements associated with toxin production. Associated with these studies are numerous opportunities to increase the geographic scope and frequency of sampling and to greatly improve the ability to increase understanding of the ecology of harmful algal bloom in relation to El Niño events.

The NMFS Northwest Fisheries Science Center staff are investigating the distribution and severity of infectious fish diseases along the Oregon coast. The increased frequency and magnitude of Vibrio infections appear associated with the warming of sea surface temperatures experienced on the U.S. west coast in the past two months, coinciding with the El Niño.

The NMFS Southeast Fisheries Science Center scientists will study the significance of increased rainfall resulting from El Niño and its effects on Gulf of Mexico fisheries productivity next spring, especially on pink and brown shrimp throughout the Gulf. In addition, agency scientists hope to determine whether increased freshwater river runoff creates an environment for algal blooms (hypoxia) in the Gulf of Mexico from the Mississippi River mouth westward along the coast to Texas.