Biological and Chemical Response of the Equatorial Pacific Ocean to the 1997-98 El Niño

Abstract

During the 1997-98 El Nino, the equatorial Pacific Ocean retained 0. 7 x 10(15) grams of carbon that normally would have been lost to the atmosphere as carbon dioxide. The surface ocean became impoverished in plant nutrients, and chlorophyll concentrations were the lowest on record. A dramatic recovery occurred in mid-1998, the system became highly productive, analogous to coastal environments, and carbon dioxide flux out of the ocean was again high. The spatial extent of the phytoplankton bloom that followed recovery from El Nino was the largest ever observed for the equatorial Pacific. These chemical and ecological perturbations were linked to changes in the upwelling of nutrient-enriched waters. The description and explanation of these dynamic changes would not have been possible without an observing system that combines biological, chemical, and physical sensors on moorings with remote sensing of chlorophyll.

Energy budget calculations indicate resource limitation in Eastern Pacific leatherback turtles

“…ENSO) might impact significantly resource abundance and distribution, thus increasing the required foraging time beyond the best-case estimate we present here. ENSO events are characterized by the advection of a warm-water anomaly across the Pacific toward western South America (Glantz 2001) depressing the nutrient-rich, cold upwelling off the South American Pacific coast, resulting in decreased primary productivity, altered marine and terrestrial food webs, and widespread changes in weather patterns (Chavez et al 1999, Glantz 2001, Stenseth et al 2002. Modeled repeated exposure to ENSO resulted in slower growth rates, delayed maturation and decreased fecundity in fishes (Harvey 2005), and oceanographic variability affects sea turtle reproduction by influencing energy acquisition, assimilation and allocation (Limpus & Nicholls 1988, Solow et al 2002.…”

“…Because ENSO events occur in the equatorial EP approximately every 3 to 7 yr (Chavez et al 1999), individual EP leatherbacks will presumably face ENSO-related conditions several times during their reproductive lifespan, which could last > 20 yr . Meanwhile, the Atlantic counterpart to ENSO, the NAO, shifts from one extreme to the other (1982 to 1983 and 1997 to 1998) show apparently higher productivity in NA leatherback foraging zones (i.e.…”

Multiyear predictability of tropical marine productivity

“…It is suspected to result from the interplay between human foraging and regional natural fluctuations in food abundance at the base of the food web such as variations in net primary productivity (NPP) occurring at interannual-todecadal timescales. These natural fluctuations impact marine ecosystems across large oceanic regions (2). In the tropical Pacific, these fluctuations are suggested to be driven by large-scale climate variations such as the Madden Julian Oscillation (3), the El Niño Southern Oscillation (4), or the Pacific Decadal Oscillation (5).…”

Understanding El Niño — The importance of Grey Literature in Coastal Ecosystem Research and Management

“…3A and B) indicates that the possible bias of the selection criteria in the first can be neglected and that the overall pattern in both categories is rather a reflection of increased interest in ENSO and climate research in the early 1980s following the severe EN in 1981/82 [12] and around the turn of the millennium after the strong EN 1997-98 [13]. Some of the best data on climate impact available at present reflect that these two events were well documented [13][14][15]. Although we believe to have achieved a good reflection of ISIliterature from the ASFA and WOS search, the contribution of ''Grey Literature'' to ENSO research presented in this work is not believed to be comprehensive.…”