Effects of the 1997–1998 El Niño–Southern Oscillation on coral communities of the Gulf of California, Mexico
Abstract:The extensive bleaching and massive mortality suffered by reef corals in Costa Rica, Panama, Colombia and the Galápagos Islands (Ecuador), due to the increase of temperature caused by the El Niño–Southern Oscillation (ENSO) event of 1982–83, have been extensively characterized. However, ENSO effects and perturbations on other eastern Pacific reef localities are almost unknown. The objective of this paper is to describe the responses of six coral assemblages of the southern Gulf of California (27°N to 23°N) to the elevated temperatures of the 1997–98 ENSO, one of the strongest of the century. In July 1997, partial and full bleaching were first observed in colonies of Pocillopora spp. at Cabo Pulmo reef (23.5°N). By the following month, with sea temperatures of 30° to 31°C, loss of color was observed in four of the genera present in the region (including Porites, Pavona and Psammocora). In October 1997, bleaching was observed in coral communities from 27°N to the entrance of the Gulf of California, but after November, when sea surface temperatures dropped to 29°C or less, no further bleaching or mortality were observed. When ENSO warming was at its peak (September 1997) coral cover of 30.08%±2.86 (mean and SE) had bleached in the study region and by the end of the year, 18.15%±1.76 of the total cover was dead. Bleaching intensity was homogeneous between depths of 0 to 12 m, but coral mortality was significantly higher in shallow areas. The 1997–98 bleaching event was the strongest documented in the Gulf of California, but its effects were far less than those observed at Nayarit, Mexico (20°N) in the same years, or in the equatorial eastern Pacific during 1982–83. This attenuated response may be due to temperatures higher than 30°C recorded in the southern gulf only from August to November in 1997, and in August 1998. This pattern also has been observed in this region during the 1957–58, 1972–73 and 1982–83 ENSO events. The infrequent presence of extreme positive temperature anomalies in the Gulf of California may have allowed corals and reefs to sustain their growth and accretion, in contrast to coral communities in other areas of the eastern Pacific region.
Document Type: Research Article
Publication date: 2001-07-01
More about this publication?
- The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites