Ed Robinson; Pacific Stock 



Searching the reef for lobsters, fish, and 

 other creatures on which to dine, a 

 Hawaiian monk seal, left, rolls beneath 

 the surf. A monk seal, below, basks on an 

 atoll in northwestern Hawaii. 



Erwin and Peggy Bauer; Bruce Coleman, Inc. 



thing to tell me. I turned to Tim Ragen, a 

 colleague at the National Marine Fisheries 

 Service, who monitors the endangered an- 

 imals. Ragen had worked as a carpenter 

 before becoming a marine biologist. Now 

 he builds models of marine mammal pop- 

 ulations instead of furniture. Ragen ex- 

 plained that the records on monk seal pups 

 only went back to 1986, but the data did 

 show a decline in first-year survival rates 

 from about 85 percent in the mid-1980s to 

 about 45 percent in the early 1990s. Like 

 Flint, Ragen didn't know the reason for the 

 decline, but after eliminating possible 

 causes such as disease, he felt that the 

 most likely cause was a scarcity of reef 

 fishes and lobsters, which make up a sig- 

 nificant part of a monk seal's diet. 



With lobsters, seabirds, and seals all 

 showing strong evidence of decline, I be- 

 came fairiy certain that something had af- 

 fected the entire marine ecosystem. To test 

 my hypothesis, I looked to the reef fishes. 

 In the early 1980s, their numbers had been 

 surveyed at selected sites throughout the 

 northwestern Hawaiian Islands. Because 

 fishing is prohibited near these shallow 

 reefs, any decline a decade later by a sec- 

 ond survey of the same sites would be fur- 

 ther evidence of environmental change. To 

 coordinate a field survey to estimate reef 

 fish densities at nine of the original sites, I 

 enlisted the help of Ed DeMartini, a coral 

 reef ecologist. 



The last biological data would come 

 from a satellite and would indicate how the 

 marine life at the base of the food chain 

 was faring. Either directly or indirectly, 

 phytoplankton, the microscopic plant life 

 that thrives near the ocean surface, pro- 

 vides almost all the food for the ocean's 

 animal life. From space, the Coastal Zone 

 Color Scanner, a special sensor mounted 

 on a satellite, could measure an index of 

 phytoplankton abundance. Unfortunately, 

 the sensor, which was especially designed 

 to pick up the light reflected from the 

 chlorophyll in the phytoplankton, was 

 only operational from 1979 to 1986, but it 

 did record data during the crucial period of 

 the early to mid-1980s. 



While the reef surveys were being con- 



ducted, and Mei Zhou, a computer wizard, 

 was computing phytoplankton estimates 

 from satellite data retrieved from a giant 

 NASA data base, I traveled to Victoria, 

 British Columbia, to attend a conference 

 on climate change and northern fish popu- 

 lations. I learned that weather patterns 

 over the North Pacific had changed signif- 

 icantly since the last decade. Every year, 

 the Aleutian low-pressure system is re- 

 sponsible for Hawaii's winter rainy season 

 and the strong winds that blow from Janu- 

 ary to March, generating rough seas and 

 the huge waves that surfers love. For about 

 a decade, from 1977 to 1988, the Aleutian 

 low was more intense and farther eastward 

 than it had been at any period since the 

 1940s, causing unusually strong winds in 

 the northwestern Hawaiian Islands. The 

 cUmate change was not abrupt. There was 

 a gradual increase in the intensity of the 

 Aleutian low, and the winds that accompa- 

 nied it, from 1977 to the early 1980s, fol- 

 lowed by a gradual decline, so by 1988 the 

 chmate was back to long-term pre- 1977 



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