Substantial increase in gelatinous zooplankton in the Bering Sea, with possible links to climate change. Fisheries Oceanography 8

• Main Authors: Richard D. Brodeur, Claudia E, James E. Overland, Gary E
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1999
• Subjects: Key words; Bering Sea; ecosystem change; physical±
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.538.4478; http://faculty.washington.edu/cemills/fishoceanog1999.pdf

We examined quantitative catches of large medusae from summer bottom trawl surveys that sampled vir-tually the same grid station on the eastern Bering Sea shelf using the same methodology every year from 1979 to 1997. This series shows a gradual increase in biomass of medusae from 1979 to 1989, followed by a dramatic increase in the 1990s. The median biomass increased tenfold between the 1982±1989 and 1990± 1997 periods. Most of this biomass was found within the Middle Shelf Domain (50 < z < 100 m). The greatest rate of increase occurred in the north-west portion of this domain. Whether this dramatic increase in biomass of gelatinous zooplankton has resulted from some anthropogenic perturbation of the Bering Sea environment or is a manifestation of nat-ural ecosystem variability is unclear. However, several large-scale winter/spring atmospheric and oceano-graphic variables in the Bering Sea exhibited con-comitant changes beginning around 1990, indicating that a possible regime change occurred at this time.