For the first time ever in the Gulf of Alaska, an anticyclonic mesoscale eddy's formation, migration, and transport have been observed and thoroughly documented. The eddy, Haida-1998, was found to be one of an annual supply of eddies that transport fresh water and nutrients into the mid-gulf from the Alaskan panhandle and the Canadian west coast.

Haida-1998's core had an unusually high elevation, making it one of the largest eddies ever observed in this region. Its strength is attributed to oceanic features associated with the 1997–1998 El Niño winter. The eddy was still active in early July 1999 and is expected to remain intact into the year 2000. By that time it will be one of the last surviving features of the 1997–1998 El Niño in the northeast Pacific Ocean.