Updated 10/02/11 – 7:00 p.m.

CHICAGO (WBBM) – The search for a missing Berkeley man, who is presumed dead, continued Sunday, after it had been suspended for a few hours due to high waves and high mercury levels in Lake Michigan.

Both Chicago police and the Coast Guard had been searching for the missing 51-year-old swimmer Sunday morning near Oak Street Beach, but the search was suspended from about 10:30 a.m. until 3 p.m. due to high waves and large amounts of mercury in the water, according to Police News Affairs Officer John Mirabelli.

Family members identified the missing man as James Garcia of Berkeley. They said they were still trying to piece together the circumstances of what happened.

Police said the victim jumped into the lake at Oak Street Beach to go swimming around 9:30 p.m. Saturday but got caught in the current and disappeared in the water.

A Chicago Fire Department spokesman said a woman who was a bystander on the beach was taken to a hospital Saturday night and treated for “stress discomfort.”

She was apparently a relative of the man who is missing.

The search was suspended overnight, but had resumed Sunday morning with a Coast Guard helicopter and boat, until the search was suspended again Sunday afternoon. The Coast Guard was not part of the search after it picked up again Sunday afternoon, believing that the man did not survive.

The search has been concentrated out from Oak Street and about two miles south of there, along the breakwalls, an official said.