MANATEE COUNTY, Fla. (WFLA) — A 76-year-old Manatee County man who was reported missing Sunday afternoon was found dead, according to authorities.

“Donald Arendt, 76, is no longer missing,” the Manatee County Sheriff’s Office said in an updated news release. “Sadly, he was found deceased this morning near Emerson Point after a boater spotted him just off shore.”

Detectives are conducting a death investigation to determine the man’s cause of death. It is not yet know how he ended up in the water.

Deputies said multiple agencies and members of the community joined forces to conduct “an extensive search” stretching from Parrish to Snead Island after several people reported a person matching Arendt’s description over the weekend. However, the 76-year-old was never located by search crews.

Deputies said the last time Arendt was seen was when he left his home near the intersection of 98th Ter East and 46th Court East in Parrish riding his dark-colored electric bicycle around 11 a.m.

Authorities said Arendt was diagnosed with late-stage Alzheimer’s. The sheriff’s office offered “prayers for his family and friends.”

Anyone with information is asked to contact the Manatee County Sheriff’s Office at (941) 747-3011.