A search for a possible missing kayaker off Nahant, ordered Monday morning after an empty kayak was found in the water, has been suspended, and no kayaker has been found. The US Coast Guard sent a boat and a helicopter, and Environmental Police and Nahant police launched boats in the search, said Petty Officer Ross Ruddell, a Coast Guard spokesman. It was not determined if someone was actually missing. The search began after an abandoned kayak was found off Nahant at about 8:09 a.m., Ruddell said. The search was suspended at roughly 12:50 p.m., he said.