GLOUCESTER, Mass. (AP) -- The state has closed shellfish beds on the North Shore of Massachusetts following the expected arrival of red tide.
  
The Division of Marine Fisheries ordered a halt to shellfish harvesting Thursday after tests conducted from Newburyport to Gloucester revealed the presence of the toxin-producing algae in bivalves. The red tide does not affect lobsters, crabs and scallops.
  
Officials had expected the arrival of the red tide, which had been spreading southward from the coast of Maine for the past three weeks.
  
While red tide is an almost annual occurrence, biologists at the Woods Hole Oceanographic Institute are concerned this year's bloom could match the massive outbreak of 2005.
  
The toxin can be potentially deadly to people who eat tainted shellfish.