BOSTON (AP) — Boaters are being warned not to touch water from the Charles River near Newton, Waltham and Weston, Mass. following the discovery of an algae bloom in the river.

The Charles River Watershed Association says it’s the first time a bloom has been noticed in the area since it began monitoring algae in the river.

Public health officials say people should not touch the algae or fish or swim in the water. Pets should be kept away from the water as well.

Contact with the naturally occurring algae can cause rashes, nose, eye and throat irritation, stomach ache and other gastrointestinal problems.

Copyright 2012 The Associated Press.