Washington  - US President Barack Obama on Friday ordered federal agencies to come up with a common national policy to protect the country's coastlines, oceans and major lakes.

US coasts and oceans - as well as the Great Lakes along the northern border with Canada - are currently managed by a patchwork of state laws and agencies.

Obama issued a presidential memorandum instructing a new taskforce to come up with recommendations for a comprehensive national policy within 90 days.

"The oceans, coasts and Great Lakes are subject to substantial pressures and face significant environmental challenges," Obama said in the memorandum.

"The United States needs to act within a unifying framework under a clear national policy, including a comprehensive, ecosystem-based framework for the long-term conservation and use of our resources," he said.

Obama said protecting the oceans was critical to the country's economic, transportation and national security needs, and the announcement was welcomed by environmental groups.

"The president has seized the opportunity not just to change the way we manage marine resources, but to transform our society's perspective about the sea from one of simple exploitation to that of careful, science-based stewardship," said Joshua Reichert, managing director of the Pew Environment Group. (dpa)