Alarmed about the death of thousands of fish in Hood Canal the past two years, the federal government has approved about $350,000 to study the waterway’s low-oxygen problem.

It’s the first federal money to be directed to the issue.

The money was secured by Sen. Patty Murray, D-Wash., in the Interior Department appropriations bill, which has passed both the House and Senate.

Volunteers have been donating time and vessels to monitor water quality in Hood Canal. Bob Hager, who heads the monitoring program for Hood Canal Salmon Enhancement Group, said he wasn’t sure how the federal money would be used.

U.S. Geological Survey officials have said they will work with local experts to decide the best use of the funds, Hager said.

One of the top priorities is to study the source of nutrients coming into Hood Canal. Nutrients trigger the growth of plankton in the presence of sunlight. When the plankton die, they suck up the available oxygen as they decompose.

Bottom fish are especially vulnerable to low-oxygen conditions.