POULSBO — Port of Poulsbo officials were unable to determine the source of an estimated one gallon of diesel believed to have spilled from a vessel in either B or C dock in mid-May.

Port Executive Director Brad Miller said June 2 that the spill was noticed the morning of May 17. Port staff emailed Port of Poulsbo Marina patrons advising them to check their bilges for diesel fuel “as soon as possible.”

“We were not able to determine the boat from which the fuel came, but we are certain it came” from B or C docks, the email stated. Miller said the diesel was unrecoverable. “Diesel spreads incredibly thin,” he said.

The Port of Poulsbo Marina has 254 permanent moorage slips and 130 guest moorage slips. Port staff members inspect new vessels that moor in a permanent slip “to make sure we’re starting with a clean boat,” Miller said. But port staff members do not regularly inspect vessels after that.

To help prevent spills, Miller recommends boaters “pay attention” to their boats. Regularly check your bilge for diesel fuel. If you see a sheen in the marina, report it immediately. “Don’t assume we know about it,” Miller said. “If we do, we’re still going to thank you.” If you see a sheen in the marina after hours, call 9-1-1, Miller said. CenCom will activate a call list so port staff is contacted and can respond.