PORTLAND, Maine — Lobstermen will get six more months to switch from floating to sinking lobster trap lines.

NOAA’s Fisheries Service announced Friday that the conversion date has been pushed back again, from October until April 5, 2009. The change is intended to protect whales from becoming entangled in the ropes.

Besides lobstermen, the sinking rope rules apply to other East Coast fishermen who use crab and fish pots and traps.

Fishery regulators say the extension will have little effect on whales, but will give fishermen more time to comply with the rules.