PORTLAND, Ore. (AP) — The federal government's management plan for protecting salmon and steelhead populations imperiled by federal dams in the Columbia River basin differs little from its earlier version and continues to rely heavily on habitat improvement.

The plan, known as a biological opinion, was released by NOAA Fisheries Service on Friday. Its various iterations have been litigated in court for more than two decades. The last plan was struck down in 2011 for depending too much on unspecified habitat improvements. Conservation and fishing groups say the new version preserves the status quo.

It does not consider the possibility of breaching Snake River dams and does not address climate change. Officials say habitat projects are starting to work, but they acknowledge that populations are nowhere close to being recovered.