Turtle Island Restoration Network, the conservation nonprofit based in Olema, has all but dismantled its longest-running local program, laying off its entire staff and leaving its large volunteer network uncertain about its future and changing priorities.

For nearly three decades, the Salmon Protection and Watershed Network, or SPAWN, has monitored endangered coho salmon and threatened steelhead trout in the Lagunitas Creek watershed, combining creek restoration, biological monitoring, advocacy and public education. The program has restored…