For nearly 90 days, oil from the BP spill has been plaguing the Gulf of Mexico. The oily wound left by an explosion that killed 11 rig workers on the Deepwater Horizon platform has now bled as much as 180 million gallons of crude oil into our waters.

It’s almost hard to believe, but a few hours ago, the flow into the Gulf finally stopped. BP installed a 75-ton cap that—for the time being—is preventing any more crude from escaping. This is a hopeful sign, but given how much has gone wrong with previous efforts to stem the flow, we’re clearly not out of the woods yet. Additionally, the cap, even if it holds, is only a temporary solution. Two relief wells, expected to be complete sometime in August, are the only method for plugging the spill for good.

The fact that oil has stopped leaking is nonetheless a significant and welcome development. We’re hopeful that the cap will hold and that the ever-expanding spill has finally reached its maximum. But reports today that hundreds of oiled pelicans and terns have turned up in Louisiana’s largest seabird nesting area are a sad reminder of the extensive damage already caused by the spill. Gulf residents, businesses, wildlife, and ecosystems will take a long time to recover from this tragedy, and they need our support in the process of rebuilding.