The U.S. Air Force has suspended plans it had proposed with Elon Musk’s SpaceX to test hypersonic rocket cargo deliveries from a remote Pacific atoll, according to a report this week in Stars and Stripes, an independent publication of the U.S. military.

The suspension came after Reuters reported that biologists and experts said the project would harm many seabirds that nest at the wildlife refuge on the Johnston Atoll, an unincorporated U.S. territory nearly 800 miles (1,300 km) southwest of Hawaii.

The Air Force had said it would undertake an environmental assessment of the project, but publication of a draft assessment was delayed after opposition to the plan by environmental groups.