Princeton University Press has acquired Island Press, the Washington, D.C.–based not-for-profit publisher of books on sustainability and the environment. Beginning in January, Island Press will become a PUP imprint.

In making the announcement, Island Press noted that it was looking for ways it could continue its mission of publishing important works on the environment in a challenging funding, publishing, and media market. Its backlist includes more than 1,000 titles.

“As we looked to the future, it became clear that we needed a partner who shared both our mission and our entrepreneurial spirit if we were to fully accomplish that goal,” said David Miller, president and publisher of Island Press, in a statement. “In joining with Princeton University Press, we gain a partner widely known for publishing excellence that shares our passion for finding creative ways of amplifying authors and their work.” Miller will continue to oversee Island Press for PUP.

“IP books have influenced policy, informed global public debate, and empowered individuals and organizations to take action toward a more sustainable, healthier future,” said Christie Henry, PUP director, in a statement. “Only twice in Princeton University Press’s history have we been entrusted with the responsibility to steward another imprint of this nature—the Bollingen Series and WILDGuides. Our commitment to these publishing legacies and their radiant, impactful futures, is profound. We look forward to further diversifying our publications program and to the collaborations with our new Island Press colleagues, authors, and partners.”