Plastered to granite in the murky waters of New England lives a curious creature: the northern star coral. While coral reefs across the world are under severe threat by warming waters, this unique coral is able to survive-and even thrive-under chronic stress from a heating planet. Randi Rotjan, a research assistant professor of biology at Boston University’s College of Arts & Sciences, has scuba dived in these waters countless times in search of answers to the mystery. What makes this coral different from the rest?
Like all other coral, the northern star coral-Astrangia Poculata-is a symbiotic organism, meaning it relies on another organism for survival. But the northern star coral is special because it can stay alive without its symbiotic partners, raising questions that Rotjan and her lab are working to understand.
Coral, as Rotjan explains, has three main components: animal, vegetable, and mineral. All three work together in a delicate balance to form the colorful, robust reefs that decorate the bottom of the sea. When water temperatures rise to unusually high degrees, the algae plant that provides coral with energy-and its trademark beautiful colors-gets ejected, causing coral to turn white, a process known as bleaching, which can be fatal for coral. Due to climate change heating up the world’s oceans, bleaching has already taken the lives of many tropical coral reefs, also threatening the livelihood of a huge number of other marine species that make coral reefs their home.
Because northern star coral shares the same basic biology as tropical corals, Rotjan and her lab are working to understand how northern star coral can withstand coral bleaching so well. Her research findings could have implications for coral reef conservation efforts around the world.