The Impact of Keystone Species in Marine Ecosystems: the Sea Otter and Sunflower Sea Star

Abstract

Kelp forests, consisting of giant kelp that many sea creatures call home, are rapidly becoming more endangered. For example, purple sea urchins are currently rapidly razing the kelp forests due to changing ecosystem dynamics. Keystone species like the sunflower sea star are essential in keeping purple sea urchins in check, as the sunflower sea star is one of the urchins’ major predators. However, the sunflower sea star is facing sea star wasting disease, drastically decimating its population. Sea otters, another natural predator of the sea urchin, are also remaining endangered from the lingering effects of overhunting. Because of the dropping numbers of their natural predators, purple sea urchins continue to overgraze kelp forests. Fortunately, there are strategies for remediating this problem. One of the main proposed solutions is to remove purple sea urchins from the environment by employing freelance divers. This can also create some profit for divers removing urchins creates space for the kelp to slowly grow back. Another solution is to raise sunflower sea stars in labs, breeding stronger and more resistant stars to sea star wasting disease. The cause of sea star wasting disease was recently discovered after being a mystery for over a decade, which will likely lead to more strategies for their repopulation. This paper will explore the history and current status of disappearing kelp forest populations. Furthermore, this research will examine how keystone species have impacted kelp forest ecosystems and how external factors, such as climate change, may be advancing these dynamics.