Mutually beneficial ecological relationships are all around us, the most well-known connection being bees and flowers. The bees benefit from the flowers’ pollen, while the flowers benefit from the act of being pollinated. This type of relationship, called mutualism, is one where both parties benefit from the existence and interactions with each other. Positive relationships, like mutualism, and negative relationships both shape an ecosystem. The complexities of some ecological networks are difficult to simplify. The overarching theme of all ecosystems is that every organism has action and consequence. This concept expands even to underwater ecosystems.
Kelp forests are one of the most productive ecosystems on the planet. Even though they are exclusively a marine community, they serve a similar purpose to terrestrial forests. Kelp forests provide essential protection and habitat for marine species and aid in the removal of carbon dioxide from the atmosphere. Kelp also provides essential nutrients for a variety of species, one of which is sea urchins. However, without the presence of natural predators, sea urchins would quickly lay waste to these important forests.
One of the predators that keeps the urchin population in check is the notoriously adorable sea otter. Larger sea urchins are a favourite in a sea otter’s diet, but that still leaves the small and medium urchins untouched. A study by Simon Fraser University uncovered that sunflower sea stars are the players that fill this ecological role. This discovery was made after Sea Star Wasting Disease wiped out 96 percent of the sunflower star population on California’s Central Coast in 2015 and 2016. Consequentially, there was a 311 percent increase in small and medium sea urchins, followed by a 30 percent decrease in kelp density.
Although this grim event led to the mortality of numerous sunflower stars, an ecological insight was revealed. Similar phenomena highlights ecosystem dynamics and important species interactions. The lead scientist in this study says that learning about different ecological niches that shape marine ecosystems is essential, especially when climate change and other environmental stressors make our future ocean ecosystems more unpredictable.
What other examples of mutualism can you think of?