A new research study found that the return of sea otters saved sea grass from extinction in one California estuary.
The BBC reports that the sea otter’s return caused a chain reaction of events that helped the sea grass. Water plants have been struggling along the coastline of California due to urbanization, which causes nutrient pollution to increase due to nitrogen-rich fertilizers.
The chain of events went something like this: sea otters feasted upon crabs, which allowed small invertebrates in the coastal waters to grow in population. These invertebrates kept a certain type of algae in check that grows on sea grass, making it harder for the sea grass to absorb nutrients from sunlight.
Scientists tried this out in other estuaries to see if they would follow a similar process. It turns out they did.
The lead author of the study, Brent Hughes, commented “This estuary is part of one of the most polluted systems in the entire world, but you can still get this healthy thriving habitat, and it’s all because of the sea otters.”
“So it’s almost like these sea otters are fighting the effects of poor water quality.”
The study examined several decades’ worth of records on sea grass and otter populations in the estuary Elkhorn Slough, according to The China Post. The data easily showed that the sea grass did best with sea otters living there.
According to the BBC, when healthy, the estuary provides a nursery habitat for several species of fish by using CO2 from the water and protecting the shoreline. This could, in turn, help against climate change.
image: Wikimedia Commons
