Sea Otters — The Guardians Of Monterey Bay’s Kelp Forest
KPBS Midday Edition Segments / May 4, 2021
California’s underwater kelp forests are in trouble. A combination of climate change and hungry purple sea urchins have decimated these vital forests. But the Monterey Peninsula has a kelp forest guardian -- sea otters.
Speaker 1: 00:00 California's underwater kelp forests are in trouble. A combination of climate change and hungry purple sea urchins have decimated these vital forests, but the Monterey peninsula has a kelp forest guardian sea otters. As [inaudible] Erica Mahoney reports, new research out of the university of California, Santa Cruz is highlighting their role.
Speaker 2: 00:24 Sea otters are adorable. They have big eyes, wispy whiskers and dense fur coats. Even their sounds are cute as captured by the Monterey Bay aquarium, but beyond all that cuteness sea otters are important to the Monterey Bay's ecosystem. Notably defending kelp forests, which are homed over 800 different animal species forests that are already in bad shape, standing near a beach on cannery row and Monterrey, Josh Smith, a PhD candidate at UC Santa Cruz describes what the kelp forest here looked like just a decade ago.
Speaker 3: 01:02 Yeah. The canopy would have spread out across this entire little Bay right here that we're in. And so right now, what we're seeing is a very patching helpful
Speaker 2: 01:13 That motivated him to research the role sea otters play in the complex story of disappearing kelp. The story begins around 2013. That's when the number of purple sea urchins skyrocketed after a disease wiped out. One of their main predators urchins Devou work help. The declining forest was further weakened by warming waters. A symptom of climate change kelp needs, cold water to survive. The result Northern California lost 95% of its kelp forest in under a decade. The Monterey Bay area fared better only losing around 60%.
Speaker 3: 01:53 One thing that our study has shown is that having predators like the sea Otter are really important in helping to buffer this ecosystem.
Speaker 2: 02:01 The PhD candidate says sea otters are slowing the decline of the local kelp forest by eating up urchins. In fact, three times, as many as they used to, to collect data Smith spent about 300 hours underwater along the Monterey peninsula. He also worked with scientists from the Monterey Bay aquarium and the us geological survey who used telescopes and range binders to record what sea otters were eating and where
Speaker 3: 02:31 That's great about studying sea otters is they consume their prey at the surface. So we can watch an Otter dive down and we can record where it came up and what it came up with.
Speaker 2: 02:42 The team's findings were recently published in the journal proceedings of the national Academy of sciences. They found that otters ignore urchin Barrens areas where urchins have overgrazed kelp to the bear sea floor. The purple creatures. There are starving often called zombie urchins. Instead the otters focus on foraging, the healthy ones and the remaining patches of kelp
Speaker 3: 03:07 Because sea otters are targeting urchins in these forests. They're helping to maintain the remnant patches of kelp forest that we actually have from overgrazing by sea urchins,
Speaker 2: 03:18 Otters live between Santa Barbara and just North of Santa Cruz. Further North from Otter territory. Urchins have no predators and that's possibly why the kelp forest decline is more severe in Northern California. Tristan McHugh, who works for the nature Conservancy is trying to find solutions in Northern California. We don't have otters. We don't have lobsters. We don't have sheep head. We don't have some flowers stars that really puts the pressure currently on humans to fill the role of that top predator. The nature Conservancy is exploring several innovative ideas, including urgent trapping to pull the spiny creatures out of the water. It's also launching an experimental kelp farm. The pilot project is scheduled to begin this spring in Humboldt Bay as for the Monterey Bay sea otters, keep urchins with an insatiable taste for kelp in check something. Dane Duran, who manages the Aquarius dive shop in Monterrey, definitely appreciates as he fills up scuba tanks. He says the kelp forest draws people from all over the world.
Speaker 3: 04:28 So we get people from England and all over Europe. I just had somebody from Iceland last week. The California's is something extremely special here
Speaker 2: 04:36 From supporting the local economy to removing carbon dioxide from the atmosphere. Luckily the local kelp forest has guardians guardians that play a larger role than just looking and sounding cute. That was [inaudible] Erica Mahoney reporting.