Sea Hares Scrub Seagrass by the Seashore | Deep Look

Teacher or professor: Deep Look
Subject: Biology
Content of the Lesson: These sea slugs may look like lazy, zebra-striped spoonfuls of jello, but eelgrass sea hares are actually environmental heroes. Their voracious appetite for algae helps keep underwater meadow ecosystems in balance–which is great news for sea otters. Deep Look Mollusk Playlist! https://www.youtube.com/watch?v=0wtLrlIKvJE&list=PLdKlciEDdCQBKKj0mY_irUMTg_yS5VEHY SUBSCRIBE to Deep Look! http://goo.gl/8NwXqt DEEP LOOK is an ultra-HD (4K) short video series created by KQED San Francisco and presented by PBS Digital Studios. See the unseen at the very edge of our visible world. Explore big scientific mysteries by going incredibly small. --- Eelgrass sea hares are tiny aquatic slugs named for the bunny-like tentacles on top of their head. They can be found munching on the microscopic algae that grow on the surface of eelgrass, a type of marine seagrass. Also known as the Taylor’s sea hare, these humble, zebra-striped slices of green jello are actually crucial to the health of their ecosystem. They don’t eat the grass itself; instead they help the meadows grow by clearing the way for sunlight to reach the plants, scraping the blades of grass clean with their rows of tiny teeth. The seagrass, in turn, serves as a safe haven to lay their eggs, and protection from predators like crabs and fish. The blades of grass also protect more than just these voracious little cleaners. At Elkhorn Slough, a large winding estuary off of Monterey Bay, the eelgrass beds form a habitat for a diverse community of animals and plant life, which includes sea otters, Dungeness crabs, clams, skeleton shrimp and various fish. For decades, nutrient overload from agricultural runoff has caused excessive algae blooms in Elkhorn Slough, as the thick algal mats block out the sunlight needed for the grass to grow. But with the reintroduction of sea otters to Elkhorn Slough in the 1980’s, ecologists observed a balancing effect on the system. The otters started eating the crabs that eat the sea hares. Because of this trophic cascade, the slug population grew, and their appetite for algae helped keep the eelgrass clean, counterbalancing the effects of the algal blooms. --- Is a sea hare a nudibranch? Nudibranchs and sea hares are both different types of sea slugs. There are various species of nudibranchs and sea hares. All sea slugs are a kind of mollusk. --- What is a trophic cascade? A trophic cascade occurs when the addition or removal of a top predator has a dramatic effect on the food web, drastically changing the structure of an ecosystem, and how nutrients cycle through it. ---+ Read the entire article on KQED Science: https://www.kqed.org/science/1970711/sea-hares-scrub-seagrass-by-the-seashore/ ---+ For more information: Paper on the ecological effects of sea otters, and their relationship to eelgrass and sea hares, by Brent Hughes, Sonoma State University - https://www.pnas.org/content/110/38/15313 Katharyn Boyer’s Lab at San Francisco State’s Estuary and Ocean Science Center, focusing on eelgrass ecology and restoration work in the San Francisco Bay http://online.sfsu.edu/katboyer/Boyer_Lab/Home.html ---+ Thank you to our Top Patreon Supporters ($10+ per month)! Bill Cass Justin Bull Burt Humburg Alex Shebastian Reyes Daniel Weinstein Egg-Roll Karen Reynolds Wild Turkey Chris B Emrick Josh Kuroda Tea Torvinen dane rosseter David Deshpande Daisuke Goto Companion Cube Tianxing Wang Elizabeth Ann Ditz Kevin Judge Leonhardt Wille Laurel Przybylski Dia Kelly Hong Robert Amling Gerardo Alfaro luna Mary Truland Sayantan Dasgupta Supernovabetty Joshua Murallon Robertson Aurora Pamela Parker Carrie Mukaida Shelley Pearson Cranshaw Cindy McGill Laura Sanborn Silvan Wendland monoirre Rick Wong Carlos Carrasco Titania Juang Roberta K Wright Misia Clive Nathan Wright Sonia Tanlimco Levi Cai Nicolette Ray Teresa Lavell Caitlin McDonough Kristy Freeman Blanca Vides Alexandre Valdetaro Guillaume Morin Noreen Herrington Scott Faunce Cristen Rasmussen Dogman Louis O'Neill Kallie Moore Geidi Rodriguez Syniurge SueEllen McCann KW Joao Ascensao Aurora Mitchell Sharon Merritt Adam Kurtz TierZoo ---+ Follow KQED Science and Deep Look: Instagram: https://www.instagram.com/kqedscience/ Twitter: https://www.twitter.com/kqedscience KQED Science on kqed.org: http://www.kqed.org/science ---+ About KQED KQED, an NPR and PBS affiliate in San Francisco, CA, serves Northern California and beyond with a public-supported alternative to commercial TV, Radio and web media. Funding for Deep Look is provided in part by PBS Digital Studios. Deep Look is a project of KQED Science, the largest science and environment reporting unit in California. KQED Science is supported by The National Science Foundation, the Dirk and Charlene Kabcenell Foundation, the Vadasz Family Foundation, the Gordon and Betty Moore Foundation, Campaign 21 and the members of KQED. #seahares #seaslug #seaslugs


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