Friday, April 24, 2009

Sea Turtles + Eelgrass = Healthy Environment

Photo: Sea turtle foraging (eating) in the Caribbean.

Sea turtles in the San Diego Bay seem to mostly feed on eelgrass which is found in throughout shallower parts of the bay. In the southern part of the bay, south of Sweetwater Marsh, where the turtles spend most of their time, the eelgrass seems to grow in shallow areas ranging from a depth of 0-7 feet. Called "eelgrass beds", these sea turtle feeding areas are very important habitats for other animals living in and around the bay.

Young fish, crabs, lobsters and more use the eelgrass beds to grow before moving on to other habitats like the open ocean. When sea turtles eat the eelgrass, they act like "lawnmowers" and keep the beds healthy and growing. By maintaining these important habitats, fish and other animals in the water can use the eelgrass as protection from predators, a food source, and a nursery. Fish found in the south bay include California halibut, Spotted & Barred Sand Bass, Striped Mullet and Kelpfish - among many others.

Eelgrass also helps keep the water clear! Because eelgrass can grow to be a few feet in length, it can slow down movements in the water that might otherwise stir up the fine sand on the bottom that makes the water murky. And because it has roots - just like normal grass - it helps trap and hold down the sand and other fine sediments.

Finally, if the water is too polluted, the eelgrass cannot grow. During the 1940s-1960s, eelgrass beds shrank and pretty much disappeared as a result of marine pollution. But when changes began to occur to improve the quality of the bay's water (like eliminating sewage deposition in 1963) the eelgrass began to grow again.

So, when we have sea turtles in the bay, we know we have eelgrass in the bay, and that the ecosystem is doing alright!

Happy Earth Day, everyone!


Key Reference: The San Diego Bay Integrated Natural Resources Management Plan (INRMP)

Monday, April 20, 2009

Since the sea turtles in the San Diego Bay don't come out of the water, how do scientists study them?


Sea turtles, as their name implies, are marine animals and spend almost ALL of their time in the ocean. The exception is when females nest on beaches, or when individuals bask, or rest, on the sand to warm up - this is common in places like Hawai'i, especially where there are not too many disturbances, like people or pets. But in San Diego, the turtles stay in the water all the time, they only eat here, they don't nest or breed here. So this can make it difficult for scientists to study this groups of sea turtles.

What researchers do instead, is use large nets, designed specifically to capture but not harm the sea turtles. And because green sea turtles are endangered and are protected by the Endangered Species Act, researchers have permits and use special techniques when working with the turtles. Always on the water and watching the nets, researchers bring the caught turtles into the small research boat, and then bring the sea turtles onto shore. A typical "exam" done by the scientists includes weighing and measuring the turtle, taking samples for DNA and contaminant testing, and tagging the turtle so its movement can be monitored.

More information coming soon on the different ways San Diego's sea turtles are tagged and tracked.

When all the information about the turtles has been recorded, the nets are removed from the water, and the turtles are released back into the bay where they were found.

This type of information is especially important in light of near-future bayfront development that will be taking place along the south bay once the power plant is shut down. More coming soon on how this research impacts San Diego residents too!

For more pictures, on how the turtles are caught, weighed and measured, visit NOAA's website: http://swfsc.noaa.gov/textblock.aspx?Division=PRD&ParentMenuId=212&id=4378

Tuesday, April 14, 2009

What does the South Bay Power Plant have to do with Sea Turtles?

Photo: NMFS Permit # 1591

Eastern Pacific Green Sea Turtles live in warm water areas of the Pacific Ocean including the San Diego Bay. Eelgrass, a favorite food of green sea turtles, grows in the bay and is also a sign of a healthy and diverse ecosystem that can support young fish, crabs, lobster and more! You can even rent kayaks and paddle around the south end of the bay and see a sea turtle popping up its head to breathe! The power plant at the end of the bay discharges warm water that the turtles like to visit – they are often seen resting at the “jacuzzi”!

The South Bay Power Plant, scheduled to be taken off-line in the next few years, will then no longer discharge warm water into the Bay. Sea turtles are endangered animals, protected by the Endangered Species Act, and to understand the impacts of these policy changes, scientists study San Diego’s sea turtles and the Bay’s environment.

Population remaining stable
Location
of sea turtles different

Movement
patterns changing

Behaviors
are slightly different

Sea turtles are not harmed

Come join me at a local talk, or email/post comments to learn more!

Thursday, April 9, 2009

Come learn about San Diego's Sea Turtles! End of May!

I will be giving multiple presentations around San Diego, to tell the neat story about these ancient reptiles that live in our backyard!

The final talk I will be giving will be held at the end of May, together with Pro Peninsula. Stay tuned for more details.

If you are from a school, nature or environmental group and would like to arrange a presentation at your facility for April-May - please contact me, as this will be for offered during April and May only.

Learn more about Pro Peninsula too at: http://www.propeninsula.org/

Monday, April 6, 2009

Interested in learning about San Diego's Sea Turtles?

As part of my Capstone project for my Masters', I will be making multiple presentations and informal talks to help increase the awareness about the research going on to learn about these great creatures in San Diego, and how these turtles can actually help our local community, while we can also help protect these endangered animals and many, many more animals and resources that live in our coastal and open ocean habitats.

I will be announcing the dates, times and locations of these talks very soon. Check back to the blog to learn more, or follow SDSeaTurtles on Twitter to get updates on San Diego's Sea Turtles and up coming talks.

Questions and Comments? Post below, or send an email to me at: SDSeaTurtles@gmail.com

Did you know that there are sea turtles in San Diego?!

Most people, even life-long San Diegans, are unaware of these amazing creatures living right in our back yard!

This population of Eastern Pacific Green Sea Turtles have been studied by scientists since 1990.

Stay tuned to learn more about the research taking place to learn more about these incredible marine animals, and how their well-being can actually provide many benefits to those of us land-dwellers living and vacationing in San Diego.