Home > Aquarium Blog > Improbable Residents: The Sea Turtles of the San Gabriel River

Improbable Residents: The Sea Turtles of the San Gabriel River

Hugh's avatar

Conservation | Volunteering | Turtles

Thursday, August 14, 2008

Hugh

It is one of the best kept secrets of Mother Nature. When you think of green sea turtles, visions of tropical Islands comes to mind. To folks in the Los Angeles/Orange County area of California, these warm water wanderers are thought to be in far off, exotic locales. And yet in an urban river near the Long Beach/Orange County border, an improbable group of sea turtles inconspicuously resides.

The San Gabriel River runs from the San Gabriel Mountains to its outlet between Seal Beach and Alamitos Bay. About two miles from the ocean, Electrical Power Plants flush warm water into the river raising the temperature way above the normal ocean temperature. And it is in this area that a little known colony of sea turtles reside.

The Aquarium of the Pacific’s Veterinarian, Dr. Lance Adams, and NOAA are getting ready to begin a study of these San Gabriel River sea turtles on August 1, 2008. Dr. Adams, Aquarium of the Pacific Vet Tech Colleen, Aquarist Amy, my wife Pam and I, in a preliminary field survey, watched from banks of the river for these sea turtles. My job that day was to document the presence of the sea turtles in the river photographically. We did see a few sea turtles, but because of the lighting condition, I couldn’t get a decent shot of the turtles. So my wife and I came back on Sunday, August 3 to again try to get images of the turtles and to start recording field notes on them.

In this week’s blog, I’d like to share some of our field notes and images.

Field notes on the San Gabriel River Sea Turtles for 08/03/08:

7:30 – 9:30 a.m.

Conditions: Overcast/Marine Layer, water surface “glassy/very smooth”

During this time, we observed approximately two (2) large, three (3) medium, and two (2) small turtles at various locations along the river. Based on the photos taken, and to the best of our skills/abilities, we have come to the conclusion that the turtles seen were green sea turtles.

During the lower tide (AM observations), most of the turtles stayed farther, about 60-70 yards (at least half way) from the east bank. The turtles usually surfaced very briefly, just showing their heads. One exception was one or both of the large turtles. They actually formed a “surfacing pattern.” The large turtles would surface for two (2) quick sets of three (3) breaths at which time their heads were visible above the surface of the water. The turtles continued to move as they breathed. When the turtles completed a series of breaths, they stayed under for 15–20 minutes. When they did not complete the series, they usually surfaced in 10–12 minutes. The medium/small turtles were very quick to surface and go back under, and did not tend to follow any kind of surfacing pattern. Four turtles were often seen at one time.

11:00 a.m. – 1:30 p.m.

Conditions: clear & sunny, water had slight ripple at surface, and turbulence from all outlets

Based on location of turtle sightings, we now estimated eight (8) turtles in the area (one more large one). Turtles were more active and surfaced more frequently, began to stay at the surface a bit longer, and were closer to the riverbank. The two larger turtles followed the AM “surfacing pattern”, and medium-size turtles would surface in a single series of 2–3 breaths. Two larger turtles spent the whole time surfacing in the same general small area; covering a distance of about 1/8 of a mile. The turtles submerged for about 10–12 minutes (shorter than the AM sightings). The 3rd large turtle was spotted surfacing mid-river, in the turbulence from the first discharge outlet. The medium-sized turtles came to the same area but would also surface closer to the bridge, and further from shore (helf way out or a little further). The small turtles usually surfaced in the “lighter” turbulence near the “water outlet discharge”, but more than half way from the riverbank.

Note: Large, adult California sea lion swam up river (during the AM sighting) and foraged near the power station outflow. Numerous large and small fish were seen leaping from the water throughout both observation periods. Some small fish leaped just as a turtle would surface.

Other incidental sightings along the river included an osprey, coyote, Snowy Egrets, Double Crested Cormorants and Brown Pelicans.

STAY TUNED FOR MORE ON THE SEA TURTLES OF THE SAN GABRIEL RIVER AS THE FORMAL RESEARCH OF THESE CRITTERS, COORDINATED BY THE AQUARIUM OF THE PACIFIC, BEGINS IN THE COMING MONTHS.

Improbable Residents: The Sea Turtles of the San Gabriel River
The Aquarium of the Pacific is set to begin a study of the sea turtle residing in the San Gabriel River in the near future. To that end, a preliminary survey of the turtles was made on August 1st, 2008.  | © Hugh Ryono
Improbable Residents: The Sea Turtles of the San Gabriel River
A green sea turtles surfaces in the river.  | © Hugh Ryono
Improbable Residents: The Sea Turtles of the San Gabriel River
A coyote forages along the river.  | © Pam Ryono
Improbable Residents: The Sea Turtles of the San Gabriel River
A sea turtle dives underwater in the San Gabriel River.  | © Hugh Ryono

<< Back

Your Comments

Have Something to Say? Leave a Comment!

MarineDepot's avatar

MarineDepot

Thursday, August 14, 2008 02:33 PM

What an awesome story! I had no idea these turtles were living in my own backyard. I will, as you say, stay tuned ...

Hugh's avatar

Hugh

Saturday, August 23, 2008 06:08 PM

Isn’t it amazing how adaptable wildlife can be.

Hugh

default avatar

Katmandu

Saturday, August 30, 2008 09:42 AM

I do stand up paddleboarding almost everyday either in Alamitos Bay or at Ray Bay which is near the mouth of the San Gabriel.  I have seen a sea turtle in Alamitos Bay about two weeks ago.  I was paddling near the Marine Bureau about 10:30 am, and I suddenly saw the sea turtle’s head near the tip of my paddleboard,  Then he/she took a breath, paused to stare, and then dove straight down with a couple of strong strokes of it’s flippers. 

A friend of mine who has surfed and dived at Seal Beach for many years has known about these sea turtles back in the 80s.  He new a marine biologist that has tagged them and were studied.  Apparently it has not been a rare pheomenon and unfortunately these sea turtles have been forgotten. 

I know the green sea turtles are on the endangered spieces list and I would be more than happy to assist in the project in any way. 

Sincerely,

VS

default avatar

shawnee

Saturday, August 30, 2008 10:13 AM

Darwin would be proud of this colony.

Hugh's avatar

Hugh

Wednesday, September 03, 2008 09:28 AM

The long times bikers I’ve talked to have said that they’ve seen these sea turtles for years as they rode along the river so I wouldn’t be surprised if this colony dates back to the 80s. Stay tuned to the Aquarium’s website for more info on the sea turtle project in the future.

Hugh

default avatar

Cindy

Tuesday, September 23, 2008 06:30 PM

Amazing what is found along the San Gabriel.  I’ve seen entire packs of coyotes, some racoons, a number of birds and now green sea turtles in the river.  I think this is great.  Anyone ever hear of the effort to restore Los Cerritos Wetlands? If not, that would be the area along the San Gabriel river bed around Studebaker Rd, Westminster/2nd Street and Seal Beach. I think to clean up the river and restore the surrounding wetlands would make a really great preserve and who knows what else just might appear there too!

default avatar

visitor

Monday, October 13, 2008 02:59 AM

I’ve seen the turtles in the river while surfing that spot, along with barracuda, sharks, rays and other assorted wildlife. San Gabriel rivermouth teems with ocean creatures…

default avatar

Barbara

Saturday, October 18, 2008 05:10 PM

I have lived on this river since 1984 and only now do I find out that there are green sea turtles! We have gone to Maui every year just to swim with the Honu and learn more about them. I am curious if they ever migrate out of their warm zone by the DWP and come to the open ocean.

Hugh's avatar

Hugh

Saturday, October 18, 2008 05:50 PM

Hi Cindy,

I think that cleaning up the river and wetlands is a great idea. Thanks for passing on the info.

Hugh

Hugh's avatar

Hugh

Saturday, October 18, 2008 05:57 PM

Hi Barbara,

Green sea turtle are occasionally seen in Alamitos Bay so some of them might be venturing out of the river at times. We hope to learn more about them in the coming months to try to answer questions like yours.

Hugh

default avatar

Paul

Thursday, October 23, 2008 06:36 PM

Hugh, My wife found your blog the other day. We had just come back from Maui, and could’t believe that Sea Turtles, lived in our back yard. We live on the river. That’s all the good news! The bad news is, I walk my dogs across the Marina bridge, every day. Today, Thursday 23rd, a fisherman had just hooked one of the Sea Turtles, that had just wandered down to the bridge. When he realized it was a Sea Turtle, he cut his line. I am writing to you, if there was anything possible, anyone could do. Thank you Paul

Hugh's avatar

Hugh

Sunday, November 02, 2008 10:08 PM

Hi Paul,

Thanks for letting us know about the turtle. We sent your information and concerns about the sea turtle to the folks at NOAA.

Hugh

default avatar

santaro36

Saturday, December 06, 2008 06:35 PM

I have heard that a sea turtle laid eggs somewhere on the sandy beach that lines the (new) inlet into the Bolsa Chica wetlands.

Hugh's avatar

Hugh

Thursday, December 11, 2008 06:39 AM

Thanks for the info. I’ll have to ask around about the sea turtle laying eggs on the beach at Bolsa.

Hugh

All blogs and comments represent the views of the individual authors and not necessarily those of the Aquarium.

<< Back