photos from MB Kircher

Sea Turtles of Bahia de los Angeles

Have you ever thought that you might like to be on one of those National Geographic Explorer Specials?  What about Survivor or perhaps The Crocodile Hunter?  The experience I just had on the Earthwatch Expedition: Black Sea Turtles of Baja was all three rolled into one. I am Mary Beth Kircher, a high school biology teacher at The Bryn Mawr School in Baltimore, Maryland.  This is the documentation of my first-ever true life adventure!

Through grants from the Klingenstein Fund, The Bryn Mawr School and the Clowes Foundation, I was able to travel to San Diego, California to meet up with Team II of the Black Sea Turtle Expedition to travel still further south and spend two weeks in Baja Mexico working on research concerning this endangered turtle.

Through the pages of this website, I will tell you about the research, the turtles and the Earthwatch team I was lucky enough to be involved with.  There are several additional internet resources that will  be linked,  particularly for teachers and students working on projects related to sea turtles.

The Research

Prior to leaving on the trip, I received a briefing prepared by the PIs (primary investigators) Jeffrey Seminoff, Ph.D. and T. Todd Jones. This is a portion of the Abstract:

The purpose of this research is to learn the in-water ecology of the black turtle ( also known as the East Pacific green turtle) Chelonia mydas agassizii, in the Gulf of California and provide information that will facilitate the conservation of this endangered species.  Building off the first six years of this project, our goals are to determine diving behavior, habitat use, digestive efficiency, trophic status, and daily energetic expenditures of this species. With the help of Earthwatch team members, we will base our efforts in Bahia de los Angeles, an important feeding and development are for these turtles.  In addition, 2002 will mark the second season of an Earthwatch environmental education program for children in the nearby community of Bahia de Los Angeles.

This research is a bi-national collaborative study that integrates both U.S. and Mexican biologists and draws from the extensive knowledge and skills of local fishermen to compile historical and biological information.  The data will be serving  as a base-line for the black turtle population status in the proposed National Marine Park in Bahia de los Angeles.

More information on the research can be found at:    http://http://tucsonherpsociety.org/feature1.html

Black sea turtle on the right in one of the tanks at Camp Archelon in Bahia de los Angeles.   Photo from MB Kircher.

Research methods used during team II, 2002:

Turtle capture - entanglement nets are set and checked approximately every two hours.  The nets are designed with  large mesh and captured turtles can rise to the surface to breath unlike those captured in most fishing nets which leads to drowning. When a turtle is caught in a the net, the 3 to 4 member group will pull the turtle into the boat and untangle it.  The turtles are rarely docile about being captured and they will bite! A damp hood is placed over their head to help keep them calm.  Once the boat returns to camp, 4 team members, one for each flipper, will carry the turtle to shore and it will be transported to a holding tank.

A variety of measurements will be recorded as well as carapace (top) and plastron (bottom) colors, measurements and description of any shell variations and epibionts like barnacles.  A skin sample is collected to compare DNA with DNA records for known nesting sites and then the turtle is tagged on the rear flippers.  This will allow for identification in case of recapture in the future. Some of the turtles will be fitted with a TDR - timed-depth recorder  upon release and will be monitored by sonar and radio for two to three days.

This turtle is being released with a TDR to track its movements and diving behavior for 2 to 3 days.   

   Photo from MB Kircher.

Digestive Study -  Some of the turtles in the tanks at Camp Archelon  remain in the tanks for an extended period of time. (these are not the turtles captured by the Earthwatch team)  These turtles are available for digestive studies.  Prior studies have already determined that the major food source for the black turtle is a red algae, gracilaria.  Our team helped monitor the quantity of gracilaria eaten by two different turtles on a daily basis.  The turtles were also being fed plastic flagging dietary markers to calculate the time it takes for digestion.

Turtle tank cleaning and obtaining a skin sample were routine activities for Team II.         Photos from Henry Marr.

Environmental Education- Alexa McDermott from the University of Kansas led an environmental education program for school age children in the nearby town of Bahia de los Angeles. The children were engaged in activities that allowed them to learn not only about the black sea turtles but about the variety of marine animals in their nearby bay and the value of conservation.

Alexa and two "early birds" waiting for the class to begin.                 Photo from MB Kircher.

The Turtles

(from the Earthwatch briefing) The black turtle is listed as endangered throughout its range.  The turtle has experienced drastic declines over the last 30 years due to illegal harvest of eggs and adults and incidental drowning in commercial fisheries.  Beginning in 1979 on-the-ground conservation started in the form of nesting beach protection at the primary nesting areas in Michoacan, Mexico (Alvarado and Figuero 1987) Conservation efforts away from nesting areas have been limited and efforts to prevent further declines have been hampered by a lack of knowledge concerning the turtles' foraging areas.

In Bahia de los Angeles the turtle fishery was particularly active. 186.47 tons of sea turtles were caught during 1962.  By the early 1980s, this population had crashed. (Marquez 1984) In 1982 only 11 tons of sea turtles were fished from Bahia de los Angeles, a 96% drop in catch rate. (Marquez 1984)

Today, black turtles migrating from southern nesting beaches are incidentally captured in the offshore drift-net and long-line fisheries and upon entering near shore development and feeding areas are subject to illegal poaching and incidental capture in local trawl and set-net fisheries.  Jay Nichols (2001) estimates that between 5,000 and 7,000 black turtles die annually in this region.

Adaptations -

Sea turtles have many adaptations that allow them to survive successfully in a marine environment.  All marine animals must have some way to deal with their saline surroundings and the turtle achieves balanced internal salinity through the use of specialized lachrymal glands near their eyes.  These glands consolidate salt from the body and excretes it from the eyes. This leads some people to think that the turtle is "crying" when it is on land.

"crying" turtle drawn by Michael E. on the site http://www.turtles.org

Unlike land turtles, sea turtles have nonretractile head and limbs. Their limbs are strong flippers with fused digits within that you can feel through the leathery skin.  These flippers extend from very strong "shoulder" muscles that allow the turtles to swim as if they were flying through the water.

Sea turtles have upper eyelids but no external ear openings and no teeth.  Their jaws are strong and they can give a nasty bite.

All turtles are ectothermic and with such a slow metabolic rate, the sea turtles can go as long as hours without coming up for oxygen.  They can slow their heartbeat to conserve oxygen and they have high quantities of myoglobin, an oxygen storing molecule, in their muscles.

Photo from Henry Marr                                        Photo from MB Kircher

Male and female sea turtles have few external differences until they become sexually mature.  At that time the male can be differentiated due to its longer tail and visible "claws" on the front flippers for mating purposed.

For more information on sea turtle adaptations and information, I recommend:

 http://www.seaworld.org/infobooks/SeaTurtle/stphysical.htm

Another site where students can Ask A Scientist about sea turtles, as well as other reptiles and birds is:

http://oceanlink.island.net/ask/repsnbirds.html

The Earthwatch Team

The Earthwatch Institute promotes sustainable conservation of our natural resources and cultural heritage by creating partnerships between scientists, the general public, educators and businesses.

As an educator I was eligible to apply for an Education Grant as mentioned above.  I encourage all educators who wish to have an energizing field experience to share with their students to apply with the Earthwatch Education Department.

Even if you aren't an educator, there are many reasons to choose an Earthwatch expedition for your next "vacation".  Check out their website at http://www.earthwatch.org for a variety of trips all over the world.

I was on Team II of the Sea Turtles of Baja.  Prior to leaving on the trip I received an extensive briefing packet from the PIs.  But as everyone knows, reading something does not always come close to preparing you for the actuality.

There were seven volunteers on this team and we met up with nine staff members in Camp Archelon.  Two of the staff,  Todd, the PI  and Travis met us at the hotel in San Diego for our ride south to the camp.

Our mode of transportation was known as the Mother Ship.  She got us there after frequent stops for water refills for the bus and squatting among the cactuses for us. It took 14 hours to reach camp.

From left to right - Flora, Joy, Kara, Henry, MB, Xavier and Karen

The scenery along the way was preparing me for an area that was to be completely different from anything I had ever encountered. (living in Maryland, USA, I am used to trees and much green plant growth)  We traveled for hours over mountainous deserts and at day's end we came to the Sea of Cortez and Camp Archelon.

Photo from Henry Marr                                                                            Photo from MB Kircher

For the next 14 days we adjusted to hot, dry conditions that none of us were used to.  The staff encouraged us to drink continually and we were required to carry water bottles everywhere we went.  There were times when the temperature exceeded 107 in the shade (that was high even for Bahia) and when the wind blew from the west, off the desert, it felt just like a hair dryer blowing full force.

We stayed in palapas along the water's edge.  At night, it was common to pull the cot out under the stars to sleep to keep cooler. The stars were magnificent from that vantage as well.

Photo from Henry Marr                Our beach palapas.

                                                                                                Photo from MB Kircher  

Regular camp duties were shared by all.  These included cleaning common areas, cooking breakfast, cleaning turtle tanks, collecting gracilaria to feed captive turtles and cleaning and untangling nets.

Net cleaning.                                                                The water "buffalo".

Research work included setting nets and checking them approximately every two hours.  This included night net checks that involved sleeping for a couple of hours at a time out under the stars with a group of 4 other staff or volunteers.  When a turtle was found in a net and brought in then camp became quite busy.  The captured turtle needed to be measured and tagged.

Todd, Xavier, Sergio and MB carrying a turtle to the tank.                   Photo from Henry Marr

Lucy, Joy, Karen and Kara measuring.                     Photos from MB Kircher

Trips to town were valued because of the possibility of  buying a cold drink or chocolate and having the opportunity to e-mail a message home.

Monitoring the nets continued even when a turtle had been caught and it was not unusual to have two or more turtles being processed at the same time.  When the turtles had been documented and tagged, they may have a TDR attached to the carapace and released.  The TDR allows for the movements of the turtle to be monitored by sonar while it is under water and by radio when it comes to the surface.  Once a turtle is released, then team members take turns tracking.

Photo from MB Kircher                           Photo from Henry Marr

While on the boats tracking or when checking nets, it was always a plus when there was other sea life to observe.  Members of our team saw fins whale mothers and calves, whale sharks, sea lions, frigate birds, blue footed boobie and brown boobies.

Sea lions        Photo from Henry Marr                        Fin whale           Photo from MB Kircher

When we weren't cleaning tanks or collecting gracilaria, cleaning bathrooms or washing dishes, measuring turtles or tracking them, there was some relaxation time with a variety of ways to spend it:

Resting!                        Card playing.

Photos from Henry Marr

                     Enjoying the morning sunrise.

Team II, 2002 - front, Todd, X-man, Flora, back, Sonia, JT, Sergio, Travis, Joy, Lucy, Henry, Kara, Alexa, Torey, MB and Karen. Liza is not in the picture.

What a group. We gathered a lot of valuable data, learned a tremendous amount in 14 days and made friends with members of our team as well as within the Bahia de los Angeles community.  It was an experience I would highly recommend.  Thank you for sharing it with me by getting this far on the web page!!

If you would like to see more of Henry Marr's pictures, you can check them out at http://www.geocities.com/baja_turtles