May 2014

Pez Maya, Mexico

Pez Maya Turtle Monitoring results presented at the

34th Annual Symposium on Sea Turtle Biology and Conservation.

Objectives

To protect, monitor, investigate and conserve the population of sea turtles that nest on the Central Coast of Quintana Roo.

To contribute to the recovery of species of sea turtle nesting on the coast of Quintana Roo supporting our local partners.

Summary

In 2013, a partnership between GVI, Flora, Fauna y Cultura de Mexico A.C. and Amigos de Sian

Ka’an was established, which resulted with conducting daily nocturnal patrols and the relocating of

nests if necessary in San Juan beach inside the Sian Ka’an Biosphere Reserve. In September,

GVI decided to participate in the 34th Annual Symposium on Sea Turtle Biology and Conservation

hosted by the International Sea Turtle Society (ISTS) in New Orleans. As a result, a poster titled

“18 years of management for the Green Turtle (Chelonia mydas) and Loggerhead Turtle

(Caretta caretta) in San Juan beach, Biosphere Reserve of Sian Ka’an, Quintana Roo,

Mexico” was presented in the Symposium.

Report

The marine turtle conservation program in Riviera Maya, Tulum, is conducted in the central coast

of Quintana Roo, Mexico, between Playa del Carmen and the Sian Ka’an Biosphere Reserve by

Flora, Fauna y Cultura de Mexico A.C. Currently, 13 nesting beaches are protected, covering 36

km of coast. These beaches represent the most important sites for nesting populations of the

loggerhead (Caretta caretta) and green turtle (Chelonia mydas), at national level1.

The breeding season for loggerheads is from April to September, showing the highest peak in

June, while the green turtle breeding season starts in May and finishes in October, peaking in

July2.

San Juan beach has been monitored by Flora, Fauna y Cultura de Mexico A.C. since 1996 during

the day time once every couple of weeks; since 2013, GVI Pez Maya team has been monitoring San Juan Beach during the night gathering new data on nesting females and more accurate results on the number of nests in the zone.

Study Area

The Sian Ka’an Biosphere Reserve has an area of 528,000 hectares, approximately 120,000 of

which is marine. The reserve is located in a partially emerged limestone plateau that gradually

slopes towards the sea, forming a gradient from dry to flooded sites 3. San Juan beach is located

within the reserve (N19°55'47.4, WO 87°26'16.0 - N 19°53'06.3, WO 87°25'48.1), with a length of

5 km. From the total nests recorded throughout the program, 5.1% of green turtle nests and 3.8%

of loggerhead nests were situated in San Juan.

Methodology

San Juan beach was divided into ten sections, only nine of which were effectively protected (4.5

km), each one of approximately 500 mts. Every time a nesting turtle was observed the following

information was collected: time, species, curve carapace length and width, scars and tags. If the

nest was located in areas vulnerable to inundation or to erosion, the nest was relocated in a safe

area.

Five categories, established by Eckert et al (2000)4 were used for the status of the nests:

predated, destroyed, inundated, unanalyzed, poached and protected.

Results

In the 18 years of survey in San Juan Beach, a total of 981 nests and 60,259 hatchlings were

recorded for loggerhead turtles, whereas 4,069 nests and 230,949 hatchlings were recorded for

the green turtles (graph 1).

a).

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Hatchlings and nests by year for the Loggerhead turtles

Hatchlings

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Graph 1. Number of hatchlings and nests for every year of survey in San Juan beach.

a) Loggerhead turtles b) Green turtles

According to the nest categories, it was observed that in the majority of the survey years there

was a higher percentage of protected nests. However, predation and poaching percentages were

relatively low for both species during all the survey years, none greater than 5% in the majority of

the cases (graph 2).

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Comparison of the nest categories for the Loggerhead turtle on San Juan Beach

Depredated Destroyed Inundated Unanalized Poached Protected Predated

b).

Graph 2. Classification of nests categories for every year of survey.

a) Loggerhead turtle b) Green turtle

Discussion

San Juan Beach is a highly dynamic area with a continually changing morphology, thus resulting

in nest inundation due to high tide levels and erosion. It was also noted that the years in which a

greater percentage of nests were inundated or could not be analyzed, the presence of natural

phenomena such as tropical storms and hurricanes were also recorded. This was more frequent in

the months of June to October, which corresponds with the nesting and hatchling season.

Conclusion

In conclusion, for the total of the survey years, more than 60% of the nests were protected and

40% were affected by different causes, mainly hurricanes and tropical storms. This represents a

great success of the nests in situ.

The Symposium

The symposium was held in New Orleans from the 12th to the 18th of April. The research was

presented in a poster to the different attendees (researchers and students), during two sessions

from 17:00 to 20:00 (Fig. 1 and 2).

On these sessions, GVI had the opportunity to explain and give more information about the turtle

conservation program carried on in Pez Maya, as well as to promote the volunteer program for the

turtle project.

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Comparison of the nest categories for the Green turtle on San

Juan Beach

Predated Destroyed Inundated Unanalized Poached Protected

Fig. 1. Poster presented in the Symposium.

Fig. 2. Marcela Rosero, head of science at Pez Maya presenting the poster.

This participation was a great achievement as 2013 was the first year that GVI Pez Maya started

with its turtle monitoring program, and from this research many recommendations for the future

years could be established.

After the conference, the poster was hung on Pez Maya, so volunteers and staffs have access to

the different information collected, as methodology, results, conclusions and recommendations.

This month the turtle monitoring program has begun with the daily night patrols and the main

objective is to make a comparison between the data obtained last year and this season, as well as

keeping improving the management of the nests on this specific beach.

To find out more about the turtle project in Pez Maya check out:

http://www.gvi.co.uk/programs/sea-turtle-conservation-mexico/

References 1. Zurita, J. C., Herrera R. y Prezas, B. 1993. Tortugas Marinas del Caribe En: Biodiversidad

Marina y Costera de México. Ed. Salazar-Vallejo, S. I. y N. E. González, Com. Nal. Biodiversidad y CIQRO, México. pp. 735-751

2. Flora, Fauna y Cultura de México (FFCM), A.C. 2008. “Reporte del Programa de Protección y Conservación de Tortugas Marinas en el Litoral Central del Estado de Quintana Roo. Temporada 2007”. 47pp.

3. Instituto Nacional de Ecología. 1996. Programa de Manejo 3. Áreas Naturales Protegidas: Reserva de la Biósfera Sian Ka’an. SEMARNAP. México, D.F. 73 p.

4. Eckert, K. L., K. A. Bjorndal, F. A. Abreu-Grobois y M. Donnelly (Editores). 2000 (Traducción al español). Técnicas de Investigación y Manejo para la Conservación de las Tortugas Marinas. Grupo Especialista en Tortugas Marinas UICN/CSE Publicación No. 4.