Ambergris Caye Marine Turtle Program

Loggerhead Turtle Hatchling
Loggerhead Turtle Hatchling

Sea turtles are increasingly characterized as keystone species in maintaining and structuring seagrass and coral reef communities. Although their importance to the ecosystem has been recognized and well documented their population is still under threat from both anthropogenic and natural sources. Their nesting habits is of prime concern since it is in conflict with human activities. Turtle nesting beaches are prime real estate for tourism development.

The Ambergris Caye Marine Turtle program is an initiative to document and quantify nesting behavior on the beaches of Ambergris Caye, Northern Belize. This project has consistently compiled 5 years of data on sea turtle nesting activities on the island.

Field Data Collection of Nesting Activity at Robles Beach
Field Data Collection of Nesting Activity at Robles Beach

A total of 77 nests were found throughout Ambergris Caye in 2014 and all were found on sandy beach ridges on the windward side of the Island. Nesting is concentrated on the northern beaches of Robles and Rocky Point. Robles Beach is approximately, 1000 meters long with the southern 200 meters having rocky intervals. Rocky Point is a smaller Beach approximately 100 meters in length.

Nesting Results 2014: In 2014 there was a 20%  decrease in the total number of nests when compared to the previous year. Rocky point had 21 nests, Robles Beach 49, Basil Jones 6 and one was recorded on WataView Resort on South Ambergris Caye.

Total Nesting Over Time (2009-20014)
Total Nesting Over Time (2009-20014)

Both, in Rocky Point and Robles beach we recorded a decrease in nests compared to the previous year with 20% and 30% decrease respectively. Basil Jones recorded an increase in nesting activity of 50%.

The nesting season starts in late May and the last nesting female came on the first of October. However, due to the incubation period the last hatchlings emerged on the 20th of November. Generally, Loggerheads nest from May to August and Green turtles form July to October.

Collecting Hatching Success Data from Nest
Collecting Hatching Success Data from Nest

Hatchling Report: A total of 8267 eggs were recorded from the 77 clutches laid this year. This represents a 16% reduction from last year. Of this, 61% were recorded as “Emergent Success” which were able to make it out of the nest successfully. “Hatchling Success” was recorded as 67% which includes all “Emergent Success” plus stragglers that could not make it out of the nest but hatched and were found alive in the nest. Stragglers were released into the ocean immediately or were kept in containers if they are too weak; but were released as soon as they recovered. Overall, average clutch size for 2014 was107 eggs per nest.

Nesting by Species: Loggerhead and green turtles have shown a consistent annual nesting fidelity to the beaches of Ambergris Caye. In 2012 and 2013 Hawksbill turtle nests were recorded but none nested in 2014.

Spatial Distribution of Sea Turtle Nesting in Ambergris Caye
Spatial Distribution of Sea Turtle Nesting in Ambergris Caye

Loggerhead turtles arrive early in the year to nest. The first crawl was observed on the 20th of May at Robles Point. Loggerhead turtles nests from May to August. Nesting peaked in June with 29 nests for that month. A total of 51 loggerhead nests were observed in 2014. There were 39 nests in Robles beach, 5 in Rocky Point, 6 in Basil Jones and one in south Ambergris Caye. There was an increase in nesting at Robles Beach (13%) and at Basil Jones (50%). The increase in Basil Jones may be due to the relationship with home owners at this location. Most walk the beach daily and notify us of any crawl they observe. There was a decrease in the number of nests at Rocky Point (50%).

The first Green Turtle nest was observed on the 3rd of July at the Rocky Point Beach. The last female turtle nested on the 1st October. Rocky point seems to be the preferred nesting beach for Green Turtles since 14 of the 24 nests were observed here. At Robles Beach we found a total of 10 nests. There was a decrease in Green Turtle nesting activity in Robles and Rocky Point Beach. A drastic decrease of 62% was observed at Robles Point and 33% in Rocky Point.

Turtle Nesting Beach at Rocky Point
Turtle Nesting Beach at Rocky Point

This year there was a significant decrease in the number of nests observed. We recorded an overall decrease at both Robles and Rocky Point Beach. The greatest change was observed with poor nesting activity of Green Turtles. Only 24 nests were recorded in 2014. The largest change was observed at Robles beach with a 62% reduction in Green Turtle nesting activity. In contrast, Loggerhead Turtles show an increase in nesting activity overall and higher nest counts at Robles and Basil Jones.

 

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