Calculating Population Size Of The Hawksbill Sea Turtle At The Bastimento Island

INTRODUCCION

• Turtles in Panama

Sea turtles date back to a pre-historic age. At one time, most Caribbean beaches were home to at least one species of sea turtle. Of the seven remaining species, four of these, from the largest to the smallest, nest on Panama beaches: the leatherback (Dermochelys coriacea), green turtle (Chelonia mydas), the hawksbill (Eretmochelys imbricata) and theolive ridley (Lepidochelys olivacea). All are considered endangered or critically endangered. 

The hawksbill has always been common here and the Bocas del Toro coast has been one of the most important nesting grounds for this species in the western hemisphere. 40 years ago hawksbill turtles were aplenty in the waters off Panama, but today there are many fewer. Green turtles, which feed on offshoresea grass fields, were also much more common in the past.

The two turtle species you are least likely to see in Panama are the Eastern Pacific green turtle, also called the black sea turtle, and the loggerhead turtle. Both are considered endangered. 

Turtle eggs have been harvested in excess and turtles have been killed for meat and their shell. No figure exists of the maximum size ofturtle population in the past, so researching has been the first step in developing conservation plans.

Between two thousand and three thousand turtles nest in Panama. The Inter-American Convention for the Protection and Preservation of Sea Turtles is the world's only international agreement designed to protect these species and their habitat. In January of 2008, Panama became the twelfth country tosign the agreement.

• The Hawksbill sea turtle

Is a critically endangered sea turtle belonging to the family Cheloniidae. The hawksbill's appearance is similar to that of other marine turtles. It has a generally flattened body shape, a protective carapace, and flipper-like arms, adapted for swimming in the open ocean. E. imbricata is easily distinguished from other sea turtles by itssharp, curving beak with prominent tomium, and the saw-like appearance of its shell margins. Hawksbill shells slightly change colors, depending on water temperature. Adult hawksbill sea turtles have been known to grow up to 1 meter (3 ft) in length, weighing around 80 kilograms (176 lb) on average.

Adult hawksbill sea turtles are primarily found in tropical coral reefs. They are usually seenresting in caves and ledges in and around these reefs throughout the day. While little is known about the habitat preferences of early-life stage E. imbricata, like other sea turtles' young, they are assumed to be completely pelagic, remaining at sea until they mature.

During the mating season between the months of May and September mating can be observes on isolated beaches. The beaches ofBastimentos and Zapatilla Cay are the beaches the Hawksbill turtles use for nesting. Between September and March you can often spot the baby turtles swimming among the underwater plants.

• Objectives

1. To understand the principles of the mark-and-recapture.

2. To describe and predict sources of bias in a population estimates based on marl-and-recapture methodology.

• Methods

Placeof study: Bastimentos Island

 Is an island with eponymous town, and corregimiento located in the Bocas del Toro District and archipelage of Bocas del Toro Province, Panama. The island is about 20 square miles (52 km2), one of the largest in Panama.

Isla Bastimentos National Marine Park encompasses a large portion of Bastimentos Island, Zapatilla Cays, in addition to the waters and mangrovesthat surround the island. The western tip of the island, better known as Bastimentos, is clearly visible from Bocas town, and is not part of the National Park itself.

Method: Mark-and-Recapture

Is a method commonly used in ecology to estimate population size. This method is most valuable when a researcher fails to detect all individuals present within a population of interest every time...