Home How TAMAR works




MARINE TURTLES CONSERVATION,
MANAGEMENT AND RESEARCH


1. Nesting Areas

In the nesting period - from September to March along the coast, and from January to June on the oceanic islands - the nesting areas are patrolled, every early morning, by the biologists and fishermen hired by TAMAR. Using internationally accepted techniques of conservation and control, biologists tag the females that come ashore, identifying the animal with an individual number and an inscription bearing TAMAR's address and a request for notification of when and where that turtle was found. This enables the TAMAR Program to study the nesting behavior, the migration routes, and monitor the turtle population. It can be also learnt how many times an adult female returns to the beach for nesting within a single reproduction period, at what intervals, the place chosen, and the period between nesting. Biometrical analysis, measuring the length and width of the shells, is also performed for each species.


During early morning patrols, fishermen locate the nests following the tracks left on the sand by the turtles. Those in places of risk for the survival of hatchlings are transferred to more protected sites or to open-air beach hatcheries in TAMAR stations, where normal conditions for egg incubation are reproduced. Eggs are protected from predatory action, or floods and tides, thus enabling appropriate management.


Today, as a result of the work of environmental education developed by TAMAR among the communities, most nests are no longer violated, nor are eggs collected to serve as food. In this fashion, they no longer need to be transferred as often as in the past. They lie in their places of origin, where the TAMAR research team analyzes the incubation conditions. We know, for example, that the sex of turtles is not defined at fecundation. The temperature of the sand is a decisive influence: average higher temperatures trigger the birth of females; lower temperatures, males. For this reason, it is ideal to maintain the greatest number of natural nests possible on the beach.


When hatchlings finally reach the surface, they are counted, identified, and set free to go on towards the sea. New threats face them on their way, such as the action of predatory animals and artificial lighting. Since hatchlings have positive phototropism, instead of crawling towards the sea, drawn by the glow of the horizon, they are, instead, attracted by the artificial light. They are run over, or die of sunstroke, or are killed by predators. The definition of priorities and the methodology employed respect the regional characteristics and the different sets of local circumstances. But in general activities follow one pattern nationwide. In each breeding season, approximately eight thousand nests are protected, enabling about 350 thousand hatchlings of the five species of sea turtle found in Brazil to be released.


2. Feeding Grounds

On marine turtles feeding grounds Tamar biologists and fishermen work patrolling fishing nets and other fishing devices in search of accidentally caught turtles. Once they are found, the animals are recovered by CPR - when possible, tagged and measured, all in order to study population biology, migration routes and growth patterns. Intending to alert the fishermen about how to save drowned turtles, Tamar also hangs educative plastic banners in the fishing devices and organizes environmental education speeches and talks.