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We monitored a total of 2.9 km of nesting beach. We extended the total monitored area 700 m northwards (Ponta de Capina) and 400 m southwards (Praia do Bessa), relative to the 2001-2002 nesting season (Mascarenhas et al. 2003). The nesting season in 2002- 2003 began on December 19 and ended May 14, for a total of 146 days. Fifty-seven crawls were observed during the nesting season, of which 56 were confirmed nests. The majority of clutches (76.8%) were laid in the southern half of the monitored area. Four clutches were poached. Of the other 52, 37 were left in situ, 14 were transplanted to a hatchery and one was relocated to a position higher up the beach. A total of 7,830 eggs were laid, with a mean clutch size of 150.6 eggs. A total of 6,246 live hatchlings were produced from all 52 nests, for an overall hatching success of 79.8% (range: 1.3-98.1%). The success rates for nests left in situ was higher than those relocated to the hatchery (Table 1). Besides the influence of the handling techniques, the amount of rainfall may have had an impact on incubation success. Most of the transplanted nests were laid between December and January, the hottest and driest part of the summer when success rates for in situ nests were also lowest the for the season (Fig. 1).

Outside of the regular patrol areas, we encountered 7 additional hawksbill nests that were also monitored during incubation. They had an average hatching success of 57.1% (range: 19.5-86.8%). Altogether in 2002-2003, a total of 63 nests successfully produced 6,800 hatchlings that were eventually released to the sea. This is greater than the 4,615 hawksbill hatchlings produced from 47 nests that reached the end of incubation in 2001-2002 (Mascarenhas et al. 2003).

Light pollution is a serious problem for sea turtles in the study area. There are streetlights, each composed of four incandescent bulbs, located at 45 m intervals along the beachfront, in addition to the other lights from residential properties along the seashore. During the 2001-2002 nesting season, all nests emerged at night and the hatchlings were kept in dry boxes to be released the following morning, to avoid the misorienting effects of artificial lights present on the beach at night (Mascarenhas et al. 2003). However, we were concerned that hatchlings that had emerged during the night but were not released until morning might have been negatively impacted, possibly through the needless expenditure of energy while waiting in the boxes (Nicholas 2001). Indeed, many of the hatchlings from the 2001-2002 season appeared lethargic when released. Therefore, in the 2002-2003 nesting season, we tried an alternative approach to the problem of artificial lights.

When possible, we divided nests into two groups: the first group (n=32) were those that were allowed to emerge at night and were kept in boxes until morning to be released to the sea, and the second group (n=31) were those removed from the nests prior to natural emergence and immediately released to the sea. For the second group, we checked each nest in the morning around the time we expected emergence to occur. If the hatchlings were within 15 cm of the surface of the sand, we removed them from the nest and released them on the beach to crawl to the sea. We measured the amount of time required by the two different groups of hatchlings to reach the sea after being released 3 meters from the current water line. Overall, hatchlings that emerged naturally but were kept in a box overnight required on average 36.3 minutes (n=32 nests) to reach the sea, while those hatchlings that were removed from their nests early and immediately released required only 6.6 minutes (n=31 nests) on average to reach the sea. We suggest that holding turtles overnight after emergence may negatively affect their ability to move to the sea and may impact their post-emergence frenzy.

Table 1. Hawksbill hatchling production from nests laid during the 2002-2003 breeding season, expressed as percentages for each category. Numbers in parentheses are total number of eggs for each category. Note that 4 additional nests were poached soon after laying, and 7 nests were laid outside the area regularly monitored (data not included).

There are campaigns, legislation and methods to prevent and solve the light-pollution problems on nesting beaches (Witherington & Martin 1996). In Brazil, IBAMA (the National Environmental Agency) has established some laws to protect recognized nesting beaches. In our study area, the current environmental laws are not enough to protect the complete process of reproduction. There is intense urbanisation along the seashore, and illumination from public and private developments is impossible to avoid for the time being. As a first attempt to minimize the negative anthropogenic influences on the turtle population in Paraíba, we are experimenting with alternative approaches to the field work, in the hope that we can one day eliminate artificial illumination of the nesting areas.

Figure 1. Pluviometric changes and hatching success through the nesting season.

Acknowledgements: We are indebted to Valdi Moreira Silva, Adailton Gaudino, Marilene Nobre, Pedro Athayde, Luis Eduardo Pontes, Caio Graco Zeppelini, Beatriz Pereira, Louisa Ma. de Andrade e Souza, Cícero Machado da Silva and Francisca Maria Lemos for their volunteer work and support in the field work. We thank the editors and the two anonymous referees for their relevant suggestions and criticism.

MARCOVALDI, M.Â. & G.G.. MARCOVALDI. 1999. Marine turtles of Brazil: the history and structure of Projeto TAMAR-IBAMA. Biological Conservation 91:35-41.

MASCARENHAS, R.D. ZEPPELINI & V.S. MOREIRA. 2003. Observations on Sea Turtles in the State of Paraíba, Brazil. Marine Turtle Newsletter 101:18-20.

NICHOLAS, M. 2001. Light pollution and marine turtle hatchlings: the straw that breaks the camel’s back? George Wright Forum 18:77-82.