Hostname: page-component-89b8bd64d-4ws75 Total loading time: 0 Render date: 2026-05-08T22:15:55.289Z Has data issue: false hasContentIssue false

Status and community-based conservation of marine turtles in the northern Querimbas Islands (Mozambique)

Published online by Cambridge University Press:  16 July 2012

Julie Garnier*
Affiliation:
The Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
Nicholas Hill
Affiliation:
The Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
Almeida Guissamulo
Affiliation:
Natural History Museum, Maputo, Mozambique
Isabel Silva
Affiliation:
Unilúrio University, Cabo Delgado, Mozambique
Matthew Witt
Affiliation:
Marine Turtle Research Group, Centre for Ecology and Conservation, School of Biosciences, University of Exeter, UK
Brendan Godley
Affiliation:
Marine Turtle Research Group, Centre for Ecology and Conservation, School of Biosciences, University of Exeter, UK
*
(Corresponding author)E-mail juliegarnier@hotmail.com
Rights & Permissions [Opens in a new window]

Abstract

Situated in the northernmost part of Mozambique, the northern Querimbas Islands support some of the most diverse and pristine coral reefs in the Western Indian Ocean. The community-based turtle conservation programme that we developed on Vamizi Island has facilitated the identification and protection of a key nesting site for the green marine turtle Chelonia mydas in Mozambique, with a mean of 122 nests per year. The area is also used by nesting female and immature hawksbill turtles Eretmochelys imbricata. Nesting activity of green turtles was observed all year round, with a peak in the summer (February–March). Incubation periods of this species showed seasonal fluctuations inversely correlated with air temperature. Hatching success was high (87%) when nests were not lost through tidal overwash and erosion, which affected nearly 40% of all nests in 2007. Using satellite tracking of four green turtles nesting on Vamizi we identified foraging grounds in marine protected areas in Kenya, Tanzania and north-west Madagascar. Migratory routes of two individuals along the East African coast were generally neritic and all passed through the waters of multiple nations and as many as six marine conservation areas, emphasizing the importance of regional cooperation. Awareness programmes were also conducted with resource users, and the development of a community-based management system triggered the creation of a marine sanctuary by the local community.

Information

Type
Conservation of Marine Turtles
Copyright
Copyright © Fauna & Flora International 2012
Figure 0

Fig. 1 The location of Vamizi Island in the Querimbas archipelago off the coast of Mozambique. The inset shows the location of the main map.

Figure 1

Table 1 Months of night-time monitoring, number of adult female green turtle Chelonia mydas tagged, number of clutches laid by tagged females, observed clutch frequency and estimated mean clutch frequency±SD on Vamizi Island in the Querimbas archipelago off the coast of Mozambique (Fig. 1).

Figure 2

Fig. 2 (a) Monthly air temperature (maximum, mean, and minimum) and rainfall in Cabo Delgado. (b) nesting activity (mean±SD) and (c) monthly incubation period (mean±SD) of green turtles nesting on Vamizi Island (Fig. 1) between October 2003 and September 2007. Incubation periods were categorized according to the date when the nest was laid.

Figure 3

Fig. 3 Frequency of inter-nesting intervals of green turtles Chelonia mydas on Vamizi Island beween April 2004 and May 2007.

Figure 4

Fig. 4 Frequency of percentage hatching success of green turtle nests (those that could be excavated; n=371) between March 2004 and June 2007.

Figure 5

Fig. 5 Monthly percentage of green turtle nests that were flooded (n=96) on Vamizi in 2006 and 2007. A nest was considered to be flooded when it had been completely overwashed.

Figure 6

Fig. 6 Migration routes of four tagged adult female green turtles (V1, V2, V3, V4) between their nesting ground on Vamizi Island and their foraging grounds. Circles are the end points of the tracking data (Table 2).

Figure 7

Table 2 Characteristics of post-breeding migrations of four adult green turtles (V1, V2, V3, V4; Fig. 6) fitted with satellite transmitters on Vamizi Island, with date of tagging, date migration began, type of migration route, location of foraging ground, minimum distance travelled, distance travelled to the breeding/foraging ground, duration of migration, and number of days tracked in the foraging ground and overall.