green turtles in the eparse islands: population status based on 20 years trend of daily track counts...
TRANSCRIPT
GREEN TURTLES IN THE EPARSE ISLANDS: POPULATION
STATUS BASED ON 20 YEARS TREND OF DAILY TRACK COUNTS
29th Annual Symposium on Sea Turtle Biologie & Conservation Brisbane, 17 – 19 February 2009
Jérôme Bourjea, Cyril Marmoex, Marie Lauret-Stepler and Stéphane Ciccione
THE 5 FRENCH EPARSE ISLANDS IN THE SWIO
GLORIEUSES
TROMELIN
JUAN DE NOVAEUROPA
BASSAS DE INDIA
STUDY SITES
DAILY GREEN TURTLE TRACK COUNTS
1987 – 2006
Tot. nesting females: 2000 to 4000 /yr
1987 – 2006
Tot. nesting females: 1000 to 3000 /yr
1984 – 2006
Tot. nesting females: 7000 to 10 000 / yr
TREND: SMOOTHING SPLINE ANOVA MODEL
Annual linear growth rate: 2 [1.7 – 2.7]
Annual linear growth rate: 3.5 [3.4 – 3.6]
Annual linear growth rate: - 1.6 [-1.8 – -1.3]
SEASONALITY PATTERN (Mean tracks per month over the period)
0
500
1000
1500
2000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
months
Mea
n T
ota
l Nu
mb
er o
f
Tra
cks
0
50
100
150
200
250
300
350
400
450
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
months
Mea
n T
ota
l Nu
mb
er o
f T
rack
s
0
50
100
150
200
250
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
months
Mea
n T
ota
l Nu
mb
er o
f T
rack
s
MAIN NESTING GREEN TURTLE POPULATION STATUS IN THE SWIO
Moheli : 4000 – 6000 (20%)
Glorieuses : 2000 – 4000 (3.5%)
Tromelin : 1000 – 3000 (-1.6%)
Mayotte : 2000 – 4000 (1%)
La Réunion : 2 +/- 1 (200%!!! )
Europa : 7000 – 10 000 (2%)
THANK YOU!