Limits...
Solomon Islands largest hawksbill turtle rookery shows signs of recovery after 150 years of excessive exploitation.

Hamilton RJ, Bird T, Gereniu C, Pita J, Ramohia PC, Walter R, Goerlich C, Limpus C - PLoS ONE (2015)

Bottom Line: Our results and the results of others, reveal that many of the hawksbill turtles that nest at the ACMCA forage in distant Australian waters, and that nesting on the Arnavons occurs throughout the year with peak nesting activity coinciding with the austral winter.Our results also provide the first known evidence of recovery for a western pacific hawksbill rookery, with the number of nests laid at the ACMCA and the remigration rates of turtles doubling since the establishment of the ACMCA in 1995.The Arnavons case study provides an example of how changes in policy, inclusive community-based management and long term commitment can turn the tide for one of the most charismatic and endangered species on our planet.

View Article: PubMed Central - PubMed

Affiliation: The Nature Conservancy, Asia Pacific Division, 245 Riverside Drive, West End, Brisbane, QLD, 4101, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.

ABSTRACT
The largest rookery for hawksbill turtles in the oceanic South Pacific is the Arnavon Islands, which are located in the Manning Strait between Isabel and Choiseul Province, Solomon Islands. The history of this rookery is one of overexploitation, conflict and violence. Throughout the 1800s Roviana headhunters from New Georgia repeatedly raided the Manning Strait to collect hawksbill shell which they traded with European whalers. By the 1970s the Arnavons hawksbill population was in severe decline and the national government intervened, declaring the Arnavons a sanctuary in 1976. But this government led initiative was short lived, with traditional owners burning down the government infrastructure and resuming intensive harvesting in 1982. In 1991 routine beach monitoring and turtle tagging commenced at the Arnavons along with extensive community consultations regarding the islands' future, and in 1995 the Arnavon Community Marine Conservation Area (ACMCA) was established. Around the same time national legislation banning the sale of all turtle products was passed. This paper represents the first analysis of data from 4536 beach surveys and 845 individual turtle tagging histories obtained from the Arnavons between 1991-2012. Our results and the results of others, reveal that many of the hawksbill turtles that nest at the ACMCA forage in distant Australian waters, and that nesting on the Arnavons occurs throughout the year with peak nesting activity coinciding with the austral winter. Our results also provide the first known evidence of recovery for a western pacific hawksbill rookery, with the number of nests laid at the ACMCA and the remigration rates of turtles doubling since the establishment of the ACMCA in 1995. The Arnavons case study provides an example of how changes in policy, inclusive community-based management and long term commitment can turn the tide for one of the most charismatic and endangered species on our planet.

No MeSH data available.


Related in: MedlinePlus

Mean remigration period for cohorts of turtles in the years between 1991 and 2007.Blue line indicates predicted values for a poisson regression of migration period against years since 1991. Grey area indicates 95% confidence intervals around the regression line. The slop of the regression line indicates a reduction in the remigration interval by 0.5/yr.
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pone.0121435.g006: Mean remigration period for cohorts of turtles in the years between 1991 and 2007.Blue line indicates predicted values for a poisson regression of migration period against years since 1991. Grey area indicates 95% confidence intervals around the regression line. The slop of the regression line indicates a reduction in the remigration interval by 0.5/yr.

Mentions: The mean proportion of turtles from the pre protection era (1991–1995) that remigrated within a 12 year window was 0.067 (SE = 0.027). The mean proportion of turtles in the post protection era (1996–2000) that remigrated within a 12 year window was twice as high; 0.137 (SE 0.021). The mean remigration interval for the breeding season’s cohorts that were followed for at least 12 years beyond their initial year of tagging is shown in Fig. 6. There were significant differences among the mean remigration intervals for these years cohorts (t-test, P = 0.011). A poisson regression of remigration interval against cohort year showed a significant decline in the average remigration interval by 5.8 [3.9, 7.2] years over the 10 years between 1991–2001 (p = 0.002, Fig. 6). During the 21 years for potential recapture no hawksbills were recorded nesting with a one year remigration interval, two year remigration intervals were rare, but increased in frequency in the later cohorts (Table 2).


Solomon Islands largest hawksbill turtle rookery shows signs of recovery after 150 years of excessive exploitation.

Hamilton RJ, Bird T, Gereniu C, Pita J, Ramohia PC, Walter R, Goerlich C, Limpus C - PLoS ONE (2015)

Mean remigration period for cohorts of turtles in the years between 1991 and 2007.Blue line indicates predicted values for a poisson regression of migration period against years since 1991. Grey area indicates 95% confidence intervals around the regression line. The slop of the regression line indicates a reduction in the remigration interval by 0.5/yr.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390367&req=5

pone.0121435.g006: Mean remigration period for cohorts of turtles in the years between 1991 and 2007.Blue line indicates predicted values for a poisson regression of migration period against years since 1991. Grey area indicates 95% confidence intervals around the regression line. The slop of the regression line indicates a reduction in the remigration interval by 0.5/yr.
Mentions: The mean proportion of turtles from the pre protection era (1991–1995) that remigrated within a 12 year window was 0.067 (SE = 0.027). The mean proportion of turtles in the post protection era (1996–2000) that remigrated within a 12 year window was twice as high; 0.137 (SE 0.021). The mean remigration interval for the breeding season’s cohorts that were followed for at least 12 years beyond their initial year of tagging is shown in Fig. 6. There were significant differences among the mean remigration intervals for these years cohorts (t-test, P = 0.011). A poisson regression of remigration interval against cohort year showed a significant decline in the average remigration interval by 5.8 [3.9, 7.2] years over the 10 years between 1991–2001 (p = 0.002, Fig. 6). During the 21 years for potential recapture no hawksbills were recorded nesting with a one year remigration interval, two year remigration intervals were rare, but increased in frequency in the later cohorts (Table 2).

Bottom Line: Our results and the results of others, reveal that many of the hawksbill turtles that nest at the ACMCA forage in distant Australian waters, and that nesting on the Arnavons occurs throughout the year with peak nesting activity coinciding with the austral winter.Our results also provide the first known evidence of recovery for a western pacific hawksbill rookery, with the number of nests laid at the ACMCA and the remigration rates of turtles doubling since the establishment of the ACMCA in 1995.The Arnavons case study provides an example of how changes in policy, inclusive community-based management and long term commitment can turn the tide for one of the most charismatic and endangered species on our planet.

View Article: PubMed Central - PubMed

Affiliation: The Nature Conservancy, Asia Pacific Division, 245 Riverside Drive, West End, Brisbane, QLD, 4101, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.

ABSTRACT
The largest rookery for hawksbill turtles in the oceanic South Pacific is the Arnavon Islands, which are located in the Manning Strait between Isabel and Choiseul Province, Solomon Islands. The history of this rookery is one of overexploitation, conflict and violence. Throughout the 1800s Roviana headhunters from New Georgia repeatedly raided the Manning Strait to collect hawksbill shell which they traded with European whalers. By the 1970s the Arnavons hawksbill population was in severe decline and the national government intervened, declaring the Arnavons a sanctuary in 1976. But this government led initiative was short lived, with traditional owners burning down the government infrastructure and resuming intensive harvesting in 1982. In 1991 routine beach monitoring and turtle tagging commenced at the Arnavons along with extensive community consultations regarding the islands' future, and in 1995 the Arnavon Community Marine Conservation Area (ACMCA) was established. Around the same time national legislation banning the sale of all turtle products was passed. This paper represents the first analysis of data from 4536 beach surveys and 845 individual turtle tagging histories obtained from the Arnavons between 1991-2012. Our results and the results of others, reveal that many of the hawksbill turtles that nest at the ACMCA forage in distant Australian waters, and that nesting on the Arnavons occurs throughout the year with peak nesting activity coinciding with the austral winter. Our results also provide the first known evidence of recovery for a western pacific hawksbill rookery, with the number of nests laid at the ACMCA and the remigration rates of turtles doubling since the establishment of the ACMCA in 1995. The Arnavons case study provides an example of how changes in policy, inclusive community-based management and long term commitment can turn the tide for one of the most charismatic and endangered species on our planet.

No MeSH data available.


Related in: MedlinePlus