Limits...
The developmental biogeography of hawksbill sea turtles in the North Pacific.

Van Houtan KS, Francke DL, Alessi S, Jones TT, Martin SL, Kurpita L, King CS, Baird RW - Ecol Evol (2016)

Bottom Line: This knowledge gap limits the effectiveness of conservation management for this globally endangered species.We find hawksbills 0-4 years of age, measuring 8-34 cm straight carapace length, are found predominantly in the coastal pelagic waters of Hawaii.This focuses attention on hazards in these ecosystems - entanglement and ingestion of marine debris - and perhaps away from longline bycatch and decadal climate regimes that affect sea turtle development in oceanic regions.

View Article: PubMed Central - PubMed

Affiliation: NOAA FisheriesPacific Islands Fisheries Science CenterHonoluluHawaii96818; Nicholas School of the EnvironmentDuke UniversityDurhamNorth Carolina27708; Present address: Monterey Bay AquariumMontereyCalifornia93940.

ABSTRACT
High seas oceanic ecosystems are considered important habitat for juvenile sea turtles, yet much remains cryptic about this important life-history period. Recent progress on climate and fishery impacts in these so-called lost years is promising, but the developmental biogeography of hawksbill sea turtles (Eretmochelys imbricata) has not been widely described in the Pacific Ocean. This knowledge gap limits the effectiveness of conservation management for this globally endangered species. We address this with 30 years of stranding observations, 20 years of bycatch records, and recent simulations of natal dispersal trajectories in the Hawaiian Archipelago. We synthesize the analyses of these data in the context of direct empirical observations, anecdotal sightings, and historical commercial harvests from the insular Pacific. We find hawksbills 0-4 years of age, measuring 8-34 cm straight carapace length, are found predominantly in the coastal pelagic waters of Hawaii. Unlike other species, we find no direct evidence of a prolonged presence in oceanic habitats, yet satellite tracks of passive drifters (simulating natal dispersal) and our small sample sizes suggest that an oceanic phase for hawksbills cannot be dismissed. Importantly, despite over 600 million hooks deployed and nearly 6000 turtle interactions, longline fisheries have never recorded a single hawksbill take. We address whether the patterns we observe are due to population size and gear selectivity. Although most sea turtle species demonstrate clear patterns of oceanic development, hawksbills in the North Pacific may by contrast occupy a variety of ecosystems including coastal pelagic waters and shallow reefs in remote atolls. This focuses attention on hazards in these ecosystems - entanglement and ingestion of marine debris - and perhaps away from longline bycatch and decadal climate regimes that affect sea turtle development in oceanic regions.

No MeSH data available.


Related in: MedlinePlus

Surface drifter trajectories from hawksbill and green turtle nesting areas in the Hawaiian Archipelago indicate young juveniles may reside near the archipelago for several months or more. Green lines are 4 PSAT drifters released from French Frigate Shoals (FFS) in July–August 2014, simulating green turtle posthatchling trajectories from their primary nesting beach in the northwestern Hawaiian Islands. Orange lines are 2 PSAT surface drifters released near Oahu's south shore (OSS) in December 2013, simulating hawksbill posthatchling trajectories from the Main Hawaiian Islands. The timing and location of release parallel predominant conditions for both populations. Paths are Argos location codes 3‐B, “x” at path endpoint indicates transmission ends, “o” indicates drifter still active, and number is trajectory age in months. Gray region is the extent of the Papahanaumokuakea Marine National Monument.
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ece32034-fig-0002: Surface drifter trajectories from hawksbill and green turtle nesting areas in the Hawaiian Archipelago indicate young juveniles may reside near the archipelago for several months or more. Green lines are 4 PSAT drifters released from French Frigate Shoals (FFS) in July–August 2014, simulating green turtle posthatchling trajectories from their primary nesting beach in the northwestern Hawaiian Islands. Orange lines are 2 PSAT surface drifters released near Oahu's south shore (OSS) in December 2013, simulating hawksbill posthatchling trajectories from the Main Hawaiian Islands. The timing and location of release parallel predominant conditions for both populations. Paths are Argos location codes 3‐B, “x” at path endpoint indicates transmission ends, “o” indicates drifter still active, and number is trajectory age in months. Gray region is the extent of the Papahanaumokuakea Marine National Monument.

Mentions: Passive drifters released in the vicinity of the primary green and hawksbill nesting grounds in the Hawaiian Islands had variable trajectories with no single path (Fig. 2). For both sets of releases, drifters took meandering paths proximate (<200 km) to the archipelago in pelagic waters for several or more months. Three of the drifters stopped transmitting; two released at FFS (3.3 and 5.8 months); and one released off Oahu (3.5 months). These three drifters all remained <300 km from land. All drifters with a lifetime of >6 months, however, moved westerly into oceanic waters following the North Equatorial Current across the dateline (180°). The longest transmitting drifter (>14 months) was released off Oahu, drifted through Johnston Atoll, passed north of Wake Island, and was last observed at 18.092°N, 155.904°E, roughly 4800 km from its release site.


The developmental biogeography of hawksbill sea turtles in the North Pacific.

Van Houtan KS, Francke DL, Alessi S, Jones TT, Martin SL, Kurpita L, King CS, Baird RW - Ecol Evol (2016)

Surface drifter trajectories from hawksbill and green turtle nesting areas in the Hawaiian Archipelago indicate young juveniles may reside near the archipelago for several months or more. Green lines are 4 PSAT drifters released from French Frigate Shoals (FFS) in July–August 2014, simulating green turtle posthatchling trajectories from their primary nesting beach in the northwestern Hawaiian Islands. Orange lines are 2 PSAT surface drifters released near Oahu's south shore (OSS) in December 2013, simulating hawksbill posthatchling trajectories from the Main Hawaiian Islands. The timing and location of release parallel predominant conditions for both populations. Paths are Argos location codes 3‐B, “x” at path endpoint indicates transmission ends, “o” indicates drifter still active, and number is trajectory age in months. Gray region is the extent of the Papahanaumokuakea Marine National Monument.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834323&req=5

ece32034-fig-0002: Surface drifter trajectories from hawksbill and green turtle nesting areas in the Hawaiian Archipelago indicate young juveniles may reside near the archipelago for several months or more. Green lines are 4 PSAT drifters released from French Frigate Shoals (FFS) in July–August 2014, simulating green turtle posthatchling trajectories from their primary nesting beach in the northwestern Hawaiian Islands. Orange lines are 2 PSAT surface drifters released near Oahu's south shore (OSS) in December 2013, simulating hawksbill posthatchling trajectories from the Main Hawaiian Islands. The timing and location of release parallel predominant conditions for both populations. Paths are Argos location codes 3‐B, “x” at path endpoint indicates transmission ends, “o” indicates drifter still active, and number is trajectory age in months. Gray region is the extent of the Papahanaumokuakea Marine National Monument.
Mentions: Passive drifters released in the vicinity of the primary green and hawksbill nesting grounds in the Hawaiian Islands had variable trajectories with no single path (Fig. 2). For both sets of releases, drifters took meandering paths proximate (<200 km) to the archipelago in pelagic waters for several or more months. Three of the drifters stopped transmitting; two released at FFS (3.3 and 5.8 months); and one released off Oahu (3.5 months). These three drifters all remained <300 km from land. All drifters with a lifetime of >6 months, however, moved westerly into oceanic waters following the North Equatorial Current across the dateline (180°). The longest transmitting drifter (>14 months) was released off Oahu, drifted through Johnston Atoll, passed north of Wake Island, and was last observed at 18.092°N, 155.904°E, roughly 4800 km from its release site.

Bottom Line: This knowledge gap limits the effectiveness of conservation management for this globally endangered species.We find hawksbills 0-4 years of age, measuring 8-34 cm straight carapace length, are found predominantly in the coastal pelagic waters of Hawaii.This focuses attention on hazards in these ecosystems - entanglement and ingestion of marine debris - and perhaps away from longline bycatch and decadal climate regimes that affect sea turtle development in oceanic regions.

View Article: PubMed Central - PubMed

Affiliation: NOAA FisheriesPacific Islands Fisheries Science CenterHonoluluHawaii96818; Nicholas School of the EnvironmentDuke UniversityDurhamNorth Carolina27708; Present address: Monterey Bay AquariumMontereyCalifornia93940.

ABSTRACT
High seas oceanic ecosystems are considered important habitat for juvenile sea turtles, yet much remains cryptic about this important life-history period. Recent progress on climate and fishery impacts in these so-called lost years is promising, but the developmental biogeography of hawksbill sea turtles (Eretmochelys imbricata) has not been widely described in the Pacific Ocean. This knowledge gap limits the effectiveness of conservation management for this globally endangered species. We address this with 30 years of stranding observations, 20 years of bycatch records, and recent simulations of natal dispersal trajectories in the Hawaiian Archipelago. We synthesize the analyses of these data in the context of direct empirical observations, anecdotal sightings, and historical commercial harvests from the insular Pacific. We find hawksbills 0-4 years of age, measuring 8-34 cm straight carapace length, are found predominantly in the coastal pelagic waters of Hawaii. Unlike other species, we find no direct evidence of a prolonged presence in oceanic habitats, yet satellite tracks of passive drifters (simulating natal dispersal) and our small sample sizes suggest that an oceanic phase for hawksbills cannot be dismissed. Importantly, despite over 600 million hooks deployed and nearly 6000 turtle interactions, longline fisheries have never recorded a single hawksbill take. We address whether the patterns we observe are due to population size and gear selectivity. Although most sea turtle species demonstrate clear patterns of oceanic development, hawksbills in the North Pacific may by contrast occupy a variety of ecosystems including coastal pelagic waters and shallow reefs in remote atolls. This focuses attention on hazards in these ecosystems - entanglement and ingestion of marine debris - and perhaps away from longline bycatch and decadal climate regimes that affect sea turtle development in oceanic regions.

No MeSH data available.


Related in: MedlinePlus