A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles.
Oceanic currents are known to broadly shape the dispersal of juvenile sea turtles during their pelagic stage. Accordingly, simple passive drift models are widely used to investigate the distribution at sea of various juvenile sea turtle populations. However, evidence is growing that juveniles do not...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2017-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC5528265?pdf=render |
| _version_ | 1818155880489680896 |
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| author | Philippe Gaspar Maxime Lalire |
| author_facet | Philippe Gaspar Maxime Lalire |
| author_sort | Philippe Gaspar |
| collection | DOAJ |
| description | Oceanic currents are known to broadly shape the dispersal of juvenile sea turtles during their pelagic stage. Accordingly, simple passive drift models are widely used to investigate the distribution at sea of various juvenile sea turtle populations. However, evidence is growing that juveniles do not drift purely passively but also display some swimming activity likely directed towards favorable habitats. We therefore present here a novel Sea Turtle Active Movement Model (STAMM) in which juvenile sea turtles actively disperse under the combined effects of oceanic currents and habitat-driven movements. This model applies to all sea turtle species but is calibrated here for leatherback turtles (Dermochelys coriacea). It is first tested in a simulation of the active dispersal of juveniles originating from Jamursba-Medi, a main nesting beach of the western Pacific leatherback population. Dispersal into the North Pacific Ocean is specifically investigated. Simulation results demonstrate that, while oceanic currents broadly shape the dispersal area, modeled habitat-driven movements strongly structure the spatial and temporal distribution of juveniles within this area. In particular, these movements lead juveniles to gather in the North Pacific Transition Zone (NPTZ) and to undertake seasonal north-south migrations. More surprisingly, juveniles in the NPTZ are simulated to swim mostly towards west which considerably slows down their progression towards the American west coast. This increases their residence time, and hence the risk of interactions with fisheries, in the central and eastern part of the North Pacific basin. Simulated habitat-driven movements also strongly reduce the risk of cold-induced mortality. This risk appears to be larger among the juveniles that rapidly circulate into the Kuroshio than among those that first drift into the North Equatorial Counter Current (NECC). This mechanism might induce marked interannual variability in juvenile survival as the strength and position of the NECC are directly linked to El Niño activity. |
| first_indexed | 2024-12-11T14:49:26Z |
| format | Article |
| id | doaj.art-664c2626c0ed4d5f8bf5a17585eb2039 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-11T14:49:26Z |
| publishDate | 2017-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-664c2626c0ed4d5f8bf5a17585eb20392022-12-22T01:01:33ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-01127e018159510.1371/journal.pone.0181595A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles.Philippe GasparMaxime LalireOceanic currents are known to broadly shape the dispersal of juvenile sea turtles during their pelagic stage. Accordingly, simple passive drift models are widely used to investigate the distribution at sea of various juvenile sea turtle populations. However, evidence is growing that juveniles do not drift purely passively but also display some swimming activity likely directed towards favorable habitats. We therefore present here a novel Sea Turtle Active Movement Model (STAMM) in which juvenile sea turtles actively disperse under the combined effects of oceanic currents and habitat-driven movements. This model applies to all sea turtle species but is calibrated here for leatherback turtles (Dermochelys coriacea). It is first tested in a simulation of the active dispersal of juveniles originating from Jamursba-Medi, a main nesting beach of the western Pacific leatherback population. Dispersal into the North Pacific Ocean is specifically investigated. Simulation results demonstrate that, while oceanic currents broadly shape the dispersal area, modeled habitat-driven movements strongly structure the spatial and temporal distribution of juveniles within this area. In particular, these movements lead juveniles to gather in the North Pacific Transition Zone (NPTZ) and to undertake seasonal north-south migrations. More surprisingly, juveniles in the NPTZ are simulated to swim mostly towards west which considerably slows down their progression towards the American west coast. This increases their residence time, and hence the risk of interactions with fisheries, in the central and eastern part of the North Pacific basin. Simulated habitat-driven movements also strongly reduce the risk of cold-induced mortality. This risk appears to be larger among the juveniles that rapidly circulate into the Kuroshio than among those that first drift into the North Equatorial Counter Current (NECC). This mechanism might induce marked interannual variability in juvenile survival as the strength and position of the NECC are directly linked to El Niño activity.http://europepmc.org/articles/PMC5528265?pdf=render |
| spellingShingle | Philippe Gaspar Maxime Lalire A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles. PLoS ONE |
| title | A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles. |
| title_full | A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles. |
| title_fullStr | A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles. |
| title_full_unstemmed | A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles. |
| title_short | A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles. |
| title_sort | model for simulating the active dispersal of juvenile sea turtles with a case study on western pacific leatherback turtles |
| url | http://europepmc.org/articles/PMC5528265?pdf=render |
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