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Lamont MM, Slone D, Reid JP, Butler SM, Alday J. Deep vs shallow: GPS tags reveal a dichotomy in movement patterns of loggerhead turtles foraging in a coastal bay. MOVEMENT ECOLOGY 2024; 12:40. [PMID: 38816732 PMCID: PMC11140867 DOI: 10.1186/s40462-024-00480-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 05/21/2024] [Indexed: 06/01/2024]
Abstract
BACKGROUND Individual variation in movement strategies of foraging loggerhead turtles have been documented on the scale of tens to hundreds of kilometers within single ocean basins. Use of different strategies among individuals may reflect variations in resources, predation pressure or competition. It is less common for individual turtles to use different foraging strategies on the scale of kilometers within a single coastal bay. We used GPS tags capable of back-filling fine-scale locations to document movement patterns of loggerhead turtles in a coastal bay in Northwest Florida, U.S.A. METHODS Iridium-linked GPS tags were deployed on loggerhead turtles at a neritic foraging site in Northwest Florida. After filtering telemetry data, point locations were transformed to movement lines and then merged with the original point file to define travel paths and assess travel speed. Home ranges were determined using kernel density function. Diurnal behavioral shifts were examined by examining turtle movements compared to solar time. RESULTS Of the 11 turtles tagged, three tracked turtles remained in deep (~ 6 m) water for almost the entire tracking period, while all other turtles undertook movements from deep water locations, located along edges and channels, to shallow (~ 1-2 m) shoals at regular intervals and primarily at night. Three individuals made short-term movements into the Gulf of Mexico when water temperatures dropped, and movement speeds in the Gulf were greater than those in the bay. Turtles exhibited a novel behavior we termed drifting. CONCLUSIONS This study highlighted the value provided to fine-scale movement studies for species such as sea turtles that surface infrequently by the ability of these GPS tags to store and re-upload data. Future use of these tags at other loggerhead foraging sites, and concurrent with diving and foraging data, would provide a powerful tool to better understand fine-scale movement patterns of sea turtles.
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Affiliation(s)
- Margaret M Lamont
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL 32653, USA.
| | - Daniel Slone
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL 32653, USA
| | - James P Reid
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL 32653, USA
| | - Susan M Butler
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL 32653, USA
| | - Joseph Alday
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL 32653, USA
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Green turtle movements in the Gulf of Mexico: Tracking reveals new migration corridor and habitat use suggestive of MPA expansion. Glob Ecol Conserv 2023. [DOI: 10.1016/j.gecco.2023.e02380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Mollenhauer R, Lamont MM, Foley A. Long‐term apparent survival of a cold‐stunned subpopulation of juvenile green turtles. Ecosphere 2022. [DOI: 10.1002/ecs2.4221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Robert Mollenhauer
- U.S. Geological Survey Wetland and Aquatic Research Center Gainesville Florida USA
| | - Margaret M. Lamont
- U.S. Geological Survey Wetland and Aquatic Research Center Gainesville Florida USA
| | - Allen Foley
- Florida Fish and Wildlife Conservation Commission, Jacksonville Field Laboratory Fish and Wildlife Research Institute Jacksonville Florida USA
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Osland MJ, Stevens PW, Lamont MM, Brusca RC, Hart KM, Waddle JH, Langtimm CA, Williams CM, Keim BD, Terando AJ, Reyier EA, Marshall KE, Loik ME, Boucek RE, Lewis AB, Seminoff JA. Tropicalization of temperate ecosystems in North America: The northward range expansion of tropical organisms in response to warming winter temperatures. GLOBAL CHANGE BIOLOGY 2021; 27:3009-3034. [PMID: 33605004 DOI: 10.1111/gcb.15563] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Tropicalization is a term used to describe the transformation of temperate ecosystems by poleward-moving tropical organisms in response to warming temperatures. In North America, decreases in the frequency and intensity of extreme winter cold events are expected to allow the poleward range expansion of many cold-sensitive tropical organisms, sometimes at the expense of temperate organisms. Although ecologists have long noted the critical ecological role of winter cold temperature extremes in tropical-temperate transition zones, the ecological effects of extreme cold events have been understudied, and the influence of warming winter temperatures has too often been left out of climate change vulnerability assessments. Here, we examine the influence of extreme cold events on the northward range limits of a diverse group of tropical organisms, including terrestrial plants, coastal wetland plants, coastal fishes, sea turtles, terrestrial reptiles, amphibians, manatees, and insects. For these organisms, extreme cold events can lead to major physiological damage or landscape-scale mass mortality. Conversely, the absence of extreme cold events can foster population growth, range expansion, and ecological regime shifts. We discuss the effects of warming winters on species and ecosystems in tropical-temperate transition zones. In the 21st century, climate change-induced decreases in the frequency and intensity of extreme cold events are expected to facilitate the poleward range expansion of many tropical species. Our review highlights critical knowledge gaps for advancing understanding of the ecological implications of the tropicalization of temperate ecosystems in North America.
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Affiliation(s)
| | - Philip W Stevens
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, FL, USA
| | | | | | | | | | | | | | - Barry D Keim
- Louisiana State University, Baton Rouge, LA, USA
| | | | - Eric A Reyier
- Herndon Solutions Group, LLC, NASA Environmental and Medical Contract, Mail Code: NEM-022, Kennedy Space Center, FL, USA
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Lamont MM, Johnson D, Catizone DJ. Movements of marine and estuarine turtles during Hurricane Michael. Sci Rep 2021; 11:1577. [PMID: 33452383 PMCID: PMC7810867 DOI: 10.1038/s41598-021-81234-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/29/2020] [Indexed: 11/17/2022] Open
Abstract
Natural disturbances are an important driver of population dynamics. Because it is difficult to observe wildlife during these events, our understanding of the strategies that species use to survive these disturbances is limited. On October 10, 2018, Hurricane Michael made landfall on Florida’s northwest coast. Using satellite and acoustic telemetry, we documented movements of 6 individual turtles: one loggerhead sea turtle, one Kemp’s ridley sea turtle, three green sea turtles and one diamondback terrapin, in a coastal bay located less than 30 km from hurricane landfall. Post-storm survival was confirmed for all but the Kemp’s ridley; the final condition of that individual remains unknown. No obvious movements were observed for the remaining turtles however the loggerhead used a larger home range in the week after the storm. This study highlights the resiliency of turtles in response to extreme weather conditions. However, long-term impacts to these species from habitat changes post-hurricane are unknown.
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Affiliation(s)
- Margaret M Lamont
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL, 32653, USA.
| | - Darren Johnson
- Cherokee Nations Systems Solutions, Contracted to U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA, 70506, USA
| | - Daniel J Catizone
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL, 32653, USA
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Iverson AR, Fujisaki I, Lamont MM, Hart KM. Loggerhead sea turtle (Caretta caretta) diving changes with productivity, behavioral mode, and sea surface temperature. PLoS One 2019; 14:e0220372. [PMID: 31390354 PMCID: PMC6685635 DOI: 10.1371/journal.pone.0220372] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/15/2019] [Indexed: 11/29/2022] Open
Abstract
The relationship between dive behavior and oceanographic conditions is not well understood for marine predators, especially sea turtles. We tagged loggerhead turtles (Caretta caretta) with satellite-linked depth loggers in the Gulf of Mexico, where there is a minimal amount of dive data for this species. We tested for associations between four measurements of dive behavior (total daily dive frequency, frequency of dives to the bottom, frequency of long dives and time-at-depth) and both oceanographic conditions (sea surface temperature [SST], net primary productivity [NPP]) and behavioral mode (inter-nesting, migration, or foraging). From 2011-2013 we obtained 26 tracks from 25 adult female loggerheads tagged after nesting in the Gulf of Mexico. All turtles remained in the Gulf of Mexico and spent about 10% of their time at the surface (10% during inter-nesting, 14% during migration, 9% during foraging). Mean total dive frequency was 41.9 times per day. Most dives were ≤ 25 m and between 30-40 min. During inter-nesting and foraging, turtles dived to the bottom 95% of days. SST was an important explanatory variable for all dive patterns; higher SST was associated with more dives per day, more long dives and more dives to the seafloor. Increases in NPP were associated with more long dives and more dives to the bottom, while lower NPP resulted in an increased frequency of overall diving. Longer dives occurred more frequently during migration and a higher proportion of dives reached the seafloor during foraging when SST and NPP were higher. Our study stresses the importance of the interplay between SST and foraging resources for influencing dive behavior.
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Affiliation(s)
- Autumn R. Iverson
- Cherokee Nation Technologies, contracted to Wetland and Aquatic Research Center, United States Geological Survey, Davie, Florida, United States of America
| | - Ikuko Fujisaki
- Fort Lauderdale Research and Education Center, University of Florida, Davie, Florida, United States of America
| | - Margaret M. Lamont
- Wetland and Aquatic Research Center, United States Geological Survey, Gainesville, Florida, United States of America
| | - Kristen M. Hart
- Wetland and Aquatic Research Center, United States Geological Survey, Davie, Florida, United States of America
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