Distribution, residency, and seasonal movements of the green sea turtle, Chelonia mydas (Linnaeus, 1758), in Texas /
Data on residency, seasonality, yearly relative abundance, distribution, movements, migration, sex ratios, sizes, and mortality factors of green turtles (Chelonia mydas) in Texas were collected through investigation of nests, and stranded, netted, and satellite-tracked turtles. Six hundred seven gr...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2000.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731990371&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Data on residency, seasonality, yearly relative abundance, distribution, movements, migration, sex ratios, sizes, and mortality factors of green turtles (Chelonia mydas) in Texas were collected through investigation of nests, and stranded, netted, and satellite-tracked turtles. Six hundred seven green turtles were located stranded along the Texas coast from 1980 to 1998, including 471 found from 1989 to 1997. Strandings were distributed throughout Texas, but were most numerous in south Texas. Of the 298 stranded turtles for which possible stranding causes were identified, 230 were victims of hypothermic stunning. Two hundred fifty-eight green turtles (n = 383 captures) were netted in the Mansfield Channel during 1149 h of effort (3.63 turtles/km?h) from June 1989 through December 1997. Seventy-three of the 258 individuals were recaptured. Yearly numbers of stranded turtles and yearly catch-per-unit-effort (CPUE) followed similar trends and were correlated. Monthly trends of stranding numbers and CPUE differed dramatically. Strandings were most numerous during the winter and CPUE was highest during the summer and fall. The sex ratio for stranded turtles (1980-1998:1.09F:1:00M; 1989-1997: 0.94F:1:00M) differed from the sex ratio for netted turtles (4.16F:1.0M). Turtles found stranded (mean = 37.8 cm SLCL) were larger than those netted (mean = 32.4 cm SLCL). Six confirmed green turtle nests were documented on the Texas coast, including one found in 1987 and five in 1998. Ninety-eight percent of the stranded and all of the netted green turtles were juveniles. The Mansfield Channel is a developmental habitat for juvenile green turtles. Some netted and tracked green turtles remained at the Mansfield Channel jetty area, some used the Mansfield Channel as a passageway between the Laguna Madre and Gulf of Mexico, and some moved southward within Gulf of Mexico waters to off the coast of Mexico. Water temperature varied seasonally and influenced strandings, CPUE, and movements. CPUE was positively correlated with water temperature and no turtles were caught in January and when mean water temperatures were below 15.5 C. Some tracked turtles moved southward during periods of declining temperatures, but others over-wintered in south Texas waters. |
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| Item Description: | Vita. "Major Subject: Zoology". |
| Physical Description: | xv, 273 leaves : illustrations, maps ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 165-215). |