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https://hdl.handle.net/11681/20464
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DC Field | Value | Language |
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dc.contributor.author | Shafer, Deborah J. | en_US |
dc.contributor.author | Nelson, David A. (David Arthur), 1955- | en_US |
dc.creator | Dredging Operations Technical Support Program (U.S.) | en_US |
dc.creator | U.S. Army Engineer Waterways Experiment Station | en_US |
dc.date.accessioned | 2016-12-30T19:54:15Z | en_US |
dc.date.available | 2016-12-30T19:54:15Z | en_US |
dc.date.issued | 1996-08 | en_US |
dc.identifier.govdoc | Miscellaneous Paper D-96-3 | en_US |
dc.identifier.uri | http://hdl.handle.net/11681/20464 | en_US |
dc.description | Miscellaneous Paper | en_US |
dc.description.abstract | The rigid deflector draghead was tested on a hopper dredge in Port Canaveral Harbor entrance channel from 16-30 September 1994. The effectiveness of the draghead was assessed by determining if turtles were: (a.) present in the channel in sufficient numbers to encounter the draghead, (b.) on the channel bottom where they were most susceptible to entrainment by the draghead, and (c.) entrained by the rigid deflector draghead at a lower rate than by the California draghead. A total of 13 turtles (0.47 turtle/hour) were captured during three standardized sea turtle trawl surveys. The activities of 12 loggerhead turtles (Caretta caretta) were monitored intermittently from 5-30 September 1994 using radio tags and depth-sensitive sonic tags. These behavioral studies showed that loggerhead turtles spent most of their time (83.2 percent) on the seafloor. No loggerhead turtles were entrained during the dredging operations; however, one small green turtle (Chelonia mydas) was entrained during the dredging (0.09 turtle/day). Based on the observed levels of sea turtle abundance, a preponderance of bottom time for loggerhead sea turtles, and a low rate of sea turtle entrainment, the rigid deflector draghead may be effective in reducing sea turtle entrainment by hopper dredge in Port Canaveral Harbor entrance channel. | en_US |
dc.description.sponsorship | Dredging Operations Technical Support Program (U.S.) | en_US |
dc.description.sponsorship | United States. Army. Corps of Engineers. Jacksonville District | en_US |
dc.description.tableofcontents | Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii Conversion Factors, Non-SI to SI Units of Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . x 1-Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Purpose and Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2-Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Previous Achievements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3-Materials and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Dredge Operation and Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . 5 Permits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Trawling Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Turtle Tagging, Handling, and Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 General Telemetry Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 7 Physical Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4-Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Sea Turtle Abundance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Rate of Sea Turtle Entrainment . . . . . . . . . . . . . . . . . . . . . . . . . 12 Sea Turtle Size Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Environmental Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Diving and Submergence Behavior . . . . . . . . . . . . . . . . . . . . . . . 17 Turtle Locations and Movements . . . . . . . . . . . . . . . . . . . . . . . . 23 5-Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Appendix A: Data Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . Al Appendix B: Turtle Trawl Net Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bl SF 298 | en_US |
dc.format.extent | 45 pages/18.09 MB | en_US |
dc.format.medium | en_US | |
dc.language.iso | en_US | en_US |
dc.publisher | U.S. Army Engineer Waterways Experiment Station | en_US |
dc.relation | http://acwc.sdp.sirsi.net/client/search/asset/1054406 | en_US |
dc.relation.ispartofseries | Miscellaneous Paper (Dredging Operations Technical Support Program (U.S.)) ; no.Miscellaneous Paper D-96-3 | en_US |
dc.rights | Approved for public release; distribution is unlimited | en_US |
dc.source | The ERDC Library created this digital resource using one or more of the following: Zeta TS-0995, Zeutcehl OS 12000, HP HD Pro 42-in. map scanner, Epson flatbed | en_US |
dc.subject | Loggerhead turtles | en_US |
dc.subject | Caretta caretta | en_US |
dc.subject | Sea turtles | en_US |
dc.subject | Rigid deflector draghead | en_US |
dc.subject | Dredging | en_US |
dc.subject | Environmental effects | en_US |
dc.subject | Dredging Operations Technical Support Program (U.S.) | en_US |
dc.title | Effectiveness of a sea turtle-deflecting hopper dredge draghead in Port Canaveral Entrance Channel, Florida | en_US |
dc.type | Report | en_US |
Appears in Collections: | Miscellaneous Paper |
Files in This Item:
File | Description | Size | Format | |
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MP D-96-3.pdf | Miscellaneous Paper D-96-3 | 18.09 MB | Adobe PDF | View/Open |