GIS_Web.FWC.sea_turtle_nest_density

Metadata:

• Identification_Information
• Spatial_Data_Organization_Information
• Entity_and_Attribute_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:

Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, Statewide Nesting Beach Survey program coordinator

Publication_Date: 20221012

Title: GIS_Web.FWC.sea_turtle_nest_density

Geospatial_Data_Presentation_Form: vector digital data

Publication_Information:

Publication_Place: St. Petersburg, FL

Publisher:

Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute

Online_Linkage: https://myfwc.com/research/wildlife/sea-turtles/nesting/

Description:

Abstract:

The State of Florida, through the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute, coordinates the Statewide Nesting Beach Survey program (SNBS). The SNBS was initiated in 1979 under a cooperative agreement between FWC and the U.S. Fish and Wildlife Service. Its purpose is to document the total distribution, seasonality, and abundance of nesting by sea turtles in Florida. Three species of sea turtles, the loggerhead (Caretta caretta), the green turtle (Chelonia mydas), and the leatherback (Dermochelys coriacea), nest regularly on Florida's beaches. Two other species, Kemp’s ridley (Lepidochelys kempii) and the hawksbill (Eretmochelys imbricata) also nest but in very small numbers. All the species are listed as either Threatened or Endangered under the Endangered Species Act. Survey data are derived from observations of tracks and other nesting signs left on the beach by sea turtles. Species identifications and determinations of nesting vs. non-nesting emergences are based on the evaluation of visible features of the track and the nest. Data are gathered on more than 200beaches through a network of permit holders consisting of private conservation groups, volunteers, consultants, academics, local governments, federal agencies, and the Florida Park Service. Nest density classifications of low, medium and high were developed for loggerheads, green turtles and leatherbacks according to quartile ranks. For the loggerhead turtle, ranking was done within genetic subunits; ranks for green turtles and leatherbacks were on a statewide basis. Hawksbill turtles and Kemp’s ridleys are denoted only as present or absent on individual beaches. Surveys in the SNBS program may vary with respect to start/stop dates, frequency, duration and beach length between years for a particular beach, as well as between beaches. Survey results are used by managers to evaluate and minimize impacts to turtles and their nests due to human activities such as coastal construction, beach renourishment, and recreation, as well as to identify important areas for enhanced protection or land acquisition.

Purpose:

The State of Florida, through the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute, coordinates the Statewide Nesting Beach Survey program (SNBS). The SNBS was initiated in 1979 under a cooperative agreement between FWC (then DNR) and the U.S. Fish and Wildlife Service. Its purpose is to document the total distribution, seasonality, and abundance of nesting by sea turtles in Florida. Three species of sea turtles, the loggerhead (Caretta caretta), the green turtle (Chelonia mydas), and the leatherback (Dermochelys coriacea), nest regularly on Florida's beaches. Two other species, Kemp’s ridley (Lepidochelys kempii) and the hawksbill (Eretmochelys imbricata) also nest but in very small numbers. All the species are listed as either Threatened or Endangered under the Endangered Species Act. Survey data are derived from observations of tracks and other nesting sign left on the beach by sea turtles. Species identifications and determinations of nesting vs. non-nesting emergences are based on the evaluation of visible features of the track and the nest. Data are gathered on more than 200 beaches through a network of permit holders consisting of private conservation groups, volunteers, consultants, academics, local governments, federal agencies, and the Florida Park Service. Annual nest counts for the state represent a minimum estimate because not all nesting activity is recorded on surveyed beaches and not all nesting beaches in Florida are surveyed. Nest density classifications of “low”, “medium” and “high” were developed for loggerheads, green turtles and leatherbacks according to quartile ranks. For the loggerhead turtle, ranking was done within genetic subunits; ranks for green turtles and leatherbacks were on a statewide basis. Hawksbill turtles and Kemp’s ridleys were denoted only as present or absent on individual beaches. Surveys in the SNBS program may vary with respect to start/stop dates, frequency, duration and beach length between years for a particular beach, as well as between beaches. This variability in the surveys, combined with the dynamic nature of sea turtle nesting activity, make the quartile ranking system for the beaches, rather than average nesting densities over a small number of years, a more appropriate measure of the level of nesting activity that takes place on a particular beach. Survey results are used by managers to evaluate and minimize impacts to turtles and their nests due to human activities such as coastal construction, beach renourishment, and recreation, as well as to identify important areas for enhanced protection or land acquisition. Direct contact by managers with the appropriate state data provider is highly recommended to obtain more detailed information about the surveys on a particular beach.

Supplemental_Information:

FWC’s Statewide Nesting Beach Survey program encompassed an annual average of 1,318 km of nesting beach during the referenced period. This included most, but not all, of the nesting beaches in the state, with the most significant gap in coverage in the Everglades region of Monroe County. Annual nest counts for the state represent a minimum estimate because not all nesting activity is recorded on surveyed beaches and not all nesting beaches in Florida are surveyed. It should be noted that sea turtles may use any sandy beaches for nesting. There are limitations to the use of the SNBS database imposed by the data collection methodology employed. Surveys in the SNBS program may vary with respect to start/stop dates, frequency, duration and beach length between years for a particular beach, as well as between beaches, making the data inappropriate for assessing population trends. Trend evaluation is the goal of a complementary FWRI program, the Index Nesting Beach Survey program (INBS) where consistency in survey effort is accomplished by following a regime of 7 days/week monitoring during a set 109-day window, and maintaining consistent survey boundaries. With some exceptions, including surveys on geographically remote beaches, SNBS surveys typically capture the majority of nesting activity on a particular beach. Surveys with less than 7 day/week frequency may result in underestimated nest totals; however, most surveyors count all new nests observed when surveys are resumed, thus reducing the error. Tracks are marked as having been evaluated when the surveys are conducted. Determination of nesting success, i.e., whether an emergence has resulted in eggs being deposited, or in a "false crawl", is made using the visible features of the track and nest. This can be challenging in areas where nest densities are high or in situations where weather has erased the marks left in the sand by the turtle. However, in a test on INBS beaches of the accuracy of surveyors correctly distinguishing between nests and false crawls, the probability that a nest counted by a surveyor was actually a nest was 96%. Nest density classifications of “low”, “medium” and “high” were determined for each species for each survey area based on average nest densities during the five-year period to which these data apply. Nest density was defined as the number of nests per kilometer of surveyed nesting beach habitat. Quartile break values at 25 and 75 percent of the observations were used in assigning nesting beaches to the three density categories. Categories were assigned as follows: “low” = density values less than or equal to the lower 25%, “medium” = nest density values greater than 25% and less than or equal to 75%, and “high” = nest density values greater than 75%. Beaches with zero density values were excluded from the quartile ranking calculations. Density classifications for loggerheads (Caretta caretta) were calculated for each of the seven Florida genetic subunits, after Shamblin et al. (Genetic structure of the southeastern United States loggerhead turtle nesting aggregation: evidence of additional structure within the peninsular Florida recovery unit, 2011, Marine Biology 158:571-587). Green turtle (Chelonia mydas) and Leatherback (Dermochelys coriacea) nesting data were both classified relative to all statewide nesting beaches because unique genetic subunits within Florida have not yet been described for those species. Nest density values were not calculated for Kemp’s ridleys and hawksbills because of the rareness of nesting by these species. Use of the quartile-based ranks (low, medium, high) to compare the level of nesting activity across beaches is recommended over the use of average nesting densities due to the variation of survey parameters (e.g., frequency, duration) and the dynamic nature of sea turtle nesting.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20160101

Ending_Date: 20201231

Currentness_Reference: 2016-2020 sea turtle nesting beach survey seasons

Status:

Progress: Complete

Maintenance_and_Update_Frequency: Annually

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -87.518470

East_Bounding_Coordinate: -80.031446

North_Bounding_Coordinate: 30.705343

South_Bounding_Coordinate: 24.545014

Keywords:

Theme:

Theme_Keyword_Thesaurus: User

Theme:

Theme_Keyword_Thesaurus: EPA GIS Keyword Thesaurus

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: sea turtle nesting

Place:

Place_Keyword_Thesaurus: None

Access_Constraints: None

Use_Constraints:

All data must be verified by Principle Investigator or Group Database Analyst prior to release. It is strongly recommended that these data are directly acquired from FWC and not indirectly through other sources which may have changed the data in some way. FWC makes no claims as to suitability of these data for other purposes. Acknowledgment of the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute as the data source would be appreciated in any products developed from these data. Such acknowledgment as is standard for citation and legal practices for data source is expected by users of these data. Please cite the original metadata when using portions of the record to create a similar record of slightly altered data, such as reprojection. If any data are modified or adjusted, please share the edited information with FWC. Users should be aware that comparison with other data sets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in mapping conventions, data collection, and computer processes over time. FWC shall not be liable for improper or incorrect use of these data. These data are not legal documents and are not to be used as such. It should be noted that shapefiles consisting of Statewide survey areas are general representations.

Data_Set_Credit:

Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, Statewide Nesting Beach Survey program coordinator

Native_Data_Set_Environment: Version 6.2 (Build 9200) ; Esri ArcGIS 10.8.1.14362

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: String

Point_and_Vector_Object_Count: 456

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: GIS_Web.FWC.sea_turtle_nest_density

Attribute:

Attribute_Label: cmDensClass

Attribute_Definition:

Nest density classifications of “low”, “medium” and “high” were determined for each species for each survey area based on average nest densities during the five-year period to which these data apply. Nest density was defined as the number of nests per kilometer of surveyed nesting beach habitat. Quartile break values at 25 and 75 percent of the observations were used in assigning nesting beaches to the three density categories. Categories were assigned as follows: “low” = density values less than or equal to the lower 25%, “medium” = nest density values greater than 25% and less than or equal to 75%, and “high” = nest density values greater than 75%. Beaches with zero density values were excluded from the quartile ranking calculations. Density classifications for green turtles (Chelonia mydas) were calculated for each Florida genetic subunits after Shamblin et al. (2015).

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: genSubUntCc

Attribute_Definition:

The genetic subunits identified for loggerheads nesting within Florida.

Attribute_Definition_Source: Shamblin et al. 2011 Marine Biology 158:571-587

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: Esri

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: lkPresent

Attribute_Definition:

Lepidochelys kempii (Kemp's ridley) occurrence during the five-year survey period. Occurrence is represented as yes (nesting by this species was observed) or no (nesting by this species was not observed).

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: genSubUntCm

Attribute_Definition:

The genetic subunits identified for green turtles nesting within Florida after Shamblin et al. (2015).

Attribute_Definition_Source:

Shamblin, B. M., D. A. Bagley, L. M. Ehrhart, N. A. Desjardin, R. E. Martin, K. M. Hart, E. Naro-Maciel, K. Rusenko, J. C. Stiner, D. Sobel, C. Johnson, T. J. Wilmers, L. J. Wright, and C. J. Nairn. 2015. Genetic structure of Florida green turtle rookeries as indicated by mitochondrial DNA control region sequences. Conservation Genetics 16:673–685

Attribute:

Attribute_Label: Beach

Attribute_Definition: Unique name of the statewide nesting beach survey segment.

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: muLength

Attribute_Definition:

The average length of the nesting beach survey effort (values in meters).

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: eiPresent

Attribute_Definition:

Eretmochelys imbricata (Hawksbill) occurrence during the five-year survey period. Occurrence is represented as yes (nesting by this species was observed) or no (nesting by this species was not observed).

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: County

Attribute_Definition: Florida county name.

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: Esri

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: dcDensClass

Attribute_Definition:

Nest density classifications of “low”, “medium” and “high” were determined for each species for each survey area based on average nest densities during the five-year period to which these data apply. Nest density was defined as the number of nests per kilometer of surveyed nesting beach habitat. Quartile break values at 25 and 75 percent of the observations were used in assigning nesting beaches to the three density categories. Categories were assigned as follows: “low” = density values less than or equal to the lower 25%, “medium” = nest density values greater than 25% and less than or equal to 75%, and “high” = nest density values greater than 75%. Beaches with zero density values were excluded from the quartile ranking calculations. Leatherback (Dermochelys coriacea) nesting data were classified relative to all statewide nesting beaches because unique genetic subunits within Florida have not yet been described for the species.

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: ccDensClass

Attribute_Definition:

Nest density classifications of “low”, “medium” and “high” were determined for each species for each survey area based on average nest densities during the five-year period to which these data apply. Nest density was defined as the number of nests per kilometer of surveyed nesting beach habitat. Quartile break values at 25 and 75 percent of the observations were used in assigning nesting beaches to the three density categories. Categories were assigned as follows: “low” = density values less than or equal to the lower 25%, “medium” = nest density values greater than 25% and less than or equal to 75%, and “high” = nest density values greater than 75%. Beaches with zero density values were excluded from the quartile ranking calculations. Density classifications for loggerheads (Caretta caretta) were calculated for each of the seven Florida genetic subunits (three on the east coast), after Shamblin et al. (Genetic structure of the southeastern United States loggerhead turtle nesting aggregation: evidence of additional structure within the peninsular Florida recovery unit, 2011, Marine Biology 158:571-587).

Attribute:

Attribute_Label: nYearsSurvey

Attribute_Definition:

The number of years, during the last five, that the beach segment was surveyed (<=5).

Attribute_Definition_Source: FWC-FWRI

Attribute:

Attribute_Label: Shape.len

Metadata_Reference_Information:

Metadata_Date: 20221024

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute

Contact_Position: Statewide Nesting Beach Survey program coordinator

Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Use_Constraints:

All data must be verified by Principle Investigator or Group Database Analyst prior to release. It is strongly recommended that these data are directly acquired from FWC and not indirectly through other sources which may have changed the data in some way. FWC makes no claims as to suitability of these data for other purposes. Acknowledgment of the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute as the data source would be appreciated in any products developed from these data. Such acknowledgment as is standard for citation and legal practices for data source is expected by users of these data. Please cite the original metadata when using portions of the record to create a similar record of slightly altered data, such as reprojection. If any data are modified or adjusted, please share the edited information with FWC. Users should be aware that comparison with other data sets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in mapping conventions, data collection, and computer processes over time. FWC shall not be liable for improper or incorrect use of these data. These data are not legal documents and are not to be used as such. It should be noted that shapefiles consisting of Statewide survey areas are general representations.