Seagrass Beds and Manatee Foraging Areas in the Ten Thousand Islands: Mapping and Characterizing by Incorporating Manatee GPS Tracking Data and Habitat Information Completed
Turbid water conditions make the delineation and characterization of benthic habitats difficult by traditional in situ and remote sensing methods. Consequently, only a small fraction of this valuable resource has been mapped or characterized.
The Science Issue and Relevance: Turbid water conditions make the delineation and characterization of benthic habitats difficult by traditional in situ and remote sensing methods. Consequently, only a small fraction of this valuable resource has been mapped or characterized. A large population of Florida manatees (Trichechus manatus latirostris) utilizes the resources in and around the TTI area, but because of the lack of adequate seagrass maps, the extent of possible manatee foraging areas and the amount of available forage are not documented. Knowledge of these forage resources for manatees will become more important in the next few decades as power plants that the animals have relied on shut down, and more animals are predicted to migrate south to TTI and the Everglades. In addition, other species, such as fish and sea turtles, rely on these seagrass beds for shelter and forage.
Methodology for Addressing the Issue: Here, we developed and validated modeling and sampling methodology for detecting and characterizing seagrass beds by analyzing GPS telemetry records from radio-tagged manatees. We developed a camera-based quadrat sampler that has proven to be both efficient and sensitive to differences in seagrass abundance and species richness. Other that the novel telemetry analysis and camera sampler, other sampling strategies are conventional, including spatially stratified sampling, 6” core samples for biomass measures of roots and shoots, and in situ shoot counts. We are analyzing the data is with a custom Bayesian zero-inflated negative binomial with a censored upper tail, and with a custom spatial Bayesian logistic model to predict spatial locations of seagrass.
Future Steps: Our camera-based field sampling proved to be effective for assessing seagrass density and spatial coverage under turbid water conditions, and would be an effective monitoring tool to detect changes in seagrass beds from climate change, sea level rise, or Everglades restoration. We are currently applying the lessons learned, and techniques and methodology developed in this project to other projects and areas. We will be authoring the TTI chapter of the upcoming State of Florida Seagrass Integrated Monitoring and Management (SIMM) publication. We are producing several publications from the TTI seagrass project.
Related Project(s):
- Comprehensive Everglades Restoration, USGS A7R-33
- Northern Gulf of Mexico Manatee Distribution and Habitat Use, USGS A7R-35
- Winter aggregations of Florida manatees and their habitat use, USGS A7R-36
- Puerto Rico: characterization of manatee habitat and use, USGS A7R-37
- Guantanamo Bay, Cuba: habitat use of Antillean manatees. USGS GGCSSB0000-5
- Deepwater Horizon NRDAR Assessment: manatees.
Below are other science projects associated with this project.
Monitoring and Assessing Effects of the Picayune Strand Restoration Project (PSRP) on the Florida Manatee
Below are publications associated with this project.
Manatee grazing impacts on a mixed species seagrass bed
Mapping spatial resources with GPS animal telemetry: foraging manatees locate seagrass beds in the Ten Thousand Islands, Florida, USA
Manatees mapping seagrass (USA & Puerto Rico)
- Overview
Turbid water conditions make the delineation and characterization of benthic habitats difficult by traditional in situ and remote sensing methods. Consequently, only a small fraction of this valuable resource has been mapped or characterized.
The Science Issue and Relevance: Turbid water conditions make the delineation and characterization of benthic habitats difficult by traditional in situ and remote sensing methods. Consequently, only a small fraction of this valuable resource has been mapped or characterized. A large population of Florida manatees (Trichechus manatus latirostris) utilizes the resources in and around the TTI area, but because of the lack of adequate seagrass maps, the extent of possible manatee foraging areas and the amount of available forage are not documented. Knowledge of these forage resources for manatees will become more important in the next few decades as power plants that the animals have relied on shut down, and more animals are predicted to migrate south to TTI and the Everglades. In addition, other species, such as fish and sea turtles, rely on these seagrass beds for shelter and forage.
Methodology for Addressing the Issue: Here, we developed and validated modeling and sampling methodology for detecting and characterizing seagrass beds by analyzing GPS telemetry records from radio-tagged manatees. We developed a camera-based quadrat sampler that has proven to be both efficient and sensitive to differences in seagrass abundance and species richness. Other that the novel telemetry analysis and camera sampler, other sampling strategies are conventional, including spatially stratified sampling, 6” core samples for biomass measures of roots and shoots, and in situ shoot counts. We are analyzing the data is with a custom Bayesian zero-inflated negative binomial with a censored upper tail, and with a custom spatial Bayesian logistic model to predict spatial locations of seagrass.
Future Steps: Our camera-based field sampling proved to be effective for assessing seagrass density and spatial coverage under turbid water conditions, and would be an effective monitoring tool to detect changes in seagrass beds from climate change, sea level rise, or Everglades restoration. We are currently applying the lessons learned, and techniques and methodology developed in this project to other projects and areas. We will be authoring the TTI chapter of the upcoming State of Florida Seagrass Integrated Monitoring and Management (SIMM) publication. We are producing several publications from the TTI seagrass project.
Related Project(s):
- Comprehensive Everglades Restoration, USGS A7R-33
- Northern Gulf of Mexico Manatee Distribution and Habitat Use, USGS A7R-35
- Winter aggregations of Florida manatees and their habitat use, USGS A7R-36
- Puerto Rico: characterization of manatee habitat and use, USGS A7R-37
- Guantanamo Bay, Cuba: habitat use of Antillean manatees. USGS GGCSSB0000-5
- Deepwater Horizon NRDAR Assessment: manatees.
- Science
Below are other science projects associated with this project.
Monitoring and Assessing Effects of the Picayune Strand Restoration Project (PSRP) on the Florida Manatee
Critical information predicting condition changes in manatee habitat resulting from the alteration of freshwater flows to estuaries is needed to develop the PSRP Detailed Design and PSRP Operations Plan components and complete consultation under the Endangered Species Act. - Publications
Below are publications associated with this project.
Manatee grazing impacts on a mixed species seagrass bed
The endangered manatee Trichechus manatus is one of few large grazers in seagrass systems. To assess the long-term impacts of repeated grazing on seagrasses, we selected a study site within Kennedy Space Center in the northern Banana River, Brevard County, Florida, that was typically grazed by large numbers of manatees in spring. Two 13x13 m manatee exclosures and 2 paired open plots of equal sizeAuthorsLynn W. Lefebvre, Jane A. Provancha, Daniel H. Slone, W. Judson KenworthyMapping spatial resources with GPS animal telemetry: foraging manatees locate seagrass beds in the Ten Thousand Islands, Florida, USA
Turbid water conditions make the delineation and characterization of benthic habitats difficult by traditional in situ and remote sensing methods. Here, we develop and validate modeling and sampling methodology for detecting and characterizing seagrass beds by analyzing GPS telemetry records from radio-tagged manatees. Between October 2002 and October 2005, 14 manatees were tracked in the Ten ThouAuthorsDaniel H. Slone, James P. Reid, W. Judson KenworthyManatees mapping seagrass (USA & Puerto Rico)
West Indian manatees (Trichechus manatus) are secretive creatures. While some of their behaviours at winter aggregation sites in Florida are readily visible to the casual observer, many of their habits and movements are difficult to observe. They rely on submerged vegetation for nutrition, and seagrasses are one of their most important food sources.AuthorsDaniel H. Slone, James P. Reid, W. Judson Kenworthy, Giuseppe Di Carlo, Susan M. Butler