Manatee Distribution and Habitat Use in the Northern Gulf
USGS works with partners to assess manatee distribution and habitat use throughout the Northern Gulf.
The Science Issue and Relevance: Florida manatees range along the Gulf coast from Florida to Texas, although little is known about manatee use areas and habits west of the Suwannee River. Along with a documented increase in the Crystal River subpopulation, winter use at alternate natural springs in northwestern Florida is increasing. Several warm water refuges in this region are the focus of a USGS integrated study on manatee carrying capacity of northwestern Florida springs, for which detailed data on manatee use are needed. Also, agency interests in the distribution and movement patterns of manatees along the northern Gulf increased dramatically following the Deepwater Horizon oil spill in 2010. Trends in sighting data suggest recent increases in use by manatees of near-shore coastal areas of western Florida, Alabama, Mississippi, Louisiana, and Texas. The U.S. Fish and Wildlife Service (USFWS) Manatee Recovery Plan and 5-year Status Review for the West Indian Manatee both identify natural springs in northern Florida as important winter habitat for manatees and recommend protection measures to ensure their future availability to manatees. Research on manatee resource use along the northwestern range will address informational needs necessary for effective management actions.
Methodology for Addressing the Issue: The area of interest for this study extends from the Suwannee River, Florida, west along the Gulf coast through Texas. Manatee distribution and habitat will be assessed through several research actions involving multiple agencies and partners. Reporting of manatee sightings from this area are compiled in a central database through coordination with local, state, and federal partners. Photo identification field efforts are enhanced through site visits by staff to selected aggregation sites, and through coordinated participation with partners. Tissue sampling of individual manatees for USGS genetic-based studies is being coordinated under USFWS permit. Radio tracking studies are conducted to determine local and regional movement and habitat use patterns. Identification of specific manatee resources will be accomplished through the use of remotely-monitored GPS tracking devices and field observations. Salinity and temperature loggers will be deployed on tagged individuals and at key sites within use areas to typify variations in timing and spatial extent of freshwater and warm-water resources. Tracking and field data are analyzed for specific resource use patterns, including identification and characterization of overwintering, foraging, and freshwater access sites, and statistics are applied to address trends in manatee abundance and distribution within discrete habitat/study units. The discerned patterns of zonal use determined through analyses of radio tracking data are valuable to parameterize models for statistically-sound aerial surveys for trends in distribution. Activities are conducted in accordance with USFWS permit issued to the USGS/Sirenia Project and comply with USGS/SESC IACUC standards.
Future Steps: This research initiative is part of an extended study on manatee distribution and use patterns in the Gulf, and characterization of local resources. The extent of field efforts has been developed on a regional basis, targeting areas with appropriate habitat or consistent manatee use, coupled with interest and participation among cooperating agencies. Specific areas for manatee radio tagging are based on field monitoring logistics and federal or state management needs. Based on cooperative interactions with agencies addressing the oil spill, there is continued interest within DOI to understand the relationship of manatee distribution and habitat use to Gulf activities.
USGS works with partners to assess manatee distribution and habitat use throughout the Northern Gulf.
The Science Issue and Relevance: Florida manatees range along the Gulf coast from Florida to Texas, although little is known about manatee use areas and habits west of the Suwannee River. Along with a documented increase in the Crystal River subpopulation, winter use at alternate natural springs in northwestern Florida is increasing. Several warm water refuges in this region are the focus of a USGS integrated study on manatee carrying capacity of northwestern Florida springs, for which detailed data on manatee use are needed. Also, agency interests in the distribution and movement patterns of manatees along the northern Gulf increased dramatically following the Deepwater Horizon oil spill in 2010. Trends in sighting data suggest recent increases in use by manatees of near-shore coastal areas of western Florida, Alabama, Mississippi, Louisiana, and Texas. The U.S. Fish and Wildlife Service (USFWS) Manatee Recovery Plan and 5-year Status Review for the West Indian Manatee both identify natural springs in northern Florida as important winter habitat for manatees and recommend protection measures to ensure their future availability to manatees. Research on manatee resource use along the northwestern range will address informational needs necessary for effective management actions.
Methodology for Addressing the Issue: The area of interest for this study extends from the Suwannee River, Florida, west along the Gulf coast through Texas. Manatee distribution and habitat will be assessed through several research actions involving multiple agencies and partners. Reporting of manatee sightings from this area are compiled in a central database through coordination with local, state, and federal partners. Photo identification field efforts are enhanced through site visits by staff to selected aggregation sites, and through coordinated participation with partners. Tissue sampling of individual manatees for USGS genetic-based studies is being coordinated under USFWS permit. Radio tracking studies are conducted to determine local and regional movement and habitat use patterns. Identification of specific manatee resources will be accomplished through the use of remotely-monitored GPS tracking devices and field observations. Salinity and temperature loggers will be deployed on tagged individuals and at key sites within use areas to typify variations in timing and spatial extent of freshwater and warm-water resources. Tracking and field data are analyzed for specific resource use patterns, including identification and characterization of overwintering, foraging, and freshwater access sites, and statistics are applied to address trends in manatee abundance and distribution within discrete habitat/study units. The discerned patterns of zonal use determined through analyses of radio tracking data are valuable to parameterize models for statistically-sound aerial surveys for trends in distribution. Activities are conducted in accordance with USFWS permit issued to the USGS/Sirenia Project and comply with USGS/SESC IACUC standards.
Future Steps: This research initiative is part of an extended study on manatee distribution and use patterns in the Gulf, and characterization of local resources. The extent of field efforts has been developed on a regional basis, targeting areas with appropriate habitat or consistent manatee use, coupled with interest and participation among cooperating agencies. Specific areas for manatee radio tagging are based on field monitoring logistics and federal or state management needs. Based on cooperative interactions with agencies addressing the oil spill, there is continued interest within DOI to understand the relationship of manatee distribution and habitat use to Gulf activities.