# Presentation: 284390

## The Florida Manatee in the Suwannee River and Estuary: Past, Present, and Future 

**The Florida Manatee in the Suwannee River and Estuary: Past, Present, and Future**

- Catherine A. Langtimm, Cathy A. Beck,
- Robert K. Bonde, James P. Reid
- Sirenia Project, Florida Integrated Science Center

**U.S. Department of the Interior**
**U.S. Geological Survey**

## Florida manatee: 

- Manatees require seagrass and freshwater vegetation for forage, freshwater for drinking, and warm water refugia to survive cold winters.

- Florida manatee:
- Federal and State listed endangered marine mammal

## Slide 3

## USGS Research Aerial Surveys: 

- USGS Research Aerial Surveys:

- 1978 – present
- (USGS and CRNWR)

## USGS Research Aquatic Vegetation Surveys: 

- USGS Research Aquatic Vegetation Surveys:

- 1974 – present
- (USGS and CRNWR)

## USGS Research Carcass Salvage: 

- USGS Research Carcass Salvage:

- 1974-1985 (USGS)
- 1985-present (FWC)

- Total of 250 carcasses collected in NW region (12/1974 – 6/2004)

## USGS Research Radio Telemetry:  

- USGS Research Radio Telemetry:

- 1978-1985 (USGS)  (N = 30)
- 1998-present (USGS, FWC, UF) (N = 6)

- 36 radio-tagged in NW region

## USGS ResearchManatee Photo-identification: 

- USGS ResearchManatee Photo-identification:

- 1967 – present
- 419 manatees photographically documented in NW region to date;
- 21 of these manatees have been documented at Manatee Springs

## Current USGS Research 

- Current USGS Research

- Monitor and estimate population parameters and status for the Northwest subpopulation
- Primary focus on photo-identification at the headwaters of the Crystal and Homosassa rivers, additional emphasis at Manatee Springs
- Supplement population research utilizing genetic analyses

## Manatees as Indicators of Ecosystem Change &  USGS  Capabilities 

- Manatees as Indicators of Ecosystem Change &  USGS  Capabilities

- The winter warm-water refuges and summer foraging areas used by manatees are dependent on important ecosystem processes in the Suwannee.
- Long-term monitoring of manatees in the region will facilitate identifying and quantifying the effects of perturbations on manatee survival and reproduction.

- We now can utilize population models to combine population and habitat data.

## The Hurricane Example: 

- The Hurricane Example:

- Retrospective analysis of photo-identification data with capture-recapture statistical models.
- Identified an effect of extreme storms on adult survival rates.
- Natural experiment now in progress with the 2004 storms.

## Year	      Storm	         Survival 	95% CI	

1985	     Elena (3)	  	0.936       (0.864-0.971)

      Storm of the	0.909       (0.837-0.951)
		    Century (3)

1995      Opal (4)		0.817       (0.735-0.878)

No storm years	 	0.972       (0.961-0.980)			

- _Year__	__      Storm__	__         Survival __	__95% CI__	_
- 1985	     Elena (3)	  	0.936       (0.864-0.971)
-       Storm of the	0.909       (0.837-0.951)
- 		    Century (3)
- 1995      Opal (4)		0.817       (0.735-0.878)
- No storm years	 	0.972       (0.961-0.980)

## Future Research

- Need for Federal and State Resource Managers to assess the status of manatees under growing habitat concerns:
-   loss of winter warm-water refuges and
-   loss of foraging habitat
- Solutions will require an ecosystem level approach that will necessitate the protection and enhancement of current habitats, identification of additional sites that might be developed for manatee use, and incorporate integrated research of biotic and abiotic processes.