April 19, 2024

Increases in Seasonal Manatee (Trichechus manatus latirostris) Abundance Within Citrus County, Florida


Joyce M. Kleen and Amber D. Breland


Abstract: Identified as critical winter manatee habitat, the U.S. Fish and Wildlife Service (USFWS) has documented a significant increase in peak and average Florida manatee (Trichechus manatus latirostris) counts during the winter months in Citrus County and Kings Bay, Florida. Manatees use the warm 22º C spring-fed waters of Kings Bay when water temperatures drop below 20º C in the Gulf of Mexico. The USFWS manages winter manatee sanctuaries positioned over and near the bay’s warm-water springs. Simple linear regressions of aerial survey data collected between 1983 and 2012 indicate that the peak counts for the survey period were 654 manatees occurring on 5 January 2012 in Citrus County and 566 manatees occurring on 13 January 2010 in Kings Bay. The average winter count has increased from 102 ± 5 (1983) to 216 ± 49 (2012) in Citrus County and from 73 ± 6 (1983) to 148 ± 41 (2012) in Kings Bay. Summer surveys were conducted consistently between 2004 and 2012. No significant change in peak or average manatee abundance was detected during this period. The increase in winter manatee counts prompted the need to review existing manatee protection measures, including manatee use within the sanctuaries. Additional analysis of habitat quality (i.e., salinity, plant community, disturbance caused by human recreation) on the abundance and distribution of manatees in the bay is needed to promote adaptive manatee management in the bay.
Key Words: Sirenian, Kings Bay, Citrus County, springs, aerial surveys, Florida manatee, Trichechus manatus latirostris
Document Type: Research article
DOI: 10.1578/AM.40.1.2014.69
Page Numbers: 69-80

Info SKU: Vol__40__Iss__1__Kleen Category: