Seasonal Variation in Sea Turtle Density and Abundance in the Southeast Florida Current and Surrounding Waters

Assessment and management of sea turtle populations is often limited by a lack of available
data pertaining to at-sea distributions at appropriate spatial and temporal resolutions.
Assessing the spatial and temporal distributions of marine turtles in an open system poses
both observational and analytical challenges due to the turtles’ highly migratory nature. Surface
counts of marine turtles in waters along the southern part of Florida’s east coast were
made in and adjacent to the southeast portion of the Florida Current using standard aerial
surveys during 2011 and 2012 to assess their seasonal presence. This area is of particular
concern for sea turtles as interest increases in offshore energy developments, specifically
harnessing the power of the Florida Current. While it is understood that marine turtles use
these waters, here we evaluate seasonal variation in sea turtle abundance and density over
two years. Density of sea turtles observed within the study area ranged from 0.003 turtles
km-2 in the winter of 2011 to 0.064 turtles km-2 in the spring of 2012. This assessment of
marine turtles in the waters off southeast Florida quantifies their in-water abundance across
seasons in this area to establish baselines and inform future management strategies of
these protected species.