Grant: 18-002R
Project Title: Impacts of the fire ant pesticide AMDRO® on reproductive success, hatchling quality, and behavior of loggerhead sea turtles (Caretta caretta): Year 1
Project Manager: Dr. Justin Perrault
Organization: Loggerhead Marinelife Center (Non-Profit Organization)
Grant Amount: $15,009.00
Completion Date: 2019-06-24
Summary: Sea turtle nests are vulnerable to poaching, nest inundation, climate change, and invasive predators, one of which is the red imported fire ant (Solenopsis invicta). The ants will prey upon hatchling sea turtles while they are emerging from their eggs underground, emerging from the egg chamber, or while the turtles are crawling during disorientation events. While the impacts of fire ants on sea turtle nests are low, these organisms still represent an important source of mortality at some beaches in Florida, especially those with low nesting densities. The goal of this project is to determine if AMDRO®, a fire ant pesticide, can be used effectively to provide protection without impacting the physiology of nesting loggerhead females, the productivity of their nests, or the quality of their hatchlings. This project will (i) document whether concentrations of hydramethylnon (the active ingredient in AMDRO®) accumulate in nesting female plasma, their unhatched eggs, dead-in-nest embryos, and dead-in-nest hatchlings; (ii) determine if nests treated with AMDRO® experience reduced hatching and emergence success in comparison to control nests; (iii) determine if loggerhead hatchlings from nests treated with AMDRO® have an altered body condition index (BCI) compared to hatchlings from control nests; and (iv) compare and contrast the seafinding orientation performance of turtles whose nests are treated with AMDRO® with hatchlings from natural nests and nests treated with an inert control substance. 
Results: The staff of Loggerhead Marinelife Center collected samples and marked nests for this project from June 18–June 29, 2018. We collected plasma samples from 25 nesting loggerhead turtles. In total, 125 nests were marked for this study (25 no treatment controls, 50 vehicle/corn grit/soybean oil controls, and 50 AMDRO®-treated nests). Fourteen of those nests washed out or were predated, leaving us with a total of 111 nests used in this study. We found that AMDRO® had no effect on hatchling morphology or reproductive success (shown in Fig. 1 as hatching success) using one-way analysis of variance. It also had no effect on the ability of hatchlings to orient toward the ocean (a visually mediated response; Fig. 2), analyzed using Rayleigh tests. However, we did notice significantly more ant and crab predators at treatment nests than are normally seen at our study site. Thus, while AMDRO® might not directly impact reproductive success or hatchling behavior, it had the unanticipated effect of possibly increasing nest vulnerability to predators.