DAO prepress abstract  -  DOI: https://doi.org/10.3354/dao03194

Brevetoxin exposure in sea turtles in south Texas during Karenia brevis red tide

Jennifer Shelby Walker, Donna J. Shaver*, Brian A. Stacy, Leanne J. Flewelling, Margaret H. Broadwater, Zhihong Wang

*Email: donna_shaver@nps.gov

ABSTRACT: Five green (Chelonia mydas) and 11 Kemp’s ridley (Lepidochelys kempii) sea turtles found dead, or that died soon after stranding, on the southern Texas coast during 2 Karenia brevis blooms (October 2015, September–October 2016) were tested for exposure to brevetoxins. Tissues (liver, kidney) and digesta (stomach and intestinal contents) were analyzed by ELISA. Three greens found alive during the 2015 event and 2 Kemp’s ridleys found alive during the 2016 event exhibited signs of brevetoxin exposure, including lethargy and/or convulsions of the head and neck. Brevetoxins (PbTx) were detected in one or more tissues or digesta in all 16 stranded turtles. Detected PbTx concentrations ranged from 2 ng g-1 to >2000 ng g-1. Necropsy examination and results of brevetoxin analysis indicated 10 of the Kemp’s ridleys and 2 of the greens died from brevetoxicosis via ingestion. This is the first documentation of sea turtle mortality in Texas attributed to brevetoxicosis.