Abstract

Since 2013, the Virginia Aquarium Stranding Response Program (VAQS) has experienced an increasing number of reports of sea turtles incidentally caught by recreational fishermen. With the inception of the Virginia Pier Partner Program in 2014, the number of hooked turtles admitted into rehabilitation, predominantly Kemp's ridley sea turtles (Lepidochelys kempii), increased as well. As a result, we updated our admission protocols and release criteria to better address these cases of relatively healthy animals presenting with only minor injuries related to hook trauma. Most hooked turtles were admitted in May and June, when turtles typically migrate to foraging grounds in the Chesapeake Bay and surrounding waters. When attempting to clear these turtles for release, albumin levels were found to be below the acceptable level for release (1.0 g/dL), as well as below the mean albumin level for wild Kemp's ridleys (1.3 g/dL).¹ Additionally, albumin levels must be processed by an outside laboratory with a 1–2 day turnover, making prompt assessment and release at the fishing pier impossible. In an effort to improve assessment of hooked turtles, we hypothesized that: 1) these early-season animals are recent migrants to the area that may have decreased albumin levels in the spring; 2) admit albumin levels would increase as the season progressed and turtles switched from migrating behavior to foraging behavior; and 3) that turtles admitted into rehab due to hook interactions would not be statistically different from wild turtles caught for research during that same time period. All blood samples were processed by IDEXX Laboratories, Inc. and blood values from the 2014 and 2015 seasons were used for "hooked" (n = 32) and research caught, "wild" (n = 4) Kemp's ridleys. There was no statistical difference between albumin levels in wild caught turtles and hooked turtles when the 2014 and 2015 season's values were combined (t = 1.1229, p = 0.31). When the albumin levels for hooked Kemp's ridleys were analyzed with a Kruskal-Wallis test by the month of the capture, the albumin level was statistically different among the months of capture (χ = 14.5936, p = 0.002), and the mean albumin level increased over the course of the season. A non-parametric Tukey and Kramer post-hoc rank comparison test confirmed that May was statistically different from July and August and that June and July were both significantly different from August, but not from each other. Additionally, the blood parameters for hematocrit, total protein, and cholesterol did not vary significantly over the course of the season or between wild and hooked turtles. These results suggest that release criteria using a standard albumin value of > 1.0 g/dL may be inappropriate in temperate areas for recent migrants. Instead, albumin levels appear to naturally vary across the course of the season in Virginia, so other seasonally stable parameters, such as hematocrit, for which there are species-specific acceptable values, may be more appropriate for evaluating health regardless of seasonality.

Acknowledgements

We would like to thank our Pier Partners, recreational fishermen, and Virginia Aquarium & Marine Science Center staff, interns, and volunteers for their continued efforts to support hooked sea turtle response.

* Presenting author

Literature Cited

1.  George RH. 14 health problems and diseases of sea turtles. In: Lutz PL, Musick JA, eds. The Biology of Sea Turtles. Boca Raton, FL: CRC Press; 1996:363–385.