Clinical Pathology Reference Intervals for an In-Water Population of Juvenile Loggerhead Sea Turtles (Caretta caretta) in Core Sound, North Carolina, USA

Abstract

The loggerhead sea turtle (Caretta caretta) is found throughout the waters of the Atlantic, Pacific, and Indian Oceans. It is a protected species throughout much of its range due to threats such as habitat loss, fisheries interactions, hatchling predation, and marine debris. Loggerheads that occur in the southeastern U.S. are listed as “threatened” on the U.S. Endangered Species List, and receive state and federal protection. As part of an on-going population assessment conducted by the National Marine Fisheries Service, samples were collected from juvenile loggerhead sea turtles in Core Sound, North Carolina, between 2004 and 2007 to gain insight on the baseline health of the threatened Northwest Atlantic Ocean population. The aims of the current study were to establish hematologic and biochemical reference intervals for this population, and to assess variation of the hematologic and plasma biochemical analytes by season, water temperature, and sex and size of the turtles. Reference intervals for the clinical pathology parameters were estimated following Clinical Laboratory Standards Institute guidelines. Season, water temperature, sex, and size of the turtles were found to be significant factors of variation for parameter values. Seasonal variation could be attributed to physiological effects of decreasing photoperiod, cooler water temperature, and migration during the fall months. Packed cell volume, total protein, and albumin increased with increasing size of the turtles. The size-related differences in analytes documented in the present study are consistent with other reports of variation in clinical pathology parameters by size and age in sea turtles. As a component of a health assessment of juvenile loggerhead sea turtles in North Carolina, this study will serve as a baseline aiding in evaluation of trends for this population and as a diagnostic tool for assessing the health and prognosis for loggerhead sea turtles undergoing rehabilitation.

Clinicopathological findings in sea turtles assessed during the Deepwater Horizon oil spill response

“…Similar concentrations of these analytes have been previously reported for sea turtles (Innis et al 2009, Kelly et al 2015. The upward trend of the Ca:P ratio at Facility A and downward trend at Facility B in green turtles was likely associated with differences in dietary supplementation.…”

“…Limited published hematology and chemistry reference ranges are available for surface-pelagic juvenile sea turtles; thus, the interpretation of blood ab normalities was based on published data from convalescent Kemp's ridley sea turtles (Innis et al 2007, Keller et al 2012, green turtles (Bolten & Bjorndal 1992, Anderson et al 2011, and loggerhead turtles (Casal et al 2009, Kelly et al 2015. The reported data of these studies were extrapolated to produce clinically reasonable analyte ranges for surface-pelagic immature turtles.…”

Blood analytes of oceanic-juvenile loggerhead sea turtles (Caretta caretta) from Azorean waters: reference intervals, size-relevant correlations and comparisons to neritic loggerheads from western Atlantic coastal waters

“…For analytes that could not be transformed to meet the assumptions of normality, the robust method for determining reference intervals was utilized. Any outliers were identified using the Dixon-Reed outlier test; these values were not removed, but are indicated when appropriate ( Kelly et al , 2015 ).…”

“…Therefore, blood analysis has been widely used in health assessment studies and mortality investigations and is increasingly applied as an important part of the development of conservation strategies for sea turtle populations worldwide. Various studies document blood analyte data of loggerhead turtles at various life stages, including nesting or adult foraging, and from different geographic regions ( Bolten et al , 1992 , 1994 ; Casal et al , 2009 ; Deem et al , 2009 ; Flint et al , 2010 ; Kelly et al , 2015 ). However, published data of the wild oceanic-juvenile life stage is limited ( Delgado et al , 2011 ).…”

Acid-Base and Plasma Biochemical Changes Using Crystalloid Fluids in Stranded Juvenile Loggerhead Sea Turtles (Caretta caretta)

“…Fluid choice should be based on patient assessment and plasma biochemistry and blood gas values [ 10 ]. However, although hematologic and plasma biochemical values from loggerhead turtles have been described [ 8 , 11 – 13 ], reports of blood gas and acid-base status of loggerhead turtles are limited [ 3 , 4 , 14 , 15 ]. In addition, the wide range for some of these reference values usually makes difficult to assess the dehydration status and to choose the appropriate fluid.…”