Preliminary results have revealed the following:

All but one turtle was in the subadult size class. Preliminary results for morphometric measurement data are as follows:

Body weight: mean 69.36 lbs +/-11.01
Range: 50.50 to 90.50 lbs
CCL n-n: mean 76.31 cm +/- 11.97
Range: 60.50-100 cm
CCL n-t: mean 78.06 cm +/- 11.80
Range: 61.60-100.50 cm
N=19

Typical clinical pathology abnormalities included: anemia (PCV 4-23%), low total protein (0.4-3.7 g/dl), low glucose, elevated BUN, CPK, sodium and chloride.

Bacterial blood culture results: Only 2 turtles in the study have had positive bacterial cultures on blood: a) Aeromonas hydrophilia, b) Shewanella putrifaciens (formerly Pseudomonas putrifaciens)

Gross necropsy summary: consistent findings included: serous atrophy of fat, barnacles in oral cavity, clear yellow fluid in the coelom, an enlarged gall bladder, and colonic ulcerations.

Histopathology summary: Full tissue sets were evaluated microscopically for twenty turtles between 2003 and 2005.  Autolysis of the gastrointestinal tract precluded microscopic evaluation of the stomach or small or large intestine for five of the twenty turtles.  All twenty turtles had marked atrophy of the bone marrow, adipose tissue, and/ or skeletal myofibers consistent with severe emaciation.  All twenty also had spirorchid trematode ova present in multiple organs.  Abundant iron pigment (hemosiderin) was present in the liver of 18/20 (90%) of turtles.  Acute, chronic, or chronic active liver necrosis was present in 12/20 (60%) of turtles.  For all turtles a specific cause for the liver necrosis could not be determined microscopically.  All turtles with liver necrosis did have abundant hemosiderin in the liver.  Ulceration and/or necrosis of the mucosa of the intestine and stomach were present in 13/16 (81%) and 8/18 (44%) of turtles respectively.  Spirorchid trematode ova were present in the wall of the affected region of the gastrointestinal tract for 9/13 (69%) of turtles with intestinal lesions and 6/8 (75%) of turtles with gastric lesions.  No other consistent findings were detected microscopically in the twenty turtles.

Epibiont study: Several new species of epibionts have been identified by Mike Frick from The Caretta Project during the course of the study. Epibiont samples have been forwarded to Dr. Brian Stacey who is interested in elucidating possible intermediate hosts for Spirorchid trematodes.  The following is a preliminary summary of epibionts found on these turtles:

Epibiota on skin
Number of species: Barnacles (5), amphipods (5), leeches (2), snails (2), slugs (1), bivalves (2), polycheate worms (1), crabs (1), hydroids (2), sponges (1),  bryozoans (4),  tanaid (1), algae (1)

Epibiota on Plastron
Number of species: barnacles (5), amphipods (3),  leeches (1),  snails (6),  hydroids (3),  bivalves (1),  bryozoans (3),  tanaid (1),  tunicates (1),  anemone (1)

Epibiota on Carapace
Barnacles (8), amphipods(4), hydroids (5),  bivalves (8),  tanaid (1),  polycheate worms (3),  annelid worms (1), crabs (4),  bryozoans (6),  snails (6),  anemones (2),  coral (1),  tunicates (1),  leeches (1),  algae (2), Barnacle (9), and bivalve species (7)

Species identified:
Chelonibia testudinaria – turtle barnacle
Balanus amphitrite – barnacle
Chelonibia testudinaria – turtle barnacle
Platylepas hexastylos – platylepadid turtle barnacle
Balanus trigonus – barnacle
Balanus eburneus – barnacle
Balanus improvisus – barnacle
Lepas pectinata – barnacle
Megabalanus antilliensis – barnacle
Anthopleura carneola – anemone
Calliactis tricolor – anemone
Astrangia danae – star coral
Molgula manhattensis – tunicate
Codium sp. – algae
Polysiphonia carettia – algae
Bugula neritina – bryozoan
Amathia distins – bryozoa
Membranipora tenuis – bryozoan
Thalamporella floridana – lettuce bryozoan
Zoobotryon verticillatum – bryozoan
Schizoporella unicornis – bryozoan
Membranipora tenuis – bryozoan
Bugula neritina – bryozoan
Crepidula fornicata – slipper snail
Type 1 snail eggs
Type 2 snail eggs
Costoanachis avara – snail
Type 3 snail eggs
Urosalpinx cinerea – Atlantic oyster drill snail
Doriopsilla pharpa – sea slug
Hexapleomera robusta – tanaid crustacean
Hydroides dianthus – feather duster polychaete worm
Sabellaria vulgaris – polychaete worm
Nereis succinea – polychaete worm
Harmothoe aculeata – scale worm, annelida
Eurypanopeus abbreviatus – mud crab
Pilumnus sayi – hairy mud crab
Porcellana sayana – porcelain crab Micropanope nuttingi – xanthid crab
Ozobranchus margoi – leech
Calliobdella vivida – leech
Hexapleomera robusta – tanaid
Cliona celata – sponge
Stylactis hooperi – hydroid
Tubularia crocea – wildflower hydroid
Eudendrium carneum – hydroid
Bougainvillia rugosa – hydroid
Tubularia crocea – hydroid
Halocordyle disticha – hydroid

Gastrointestinal tract parasites were found commonly in these turtles but typically did not contribute significantly to the turtle’s debilitation. Adult parasites and ova were identified by Dr. Ellis Greiner from the University of Florida.  The following summarizes preliminary results for parasites found in these turtles:

Trematodes: Orchidasma amphiorchis, Hapalotrema, Astrochis, Carettacola, Enodiotrema, Pachypsolus, Cymtocarpus, Diaschistorchis, Pleurogonimus, Laphotaspis, Enodiotrema carettae

Nematodes: Cucullanus, Tonaudia, Kathlania, Sulcascaris, Rhytidoides, Ruicephalus, unsporulated coccidian, Plesiochorus cymbifro (found in bladder)
Contaminant analysis is being funded and performed by the NIST laboratory. Overall Hg levels in scutes ranged from 62 ng/g to 3782 ng/g, with a mean and standard deviation of 574 ± 597 ng/g. The Hg concentration in scutes from stranded loggerheads was significantly higher than apparently healthy live captures (Figure 1).  Separating the strandings into chronically ill debilitated turtles and victims of boat strikes shows no difference in Hg levels between debilitated and healthy turtles, but significantly higher (p = 0.0011) Hg in boat strike victims (Figure 1).

These data suggest Hg does not play a role in the debilitated syndrome that has been observed in the southeast United States.  It is not clear whether the higher Hg levels found among boat strike victims is a sampling artifact or is indicative of these individuals having diminished diving behavior due to compromised health or Hg neurotoxicity.  Further analysis of additional samples that have been collected in 2005 from stranded turtles and all samples from rehabilitated turtles still need to be assessed, however, before final conclusions can be drawn.

Samples from necropsied animals have been assessed for some organic contaminants.  Blood, liver, and fat samples were collected for organic contaminant analysis in 2004-2005 from North Carolina to Florida.  Contaminants, including polychlorinated biphenyls (PCBs), pesticides, and polybrominated diphenylethers (PBDEs) were measured in 21 fat samples using gas chromatography/mass spectrometry. Preliminary data analysis suggests that mean PCB 153 and 4,4’-DDE concentrations were 4070 and 2630 ng/g lipid, respectively.  These values are seven times higher than mean concentrations measured in fat biopsies collected from 44 apparently healthy turtles from North Carolina in 2000-2001 (571 and 372 ng/g lipid, respectively).  Mean lipid content in fat of debilitated turtles and healthy turtles was 0.745% and 27.9%, respectively.  These findings suggest that either debilitated turtles accumulate higher contaminant concentrations or contaminants become more concentrated as the lipid stores are depleted.  Either way, preliminary data show that blood contaminant concentrations (wet mass basis) are also 5-10 times higher in debilitated turtles than in healthy turtles.  These higher levels, circulating to target tissues, may contribute to the progression of this illness.  Analysis of additional blood samples of turtles in rehabilitation will assess changes in blood contaminant concentrations during their recovery and may elucidate more information related to this condition.

Immune function testing is being funded and performed by Dr. Margie Peden-Adams from the Medical University of South Carolina (MUSC), Marine Biomedicine and Environmental Science Center.  All immune analysis on rehabbed turtles has been completed but not all data analysis are complete to date.  Preliminary results do not indicate a specific trend at this point in T- or B-cell proliferation but this data must be assessed in relation with clinical blood parameters and contaminant analysis (which to date has not been completed for the rehabilitated turtles).  Superoxide production by phagocytic cells indicates a trend in higher production at stranding/rehabilitation admittance that declines over time during rehabilitation (Figure 2).  Superoxide is a free-radical produce by cells as part of innate immunity that is used to kill bacteria.  As most of these turtles present with secondary infections of some sort and are given antibiotics as a treatment during the rehabilitation process, this trend observed in superoxide production could be expected.  This data still must be assessed in relation to clinical blood parameters and contaminants however, before final conclusions can be drawn.  All the information gathered on immune function  will be compared to data collected from live-capture release studies of apparently healthy turtles being conducted by SCDNR.

Many results and statistical analysis of the data are pending. However, much of the information will be able to be compared to data collected from live-capture release studies of apparently healthy turtles being conducted by SCDNR.  This ability to leverage data collection from healthy loggerheads by working in coordination with SCDNR is an important collaboration that has allowed us to keep sampling cost to a minimum in this project while being able to leverage the study.

Preliminary results from the project were presented at the 2004 Annual meeting to the American Association of Zoo Veterinarians and Wildlife Disease Association and at the International Sea Turtle Symposium in Savannah, GA in January of 2005 and in Greece in 2006.  We plan on preparing a final manuscript(s) for a peer-reviewed journal.

Presentations:

Norton, T.M., M. Dodd, A. Segars, J.M. Keller, M. Peden-Adams, R.D. Day, C. Harms, E. Jacobsen, A. Foley, S. Murphy, W. Cluse, W. Teas, M. Bresette, B. Schroeder, A. Mackinnon and N. Stedman  (2004),   Debilitated loggerhead turtle (Caretta caretta) syndrome along the southeastern US coast: incidence, pathogenesis, and monitoring.  Platform, American Association of Zoo Vets and Wildlife Disease Association annual joint conference.  San Diego, California.

Norton, T.M., M. Dodd, A. Segars, J.M. Keller, M. Peden-Adams, R.D. Day, C. Harms, E. Jacobsen, A. Foley, S. Murphy, W. Cluse, W. Teas, M. Bresette, B. Schroeder, A. Mackinnon and N. Stedman (2005).  Debilitated loggerhead turtle (Caretta caretta) syndrome along the southeastern US coast: incidence, pathogenesis, and monitoring. Platform,  25th Annual Symposium on Sea Turtle Biology and Conservation- Sea Turtle Symposium 2005, Savannah GA.

Day , Rusty D., Jennifer M. Keller, Terry M. Norton, Mark Dodd, Al Segars, David Whitaker, Mike Ardnet, Sally Murphy, Tom Murphy, Dubose Griffin, Matthew Godfrey, Wendy Cluse, Steven Christopher, Michelle Lee, Margie Peden-Adams (2005).  Mercury and health in the loggerhead sea turtle. Poster, 25th Annual Symposium on Sea Turtle Biology and Conservation- Sea Turtle Symposium 2005, Savannah GA.

Jennifer M. Keller, John R. Kucklick, Craig A. Harms, Al L. Segars, Wendy Cluse, Matthew Godfrey, Allison Tuttle, Joanne Braun-McNeill, A. Michelle Lee, Rusty Day, Margie Peden-Adams, Mark Dodd, Terry Norton (2006). Organic Contaminant Concentrations Are Higher In Debilitated Loggerhead Turtles Compared To Apparently Healthy Turtles.  Submitted to the 26th Annual Symposium on Sea Turtle Biology and Conservation- Sea Turtle Symposium 2006.

Published Abstracts:

Norton, T.M., M. Dodd, A. Segars, J.M. Keller, M. Peden-Adams, R.D. Day, C. Harms, E. Jacobsen, A. Foley, S. Murphy, W. Cluse, W. Teas, M. Bresette, B. Schroeder, A. Mackinnon and N. Stedman  (in press),  Debilitated loggerhead turtle (Caretta caretta) syndrome along the southeastern US coast: incidence, pathogenesis, and monitoring. Proceedings of the 25th Annual Symposium on Sea Turtle Biology and Conservation- Sea Turtle Symposium 2005, NOAA Technical Memorandum.

Day, Rusty D., Jennifer M. Keller, Terry M. Norton, Mark Dodd, Al Segars, David Whitaker, Mike Ardnet, Sally Murphy, Tom Murphy, Dubose Griffin, Matthew Godfrey, Wendy Cluse, Steven Christopher, Michelle Lee, Margie Peden-Adams (in press). Mercury and health in the loggerhead sea turtle. Proceedings of the 25th Annual Symposium on Sea Turtle Biology and Conservation- Sea Turtle Symposium 2005, NOAA Technical Memorandum.