Today was another good one for the OMTU. No externally oiled turtles or mammals were found, we worked through many logistical challenges getting supplies and equipment ordered (through Trevor’s diligence and sweet-talking the Logistics staff), we think we have figured out how to transport dolphins from very remote locations back to facilities for full pathological workups (via Sarah’s dogged determination and exploring all the options), and the three de-oiled live sea turtles are doing very well at Audubon Aquarium.
Speaking of the necropsies, I can now share with you, my loyal readers, some of the findings in the report. We (this being the royal we, as Dr. Brian Stacy and his technician Jennifer Muller did the lion’s share of the work) evaluated 67 turtles (65 Kemp’s ridleys; 2 Loggerheads), of which 40 were complete carcasses and 16 were incomplete (e.g., scavenging, decomposed). Some of the key findings are as follows:
- No visible external or internal oil was observed.
- Most turtles were in good nutritional condition, with fish in the digestive tracts. As sea turtles typically do not prey on live fish, this may be from scavenging dead fish from dead bycatch or fish kills.
- More than 50% of intact carcasses evaluated showed signs consistent with sediment aspiration/drowning, with no evidence of disease as a cause of the strandings. Based on this, primary rule-outs for these animals are forced submergence or acute toxicosis.
So, it appears (at least visually) that oiling is not a primary cause of these turtles stranding. We are still pursuing the microscopic evaluation of the tissues, as well as the chemical analyses of the samples, but are also exploring other potential causes such as harmful algal blooms. Additional, NMFS personnel are delving deeper into other causes of “forced submergence” beyond that which could be explained by toxins or oil exposure. As I have said before, there is often not a “smoking gun” during such investigations, but often several different factors that can lead to an “outbreak” of this magnitude.
So, in closing (and closing quickly – only after 350 words!) for tonight, I’ll leave you with a couple of things. First, I will most likely have another guest blogger tomorrow, but a different one to mix things up a bit. I am trying to find different folks here and elsewhere in this response to give you some different perspectives and voices. Second, thank you all for all your very nice and heartfelt comments on this blog. It has been difficult for me to do, both from keeping the energy up to do in the evenings as well as try to move away from my scientific writing style to one a bit more personal, so it is gratifying to know that many of you have appreciated it. Third and last, just another reminder of why we are doing what we are doing (this one from Sarah):