Marine Turtle Newsletter Issue Number 151 October 2016 Leatherback hatchlings emerging from the wooden incubation device after 60 days. See pages 6-8. Photo by: Grande Riviere Nature Tour Guide Association, GRNTGA Editorial Fibropapillomatosis Tumors at Honokowai: Underwater Observations with Potential Broad Application..........................................P Bennett & U Keuper-Bennett Articles Artificial Incubation Trials of Leatherback Eggs at Grande Riviere Beach, Trinidad, West Indies (Phase II).......R Shoy The effect of invertebrate infestation and its correlation with loggerhead sea turtle (Caretta caretta) nest success in Laganas Bay, Zakynthos, Greece.......................................................AJ Andrews et al. Assessing the Impacts of Hatcheries on Green Turtle Hatchlings............................................CM Balsalobre & I Bride Evidence of Turtle Poaching On Agalega, Mauritius.................................................................................I Webster et al. Hatching of Eggs Rescued from a Green Turtle Involved in an Automobile Collision..............................I Kawazu et al. Northernmost Records of Hawksbill Turtle Nests and Possible Trans-Atlantic Colonization Event...........SA Finn et al. Report Obituary and Tribute Recent Publications Marine Turtle Newsletter No. 151, 2016 - Page 1 ISSN 0839-7708 Editors: Managing Editor: Kelly R. Stewart Matthew H. Godfrey Michael S. 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Marine© Turtle Marine Newsletter Turtle No. Newsletter 151, 2016 - Page 1 Editorial: Fibropapillomatosis Tumors at Honokowai: Underwater Observations with Potential Broad Application Peter Bennett & Ursula Keuper-Bennett 3-24 Reid Drive, Mississauga, ON L5M 2A6 Canada (E-mail: [email protected], [email protected]) Forward. Decades of research and dozens of science publications turtle population. Such worries, while fully justified at the time, have have provided useful insights into the tumor-forming disease failed to come true and likely never will. Indeed, two of the world’s known as fibropapillomatosis (FP) affecting primarily green turtles, most historically FP-afflicted green turtle populations (Hawaii and Chelonia mydas. Yet the cause, cure, and manner of transmission Florida) have shown phenomenal long-term growth to the present of this affliction remain substantially unresolved. The leading day. This fact lends credibility to the Bennett’s observations and etiological candidate continues to be an alpha-herpes virus, parsimonious reasoning. That is, that the spread of FP is exacerbated but how and where is it spread, and under what environmental in dense green turtle populations, and deterred by lower densities. conditions? The answers to date remain inconclusive and Thus, while some of the material in this essay has become outdated elusive. But might important information available in plain view with progress in the research concerning fibropapillomatosis, and on the world wide web for the past 20 years have gone unnoticed or also with our own continuing education about the disease, this essay ignored? On 17 December 1995 Canadian naturalists Peter Bennett remains valuable. and Ursula Keuper-Bennett composed the following essay based on My congratulations to the Marine Turtle Newsletter for ensuring a 8 summers of meticulous underwater observations of green turtles place in the published literature so the Bennett’s essay can seriously off West Maui in the Hawaiian Islands. Their insightful thought- be taken into account by FP historians and researchers of the future. provoking article was prominently posted where it remains today The original essay can be found here: on one of the world’s first web sites devoted exclusively to sea www.turtles.org/tumoursa.htm turtles, Turtle Trax (www.turtles.org). When the essay was written George Balazs - 992 Awaawaanoa Place Honolulu, Hawaii 96825 FP seemed to signal the eventual collapse of the Hawaiian green USA (E-mail: [email protected]) “Pollution, right?” That is the first reaction of nearly everyone who We have therefore spent considerable time trying to make sees our images of tumored turtles. If only it were that simple. sense of what we have seen and learned. From our observations No one really knows what causes turtle tumors. Although and the inquiries they prompted, we think we have a plausible scientists have made progress towards understanding explanation of the dynamics of the disease and its transmission. fibropapillomatosis (FP), the cause is still uncertain. Until someone Certainly it explains our observations and many of the points finds the cause, no one can know how tumors spread. This makes raised by researchers in the papers we’ve studied. it difficult - but not impossible - to know what to do about the We have no doubt that our explanation is incomplete and disease. probably wrong in some areas. Nevertheless, it does fit the facts We reached this conclusion after reading many scientific papers, we have gathered from various papers, as well as our personal consulting Internet sources, and soliciting information through observations underwater. We believe that if we are correct, we can email from marine turtle specialists, virologists, government identify potential hot-spots, where the incidence of tumors will be officials, and fellow divers. exceptionally high (>50%). Note that we did not say fellow scientists. Scientists we are not. In this essay, we show how our thinking arose from our We are turtle-watchers. We have eight summers of observations observations and inquiries about our Honokowai dive site, and in the waters of Honokowai, West Maui, Hawaii, USA. Over that explain why we believe it can explain aspects of the development of time, we have done nearly 1000 dives averaging about 75 minutes the FP tumors worldwide. each, with 35-40 of those minutes spent actually watching turtles. Some premises: We have made over 90 hours of videotape and taken over Seaweeds, like any algae, respond to nutrients (Brodie 1995). If 2500 photographs. We have paid close attention to watching and you allow extra nutrients into a shallow coastal area, one where documenting the changes in the environment. We have developed they will not be quickly diluted and carried off, you will get a reliable method of identifying individual turtles (>100 so far) increased seaweed growth. allowing us to track the changes in their condition from year to Sea turtles, like other animals, tend to cluster at places where food year. is most plentiful. Green sea turtles feed primarily on various Why we wrote this. Since we first discovered the turtles of seaweeds (Balazs 1980). It seems likely that if you find an area Honokowai and their tumors, we have frequently been asked of abundant seaweed, you will find more turtles than you would to explain the problem. When we tell people that science is still in areas with less seaweed. s e a r c h i n g for the answers, we are next pressed for our opinion. Because we now maintain Turtle Trax, a webpage dedicated to When the turtle population density increases, there is more contact spreading information about marine turtles, we felt a need to make between individual turtles, and each turtle has contact with a sure that whatever opinions we expressed were solidly based. larger number of other turtles. This provides more opportunities Marine Turtle Newsletter No. 151, 2016 - Page 1 Figure 1. Turtles Clustering: This picture shows the end of Hilu’s return from a trip to the surface for air. He could have picked an empty spot anywhere in the area, but he chose instead to land literally on top of two other turtles. This emphasizes the affinity turtles have for the company of other turtles, and the resulting close contact. It is this social nature that we believe ultimately