UPSTART BAY FIELD RESEARCH UPDATE #5 The Rivers to Reef to Turtles Project On 14 June we all met at our reference site in Upstart Bay to sample the environment and turtles for the Rivers to Reef to Turtles (RRT) project. This marks the fifth field trip of the project and the second sampling event at Upstart Bay to detect differences between pre- and post- wet seasons. The first step in the RRT project is to characterise and quantify the environmental (water, sediment and seagrass) and bio-accumulated contaminant exposure of green turtle populations in the study sites. The first year of this project is a non-targeted screening phase, meaning we are not targeting any pollutant in particular. The results of these analyses will guide the future targeted monitoring program. Over the life of the project, the data will be used to determine if environmental pollutants exist and if so, whether exposure can be correlated to turtle health at both the individual and population level. This knowledge will help us understand whether exposure to land-based pollutants may be adversely affecting coastal green turtle populations of the Great Barrier Reef. The Field Trip 14 to 21 June 2015 Study site #3 the primary site at the southern end of Upstart Bay. Contaminant exposure to green turtles at this site will be compared to Cleveland Bay and the Howick Group of Islands in an attempt to unravel page 1
WWF-AUS / CHRISTINE HOF the mass stranding mystery that occurred in Upstart Bay in 2012 and identify if contaminants are affecting green turtles. It is also the receiving waters of the Burdekin River, one of the biggest contributors of pollutant loads into the Great Barrier Reef. The research team consisted of volunteers and scientists from all over Queensland including turtle biologists, water quality scientists, Traditional Owners, rangers, government representatives and WWF working together to deliver the objectives of the trip! With so much to achieve, we started with the briefing on all on things boating and safety. The environmental sampling team hit the water on 14 June in advance of the rest of the research team. Representatives from the Great Barrier Reef Marine Park Authority (GBRMPA) guided by scientists from TropWATER, astutely deployed passive samplers (which accumulate a range of environmental pollutants) and grabbed water, sediment and seagrass for chemical analysis. Additional samples around these sites were collected this trip in an attempt to reduce variability and provide more certainty in the results. Working with the prevailing conditions, we targeted the previous surveys foraging grounds, working long days to make the most of the tides. The research team hit the water on the morning of 15 June facing not the best of weather and worked hard at all four foraging sites during the week to catch every turtle we saw. The most important weather conditions for catching turtles are clear water, low wind and bright, bright sunlight. It wasn t until the last day of the trip that all three elements aligned. The Science: Due to limited rain at the study and reference sites this wet season, the first flush sampling event in Cleveland and Upstart Bays was cancelled. This trip s focus was to detect pollutant changes in type and concentrations in pre- and post- wet season environmental samples and recaptured turtles, and to refine the environmental sampling methodology. WWF-AUS / CHRISTINE HOF The trip s objective was to also tag, weigh and measure as many turtles as possible to increase turtle numbers for mark/recapture population studies. Other complimentary project data were collected, including turtle photo identification and a future turtle health project to investigate the effects of contaminant exposure on green turtle physiology, but still too soon to tell all! page 2
161 TURTLES CAUGHT 36 adults 27 sub-adults 98 juveniles Turtle Stats: 150 green turtles caught, tagged and measured 130 primary (first time) turtles caught 3 within-season recaptures 17 inter-season recaptures Smallest was 40.5 cm and largest 117.0 cm We caught an adult female originally tagged while nesting at Wreck Rock, south of Gladstone in 2009, and another adult female previously tagged in 1996 and 2012 while nesting on Heron Island. 26 blood and scute turtle samples from all age classes taken for toxicological (metal and organic) and health analysis 12 sub-adult and juvenile turtles lavaged (to determine diet composition and for toxicological analysis) Environment Stats: 3 passive samplers deployed, for assessment of metal contamination 3 passive samplers deployed for assessment of organic contaminants 3 different foraging areas sampled for water, sediment and seagrass with multiple grab sub-samples collected With limited recaptures to date, there is no mixing of turtles between the foraging areas we sampled. Of the 150 turtles caught 58 were adults (50 females; 7 males; 1 indeterminate), 17 sub-adults, and 75 juveniles. The sex ratios of females to males for adults was approximately 7:1. The lavage samples showed that the turtles were feeding primarily on seagrass with limited evidence of algae and mangrove fruits. There seemed to be three species of seagrass flourishing in each of the foraging areas. Three turtles caught were emaciated and two showed signs of fibropapilloma. Three turtles had either front or rear flippers missing, and four exhibited some kind of eye infection. Two turtles presented with significant boat strikes. Other samples were taken for complementary or other projects including: 16 blood samples from 6 adults, 7 sub-adults and 2 juvenile turtles were taken for future investigations into the physiological effects of contaminant exposure in green turtles 72 photos of turtles post-ocular scutes were taken to add to the new Turtle Photo ID database. page 3
WWF-AUS / CHRISTINE HOF The remaining samples and data collected will be taken back to our RRT collaborative partners for the screening analysis and future comparison to the other study sites as part of the RRT project. Highlights from the trip: We saw one dugong but were unable to catch it. We saw two pods of snubfin dolphins with calf. As always, our crackers, spam and bottled cheese but this time with the delightful addition of dip. WWF-AUS / CHRISTINE HOF Night times spinning blood, making friends, and sharing daily adventures. The field trip was primarily led by WWF, the GBRMPA, and the Queensland Government s Department of Environment and Heritage Protection. A big thanks to Dr Ian Bell for all the logistical support and role as principal investigator for the trip. Without the assistance and support of government departments - this trip could not have occurred. A big shout-out and thanks must go to the hosts, Paul and Claire, and to Molongle Creek Caravan Park for providing us with our accommodation needs and more your efforts to make us feel at home, and your BBQ expertise was delightful. A very welcome and appreciated helping hand on the water from the Girringun Aboriginal Corporation, Queens Beach Action Group s Jim Jeynes. Thanks also to North Queensland Dry Tropics NRM group and our Project Catalyst farmer Joe Linton. WWF-Australia and its partners are leading this pioneering research to protect the Great Barrier Reef and the turtles that call it home. Collaborative project partners of the RRT project include the National Research Centre for Environmental Toxicology at the University of Queensland, the Centre for Tropical Water & Aquatic Research at James Cook University, Vet-MARTI School of Veterinary Science at the University of Queensland, state and Commonwealth Government agencies, local Traditional Owners and natural resource management groups and other supporters and volunteers in the local community. The next field research trip will be conducted at the Howick Group of Islands, as we continue to sample our way towards unravelling how much a turtle can take Until then, I m signing off Chris Hof. Rivers to Reef to Turtles investigation is made possible with the help of Banrock Station wines page 4
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