- Published on Tuesday, 18 February 2014 11:09
Turtle rehabilitation at Bayworld - A case study – The Story of Ms Green cont.
In the Western Indian Ocean, green turtles have nesting grounds at Europa Island, Comoro Islands, Seychelles, Tromelin and Mascarenes islands; Democratic Republic of Yemen, northeast of Oman and Masra Island (Marquez 1990). Other nesting areas where sporadic nesting occurs includes Madagascar and Mozambique (Hughes 1974). The recent status of nesting beaches is uncertain, but in certain parts of northern Mozambique, there are signs of continued exploitation by people, suggesting that they continue to be threatened in this region (Branch, pers. comm June 2001). Because South Africa does not host a nesting population, it is believed that the green turtles found on the east coast are drawn from Mozambique and/or Madagascar (Hughes 1974).
Nesting has been observed from August to November in different south-west Indian Ocean islands (Hughes 1974), where water temperatures are approximately 25o C. They are able to thermo regulate in cooler waters using solar radiation. They lay 1-5 times and each clutch numbers some 85-144 eggs. They breed every 2-5 years. Estimated age at first maturity varies from 6-34 years but recent work suggests that they are 25-30 years when they first mature. In captivity, they reach 35 kgs in 3 years and reproduce in less than ten (Marquez 1990). Incubation is 48-70 days and there is high predation through out the life of green turtles starting on hatching.
This and the black turtle are the only herbivorous turtles in adulthood but can be maintained in captivity on a carnivorous diet. Feeding of young stages is not known.
Green turtles feed during the daytime on sea grass beds in shallow waters. Food includes both sea grasses (e.g. Zostera and Cymodocea) and algae including Gelidium, Gracillaria, Hypnea and Caulerpa.
Robyn with Gareth
On the 27 April, a badly injured green turtle was brought to Bayworld. Numerous sick, injured and juvenile sea turtles have been brought to Bayworld previously and most have been treated and released by the aquarists. In this presentation, I will describe the symptoms and the steps taken that led to the successful treatment of this individual.
Bayworld is in a prime position on the south east coast of South Africa for turtle rehabilitation
* Our holding facilities can be easily adapted to accommodate various age and species groups (on average we receive 15 animals a year)
* Fresh sea water is on line
* Experienced animal husbandry curators as well as a leading herpetologist are on the staff
* The location is within the range of 4 sea turtle species (Loggerhead, Green, Hawksbill and Leatherback) all of which have been handled by Bayworld previously.
* Bayworld already has an existing education and public relations infrastructure.
The green turtle brought to us was badly injured as a result of gut entanglement, severe emaciation and total exhaustion. In the water she was lopsided and completely buoyant, she was unable to dive at all. This animal did not look like it could possibly survive the first few days.
Rehydration began by orally tubing her 160 ml of Ringers Lactate solution twice a day. Initially we struggled a bit to pass the tube through the oesophagus, but by the third day the turtle was swallowing the tube quite easily. She was also given multi- vitamin supplements and covered with an injectable broad-spectrum antibiotic (Enrofloxacin).
We weighed our resident green turtle, with a 1cm smaller carapace length as a comparison. Our animal weighed 23,9kg against the 11,1 kg stranded animal.
Initially the animal showed a weight gain of over 1 kilogram, and then she started losing weight again. Her buoyancy hadn’t improved; she was still lopsided and was still unable to dive. We suspected that she might be vomiting, but weren’t sure as there was no visible movement or obvious muscular contractions. It was only when we added food colouring to the tubing’s that we discovered she was vomiting after almost every feed.
At this stage there was concern that the animal had ingested plastic or fishing line, causing blockage somewhere in the gut.
Sea temperatures also dropped down below 20o C. Too cold, for rehabilitation purposes, we believed that 25 o C water would speed recovery
We decided that it was necessary to X-ray her to investigate the nature of the apparent blockage. The turtle was transported to the hospital in a plastic chicken crate, supported by an inner tube and covered with damp towels. The X-ray revealed an obvious blockage of the gut with a massive build up of gas in the bowel loops. Radiologists were all of the opinion that it would need medical intervention to correct. As the animal was so weak at this stage, we were considering euthanasia. However we then consulted with the hospital gastro-enterologist, he offered to assist us the following morning.
We returned to the hospital where “Ms Green” was admitted to the ward. A gastro scope, inserted to the caecum was passed to 1 m. Algal compaction was found in the lumen, the gut was flushed continuously with warm water during the entire procedure. Most of the alga was moved except for a small section which was adherent to the mucousa, this needed to be removed with an instrument known as a stone basket. The turtle tolerated the procedure with no sedation and was returned to a heated pool within two hours.
Initially we dosed her with Prepulsid to stimulate gut function, changing to Maxalon (Clopamon) as she continued to vomit. Her first feeds were tubed the day after the procedure. First using a blend of Hill’s A\D and electrolytes, then gradually adapting the formula to include lettuce, spinach, squid as well as vitamins and cod liver oil.
However 16 days after the blockage was cleared the animal was still vomiting, even after we had kept her vertical for up to 45 minutes. As green turtles are prone to swallowing plastic debris we feared there might be another blockage nearer the animals stomach, which we had missed. The X-ray department sent us steel beads to dose to the “patient”. We tubed her and included ten beads with her formula, and planned to do a follow up X-ray after 7 days. Fortunately we never needed to take this X-ray as “Mrs Green” decided to start eating and passed faeces.
Once we had given her the beads we moved her to our nursery room, placing her into a much smaller holding tank. The water was 24 o with access to sunlight through a clear plastic roof. In this smaller tank we were able to restrict her movement and monitor her faeces. Various foods were offered ad lib and 28 days after arrival, she was observed picking on red seaweed. After this she has gone from strength to strength rather quickly. She is now residing in our 100-000L Tropical Tank, competing well with the fish and spending most of her time grooming.
There were a few things we discovered that may be of use to others doing turtle rehab in the future.
* Tinting the formula with food colouring – allowed us to observe any vomiting without any guessing
* Straining the formula before tubing it, avoided the tube becoming blocked during feeding
* Small inner tube was perfect for supporting the animal while it was being fed and treated.
* “Nutristim” is a high calorie supplement, which comes in a tube like toothpaste and is easy to use and too sticky for the animal to be able to spit it out.
* Initially we used a soft piece of electric cable to gag the mouth. This allowed us to pass the tube without getting bitten. After a few tubing’s we were able to pass the lubricated tube while the turtle was swallowing it.
* Probably the most important thing we learnt was to keep the animal vertical during and after feeding. This prevented regurgitation to a large degree.
We are hoping to make turtle rehabilitation a core function of the Aquarium department at Bayworld. Already future plans for the workshop area have been adapted to accommodate sea turtles. Over the last two months good contacts have been made with overseas sea turtle rehabilitation centres. The bottom line is we need to find some serious funding for this rehab!
Dr M Smale. Natural Scientist Bayworld
Steven Warren. Chief Aquarist Bayworld
Dylan Bailey. Aquarist Bayworld
Hughes, G.R. 1974. The sea turtles of south-east Africa. 1. Status, morphology and distributions. Investigational Report of the Oceanographic Research Institute. 35: 144 pp.
Máquez, M.,R. 1990 FAO species catalogue. Vol. 11: Sea turtles of the world. An annotated and illustrated catalogue of sea turtle species known to date. FAO Fisheries Synopsis. No. 125, Vol. 11. Rome, FAO.. 81pp.