Mammal and Turtle Conservation Abstracts
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Life History of Spotted Seals in Liaodong Bay China: A Case Species Conservation Study Through Individuals Housed in an Aquarium
Peijun Zhang, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences Watch Video (Login required) Full Abstract
The spotted seal (Phoca largha) is a subarctic pinniped species inhabiting around North Pacific Ocean. They distribute into eight breeding populations around the world with Liaodong Bay population in China being the south most one. Animal counts at Liaodong Bay have decreased to 25% of its largest counts during last 70 years due to human activities. Exhibits of Liaodong Bay seals in Chinese aquariums are popular, but scientific research on this species is poor and most of its life history strategy remained unrevealed. In the present study, we conducted several studies in seals housed in Dalian Sun Asia Aquarium aiming to reveal some life history details and therefore help in developing protection programs in this threatened species. Knowledge related to nursing, growth, sex maturity, migration, reproductive behavior, and acoustic behavior are investigated through different studies including nutrition, endocrinology, satellite tagging, ethology and acoustics. We observed that spotted seals have an average lactation time of 15-30 days. Pups can intake more than 2200 mL milk each day leading to a growth rate of 1.1 kg/d before molting. Spotted seals reach sexual maturity at 4 years of age, when fist pregnancies occurred. Adults can grow up to 166 kg in body mass and 170 cm in length. Spotted seals show typical reproductive seasonality: they mate during February and March and give birth 11 months later. The end of their embryonic diapause is in August. Vocalizations are mainly emitted for reproduction purposes. A yearly regular migration route for foraging and breeding was also monitored. Our results covered some knowledge gaps in spotted seals, which can benefit both artificial breeding and wild population protection programs. This study could serve as an example of a research program conducted through an aquarium population, with a potential impact on wild animal conservation. |
Turtle Rehabilitation and Conservation Efforts by the Two Oceans Aquarium in Cape Town South Africa Maryke Musson, Two Oceans Aquarium Watch Video (Login required) Full Abstract
Every year thousands of Loggerhead turtle hatchlings navigate their way down the coast of South Africa in the warm Agulhus current. Sadly many of these turtles are washed ashore, fatigued, dehydrated and in desperate need of a helping hand. The Two Oceans Aquarium in Cape Town, South Africa, rehabilitates these turtles and prepares them for release back in warmer waters. Since 1963, Ezemvelo KZN Wildlife has spearheaded turtle conservation efforts in South Africa. These efforts, combined with the long-term commitment to continuous monitoring, has contributed to the increase of nesting Loggerhead numbers from about a 100 in the early 1960’s to 500 nesting annually, currently. The number of successful releases of rehabilitated turtles at the Two Oceans Aquarium has increased from 8 in 2009 to 162 in 2015, which also indicates the increase in nesting numbers. The Aquarium has also rehabilitated green, olive Ridley, leatherback and hawksbill turtles and the rehabilitation process can take a year or more, depending on the needs of each individual. Some turtles are injured and require specific medical intervention and treatment. During 2015 two hawksbill turtles were rehabilitated, fitted with satellite transmitters and released 30 nautical miles off Cape Point. The adult hawksbill turtle, weighing 86 kilograms, has since travelled more than 4000 kilometers up the East Coast of Southern Africa, past Maputo and crossing the Mozambique Channel. She travelled an average of 45 kilometers per day with longest distance covered in one day of 159 kilometers. The smaller hawksbill turtle of 12 kilograms moved up the West Coast of Southern Africa, and has travelled more than 1,500 kilometers, at about 21 kilometers per day. The longest distance covered by this turtle was 75 kilometers in one day. The Two Oceans Aquarium will continue its rehabilitation and release efforts to contribute to the conservation of these marine animals. |