A killer whale leaps out of the water when swimming—a behaviour known as porpoising. Credit: Minette Layne/Wikipedia/CC More information: Orca (Orcinus Orca) Captivity and Vulnerability to Mosquito-transmitted Viruses. Journal of Marine Animals and Their Ecology. Vol. 5, No.2. 2013. (PDF) Three dead in Serbian West Nile virus outbreak (Phys.org) —Marine biologists John Jett and Jeffrey Ventra of Stetson University and Louisiana State University respectively have published a paper in Journal of Marine Animals and Their Ecology that suggests captive orca may be more at risk of dying from mosquito borne illnesses than has been previously thought. Citation: Study highlights risk of mosquito borne illnesses to captive orca (2013, May 31) retrieved 18 August 2019 from https://phys.org/news/2013-05-highlights-mosquito-borne-illnesses-captive.html In their paper Jett and Ventra note that two captive orcas have died from mosquito born ailments since the animals became tourist attractions at water parks. One was a 25 year old male that died of encephalitis in 1990, the other a 14 year old male that died of West Nile Virus in 2007. Both highlight the fact that orca are subject to mosquito bites and because of that are at risk of contracting mosquito borne illnesses.To learn more about the problem the researchers studied the habits of the whales at water parks. They found that orca engage in a practice known as logging, where they simply float on the surface of the water rather than engage in swimming or diving. When logging, they note, mosquitoes congregate on the exposed surfaces of the whales, biting them. The two also noted that the whales are subject to sunburn, which they say, reduces immunity response to illness. Another problem is captive orca have substantial dental health problems which can lead to bacterial infections which in turn can also weaken an immune response.The two also point out that because Congress mandated that the National Oceanic and Atmospheric and Administration keep track of captive orca, records exist of whale births and deaths. In looking at the record they discovered that the whale that died of West Nile Virus in 2007 was listed as having died of pneumonia, suggesting that other whale deaths might have been listed incorrectly as well.The problem, the two say is that water parks are typically located in areas near other facilities that have standing water, which make them prime breeding grounds for mosquitoes. Also, there is no known way to apply sunscreen or mosquito repellant to orca to protect them. They also note that using fogging chemicals around water parks doesn’t appear to be a solution either as most research has shown it to be ineffective as well as hazardous. Curiously, not discussed is the possibility of covering water park tanks with mosquito netting. In any case, Jett and Ventra suggest that more research be done to ascertain whether anything can be done to make life safer for captive orca. © 2013 Phys.org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further
Kolkata: Though people of South Bengal witnessed thundershower on Friday evening, there is no chance of getting relief from heatwave conditions in the next few days.On Friday evening, thundershower occurred in Kolkata and some other districts of South Bengal providing temporary relief to the people. Temperature on Saturday will go down a bit due to the effect of thundershower. But the temperature will rise again from Sunday. On Friday, Kolkata recorded a maximum temperature of 39.6 degree Celsius, which is 5 degree above the normal. According to weather office, Friday was the hottest day in Kolkata of the year. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataAccording to Alipore weather office, since the West wind is dominating over South Bengal the monsoon is getting obstructed from entering South Bengal districts. But it is assumed that monsoon may hit North Bengal in 2-3 days. After entering the northern part of the state, it can be assumed that the monsoon will enter South Bengal. Sources informed that due to the thunderstorm in South Bengal districts and Gangetic West Bengal, the temperature on Saturday will slide by a few degrees which will provide relief from the last few days of heat wave. Also Read – Lightning kills 8, injures 16 in stateBut the temperature is likely to rise again from Sunday and will stay around 38 degree Celsius. According to the weather report, rain or thundershowers is likely to occur at most places over Andaman and Nicobar Islands, Darjeeling, Jalpaiguri, Coochbehar, Alipurduar and Kalimpong districts of Sub Himalayan West Bengal. Also light rain and thunderstorm may occur in Malda, North Dinajpur, South Dinajpur, Murshidabad, Nadia, North 24-Parganas, South-24 Parganas and Birbhum in South Bengal. Since Sunday, the temperature will be at least 2-3 degree Celsius above the normal. Also, the humidity level will be high, which may create discomfort. Since the past few days, due to the heat wave, streets of Kolkata remained deserted during the day time. Doctors have advised people to avoid getting out during the day time and drink plenty of water to remain hydrated. Also, if people need to go out in the sun, then they must use umbrellas, sunglasses and sunscreen lotion to avoid skin allergies and heat stroke. Doctors have also advised people not to have heavy and spicy food to stay fit at this time.