Experts urged to ratify Minamata Convention to phase out mercury-added products পারদযুক্ত পণ্যের ব্যবহার বন্ধে মিনামাতা কনভেনশন অনুমোদনের আহ্বান সেন্টমার্টিন সৈকতে প্লাস্টিকের আগ্রাসন 72 birds die eating pesticide-treated masakalai Educate girls to save the planet শিশুর সর্দি-কাশি সারানোর ঘরোয়া উপায় 50 Books All Kids Should Read Before They’re 12 24 thousand under 5 children die of pneumonia in Bangladesh annually গ্রিনহাউস গ্যাস কমানোর লক্ষ্যে নানা উদ্যোগ Maldives: Eco-friendly product export destination for Bangladesh

How will offshore wind farms affect bird populations?


Offshore wind farms which are to be built in waters around the UK could pose a greater threat to protected populations of gannets than previously thought, research led by the University of Leeds says. It was previously thought that gannets, which breed in the UK between April and September each year, generally flew well below the minimum height of 22 metres above sea level swept by the blades of offshore wind turbines. However, while this is the case when the birds are simply commuting between their nest sites and distant feeding grounds, this new study shows that they fly at an average height of 27 metres above sea level when actively searching and diving for prey.

Crucially, the study also shows that the birds’ feeding grounds overlap extensively with planned wind farm sites in the Firth of Forth, heightening their risk of colliding with turbine blades. The researchers estimate that up to 12 times more gannets could be killed by turbines than current figures suggest, although they stress that the figure is based on calculations using current typical turbine sizes, which could be different to those actually installed, and that there is great uncertainty over actual turbine avoidance rates.

Previously data on gannet flight heights were obtained by one of two methods: trained surveyors on boats estimating heights by eye, or radar, which usually has a limited range of about 6km and is costly. The researchers conclude that more sophisticated methods of assessing risk should be adopted urgently. Professor Keith Hamer, of the School of Biology at Leeds, oversaw the study, published today in the Journal of Applied Ecology. His research group, together with colleagues from Exeter and Glasgow, based their work at Bass Rock, the world’s largest colony of gannets with some 70,000 breeding pairs, situated in the Firth of Forth in south-east Scotland, less than 50 kilometres from several planned wind farm sites.

He said: “Our study highlights the shortfalls in current methods widely used to assess potential collision risks from offshore wind farms, and we recommend much greater use of loggers carried by birds to complement existing data from radar studies or observers at sea.” Dr Ian Cleasby, of the University of Exeter and lead author of the study, said: “Previous data had seriously underestimated the number of birds potentially at risk of colliding with turbine blades. There’s a lot of uncertainty over how many birds would actually be killed this way, but our predictions – if realised in the field – are high enough to cause concern over the potential long-term effects on population size.”

Source

http://www.enn.com/wildlife/article/49014

Posted by on Oct 5 2015. Filed under Wildlife. You can follow any responses to this entry through the RSS 2.0. You can leave a response or trackback to this entry

Leave a Reply

Polls

Which Country is most Beautifull?

View Results

Loading ... Loading ...