EVEN THOUGH dolphins were located on more than 90 per cent of trips in the Shannon Estuary last year, it was a relatively poor season for tourist trips run by commercial dolphin-watching operations.
A study by Dr Simon Berrow and Conor Ryan of the Shannon Dolphin and Wildlife Foundation reported “a very poor season” for dolphin-watchers in the estuary.
The estuary is home to a bottlenose dolphin population and commercial dolphin-watching has taken place for more than a decade.
The authors say one explanation for dolphins proving more elusive may be changes in the numbers and timing of salmon in the estuary.
“Shannon Regional Fisheries Board reported a 50-60 per cent decline in salmon entering spawning rivers during 2009 compared to 2008, which was down 50 per cent from 2007,” they say. “This equates to a decline of around 75 per cent between 2007 and 2009. This decline in salmon numbers in the estuary may be forcing the dolphins to forage further afield to Loop Head, Tralee Bay, in order to obtain their daily food requirements.”
However, the authors say: “As 2007 was a good year for salmon returning to spawning rivers it is hoped that 2010 is a good year as most fish return after three years.”
The report says the monitoring indicates the “relative abundance” of dolphins. However, it says the dolphin-watchers “not only had to operate in a poor tourism season and poor weather, especially in August, but also struggled to find dolphins when conditions were good”.
“This is evident from the increase in time to locate dolphins and length of dolphin trips.”
The report – conducted on behalf of the Government’s National Parks and Wildlife Service – says dolphins were located on 91 per cent of trips; with nine trips from Carrigaholt and 12 from Kilrush failing to locate dolphins.
It says the mean time to locate dolphins increased significantly, up 27 per cent from Carrigaholt and 20 per cent from Kilrush. This resulted in the mean trip length from Carrigaholt and Kilrush being the highest recorded since monitoring began 10 years ago.
