#MarineWildlife - The Irish Whale and Dolphin Group (IWDG) is marking 20 years of researching the dolphins of the Shannon Estuary.

As the IWDG's Dr Simon Berrow relates, it was not an auspicious start on 2 May 1993 when the first research trip on the estuary returned after five hours without having seen a single cetacean.

But the following day brought a bounty, with 16 dolphins across three different groups located by the IWDG - the beginning of two decades of sightings and recordings for the Shannon Dolphin Project, which has identified around 230 individual dolphins to date.

Thanks to that project, we know today that at least six of those dolphins first seen in 1993 are still in the estuary as of last year.

The Shannon Dolphin Project now has a website explaining its achievements and the work of the Shannon Dolphin and Wildlife Foundation (SDWF) over the years.

Meanwhile, Afloat reader Karl Grabe has also produced a spectrogram and edit of hydrophone recordings captured by Dr Berrow of Shannon dolphins just a few weeks ago.

Grabe previously uploaded a wonderful snippet of dolphins vocalising in the estuary late last year.