Breeding ground for humpback whales feeding in Irish waters discovered for the first time

A BREEDING GROUND for humpback whales feeding in Irish waters has been discovered by the Irish Whale and Dolphin Group (IWDG) after 16 years of searching. 

While on an expedition to the Cape Verde islands off the West African coast, IWDG spotted and photographed a humpback whale which had been seen 4 years previously off west Kerry. 

Humpbacks undergo one of the longest annual migrations travelling from rich feeding grounds at high latitudes, such as Ireland, to tropical breeding grounds close to the equator. 

This is the first re-sighting of an individual humpback whale from Ireland to a known breeding ground. 

Humpback whales off Santa Monica, Cape Verde, 23 April 2019 Source: Simon Berrow/IWDG

Dr Simon Berrow and Fred Wenzel in Cape Verde April 2019 Source: IWDG

Over the past 20 years, Ireland has become an important site for humpback whales with 92 individual whales having been recorded from unique and permanent markings on their tail flukes and dorsal fins.

About 80% of these whales have been recorded more than once in Irish waters with two-thirds recorded over five times and 14% recorded over ten times. 

According to the IWDG these whales are not just passing through Irish waters but staying for weeks, often months, during the spring, summer and autumn. 

In 2003, the group first travelled to the Cape Verde islands with the belief that this was most likely the origins of the humpbacks that appear in Irish waters. However, the Cape Verde humpback whale population is small and has not recovered from years of whaling in the 18 and 19th centuries – which made things more difficult for the IWDG. 

After not being able to match any of the whales to the those photographed in Ireland the IWDG returned to Cape Verde in 2006, 2011, 2012 and 2014. But with no luck. 

It was during a chance excursion to Santa Monica off the southwest tip of Boavista during a two-week expedition to Sal Rei on Boavista in April of this year that the group got lucky. 

Two whales surfaced near the research boat towards the end of a day trip. Both whales were photographed by Simon Berrow, CEO of IWDG, and one of these whales was the same individual photographed off west Kerry in 2015 by Nick Massett.

Berrow said it was a relief to finally find at least one breeding ground for Irish humpback whales but added that it raises issues regarding how is Ireland going to use this finding to enhance the conservation status of this endangered humpback whale population. 

“Those responsible for marine conservation in Ireland will have to build relationships with, and provide assistance to, the Cape Verde government in their efforts to protect this critically important breeding ground,” Berrow said. 

The IWDG is planning another expedition to Cape Verde in September to explore the waters around Cape Verde and train up local biologists in survey techniques and species recording.