More Pembrokeshire Porpoises

After the excitement of Strumble Head and breaching Risso’s dolphin during the Sea Trust watch Morgan headed off around the Pembrokeshire area with a company called Pembrokeshire Marine Environmental, and found that it is not just volunteers who spend their time searching for the smallest of the UK’s cetaceans. As Morgan learned last time the waters around Strumble Head and Ramsey Island off Pembrokeshire, West Wales provide really good feeding habitat for harbour porpoise. The strong tidal currents and trenches within the channel of Ramsey Sound means there is a lot of food for porpoise to eat. Harbour porpoise eat a wide range fish, cephalopods like squid, and crustaceans like crabs.

The harbour porpoise 

The problem, Morgan has learnt, is that strong tides are also a great source of energy, which people are looking to harness in order to provide electricity to power our modern lives. Renewable energy from wind, sunshine (solar) and tides is an important development in the way we create electricity as they are a lot ‘greener’ and kinder to our environment since they do not release gases like carbon dioxide that are contributing to global warming and changes in the world’s climate.  

Tidal turbines are a comparatively new way of harnessing energy from a renewable resource, taking advance of the high energy and predictability of tides. Tidal turbines are like the wind turbines we see on land or out at sea, windmills that in this case are driven round by the currents.

While renewable energy is a wonderful, clean alternative to coal, oil and gas, there are still some concerns for marine wildlife. Morgan learnt that there are concerns over the impacts of installing such equipment, with the noise produced, as well as concerns over changes to the flow of water and whether that could disrupt fish movements, plus whether birds or fish could be trapped and hurt by devices.

Environmental Impact Assessments are a process which developers need to undertake in order to understand the effect of a development on the natural environment. This includes understanding what animals use and area and how they might be affected by a development and that means getting out there are finding them. Once again the coastal nature of the harbour porpoise and the location of strong tidal areas near to shore, means that many of these surveys can be done from the land.

So Morgan joined Malcolm from Pembrokeshire Marine Environmental and WCA partner, who has been studying the harbour porpoise here for almost 8 years, for another day of searching and recording, this time overlooking Ramsey Sound. Here there are plans to install a prototype tidal turbine, but not before the impacts on porpoises have been assessed. With colleague Nick and his superduper binoculars and with weather conditions so calm it was not long before the small, dark triangular shaped fins of harbour porpoise were being counted all over the Sound. 

Counting harbour porpoise with Nick and Malcolm