Projects Updates:

03/12/2009 10:07: Mobile phone technology is helping to unlock the secret life of the Solent’s seal colony.

The Solent is home to a small but regionally significant population of harbour seals. Nationally, harbour seals numbers are seeing significant signs of decline and the causes are unknown.

The Solent Seal tagging Project, run by The Wildlife Trusts’ South East Marine Programme and Chichester Harbour Conservancy, funded by SITA Trust, aimed to gather information on the Solent harbour seal population to aid their conservation.

Harbour seals are showing alarming declines and with over 40% of the world’s population making their homes around the UK’s shores, this has serious implications for the species survival.

Nobody yet understands exactly what may be contributing to these declines but we all agree that increased monitoring is needed to enable conservationist to get a better understanding.

Studying seals can be a tricky business, they can range hundreds of kilometres and spend significant amounts of time underwater. The best way to follow them is to utilise the latest technologies.

The Wildlife Trust and Chichester Harbour Conservancy have worked with the Sea Mammal Research Unit at the University of St Andrews, the world leaders in seal monitoring, to deploy their latest tracking devices. These systems are essentially mobile phones with a built-in GPS to provide location data.

Building the tags is one thing…putting them onto the seals is quite another! Seals are very powerful, agile creatures and the tagging team often felt that they were being mocked as the seals literally swam rings around them! However by the end of the four day tagging ‘mission’ in March 2009 five seals had been fitted with tags.  Four males each weighing in at a whopping 100kg and a juvenile female weighing just over 60kg – a sign that the seals are finding food sources plentiful.

Following the tag and release operation all of the seals remained in the area curiously swimming around the boats.

The data received from the tags has been hugely informative. We will give an example here of information found about feeding sites. Before the tagging exercise very little was known about where the seals went to feed. The team discovered that all of the harbours around the Solent are used for feeding including those on the Isle of Wight. It’s still unknown what prey the animals are targeting in these areas but it is likely to be flatfish and species like bass and mullet which come in to the harbours to breed. Dive and towed video surveys have been carried out in the feeding grounds and shown that seals are often attracted to seabed features, such as rocky reefs and underwater structures.

Data gathered so far has helped The Wildlife Trusts’ South East Marine Programme to ensure that seals are now considered in management and conservation plans. The work of this project will help ensure that seeing a seal in the Solent will remain a possibility for future generations.