Have a look at this picture, these gulls are stuffing themselves on little fish at the surface, the one taking off has a mouthful of sandeels.
Sandeels are important for all sorts of predators including lots of gulls, porpoise and dolphins, if there is a lack of sand eels all these predators will suffer. In the past there has been overfishing of sand eels for food and also bizarrely to fuel danish power stations in the North Sea leading to a real decline in seabirds and also porpoise. The sandeel populations have picked up a bit as it is recognised that overfishing for these small fish has a huge impact up the food web including on other commercial species such as cod. However, we are always delighted and relieved to see bait balls forming in the early summer indicating that there is a good level of food in the water for all the seabirds and porpoise. Bait-balls form when small fish aggregate in an attempt to protect themselves by sheer numbers, there is no coral for these fish to hide in so they form these large moving balls with the fish constantly moving and hiding in among each other. This is not fool proof as dolphins or porpoise drive these large numbers of fish to the surface and break up the ball as they feed, the gulls are winners on the surface gorging on the fish at the top. Its a great sight to see this level of activity in and on the sea as it means there are going to be great sighting as we go forward into summer, come and join us on a trip!