Winter chills life on land, but at sea life naturally thrives
On land, winter is the season of muted colours, but underwater, it’s a different story. This season turns the sea into a lively spectacle that never fails to surprise. You never really know what you’re going to find, which makes a winter beach walk a really rewarding experience.
The biggest threat for sea life at our latitudes is not the cold, but the tumult of storms that batter shorelines and shallows.
Seals, covered in blubber and fur, don’t mind the biting cold. Grey seals can give birth in midwinter, and their pups are very tough. That’s not to say life is easy, and many dont make it through the physical challenge of their first winter. Ravaging storms are bad news for seabirds, too. Puffins sit out winter on the sea’s surface far from land, and those winters when one stormfront seems to follow another can lead to birds “wrecking” on the beach.
It’s sometimes sad to see, but carcasses and remains, shells and skeletons washed ashore provide a window on the sheer variety and volume of life to be found underwater. Starfish, heart urchins (or sea potatoes) and seabed-dwelling razorshells can end up on the beach in their thousands. This may come from a single storm, lifting sand and its animal contents in one fell swoop.
Some kelp seaweeds are growing underwater right now. They’ve been shedding their fronds since autumn, making them less prone to being battered by waves, and the organic matter that floats away is a crucial source of nutrients. On the beach, this helps plants set root in sandy soils, helping stabilise coastlines over turbulent seasons to come.
The life of the blue-rayed limpet is intertwined with kelps, and they breed early in spring to colonise and graze on maturing fronds. Small (the size of a little fingernail) but with rays of kingfisher-blue, they stand out amongst the freshest kelp fronds washed on the shore.
Crustaceans and a surprising number of insects will find food and shelter in the decomposing warmth of beach-prone seaweeds. And these attract birds in big numbers, especially waders which may come from all over Northern Europe.
Pollock spawn in January, their eggs developing rapidly so that their colourful fry are ready for early spring plankton blooms. Across the Atlantic, the mysterious common eel breeds in the Sargasso Sea. Their tiny offspring will head to our shores late in the year, and you may find some stragglers even now amongst rockpools before they head to freshwater.
Some animals do go dormant in winter - the turf of seasquirts, hydroids and bryozoans dies back, to regrow in spring (just when their seaslug predators breed and reproduce). All in all, our sea life is well adapted to the ravages of the season. Even now, when trees are leafless and nature on land goes dormant, the ocean never sleeps.