By Julie Hatcher
Marine Awareness Officer

Sea creatures of the night!

The thought of getting into the cold, dark sea with only a torch to light your way isn’t everyone’s idea of a good time. On the other hand it is a good way to see creatures that normally hide away during daylight hours and a great opportunity to get close to them. In the dark a different set of animals are active to those we see in daytime, and they don’t seem worried by our presence – maybe they are just not used to us entering their realm.

This autumn has seen unusual weather patterns – a change from the usual conveyer-belt of Atlantic storms blowing in from the south west. With high pressure and mainly northerly and easterly winds, the sea has remained relatively calm along the Dorset coast, and as a result, the water has been very clear. Divers venturing in for night dives have had the pleasure of seeing some unusual and rarely seen wildlife activity.

Aggregations of sharks and rays have been encountered in surprising numbers and a mix of species. One pair of divers saw 20 rays on a single dive. Types seen have included blonde rays, undulate rays and spotted rays alongside lesser spotted catsharks and nursehounds. These animals, often nervous during the daytime, seem quite happy to let people approach and take photos at night. 

John Dory is a bizarre and instantly recognisable fish with an exaggerated dorsal fin resembling a giant cock’s comb and a thin body like an after-eight mint when viewed head on. These are solitary fish so it is unusual to see up to ten in a small area, as has happened recently. On close inspection this striking fish is almost always covered in tiny parasites which hang onto its sides, moving around before your very eyes. It also has a huge mouth which shoots forward to engulf small fish and other prey before folding back into place.

However, the real star of the show this autumn has been the octopus – an extremely rare sighting in Dorset. These have been seen by lucky divers in at least three separate instances at a couple of sites, including one seven-armed individual that was encountered on a couple of occasions, having lost part of one arm. Octopuses are experts at camouflage and also prefer to hide away in tiny crevices and secret holes, squeezing into the tightest gaps thanks to a boneless body. 

Considered the most intelligent of invertebrates they can also change their colour to blend in with whatever background they find themselves in, so it is not surprising they are hard to spot in daylight. At night however, they are out and about hunting their crustacean prey, perhaps making an encounter more likely.

So next time you take a moonlight stroll along the beach, just imagine what wonderful creatures and secret activities are going on beneath the surface.

Dorset Wildlife Trust would love to hear what marine life you have encountered by day or night. 

Please send your sightings to Kimmeridge@dorsetwildlifetrust.org.uk