Signs of ‘sharks’ on seashore
OUR beaches are great places to see some of the things that live in the muddy depths of the Irish Sea.
In fact The Lancashire Wildlife Trust depends on shore searches to understand just what is out there, because we tend not to do a lot of deep sea diving.
Obviously there are the odd cases of a turtle, seal or whale being washed ashore but, generally, it’s mussels, cockles, oysters and razorshells that we find along the tideline.
Seabirds will make the most of the feast that is washed up, leaving many of the shells and other items picked clean of life.
And, of course, there is usually a big wadge of seaweed, often interspersed with litter from ships and junk from messy folk at seaside resorts.
My favourite finds on the beach are black rectangular objects with a ‘tail’ at each corner. I honestly thought these were just sea plants, until recently.
These are actually the egg casing of a shark, well, a dogfish to be exact. They are casings that have been dislodged after hatching and the embryo of the fish is missing in most cases.
It’s fascinating that these eggs are lying around on our beaches in such numbers because it proves that the lesser spotted dogfish is doing pretty well in the Irish Sea.
The dogfish are real sharks, being predators feeding on smaller fish and some of the shellfish mentioned previously.
Only 75cm long, the lesser spotted dogfish is the most commonly seen of all the shark family, having a larger, scarcer relative the large spotted dogfish. It is more spotty than its cousin, with pale cream skin, large dark eyes and a small mouth.
The skin, like other sharks, is rough and covered in hard ‘dermal denticles’.
This means skin teeth and if you rub a dogfish the wrong way it feels coarse like sandpaper. This protective coating is a barrier against predators.
Yes, you can tell all this from a small parcel you found on the beach - it’s great detective work.
And throughout the year The Lancashire Wildlife Trust, and our colleagues at Cumbria and Cheshire, take part in shore searches and sea watches along with other experts.
If you are spending a couple of days at the beach, don’t just paddle in the water, take a look at what is under your feet. And then imagine it living in a sea that is full of life.
The Wildlife Trust for Lancashire, Manchester and North Merseyside is dedicated to the protection and promotion of the wildlife in Lancashire, seven boroughs of Greater Manchester and four of Merseyside, all lying north of the River Mersey.
To become a member of the Trust go to www. lancswt.org.uk or call 01772 324129. For more information about Cheshire Wildlife Trust call 01948 820728 or go to cheshirewildlifetrust. org. uk