
On May 24th 2011, photographer Mark Harrison took a few photos of the large marine creature he saw off the Wirral Peninsula, near Liverpool (UK). Harrison initially thought that the animal might be a seal, but then decided to put the photos online as a sort of joke. Several newspapers then ran the photos as depicting a “sea monster” – dubbed the “Mersey monster” – that “baffles marine experts”. Most of the coverage has appeared in the Liverpool Echo. So – OMG! – a new sea monster photographed!! Can we ever solve this most mysterious monster mystery??!? Well, duh.

The Liverpool Echo originally quoted a Paul Renolds of the Blue Planet Aquarium. Renolds said that the animal is “virtually impossible to actually identify”, but did note that Basking sharks Cetorhinus maximus can be seen around the Wirral coast at this time of year. The unfortunate implication from a quote like this is that Renolds favoured a Basking shark identification, whereas this isn’t what he was saying at all.
A couple of days later, the Liverpool Echo stated that Danielle Gibas of the Sea Watch Foundation had “solved the mystery”. Gibas, the paper says, said that the animal was actually a Harbour porpoise Phocoena phocoena. Sigh. The newspaper assumed that she was right. She isn’t, sorry (caveat: as explained below, this might not be what she said at all). ['Mersey monster' photos above and below by Mark Harrison.]

The photos show that the animal lacked a dorsal fin or vertical tail fin, they show a large water-filled gap between the animal’s back and head, and they reveal a squared-off snout with a flattish dorsal surface. These features alone immediately rule out porpoise or shark. Indeed, as was obvious as soon as the photos first appeared (I first saw them at Weekly World News), the animal is almost certainly a Grey seal Halichoerus grypus.

The first photo shows a large gap between the top of the animal’s head and the hump formed by its back. Cetaceans can’t produce such a gap: their profile is continuously convex across the top of the head and back. Seals can and do do this. The second photo shows that the animal had a blunt, sub-rectangular snout and jaws where the corner of the mouth is located quite far back. The shape of the head is immediately reminiscent of a male Grey seal, so much so that – on looking at the photo – you should immediately think “Oh, that looks like a male Grey seal” [adjacent Grey seal image from TWT's Seal Project page. Harbour porpoise shown below: compare and contrast with 'Mersey monster' photos. By Erik Christensen, from wikipedia].
In all fairness to Gibas, the quotes attributed to her don’t necessarily reflect what she said, and it’s very possible that what she really did say was taken out of context. When you hear that an ‘expert’ has declared an opinion on a given ‘mystery animal’ photo, you might imagine that said ‘expert’ has sat down with a blown-up version of the photo, a magnifying glass and a stack of reference books. In reality, said expert (who has no special interest or experience in identifying ‘mystery’ animals) typically receives a phonecall from a journalist, with the following sort of conversation ensuing.
Journalist: “I wonder if you’ve heard about this sea monster, photographed off the coast of Liverpool. We wondered if you could say what it is.”
Expert: “No, I haven’t heard of it.”
Journalist: “Well, it’s described as a sea monster. It was seen in the sea. Off the coast of Liverpool. Could it be a monster?”
Expert: “An animal seen off the coast of Liverpool at this time of year could be… well, a porpoise I suppose.”

Nevertheless, I’m disappointed that the ‘experts’ quizzed by the journalists didn’t even mention Grey seal as a contender when it’s so transparently obvious that this is what the ‘monster’ really is. If said ‘experts’ really did suggest seal and suffered from selective quotation by the journalist involved, I apologise.
PS – I need more followers on twitter. Find me @TetZoo.
For previous articles on alleged sea (and lake) monster photos, and on pinnipeds and similar topics, see…
- Sea lions really are quite impressive
- Really: photos of the Loch Ness monster
- Best lake monster image ever: the Mansi photo
- The amazing Hook Island sea monster photos
- Santa Cruz’s duck-billed elephant monster
- Professor Sharpe’s mysterious sea-serpent photo
- Where are all the dead sea monsters?
- Filming Migo, the monster of Lake Dakataua
- England ‘does a Montauk’
- Harbour seal kills and eats duck
- Bownessie the Lake Windermere monster is captured on film, and how we rejoice!