Why go 'Rockpooling'?
It happily combines wholesome learning about aquatic wildlife with gaining marine foraging expertise. Both skillsets are incredibly useful and may prepare you and your family for possible future societal collapse.
Also, your dog will enjoy rockpooling too!
But anyway, let's escape from UK politics for a few minutes and dive into the enchanting world of rockpools themselves. Also, these magic puddles contain their own societies, all with their unique hierarchies, majorities, cultures and divisions..
...and all dependent on regular offshore investment.
So, if you're brave enough to drop into these neighbourhoods...
...and explore their Urban Greenspaces);
...and if you're reckless enough to brave the sub-aqua alleyways...
(As with any alleyway, make sure you avoid the weird people with cameras)
...then these are just some of the curious characters you're likely to meet:
Rockpool Prawn (Palaemon elegans)
Their exoskeleton may be almost translucent, but what they lack in pigment, they absolutely make up for with personality.
Left: Shout when you can see them. Right: Shout anyway.
In fact, science has accused them of having too much personality. If you've ever been rockpooling, you may notice that some of these critters will swim up to you out of sheer curiosity. Although this risk-taking behaviour often results in creepy rockpool prawn selfies, it can put them at a disadvantage. The more cautious of the species tends to do better in terms of access to food.
Sometimes it doesn't pay to be shellfieish.
Their inquisitive nature also means that they are super easy to catch. If you're reading this blog, there's a high probability you've caught one right now, so I may as well tell you that they're edible. Although, before you go ahead and eat hundreds of them at once, it's best I inform you that they often accumulate the environmental pollutant cadmium. Perhaps those prawns are using their media spotlight to tell us to think responsibly about what we're dumping into the ocean.
Pictured: Unimpressed prawn
Although, it's more likely that they're just mesmerised by gigantic fish-eye lenses..
Two-Spotted Goby (Gobiusculus flavescens)?
It's very difficult to capture a photo of these in the wild, so their identification here is up for debate. Their behaviour includes swimming at 500mph probably.
Woah, what are those?!
So, they are small fish, at least we can tell that much.
Oh look there they are!
Wait!
Oh, OK, you're all very busy swimming away. Bye then!
Whatever these tiny fish are, there's a good chance that they tend to feast on zooplankton (e.g. microscopic shrimp larvae). Zooplankton look incredible under a microscope and according to marine scientists, they are an important indicator of changes to ecosystem health.
Beadlet Anemone (Actinia equina)
Also known as "what on earth are those slimy red blobs?"
For something we don't know much about, they are sure are everywhere.
The slimy mucus they secrete is keeping them alive at low tide by protecting them from dehydration. Interestingly, the mucus also has antibacterial and hemolytic activities due to it containing equinatoxins. These molecules help anemones to defend against infectious microbes and to immobilise their prey, respectively. Equinatoxins are produced from venom-secreting cells (or nematocytes/cnidocytes) amidst their tentacles.
The beadlet anemone 'tentacle fro' is usually only seen when they're underwater.
Equinatoxin Science
All this talk of toxins sounds quite scary, but they're not dangerous to humans (unless you have a particular allergy to them). In fact, they seem to be of benefit to humans. Equinatoxins have been shown to be effective against human leukaemia and human glioblastoma cells, but also normal fibroblast cells. The highly basic (positively charged) equinatoxin has been extracted and demonstrated to promote the survival of mice with Ehrlich carcinoma.
Cartoon representation of the X-ray Crystal Structure of Equinatoxin II (Athanasiadis et al 2001, PDB: 1IAZ)
Equinatoxins damage their cellular victims by 'punching holes' (or forming pores) in their membranes. They attach to cell membranes that contain sphingomyelin, which is a type of lipid (or fat) molecule. The toxins then undergo oligomerization, in which a limited number of these molecules group together to form a much larger molecule called an oligomer. It is this oligomer which becomes the 'hole-punch'.
X-ray crystallography, NMR (Nuclear Magnetic Resonance) and peptide synthesis techniques have been used to study equinatoxin structures and how they form these pores. This is important work because it's essential that we understand how natural toxins damage cells and how we can best combat them. How equinatoxins interact with membranes is also really interesting from the point of view of those (masochists) who study transmembrane proteins.
Rock Gobies (Gobius paganellus), Common Gobies (Pomatoschistus microps), Giant Gobies (Gobius cobitis)
Rockpools are the ideal habitat for these often well-camouflaged creatures.
Is it a rock or a goby? It could be both!
They will often change their appearance to suit their environment. When young they will often be darker in colour and then lighten up to adapt to sandy rockpool environments.
Tiny baby gobies near a beadlet anenome and limpets.
They are often used as bait for fishing the much larger and tastier sea bass. A note of caution; gobies are not as easy to catch as you might think. Any glimpse of a shadow will cause them to dart away to their hiding places, never to be seen again.
Time was slowed down in order to take these photos..
Blue Mussel (Mytilus edulis)
As you're probably aware, mussels can be very tasty creatures. You can often find mussels clumped together on rocks at low tide. When picking mussels for your evening meal, make sure you collect the ones that have tightly closed shells at low tide. If you're able to find and eat such live mussels, they are an excellent source of the dietary mineral selenium.
Mussels find strength by sticking together.
The Science of Byssus Threads
Mussels aggregate via exceptionally tough byssus threads. These strings of collagenous composites are tougher than our tendons. Byssus threads depend on mfp-1 (aptly named 'mussel-foot protein-1'), a protein that contains a special form of the amino acid tyrosine (DOPA, or 3,4-dihydroxyphenylalanine). DOPA reversibly coordinates with iron ions to further enhance the toughness of byssus threads. Unsurprisingly, these findings are inspiring the development of incredibly tough (and self-healing) industrial and surgical materials.
And yes, as you've probably realised - that same amino acid DOPA (also known as L-DOPA or levodopa) is also a precursor to our well-known neurotransmitter dopamine. Isn't science just so unbelievably cool and connects literally everything to everything else just like byssus threads connect mussels to all the other mussels?! I'm sure I'm not the only one that feels like this?!
European Green Crab/Shore Crab (Carcinus maenas)
Anyway, back to Rockpooling, which can also be referred to as 'crabbing'. The aim is to find and collect crabs in a bucket of sea-water, then release them back to the wild (or eat them). During my own Rockpool adventures in Cornwall, it took me ages to actually find any crabs. And, well, once I did find them...
I hope they checked themselves for crabs beforehand.
...I assumed that they would be pretty pissed off with me if I interrupted them.
If you're a more successful 'Crabber' than I, then you're very likely to find loads of these Shore Crabs, so make sure you know how to pick them up without getting snipped by their painfully strong claws. Since its Latin name translates to 'mad crab', probably because of its aggressiveness (it will pick a fight with literally anyone) and since its pincers are tough enough to crush oyster shells you'll want to protect your fingers.
Rockpooling and Cornwall Travel Advice
So, if you want to meet these interesting Rockpool characters, wear your Winter shorts, get some beach shoes and fill up a bucket with bait (bacon strips work well). Just make sure that bucket has a lid, otherwise it will attract the interest of militant seagulls.
Or your fluffy and very helpful hunting companions...
And if you're visiting Cornwall, (also known as Kernow) make sure you check the tide timetable before Rockpooling. If you're searching for your dinner at the beach, then chons da (that's Cornish for good luck). If you don't catch anything, you can always treat yourself to the local delicacy - the famous Cornish Pasty!
