I, Jellyfish

March of the jellies

2011-07-04T05:58:00.000-07:00

You might think dangerous hordes of brainless creatures are the stuff of zombie movies, but the threat is real: only they take the form of floating gelatinous zooplankton.

According to the BBC, huge numbers of jellyfish floating in the seawater entering a Scottish nuclear power plant forced it to close last week. The Torness nuclear power station is now undergoing a clean-up operation to rid the plant of jellyfish.

Swarms of eerie translucent creatures and the shutting down of a nuclear power plant might seem to herald the end times, but jellyfish are harbingers of the apocalypse in a very different way. Jellyfish thrive in warm water and their numbers are increasing, and climate change warming the oceans is increasingly being seen as the reason for their explosion in population [pdf]. Unless there are greater cuts to carbon emissions, we can expect to be dodging plenty more of these marine beauties at the beach.

Yoyo sushi

2011-06-27T13:49:00.000-07:00

To kick-start I, Jellyfish after its temporary hiatus, feast your eyes on UK newspaper The Guardian's clever pictographic on guilt-free fish for your plate.

The message is gradually spreading that marine stocks are dwindling fast. Untamed consumption of smoked salmon blinis, not to mention our taste for deep-sea fish like the orange roughy (pictured left), are causing havoc in oceanic ecosystems. Luckily campaign groups like Fish2Fork are loudly pressurising restaurants to source their salty delicacies from sustainable suppliers, and encouraging consumers to favour restaurants with a clean conscience.

Fish2Fork have even scored big victories by causing major chains like YOSushi! to rethink their policies. Previously a major offender on Fish2Fork's blacklist, YOSushi! has done a huge u-turn in casting off endangered eel from its menu. Whether this is a decision of the heart or the PR machine, lobbying restaurants is evidently working. Heartening news when faced with as daunting a task as turning around the vast damage we're doing to the even vaster seas.

Boxing clever?

2009-08-25T02:07:00.000-07:00

If reality TV isn't gruesome enough for you, it's high time you met Dr Mike Leahy. This thrill-seeking virologist is on a mission to get bitten and stung by the world's nastiest pests, and is coming to a TV screen near you. Jellyfish fans might raise an eyebrow at the episode where he rubs the tentacle of translucent sea-creeper the box jellyfish (see left) on his arm. This jelly is one of the most venomous beasts on earth. A large enough dose of the poison can kill a human within minutes, so Dr Leahy's show is surely one for the "don't try this at home" pile.

It would take contact from about ten feet of box jellyfish tentacle - that's a serious undersea cuddle - to kill an adult human, so Dr Leahy isn't exactly dancing with death. However, it will be interesting to find out whether the show contains gems oof insight into the natural world, or is merely daredevil masochism in the vein of Jackass (in which Steve-O went "bobbing for jellyfish" during one famously wince-inducing episode).

The week in jellyfish: six-foot siphonophores and the sweet smell of the sea

2009-08-21T02:51:00.001-07:00

An athlete's attempt to complete a 25-mile swim across Monterey Bay, California, was scuppered by painful jellyfish stings. Bruckner Chase had been told that jellyfish numbers were down when he undertook the challenge, only to find that "it was like scene from 'Finding Nemo' when they're swimming though jellies". [Chase's bay-crossing big stymied by jellyfish, The Mercury News]

Chinese immigrants in Italy are scooping up stranded jellyfish for a quick deep-fried snack. Locals aren't sure whether to be squeamish about this unfamiliar foodstuff, or grateful for the beach clean-up. [Italians balk at Chinese habit of deep-frying jellyfish, The Guardian]

Next time you're gingerly stepping around sea nettle jellies (see picture) washed up on the shore, remember that without them you might not be able to tuck in to oysters on the half-shell. An interview with a jellyfish scientist reveals the role of sea nettles in the marine ecosystem. [Stings or seafood? The dilemma of the sea nettle, Southern Maryland Newspapers Online]

Hawaii's beaches have been on red alert after amore than 2,000 Portuguese Man O'War, jellyfish-like creatures known as siphonophores, washed up on Hanauma beach. [Man-O-War invasion forces Hanauma Bay closure, Honolulu Advertiser]

The invasion continues as far afield as Dorset, UK, where beach-goers have been told not to panic at news that six-foot long Portuguese Man O'War have been spotted on the coast off Weymouth. (What a pity no one interviewed for the article pointed out that they aren't actually jellyfish.) ["Don't panic" advice after jellyfish seen off Weymouth, Dorset Echo]

And finally, the delicate tang of an ocean breeze has been explained as a bacterial belch. An East Anglian scientist has cracked the biochemical pathway that produces dimethyl sulfide, the chemical responsible for the smell of the sea. [The science behind that fresh seaside smell, The Daily Telegraph]

Jellies sabotage aquarium

2009-08-13T03:07:00.000-07:00

An influx of Chrysaora jellyfish has overwhelmed a Californian aquarium's water filtration system. The Monterey Bay Aquarium pumps gallons of water from the bay into its tanks, and this week a surge in the jellyfish population caused thousands of jellies to drift towards the aquarium and crack a filtration screen. Astonished aquarium workers now have the unenviable task of sifting ground-up jellyfish from the water pumps.

Causing a stink

2009-08-11T04:22:00.000-07:00

The urgency of protecting coral reefs receives a great deal of media coverage, but did you realise that corals and jellyfish are very similar organisms? Jellies and corals are both cnidaria, but while corals stay put, attached to rocks where they grow and spread, jellyfish are only polyps in the early stages of their lives. After that stage of development, they bud off the rocks and float away.

One crucial thing they share with each other and with other marine life is their sensitivity to nitrates. Huge quantities of these salts, which are used as fertilliser in intensive pig and poultry farming, run off into the sea, and the latest chapter in this ecological disaster is unfolding on the north-western coast of France. Beaches including the famously glam Mont-Saint-Michel are being inundated with thousands of tons of sea lettuce (a common seaweed), which has being growing at an unnaturally rapid rate because of nitrates because of a process called eutrophication.

This isn't just disrupting the marine ecosystem, the heaps of sea lettuce are causing a deadly problem for us, too. As organic matter rots, it produces hydrogen sulphide, which gets trapped under the blanket of seaweed. This gas can have a devastating effect on the nervous system of animals and humans if a concentration of it is breathed in. The near-death experience of a horserider and council worker who were exposed to concentrated gusts of the gas are making the French beaches a no-go area.

What's the solution to the devastation wrought by nitrate fertillisers? Research into whether organic farming would reduce the amount of nitrate leaching into the seas hasn't provided an definite answer. One thing is for sure: if we don't move towards more environmentally-friendly farming practices, you might need more than a bucket and spade for your next day out at the beach. Does this gas mask match my bikini?

Attack of the killer walnuts

2009-08-06T03:55:00.001-07:00

Italians are in a lather over the arrival of the fish-destroying Mnemiopsis leidyi, a tentacled comb jelly whose less threatening nickname, "sea walnut", belies its hearty appetite for fish eggs, larvae and crustaceans.

Sea walnuts can drift in vast blooms, and no larger animal (it can grow up to six inches in diameter) is thought to be more numerous. Swimmers, at least, are safe, as these beasties' sticky tentacles are harmless to humans. However, sea walnuts are known to have a terrible impact on other fish populations: a couple of years ago, leading Italian jellyfish expert Prof Ferdinando Boero described their impact in the Black Sea as "devastating". Knowing this, Italians are understandably nervous about the potential effects of sea walnuts on their own marine life.

The Italian "Look out for the jellyfish" (Occhio alla medusa) campaign has distributed leaflets (see left) detailing different species of jellyfish, urging keen-eyed beach-goers to e-mail Prof Boero with their sightings. This should enable scientists to track the movements of the walnuts. They were sighted in recent months on the coast of Israel, but lately the jellies have been drifting towards the Mediterrannean.

It's not clear what "Looking out for the jellyfish" can do to prevent damage to fish populations on the Italian coast. There is no safe way to reduce the spread and impact of the sea walnuts, and their spread suggests they have adapted to live in a range of sea temperatures. Says Prof Boero of the most recently spotted sea walnuts: "This is the first sighting in the eastern zone: and if it's here, it means that it is everywhere."

This week in jellyfish: churning the seas and being served with cheese

2009-07-31T03:20:00.000-07:00

The movements of marine animals like jellyfish contribute to ocean turbulence, it emerged this week. Scientists used dyes to show how jellyfish churn water as they move, causing "biogenic mixing". [Jellyfish help to stir the oceans, BBC News]

The role jellyfish play in stirring the oceans may also be staving off climate change. According to a study published in Nature, jellyfish help churn downwards the carbon dioxide-rich water at the surface of the ocean, temporarily preventing its release into the atmosphere. [Jellyfish may help keep the planet cool, NPR]

This good news doesn't stop a certain amount of trepidation regarding our wobbly friends. Vancouver Island and Nanaimo in Canada are experiencing a mysterious surge of moon jellies, and are worried that a flood of stinging Lion's Mane jellyfish may follow. [Residents notice a surge in jellyfish, Canada.com]

Meanwhile in Oklahoma, United States, residents were surprised to discover freshwater jellies in Lake Murray. These harmless, coin-sized jellies sound like they might be peach blossom fish. [Jellyfish at Lake Murray?, KTen]

As jellyfish increase in number, we must chow down on them with a wry smile, according to Wired Science. Jellies were once considered "unpalatable goo", but as their natural predators get overfished, serving up jellyfish is requiring some tricky marketing moves. [Saving fish is possible, unless they're past the tipping point, Wired]

Japan is ahead of the game, having put jellyfish burgers on the menu. These ocean patties are a blend of minced pork, beef and dried jellyfish, served with bacon and cheese. [A Real Jellyfish Burger, Guilty Planet]

And finally, what better way to celebrate a cnidarian sighting than with a jellyfish-inspired cocktail? These drink recipes may look like jelly, but you might have to wait for the Japanese to invent a drink containing actual jellyfish. [Jellyfish & jellyfish drinks, Cape Cod Today]

Over the moon

2009-07-30T02:22:00.000-07:00

The winners of Lonely Planet's photography contest on the theme of "floating" were a bloom of moon jellyfish! We can't know for sure whether the photographer had taken on board the I, Jellyfish tips for snapping sea jellies, but the image is a great example of how jellyfish catch the light when photographed well.

Fight them on the beaches...

2009-07-29T09:11:00.000-07:00

...or on second thoughts, don't go anywhere near them.

News outlets throughout the UK are reporting that Portuguese Man O'War have been washing up on British beaches. Eight were found in Cornwall and another two on a Devonshire beach, leading to concerns about beachcombers getting a nasty shock from these alluring 'blue bottles'.

However, the Man O'War is not a bona fide jellyfish, but a siphonophore, meaning it is a group of creatures living together in an interdependent colony. The colony is certainly co-operative enough to deliver a agonising sting that could lead to shock, fever, heart problems and ultimately, death. Whatever you do, don't attempt the vinegar cure with this one: removing the tentacles, rinsing with saltwater and seeking medical treatment are your only options. Since their tentacles can stretch up to 130 feet, let's hope you only encounter a little one...

Jelly belly

2009-07-28T03:28:00.000-07:00

The Welsh reckon we might be eating jellyfish and chips out of a newspaper instead of cod, a prestigious Spanish chef has been incorporating them into risotto and noodle dishes, and spicy jellyfish salad has long been a staple in Vietnamese cuisine. Jellyfish are making their way to a table near you, and as overfishing robs the oceans of more conventional dishes, we need to be armed with the knowledge about how to sizzle up a jelly feast.

So is it safe to eat a beastie covered in stinging cells for your dinner? Processed jellyfish has had its tentacles removed and been cured in salt and alum. These pancake-shaped pieces simply need soaking overnight in the fridge, before being drained, sliced and blanched in boiling water.

The salting process breaks down the poison in the stinging cells, and should make for a pain-free dining experience. However, some people still report a tingling sensation in their mouths, or experience minor outbreaks of hives when eating jellyfish.

If you're still not convinced, frying it in batter and dipping it in chilli sauce might be an easy foray into jellyfish cookery. A more adventurous chef might want to serve some sesame jellyfish or a hearty soup at their next dinner party. If your guests seem uneasy, remind them that it's a superfood: low in calories and fat. Failing that, at least they'll offer to cook next time.

An inconvenient jellyfish

2009-07-22T04:13:00.000-07:00

A mysterious goop stretching for 12 miles, floating off the coast of Alaska, has been befuddling scientists and alarming locals. This blackish substance swept up birds and jellyfish, and tangled marine life in its wake into a mess of fibrous matter. It has recently been identified as an algae bloom but scientists initially struggled to identify this mass of organisms.

No doubt the blob's appearance and potential impact on the ecosystem will be a source of further study, but in general these studies can be dishearteningly tricky. I've shown in some other posts how jellyfish can have a huge impact on other species, as well as human activity, so it's alarming that they don't receive the attention they need from scientists.

The Environmental News Network (ENN) quoted a senior marine scientist as admitting that jellies are not even in most existing ecosystem models. How can a realistic account of an ecosystem be created with jellyfish out of the picture, and why are they being omitted?

The University of British Columbia found that only around a quarter of the most popular marine ecosystem models account for jellyfish, and when they do, they "collapse all things considered gelatinous into a single functional 'jellyfish' group". This means their role in undersea life isn't properly considered.

Jellyfish life cycles are already tricky to track, and the ENN suggests that another factor in ignoring the jellies is their supposed lack of relevance to the fishing industry. Research naturally occurs where the money is, so a study of cod is likely to gain more funding than jellyfish.

However, as the impact of jellyfish blooms on fish farms continues to be felt from Northern Ireland to Japan, and jellyfish becomes more widely promoted as a tasty treat, funding for their study is bound to surge. Hopefully this will happen before they have smothered many more fisheries.

Peachy keen, jellyfish

2009-07-20T06:27:00.000-07:00

We're well accustomed to marine jellyfish, but sightings of freshwater jellyfish are also hitting the headlines, most recently in the US and Sri Lanka. Freshwater jellies, otherwise known as Craspedacusta sowerbyi, can be found in almost any calm waters and have made appearances on nearly all the continents.

Freshwater jellyfish, like their sea-dwelling brethren, start off life as minuscule larvae which attach themselves to hard surfaces like rocks or corals before turning into tiny polyps. These then reach the ephyra stage, during which the stalk of the polyp develops ridges, and grows in size. It now resembles a stack of dishes, and the top-most "plate" matures most quickly, eventually detaching itself. This floats off and becomes a medusa, at which stage which we recognise it as a jellyfish. (You can look as some great pictures of developing freshwater jellies here.) Craspedacusta sowerbyi usually only peak at a diameter of about three centimetres, making their translucent bodies easy to miss in the water.

Easier to pronounce is their alternative name, peach blossom fish, which better evokes the floral patterning on these jellies. These jellyfish are commonly found in China, where it is said that they float to the water's surface during the blossom season.

Legend has it that the 1st century Chinese beauty, Wang Zhaojun, wept as she floated away from her home on a dragon boat, and her tears became jellyfish. This romantic origin makes the peach blossom fish desirable pets and there have been moves to prevent people from scooping these little fellas up and keeping them in the home. And rightly so: peach blossom fish are better left in their home environment as they can be crucial indicators about water quality. (Not to mention the fact that they'd much rather be swirling among the fallen blossoms than in a jar on top of your mantlepiece.)

Pretty in pink

2009-07-17T04:19:00.000-07:00

A gorgeous slideshow of jellyfish likely to be spotted by keen-eyed British beach-combers was posted by the BBC today, including one of the more glamorous cnidarians, the mauve stinger (Pelagia noctiluca). So behold, five facts about this special little jelly:

1. The mauve stinger is small but perfectly formed. Much of its body is transparent, but it has distinctive pink or purple buds (which hold the stinging cells) on the outside of its bell. It can grow to a diameter of 10cm.

2. Jellyfish can reproduce sexually or asexually, depending on their species, but the mauve stinger is a definite romantic. This passionate critter isn't confined to seasonal changes and reproduces throughout the year.

3. Its sting can be a gift that keeps on giving. Although not deadly, a nip from this jellyfish can cause recurring skin eruptions at the site of the injury for years to come.

4. An unprecedented bloom of these jellies destroyed Northern Ireland's only salmon farm. Two years ago, billions of mauve stingers swept in and caused millions of pounds worth of damage by wiping out the Glenarm bay salmon farm. 120,000 dead fish had to be incinerated, and the jelly influx was blamed on unpredictable tides.

5. It's widely thought that human activity is responsible for the increase in population of mauve stingers. This jellyfish is a top predator, and overfishing removes from the food chain organisms with which the stingers compete over food. Fewer big fish means more delicious water fleas (cladocera) and tiny crustaceans (copepods) for the mauve stingers.

Crouching tiger, humungous jellyfish

2009-07-14T04:16:00.001-07:00

How do you solve a problem like Nomura? The enormous Nomura's jellyfish (known in its native Japan as Echizen nurage) is causing concern among scientists who are monitoring unusually large blooms in the Yellow Sea and on the East China coast. The Nomura's jellyfish can grow to the size of a sumo wrestler, and for the first time they may reach the Pacific Japanese coast.

These beasts are blamed for rupturing fishing nets and destroying hauls of fish when they get caught in nets, but human meddling might be to blame for the surge in these jellies. Numerous theories have been suggested about the human impact on their population growth, from the overfishing of their natural predators to the warming of the oceans, which creates a balmy, jelly-friendly breeding environment.

This colossal cnidarian has a clever response to attack, which is sabotaging human attempts to cut down its population. The jelly ejects millions of tiny offspring into the water when under attack, and these little critters then stick to rocks and corals where the fittest will eventually detach and grow into full-size jellyfish. A survival strategy like the mythical Hydra makes a formidable foe indeed.

Experts are foreseeing a disastrous effect on the Japanese fishing industry and scientists at Hiroshima University are working flat out to control these unprecedented explosions in the jelly population. A net has been developed that would make it easier to release these giant jellyfish if they become caught up in a trawl, but some fisherman are worried about its efficacy. The problem remains unsolved for now, and the battle of man vs. Nomura's seems likely to become an epic struggle...

Ground control to Major Jellyfish

2009-07-10T03:10:00.000-07:00

Barrel jellyfish on the South Welsh coast are being fitted with microchips as part of a research project. The Swansea University scientists behind the EcoJel project hope to learn more about how far and how deep jellies travel, the impact of climate change, and how jellies affect other species. Their press release last summer cites the destruction of a Northern Irish salmon farm by an enormous bloom, but also mentions potential jelly benefits such as ecotourism.

Scientists are hoping that when the jellyfish shuffle off this mortal coil, the tags will wash up on beaches and be found by members of the public, who will report back on the location of the tags for a £25 reward.

“The project will also explore the potential of harvesting jellyfish in a sustainable way for food to export to Asian markets,” said Ieuan Wyn Jones, Deputy First Minister for Wales. So in dragging these tags around, certain jellies may be hastening a sticky end involving chopsticks and a smattering of soy.

CSI (Cnidocyte Sting Investigation)

2009-07-08T09:10:00.000-07:00

News that over 100 bathers in Alicante needed help from the Red Cross after being stung by jellies suggests a health epidemic, and the old wives' tales surrounding the treatment of these stings probably exacerbates the panic. The myth about peeing on the wound to relieve the pain persists, despite being debunked by Scientific American. Other rumoured cures include rubbing sand into the wound, or covering it in shaving foam and shaving off any stingers sticking to the skin using a razor (as if you'd carry one in your beach bag).

Jellyfish stings happen when something stimulates the outside of the jelly's stinging cells (cnidocytes) - such as a fish swimming against it, or your leg brushing past. The cnidocyte contains an sub-unit (organelle) called the cnidocyst, which consists of a small balloon-like structure containing a coiled-up tube. This tube rockets out and injects toxins into the creature unfortunate enough to touch the jelly. If the stimulus was a tiny fish, it would be paralysed and then devoured, but a much larger beast like you would merely suffer an instant jolt of pain. That said, the burning sensation can last for hours.

Quite apart from the awkward contortions needed for the pee cure, you may actually make the pain worse. An alkaline jellyfish sting requires an acid to neutralise it, and dilute pee could make intensify the discomfort by unbalancing the concentration of salts in the cnidocytes.

For the same reason, you shouldn’t try to wash the wound with fresh water. Your best bet is rinsing off any remaining tentacles from your skin with sea water, and removing the rest with a pair of tweezers (or ‘shaving’ them off with a credit card. This seems to be where the shaving foam myth came from).

Vinegar can help to relieve the pain, but should not be used if the stinger is a Portuguese Man O’War (which, although it isn’t technically a jellyfish, is often thought of as such). Anyone showing signs of an allergic reaction, such as shallowness of breathing, dizziness or loss of consciousness, should of course seek immediate medical attention, but most of us should make do with some painkillers and resolve to swim more carefully in future.

Get jelly for your close-up

2009-07-03T04:03:00.000-07:00

London artist Mark Mawson’s haunting photographs hit the headlines in the Daily Mail today. Underwater photo specialist Mawson created images strongly resembling jellyfish by dropping paint into water, illuminating the impact with a strobe light. Photographing real jellyfish also demands time and patience, partly because many are wholly or partially transparent. Most aquaria display their jellyfish in front of a bright blue background so viewers can enjoy the colour contrast.

In the wild, you’re most likely to find the common moon jellyfish, which can live in temperatures from 6° to 31°C. This little beauty, often recognisable by a dainty four-leaf clover crest on its bell, is almost totally transparent, so how would you go about producing a photograph of it? Light passes straight through these near-invisible monsters, and one enthusiast sensibly recommends a controlled environment: a darkened room, a tank containing jellies and a digital camera with a very large memory.

This is all very well for the photographer, but not too jellyfish-friendly. Jellyfish are used to large spaces where they can drift on the sea currents, and you may find your model simply sits at the bottom of your tank sullenly rather than floating majestically in front of your lens. Also, if you don’t return it to the sea soon after taking the pictures, the jellyfish will die (if it hasn't already injured itself on the sides of the tank).

If you’re a keen snorkeller with a waterproof camera on hand, you can snap moon jellies in their natural environment. The Jellies Zone has some excellent advice on equipment, and tips on using the sun to backlight jellyfish. (Backlighting is likely to catch other particles in the water, so you might want to keep your Photoshop skills up to scratch for later.) Unlike most fish, which scatter when they sense a diver with a Nikon, you can get reasonably close to jellies. This may not be advisable if your subject is a Portuguese Man O'War, but then again, some human supermodels can be rather venomous too...

Dawn of the jellyfish

2009-07-02T06:54:00.000-07:00

Each summer, jellyfish hit the headlines, prompting beach-goers to look twice before dipping their toes. This year, we are steeling ourselves for huge numbers of stingers hitting UK shores. Last year, we fought them on the beaches, and before that, villages up and down the Med were arming against an expected onslaught. Something about swarms of sea jellies lends itself to thrilling news stories. Even the collective terms for jellyfish – a ‘smack’ of jellyfish, or a ‘brood’ – suggest a battle in the making.

While everyone loves a good plague story, what makes the jellyfish so compelling? And aside for comic hyperbole, what is behind journalists’ description of the jellyfish peril in such apocalyptic terms?

Jellyfish don’t possess eyes, brains or specialised respiratory systems. While some use jet propulsion to power themselves forward, or hitch rides on seaweed, most rely on sea currents. When they sweep towards our beach resorts, the unthinking, but relentless, movement is rather like the slow, lumbering assault of our horror-movie friend, the zombie.

While the sluggishness of the zombie’s movements has been hotly debated of late, any horror aficionado will tell you that the tireless gait of the zombie represents the inevitability of death lumbering after us. You can outrun a zombie, but only for so long. Subconsciously, we see a similar menace in the broods of jellyfish moving towards our beaches: motiveless, unthinking, but as unstoppable as the tide itself.

Just as zombies uncomfortably remind us of our mortality, jellyfish invasions evoke the unconquerability of some of nature’s systems. But if we look deeper, there is nothing ugly or menacing about the jellyfish: as I hope to show in this blog, they have amazing qualities and are involved in some of the natural world’s most fascinating symbiotic relationships. Reader, embrace the wondrous jellyfish – but nonetheless, keep an eye out where you’re swimming this summer…