Did you know when you're picking up a shell on the beach you're actually holding a lil critters skeleton? Seashells are kinda hard to define, but generally speaking they're the hard protective outer coverings of marine animals. Most seashells come from dudes called mollusks. We have our skeletons inside, but mollusks have 'em outside - and are what what we know as a shell. So when you're walking along the beach admiring all the shells - you're actually walking along admiring a graveyard of marine skeletons. Cool, huh!? Mollusks exude shells as a protective covering. The shells are excreted from the outer surface of the critter which called the mantle, and are made up of mostly calcium carbonate. So how come there are so many different types of shells? Well, there're over 110 000 species of mollusks! After the lil dude dies, the durable shell remains. Ocean currents carry shells underwater, which is how they end up on the beach for us to find and wonder over. Although there's a moer of a lot of species of mollusks, they come in 2 major types, bivalves and univalves. Remember latin class? "Bi" means "two", so bivalves are mollusks that have two shell halves that form a whole shell. Stuff like clams and oysters. "Uni" means "one", so univalves just have a one-piece shell, usually a spiral-type shell, often looking something like a larger, stronger and more elaborate snail's shell, guys like conch, whelks and nautilus. So how come shells come in so many different patterns and colours? Some theories suggest this helps with camouflage against predators. Or that maybe bright colours imply to a would-be eater that the shell is poisonous,like a big sign saying "don't eat me!" Another theory is that the colour patterns often align with the shell's spiral or axial sculpture. This sculpture, like corrugation in cardboard, strengthens shells against predators such as crabs, and pigment might further strengthen it. So instead of just trying to have a thicker shell, it might be more energy efficient for mollusks to make pigments to help with strengthening the shell. So where do the colours come from? The food that the mollusk chows causes pigments to be produced within it's mantle. If the pigment secretion is continuous, then spiral or radial lines or bands will be laid down. If pigment secretion is periodic, then spots or flecks will appear on the shell. If the whole mantle is secreting pigment at the same rate, the shell will have uniform color, but if the process is interrupted, then axial or concentric lines appear. If the pigment is secreted in zones, then wavy bands or angular markings occur. Why are there so many different shapes of shells? Mollusks' shapes are a product of habitat and life style for the most part. Shell shapes have evolved to make their lives easier. A snail that burrows through sand needs a shell that will move through wet sand easily, so a slender and gradually tapering shell, narrow end at the front, would work well. Whereas a mollusk that needs lots of camouflage may have evolved a shell that has a spiny or irregular surface which will catch and hold all sorts of camouflaging encrusting organisms. The inhabitants of shell's can be some pretty crazy characters. Take for instance the muricid snail - he climbs aboard an oyster, drills a hole through its shell, then inserts its proboscis and uses the teeth at the tip to rasp up the oyster's flesh. The Cooper's nutmeg snail dines on shark! He works its way up through the sand underneath angel sharks resting on the bottom, then it threads its proboscis into a vein in the gills and sucks the shark's blood. For the shark, it's just like a gooey mosquito bite!
So before picking up that shell on the sand - make sure no-one is home, as you might just end up with a sting or a bite! 15 years ago, this month, members of the surf clubs in Jeffreys Bay formed the Supertubes Surfing Foundation, ostensibly to maintain the beaches and to protect the dunes. In the early years, 4T of glass and piles of litter were removed from the beaches. Prior to the RDP houses being built, approximately 3000 aloes in that area were rescued and planted at Supertubes and the other beach breaks. Other plants, at one stage there were over 4000 in black bags in a private garden, were rescued and then replanted at Supers, Point, Lower Point, Main Beach, Tourism Office, along Da Gama Road, Secrets and Magnatubes. When bush sleepers started erecting their shacks in the natural coastal bush in the Supertubes Park, the Foundation raised funds to erect razor wire to protect the bush, the tiny duikers and the mongoose that live in there. Beds were dug and the rescued plants planted therein. All of these plants, being indigenous, survived the serious drought of a couple of years ago and require no watering. The Indigenous Plant Rescue Centre is situated in the Park and the Foundation's operations take place from there. The Point garden was started with plants rescued from what is now Die Opstal next to the Caltex garage. The Supertubes Surfing Foundation has also been involved in community project such as fixing up the toilets at one of the local schools, planting indigenous trees and plants in the school yard, starting veggie patches both at the school and with private households in Oceanview and is very involved with the JBay Recycling Project The Foundation has paved paths and dustbowl areas and made paths wheelchair friendly. It also developed the idea of the penguin recycling bins which are now a feature in the Park and have collected 5.5T in the 7 months that they have been there. Smaller penguins will be placed at certain beach breaks. The penguins at the SuperTubes Park have recently has not 1 but 10 Babies!!! The stunning birds were created by Arno Seyfert from Custom Works and painted by Stephen Bibb Art The project was funded by the Supertubes Surfing Foundation. The babies will spend some time adapting to their surroundings in the Park before fleeing the coup. The parent birds have produced a massive 5.5 tons of recyclable matter in the 7 months that they have been in the park! Maintenance is now one of the huge tasks of the Foundation from the lawn mowing of the Supertubes Park, Point and Lower Point, maintenance of the various gardens and beach breaks etc to the upkeep of the boardwalks.
Future plans include a cycle track, more seating at Supertubes, creating a marine reserve, outdoor gym, setting up an education centre, upgrading of the toilets in the Park, moving the showers at Point and the anti nuclear call is on going - amongst others. The Supertubes Surfing Foundation only does what it does because of the vision of those surfers 15 years ago, spearheaded by Koffie Jacobs. Salute. Ask any East Cape surfer which wind they hate and it'll be the Devil Wind. The north west is the curse of all the premier surf spots in PE and JBay. It's a horrid cross shore that blows sideways up the wave face and turns a decent wave into a trip down a washboard dirt road. Bump bump bump bump gatvol. Many a solid winter swell has been ruined by the ravages of the north. Utter punishment to watch good waves being decimated. Calling it a Devil Wind seems most appropriate. Not sure who coined the term, but it does seem to be of East Cape origin. JBay handles it a little better than PE, but you're still going to have to keep those knees bent to absorb the chatter. Crouch and go. And yes, there are a few hidden corners that can deal with a NW, but anyone keen to take them on in a 6ft groundswell? So why are we so cursed? Blame it on the Berg winds - those fiends that blow down from the mountains. The winds are channeled by the mountain ranges just inland and swoop down through the valleys. In Jbay they get funneled between the Groot Winterhoek and the Klipfonteinberg. The angle of the valley actually amplifies the northerly component (see below). The Berg winds are usually associated with pre-frontal conditions. If a coastal low is developing off Cape Town the barometer drops, and hot air from the Kalahari (our semi-desert interior) is sucked down off the plateau to the coast and into the low pressure system. So basically you have descending winds from a high pressure cell that has developed in the north eastern interior. For all the weather purists who'd like to be able to spot it on a synoptic chart, look for this. The winds often mimic the temperature of the interior - so in summer the NW will feel like someone's blowing you with a hairdryer, but in winter - with much cooler temperatures inland, it can send an icy chill down your spine.
The longer the devil winds blow, the more they super-charge the storm. A deeper low means stronger winds, and stronger winds make bigger waves. So there may be a silver lining after all! Once the front arrives - the wind swings to the SW, and everyone starts smiling again. But yrrr, we still hate the bloody things.... Let's be honest, you gotto know weather if you wanna make sure you score the surf. Sure, it's as easy as logging on to your favourite surf report or wind forecast sites, but it's still a helluva lot cooler if you're able to have a stab at what the weathers gonna be doing without having to consult www.com Here's a few old school ways to predict the weather. Starting with an easy one. Sure you've heard the old saying that goes "Red sky at night is a sailors delight, red sky in the morning a sailors warning" which implies it's gonna be a lekker day tomorrow if there's a kiff sunset, and the possibility of a kak day if there's a beaut sunrise. But where does the saying come from, and does it actually make any sense? The saying dates back thousands of years and just might have some scientific truth behind it. Kind of. The colors we see in the sky are due to the rays of sunlight being split into colors of the spectrum as they pass through the atmosphere and bounce off the water vapor and particles that it contains. The amount of water vapor and dust particles in the atmosphere turn out to be pretty good indicators of weather conditions. And guess what - they also determine which colors we will see in the sky. During sunrise and sunset the sun is low in the sky, and so light is being transmitted through the thickest part of the atmosphere. A red sky suggests an atmosphere packed with dust and moisture particles. We see the red, because red wavelengths (the longest in the color spectrum) are breaking through the atmosphere. The shorter wavelengths, such as blue, are scattered by the dust & moisture and broken up. The red sky at sunset often results from clear skies, which means there's most likely a high pressure cell around which will keep storms at bay. "A Ring Around the Sun or Moon, Rain or Snow Is Coming Soon" is another of the old sayings. It’s an effect of our own atmosphere that meteorologists call a “halo effect,” because diffracted light rays create a halo around a bright object. The halos are caused by tiny ice crystals that have gathered thousands of feet above the ground, as thin, wispy clouds (called cirrostratus for the technically minded). These clouds are so thin, you might not notice them at all if it weren't for their effect on the sun or moonlight. The incoming light rays from the sun or moon are bent, or diffracted, by these ice crystals at an angle of 22 degrees. This means that in addition to the direct sun/moonlight, you will also see diffracted sun/moonlight in a circle 22 degrees away from the sun or moon. This is about the distance of your fist, held at arm’s length. Which is what we see as the halo. Does it mean that rain is coming soon? Those high, wispy clouds could be the forerunners of storm clouds right behind them, so yip - rings could mean rain. Another good way to find out if a front's on the way is to ask a ballie! If he moans about joint or bone pain, then there could be waves on the way. Arthritis pain and physical discomfort kick in when the barometric pressure changes. Many people with joint problems, teeth issues or recently healed broken bones will feel some aches as the barometer drops. Low barometric pressure means an approaching cold front, which might bring some surf with it. Big Dave's had a hip replacement - so he's a walking barometer....just drop him a line to ask him how the hips feeling! Moving from old wives tales to new urban legends. This one may or may not be true. But given the amount of posts I see every morning on my Facebook feed of ou's cups of coffee - I'm thinking there should be plenty peeps out there that can give this one a test. You just gonna have to forgo the fancy froth and go old school basic for this one though....
So, wanna know what the weathers doing - take a look at your cuppa coffee in the morning and check out the bubbles (no bubbles? no problem. Just give your cup a good stir!) Do the bubbles collect in the center? Supposedly that means you’re in a high-pressure system, which is making the coffee’s surface convex (higher in the middle). Since bubbles are mostly air, they migrate to the highest point. It’s going to be a lekker day. If the bubbles form a ring around the sides of your mug, you’re in a low-pressure system, making the surface concave - so the highest points on the surface of ya coffee are around the edges. Rain is likely. A word of caution about the coffee barometer - you gotto be drinking strong, brewed coffee, as this has enough oil for the trick to work, and your mug must have straight sides. Those instant coffee granules ain't gonna tell you nothing. Another good reason to drink real coffee! Keen to see what the local PE coffee-culture surfers make of this - please report back on your bubbles guys! Jamie Bell, Gino Fabbri and the rest of the coffee crew - we await your verdict on this one.... UPDATED Listen up!!! Turns out the plankton partying along our coastline are NOT what we thought they were, and have now been identified as dinoflagellates Lingulodinium polyedra (F.Stein) and/or Gonyaulax polyedra (J.D.Dodge). Initial reports coming in last night were that these guys could be super nasty - producing a horrid toxin which gave rise to Paralytic Shellfish Poisoning (PSP) - and I posted a blog early this morning warning peeps about it cos it's pretty hectic stuff. But have just got word from those in the know that it looks like the toxins the newly identified plankton strain produces are NOT the mean PSP variety, but rather the milder yessotoxin. Shew - crisis averted. So instead of this mini-bugger putting you in the hospital with nausea, vomiting and a host of other nasty symptoms (which could even culminate in death!), it's back to looking like it isn't gonna do anything to you at all. Apologies for any unnecessary panic caused by the earlier warnings of it being poisonous! Rather it can be down-graded to potentially poisonous. Mentioned the yessotoxins a few days ago in a blog - the one's that seem to show symptoms in mice, but not humans. So provided you aren't a mouse you should be fine. Still, because so little is still known about it, it makes sense to adhere to the warning not to eat shellfish. Better safe than sorry. Info around this whole red tide is forever changing as it's a totally new species for this area and little is known about it. The info on the new species came to light late Monday arvo - after super-sleuth Dr Tommy Bornmann from SAEON wanted to double check the ID they had on the bloom. He wasn't satisfied that this was indeed P.reticulatum cos it isn't known for spectacular glow-in-the-dark displays. Lucky for us scientists like Tommy like to question everything. So some plankton went by plane to Croatia to get sussed out by experts there. They got back to him with a revised identification. New kid on the block. The scientists at DAFF (Department of Agriculture, Forestry & Fisheries) are also conducting more studies but at this stage seem in agreement with the new ID's. They've also done testing at the oyster farm in PE and so far haven't picked up signs of any toxicity, although there is a few days lag in the testing, so new results may come to light in the future. Although this species looks almost identical in structure to the Protoceratium reticulatum, this one is a slightly more evil twin. Let's be honest, any plankton that has "Dodge" in it's species name should give you a hint he's up to mischief. But at least he isn't as nasty as initially feared. Unless you're a mouse. Reports of fish deaths in the Sards area continue, with mussel crackers and blacktails appearing some of the worst affected. Remember the fish are dying cos of hypoxia, not directly from exposure or ingestion of the plankton (see this blog post for more details). Plenty of peeps are concerned about whether it's safe to eat fish. Seems it is. Not likely that the toxin can make it's way up the food chain from shellfish to the fish themselves even if the fish eat them. But it would be pretty doff to eat any of the dead fish you pick up on the beach - purely cos they've been lying there in the sun and most likely are a bit vrot! A serious concern is that cos it's a new species for the area, the cells of the plankton will form cysts on the sea floor which can re-emerge when the environmental conditions are right. So, looks the lil bastards are here to stay. Lurking in the shadows until conditions to come out and jol again look perfect again.
We really need a big storm with decent swell and pomping west to try shift these plankton poepals offshore and disperse them. Anyone with good connections in the Antarctic, please ask em to rustle up something down there for us and send it this way. So here's what we know to date - safe to swim in the sea, safe to eat fish, better to avoid shellfish. Thanks to Dr Shirley Parker-Nance (NMMU), Dr Tommy Bornman (SAEON) and Prof Peter Britz (Rhodes) for the info. Special thanks to Dr Bornmann who kept on digging til he found out what this critter was. All that glitters is not gold. Turns out that all that glows has a dark side too. The plankton party that has had everyone in awe by turning the wildside shoreline into a spectacular light show has got a sting in the tail. There were reports of a large number of dead fished washed up on Sards beach yesterday. Local scientists had warned that this could be one of the side-effects of the recent red tide. The party can go bad for two reasons, both oxygen-related. Firstly the plankton are on such a mad jol with their nocturnal glow antics that they suck all the available dissolved oxygen out of the water at night cos of some heavy breathing (cellular respiration in science-speak). Pretty much the same way you'd get breathless busting out all your moves on the dance floor. Secondly, all epic jols have to end. The mass death of the critters once the party is over results in a whole big pile of bodies on the ocean floor. Along come hordes of bacteria - who are the grim reapers of the sea and pitch up wherever things are dying. These ocean street cleaners have to decompose all the dead stuff. But guess what, decomposing death is hard work! All this effort means the bacteria suck up most of the oxygen in the surrounding water. Although not a great thing, it isn't a train smash as long as the bottom waters are mixing well with the oxygen-rich surface waters - which means the oxygen content down below gets renewed. The hiccup comes if due to localised sea conditions the water becomes stratified. This is basically like a Water Apartheid. The water on the top don't mix with the water on the bottom. It often occurs in bays and coves, such as Sards, that are cut off from the large-scale circulation patterns that promote mixing. Probably find the lack of swell on that side has amplified the weak local currents even further.
Because the oxygen-depleted bottom waters don't get refreshed, it causes hypoxia. This makes it really hard for fish and other marine creatures to breathe. Pretty much a case of "Move or die, fish". Sometimes the oxygen depletion happens so quickly that it cuts off escape routes and then results in the death of marine life through suffocation. This is called a black tide, and seems to have been the case at Sardinia Bay - with upwards of 300 fish washed up onto the beach on Saturday afternoon. It's pretty ironic considering the bacteria are there to clean up the dead to start with. You're maybe not doing your job so lekker if you cause death whilst you're cleaning death up. Just saying. Nature can be weird sometimes. And there's still possibly another twist in the tale. Low oxygen conditions can allow certain bacteria to convert sulphates in the water to hydrogen sulphide gas. Remember the stuff that smelt like rotten eggs in science class? This stuffs so hectic it can even corrode metal objects and cause respiratory problems if you live close by. So if the water is ponging like your fat uncle's fart, probably don't swim with your Rolex or stand there for hours gulping in lungfuls of the stinky air. Let's hope these sulphate-converting bacteria don't show up, cos besides the pong it could result in even greater fish deaths. Scientists from Bayworld have collected samples of the dead fish from Sards and will be investigating further. Red tide - you can run but you can't hide. Super-sleuth Dr Tommy Bornman from SAEON has managed to nail an ID onto the predominant critters in the algae blooms off our coast.
Introducing Protoceratium reticulatum, or let's just call him Mr P. Turns out Mr P is two things, first is that he's lost, second is that he's toxic. Sort of. He's previously been recorded in the North Sea, off the coast of Brazil and the Southwest Atlantic (west coast of the Western Cape). So what he's doing in PE who knows. No doubt climate change will be partly to blame cos of changing currents, winds and water temps. Prof Peter Britz from the Ichthyology department at Rhodes points out that harmful algal blooms are increasing around the world as ships move toxic species in their ballast water. Any increase in nutrient pollution thanks to things like sewage effluent provides the fertiliser they need to breed like bunnies wherever they land up. Mr P's species is listed by UNESCO as a harmful microalgae. It's been proven toxic to mice. But that's only really when you inject them full of the stuff. If they swallow it, not so bad. It's effect on humans is still unknown. A bunch of studies have sussed out the potential toxicity of the yessotoxins that Mr P produces. To date none of them have found any toxic effects when they are present in humans. Just the poor mice don't seem to do so well when spiked with it. So although no data exists to point a finger at a direct association of the yessotoxins causing problems for humans, the warnings of their potential health risks to us still stand due to the significant animal toxicity observed. It's a tough lil bastard, cos unlike other algal toxins present within shellfish, this stuff isn't destroyed by heating or freezing. Wonder if the perlie poachers will be printing a health warning on the bags of perlemoen they're smuggling out? So there ya have it - don't feed your pet mouse mussels or oysters. And it would be a good idea not to eat them yourself either. Just to be safe rather than sorry. Probably fine to surf in it, provided you don't gulp down gallons of it. Brad & Scott - your Noordhoek sesh in the stuff won't kill you! PS - take a drive out to the Schoenies/Maitlands area at night to go check out the amazing light show. It does depend on the wind & weather as to how big the plankton party is, so you don't know til you go. But if you luck into seeing a rad display it'll be so worth the effort. Even the sand glows under you feet. Thanks to Dr Tommy Bornman (SAEON), Dr Shirley Parker Nance (NMMU) and Prof Peter Britz (Rhodes) for the info. UPDATE: Turns out this ID was not correct. Samples sent off to experts in Croatia have returned findings of another, far more poisonous species. See here for more details. Here's some shots from Friday night at Maitlands. And yip - it really does look that blue in real life! Went and saw it for myself. The last few night have seen a few glow-in-the-dark plankton parties along the wildside. Here's a collection of some amazing shots of the red tide going blue neon. Thanks to all the photags for sharing their shots with us. The above 2 shots by Marius from Full Circle Photography (http://www.fullcirclephoto.co.za) The above 2 shots by Nick Cadle Photography (https://www.facebook.com/nickcadlephotography) The above by Niki M Photography (http://www.nikimphotography.co.za/) The above by Karin Anker from Design Studio Photography (http://www.tdsp.co.za/)
Beware of colours! If the blue bottles don't get ya, the red tide might. (and on a side note: word is that some of the ou's visiting Casey lately have gone home a bit green.) But back to the critters. Sounds like what everyone had thought was an innocuous algeal bloom might turn out to be a bit more serious than expected. Basically a Red tide is the result of an increased occurrence of some plankton cos of more chow being available. Main culprit is upwelling of cold nutrient-rich water with Mr Plankton in it, which when it lurks about at the surface catching some warm summer rays it goes "yih-hah" and makes hay (or more specifically, plankton) as the sun shines. The usual suspect is a species called Noctiluca. But this current bloom seem a bit more sinister. Samples taken and currently being analysed by NMMU show that this bloom might be Noctiluca AND friends. Problem being is that one of the friends remains anonymous. No-one can work out what he is yet. Good guy? Bad guy? Who knows? Dr Tommy Bornman from the South African Environmental Observation Network (SAEON) has been monitoring the bloom and is still busy with DNA testing. He cautions that although the full array of plankton buddies has not been clarified, the fact that they're such a diverse crowd of lil dudes might be an indicator that it could be toxic. Oh-oh. So, spit not swallow in the surf. Don't eat the shellfish. And surf at night cos the neon-glow from the critters is gonna look super-cool when you hook that big off-the-top. Critter #2 lurking in our bay at the moment are the blue-bottles. Bit of east wind has plonked them into the inshore area and beach. Bit of a challenge cos the warm water means peeps are wanting to trunk it, but that means lots of exposed skin to get yourself stung in your mielie. These ou's sting the crap outta you cos they have cells called nematocysts which are found in the long tentacles that trail behind em. These lil critters screw up your sesh by injecting a protein-based venom into your unsuspecting flesh, which can have varying reactions - none of them good. Firstly it stings like crazy, but if your luck is really out then you also get a nasty allergic reaction. Rule number one is to try avoid getting stung in the first place. It’ll help if you wear a rashie or a T-shirt as it means there’s less open skin area for the terror tentacles to stick to. Plan B – what to do if you do get stung. First off try rinse the tentacles off you using hot water. How hot? They reckon it has to be over 50C to work, that’s about as hot as you can bear. Chances of finding hot water at the beach? Bogger all. So let’s scratch that piece of advice then! Next best thing is to rinse em off using salt water, cos fresh water might actually make the stinging worse. And no, don’t piss on it either! The old wives tale about urine don’t fly, it just isn’t acidic enough. Plain white distilled vinegar like you would find in your kitchen has long been the standard first aid treatment for stings. Its use has been questioned in the last few years and several studies leave us wondering whether vinegar really works. Again, chances of finding vinegar at the beach are also bogger all, unless you get stung at Pipe and you can pop over to Something Good - grab some chips to go with your vinegar too. Just make sure when you rinse that you get those tentacles off. Peel the buggers off. Not with your fingers though! Grab a stick, a shell, use a T shirt over your hand, whatever. Just get those things off else they’ll keep pumping poison into you. Keep an eye out for anaphylaxis. Ana – what?? Anaphylaxis is a severe allergic reaction that can result in hectic itching, shortness of breath, wheezing, tightening of the throat, flushed skin, weakness or dizziness. And if things get real bad you go into shock. If you’re experiencing any of these symptoms make sure a mate gets you to the doc asap. Otherwise if you’re just stinging like hell, pop to the pharmacy and grab some anti-inflamm’s and then stick some ice on it. Moral of the story – don’t get stung, it sucks…well, it stings! Thanks to Dr Shirley Parker-Nance for providing the info about the red tide.
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AuthorMillerslocal Archives
July 2021
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