Launching on Sunday from Oceana Powerboat Club (Granger Bay), at 9.00 and 11.30 am. We will visit North Lion’s Paw and then South Lion’s Paw with the possibility of a third launch if conditions warrant it. Text or email me to book.
The waterfall above Simon’s Town
The week that was
Last weekend’s rain, mudslides and run-off turned almost all the inshore sites into coffee. Weird winds switching 180 degrees from one day to the next has made choosing sites during the week more of a ”take a look first and then decide” kind of situation. The good news is that False Bay is not looking that bad, probably around 6 metre visibility, and the Atlantic is getting a good clean from a few days of south easterly wind.
Fish Hoek beach
Weekend diving
Hout Bay or Table Bay should be really good on Sunday. There is too much wind on Saturday, so the plan is to dive Table Bay as the sites there are awesome and we don’t go often enough. Besides, Chapmans Peak drive will be closed until close to Christmas by the sounds of things, and going all the way round and over from here is a ten day camel ride. So we launch at 9.00 am and 11.30 am, we will dive North Lion’s Paw and then South Lion’s Paw. If conditions are good we may squeeze in a third launch to Justin’s Caves.
Long Beach, Simon’s Town
If you’re diving, please be there half an hour before the launch. If you haven’t been to OPBC before, directions are here.
Early on the morning of Wednesday 13 November, the remains of a whale washed ashore on Danger Beach at St James. For reasons well known, in Cape Town it’s tricky to leave a whale on a beach or to tow it out to sea and dump it there, much as this would be an ecological boon. The SA Navy attempted to tow the whale to Simon’s Town harbour for removal, but ran into engine trouble.
Whale on the beach in Fish Hoek
Fortunately one of the local shark cage diving operators was able to supply a suitable boat to continue the tow. Shark Explorers took the whale as far as possible, but the wind was coming up and the carcass was very heavy. It was decided to drop the carcass off at Fish Hoek beach and remove it from there. Two of their crew swum the line attached to the whale to the beach, where it was attached to a front end loader. The front end loader was attached to a truck, and much of this ensued:
Several hours later the whale was at the top of the beach, on the edge of the parking area. The front end loader was now behind it, shoveling the carcass forward.
When the whale was close enough to the flat bed truck, it was attached to the winch on the truck, and hauled up onto the trailer. The trailer was backwards, not attached to the truck, so the winch line had to be taken over the top of the trailer to the ground. There is movement in this last video, but it’s very slow!
The operation was smoothly handled with great professionalism. This is not the first time, and won’t be the last, that local authorities have had to remove large cetacean remains from our beaches. Muizenberg, St James and Fish Hoek beach were closed for much of the next couple of days owing to increased shark activity as a result of the bits of whale and oils in the area. Tony saw some large chunks of blubber floating at Long Beach when he dived the following day, too.
Here are some photos we took of the removal process. In between sunset and darkness, when there’s an obvious gap in the sequence, we went home to have dinner! Shark Spotters also put an album on their facebook page that shows the process from start to finish (our album spans 6-7.00 pm and 8-9.00 pm).
Preparing to put the whale on a truck
We much prefer seeing whales that look like this, or this, or this!
Ed Yong at Phenomena writes about the information that can be gleaned from a plug of blue whale earwax. Earplugs of blue whale wax look a bit like battered candles, and contain alternating layers of dark wax (from when the whale is migrating) and light wax (from when the whale is feeding). Counting rings of earwax provides a way to estimate the age of blue whales – there are two rings for each year of the whale’s life.
The wax also absorbs pollution from the whale’s environment, and contains some of the hormones that the whale’s body produced in life. Researchers at Baylor University analysed a plug of wax from a male blue whale that died as a result of a ship strike and washed up on a beach in California. From concentrations of testosterone and cortisol (a stress hormone) they were able to determine when the whale reached sexual maturity. They also found a disturbing array of pollutants including DDT and mercury. Sadly, the highest concentration of pollutants appear in the earwax from the first six months of the whale’s life, suggesting that they were passed along in its mother’s milk.
The scientists intend their study to be a “proof of concept” – they only analysed a single earplug, but these samples exist in museums around the world and should be kept and studied from future whale necropsies. Science at work!
Possible launch in the Atlantic on Sunday, for hardened veterans who don’t mind rough surface conditions, possible rain, and cold water. If this sounds like you, let me know and I’ll text you if we go ahead! I’ll decide on Saturday late afternoon.
Email
We changed website hosts this week, and emails to learntodivetoday.co.za are bouncing at the moment. Please use my gmail address instead (my name and surname at gmail.com) for the time being.
Whale on the beach
Earlier this week a whale carcass washed ashore at St James beach. It didn’t look much like a whale any more. Such a large animal will feed millions of mouths in the ocean from the tiniest organism to the great white shark. Out in the ocean and left to nature, such a carcass would slowly be consumed down to the last morsel, but given the proximity to us human beings such matters need some intervention. Plan A was to tow it out to sea, plan B was to remove it to a landfill. It was taken under tow but sadly the weather was against this succeeding, and left anywhere in False Bay the wind would most likely return it to shore.
Whale on the beach in Fish Hoek
At around 5.30 pm it was landed in Fish Hoek, dragged and pushed up the beach and loaded onto a flat bed truck. This took about four hours. It was estimated to weigh between 3-4 tons so this was no easy task. We watched from around 5.00 pm and I was very impressed by Shark Spotters,Cape Town city officials, Solid Waste staff, the work crew and everyone else who really made a huge problem go away in a matter of hours. Before you say, ”why don’t they leave it to nature?” bear in mind that given the time of year – with lots of people in the water, seasonal inshore shark movement, and onshore prevailing winds – and it all adds up to, it was the best and only option available.
Preparing to put the whale on a truck
We dived at Long Beach today and found a few chunks of this carcass in about 6 metres of water. There are most likely more around and Solid Waste staff have been removing these chunks as and when they wash up on the beach. Be vigilant!
Weekend plans
What about the weekend? Well, I do not hold much hope for great conditions on either of the days. However, Sunday may just pan out. The south easter is set to blow between 30 and 60 km/h from midday tomorrow until late on Monday. This wind direction cleans the Atlantic but it is set to blow there too, possibly 30+ km/h, making for appalling surface conditions. Down below it will most certainly be crystal clear so if a really rough boat ride does not bother you let me know. If the wind does drop it will be a day of really good diving.
I have also scheduled boat diving for Tuesday as I have an Open Water course to complete, and Tuesday looks really good. Take the day off work!
There is always the option of great conditions in Gordon’s Bay when the south easter blows so check with Deon from Indigo Scuba late on Saturday for Sunday dives.
Fish Hoek beach after a strong south easterly wind
This is why the shark barrier net at Fish Hoek is removed every evening, and only put into the water when conditions are favourable and the wind isn’t too strong. It would be weighed down and damaged by the volume of kelp that gets washed up the bay when the wind blows like this for a prolonged period.
The four episodes of this History Channel series cover waves, tides and currents, predators, and pressure – all powerful features of the ocean that can be sensationalised (some more easily than others) and presented for shock value and as imminent threats to human life. Full advantage is taken of this fact.
This very American offering doesn’t boast the measured, mellifluous tones of Benedict Cumberbatch or Steve Toussaint as narrator, but the line-up of (mostly in-studio) guest narrators is quite impressive. Bruce Parker (The Power of the Sea), Susan Casey (The Devil’s Teeth and The Wave), David Gallo (scientist presenter of the TED Talk I mentioned here), Scott Cassell (student of the Humboldt squid), Richard Ellis (writer of a number of ocean history, art and sciencebooks), and Neil Hammerschlag (shark scientist) were familiar to me, as was big wave surfer Ken Bradshaw, from this article. The strange, uncomfortable way in which the studio narrators were filmed, with silent close ups interspersed with talking, was very annoying and must have been incredibly embarrassing to shoot. Or perhaps the cameraman took the footage when the narrators didn’t realise they were being filmed.
Unlike BBC documentaries, which tend to rely purely on incredible photography and fluent narrative to convey information, the History Channel favours a CGI-heavy approach that we encountered in Treasure Quest,Deep Sea Salvage, and also in the National Geographic SharkMen series.For the subject matter of this series – particularly the sections on waves, tides and currents – it was very appropriate and informative. The first episode, devoted to tsunamis, rogue waves and “monster waves”, made good use of CGI to illustrate the concepts as they were explained. The series was produced shortly before the Japanese tsunami of 2011 (there is a hastily tacked on “thoughts and prayers” disclaimer) and features interviews with a survivor of a tsunami in Samoa. I am fascinated by rogue waves – the whole episode could have been devoted to them but they don’t make for good television – we only have indirect evidence of their existence. Also, I could have done with more footage of giant ships battling storms, but that’s what youtube is for…
The least interesting and most irritating episode was the one devoted to the ocean’s top predators, which suggested that orcas are a serious threat to humans. As evidence, the cases of captive killer whales drowning and injuring their trainers at marine theme parks were cited. No mention was made of the psychosis that these whales suffer from as a result of confinement in a small, barren, completely unnatural environment. An incident in which orcas inexplicably rammed and sank a yacht in the Pacific Ocean is also described and re-enacted. Whether the orcas did what they did because they wanted to kill the people on board is highly debatable. There is also a half-hearted attempt to paint whales as potentially vicious killers, recounting incidents when sperm whales rammed whaling boats in the 19th century. More power to the sperm whales, I say.
The other dangerous predators were (predictably) white sharks, Humboldt squid, saltwater crocodiles and Australian box jellyfish. There was a small environmental message at the end of this episode, mentioning that squid will probably end up the top predators in our oceans if current trends – fishing out large predatory fish and global warming in particular – continue.
The third episode, on the immense pressures that objects in the deep ocean are subjected to, was very interesting to Tony and me as divers. A confusing interview with a diver whose brother got DCS on a wreck dive leaves (I suspect) much out. Were they even qualified divers? Why was he surprised that his brother felt unwell and confused as to the cause after he popped to the surface from 30 metres after a 30 minute dive?
The bulk of the third episode, however, recounts a 1981 experiment called Atlantis III in which three volunteers were taken in a saturation system to a simulated depth of 686 metres while breathing Trimix 10 (70% helium, 20% nitrogen and 10% oxygen). It took 31 days for them to decompress. The chief of the experiment, Peter Bennett, was the founder and former CEO of DAN. There’s a more information about the project here – worth a read (download the pdf slowly), and a briefer account here.
The series concludes with an episode on tides and currents, including rip currents. The massive tidal range of Morecambe Bay in the United Kingdom, is discussed at length. At low tide, up to 300 square kilometres of mudflats is exposed, and flooded again when the tide comes in. The guides who escort people out onto the mudflats when the tide is out seem like charming individuals – it is recommended not to wander around at low tide without local guidance. In 2004, the rising tide trapped and drowned 23 Chinese immigrants who were working the cockle beds – with such a large expanse of land to cover, the rising tide comes in at great speed. There is also a harrowing re-enactment of a father and his two sons getting washed out to sea in a rip current in Kauai that should make you think twice about swimming at beaches with warning signs on them.
You can get the DVDs here if you’re in South Africa. Foreigners, go here or here.
John Steinbeck was the author responsible for some of the best known works of American 20th century fiction – you may have read The Grapes of Wrath (or The Wrath of Grapes, as my sister is occasionally wont to call it) at high school, for example. The Log from the Sea of Cortez is a non-fiction work, recounting a marine specimen collecting trip that Steinbeck and his friend Ed Ricketts made in the Gulf of California, in 1940. This extremely biodiverse piece of ocean has been the site of studies of Humboldt squid, Shark Men expeditions, and studies of whales.
Ricketts was a biologist, and inspired some of Steinbeck’s fictional characters. The two of them chartered a fishing boat, and sailed from Monterey Bay and spent six weeks making various stops in the Gulf, anchoring the fishing boat and using their unreliable tender to travel to shore and back. They concentrated chiefly on the intertidal zone, and collected samples of as many species as they could find.
To most modern readers, accounts of them trying to spear manta rays and eating dolphin will be upsetting, but in general the curious delight that Steinbeck and his companions took in their discoveries is infectious. More than this, however, I enjoyed the way Steinbeck evoked life on board the fishing boat, the warm evenings, the companionship of the crew, and the sun-baked, sleepy towns they encountered en route. Steinbeck was distressed by Japanese shrimp trawlers wreaking havoc on the ocean floor, and horrified by the tons of bycatch (specimens, to him!) that was thrown back into the ocean, dead and dying.
In between accounts of their life on board the ship, and their forays to shore searching for specimens, Steinbeck ruminates beautifully and gently on man’s connection to the ocean and to everything else, materialism, contemplation, politics, love, freedom, and any number of other lofty themes.
We have thought often of this mass of sea-memory, or sea-thought, which lives deep in the mind. If one asks for a description of the unconscious, even the answer-symbol will be in terms of a dark water into which the light descends only a short distance.
A group of scientists reproduced Steinbeck and Ricketts’s journey in 2004; while the website that recorded their voyage has disappeared from the internet, a description of their expedition has not.
This is a book to be read during a summer holiday, or when one wishes to invoke the feeling of summer, and with ample time to hand for slow-paced philosophical musing. It’s a travelogue that says much about the interconnectedness of things, and more.
You can get a copy of the book here if you’re in South Africa, otherwise here or here.
An article at Wired.com reports on the necropsy of a fin whale that was stranded on a beach north of San Francisco, and subsequently died. A necropsy is like an autopsy, for animals. Opportunities to study freshly deceased cetaceans are relatively rare. Usually, when a whale carcass is available to scientists, it’s been dead for some time – have a look at this whale that washed ashore near Muizenberg. The thick layer of blubber that whales have means that the carcass retains its internal temperature for a long time, speeding up decomposition and providing only a very narrow window for useful science.
Fin whales are the second largest whales (after blue whales), and are very fast swimmers. They are endangered. Their only predator is the orca. Collisions with ships are a real threat to this species, and it seems that the whale described in the article was struck by a small ship. Apart from a lesion on the underside of its body, the whale appeared in good health, with ample abdominal fat.
When the researchers were finished with their analysis, the whale was buried on the beach. This is a good way to dispose of a whale carcass, as the years of nutrients it has consumed are returned to the ecosystem as it decomposes in the sand. Unfortunately we can’t in good conscience bury whales near swimming beaches in South Africa, because we have sharks who will be attracted to the beach by the mini chum-slick that the decomposing whale’s bodily fluids will generate.
Read the full article here. There are some fascinating photographs. If you are squeamish, easily upset, a delicate flower, or just don’t want to see close ups of a whale dissection, DO NOT CLICK ON THE LINK.
Yesterday we had Craig’s point of view… Here’s Christo van Schalkwyk’s account of the Clan Stuart dive on which he and his fellow divers encountered a white shark. Christo has been diving since March 2012, and in the time since then has logged over two hundred dives, most of them here in Cape Town.
About 30 seconds into the dive, just as I got to the bottom, a little to the north of the engine block, I saw the shark approach from the south. It swam past us towards the north. It turned and swam back down the wreck in a southerly direction, on the inshore side. For a while it was out of sight. We kept looking out for it, while motioning to the other divers to bunch together and stay low on the wreck. A few seconds later we saw it approaching from the south again. I could see both eyes as it swam straight at me. When it was about three metres away it veered off slightly to swim past us, parallel to the wreck. At this point it was only about two metres away from Craig and me. I remember choosing the spot where I was going to hit it if turned back towards us.
Fortunately it kept gliding past and as the pectoral fins came past, something seemed to disturb it. It flicked its tail once and shot away to the north. (Seeing the video taken by Vlad later, it seemed as if one of us exhaling was what disturbed the shark, but this is only speculation.) After a second or two, it was out of sight and we didn’t see it again.
We crouched down low on the wreck, looking around, and repeated the instructions to the other divers to keep close and low down. At this time we saw Sergey coming towards us from a rocky outcrop (or piece of wreckage) about 3-4 metres away from the main wreck, towards the deep side. We beckoned (with some urgency) to him to come closer. He swam quite slowly towards us, but when he got close enough, we pulled him down onto the wreck with us. As he was positioning himself, his weightbelt caught on a piece of the wreck and came off. I had to help him put it back on from underneath.
We stayed where we were (just north of the engine block of the wreck) for about another minute or so. I remember looking at my dive computer which read 2 minutes at that point. It didn’t seem a viable option to surface, even though I knew Tony would be close with the boat. I didn’t fancy the notion of hanging around on the surface, trying to get all 6 divers on the boat, all the while not knowing where the shark was. After another half a minute or so, Craig and I had a hand signal discussion on what to do next. He suggested heading south down the centre of the wreck, in the opposite direction to the shark’s last known heading. I thought we should go for the beach, to the north west. We agreed on the beach and started off in that direction, staying very low.
Just before leaving the wreck, Craig’s weight belt came loose as well. I took the reel from him and held on to his BCD with one hand and the wreck and reel with the other, while he tried to put the weight belt back on. This seemed to take forever – I remember seeing Vlad sliding in under a raised sheet of steel and hiding there (and feeling a bit jealous of his nice cover…). Eventually I gave the reel back to Craig and got him to hold on to the wreck and got in underneath him to try and see what the problem with the belt was. Once the belt was back on, we dropped down onto the sand on the shore side of the wreck.
Then we had to swim over the sand, without cover, towards the beach. It took a while to gather the group together to do this. We stayed very low, flat on the bottom. As we swam the group seemed to fan out, so we stopped once or twice to reassemble. Craig kept watch to the north, while I scanned the southern arc. Once we got into shallower water the surge took us along quite quickly and the group spread out even more, but it wasn’t possible to do anything about that any more. We got tumbled a bit in the breakers on the beach, but in the end managed to help each other to the beach unscathed with only the loss of one mask.
Total dive time: 13 minutes
Boat entry, shore exit.
Christo’s diagram of the dive site, with indications of what happened where, is below. Click on the image to enlarge it!
Here’s Craig Killops’s account of the dive at the Clan Stuart last Saturday. Craig (on the far left in the photo above) is just about to qualify as a Divemaster, and has just passed one of the most stressful tests any DM will have to face!
3, 2, 1…. Backward roll! Four divers perform a negative entry whilst I and a diver with drysuit remain at the surface after a positive entry. Diver with drysuit starts drifting slowly away from me, about 4 metres, whilst trying to organise himself. We give each other the okay signal and go down. I see the all too familiar silhouette , as seen on documentaries, glide between myself and the diver wearing the drysuit. I keep an eye on drysuit diver and try signal but diver too busy with equipment.
I head off to the rest of the group to signal that a shark has been spotted. Before the message has even been conveyed I see all eyes enlarged and focused behind me, the now clearly visible shark circled back showing its true inquisitive nature. Now with the group I notice that the drysuit diver is not with us and Christo also discovers this whilst we carry out a head count. We lay low on the sandy bottom at 10 metres and make our way quickly and calmly to the wreck.
As we are seeking cover in the kelp on the wreck a sillouette approaches again – it is not the shark but the drysuit diver, mid water. We signal him to stay low and to quickly come join the group as he is still oblivious to the presence of the shark. About ten seconds after he joins us the now very curious shark makes a full frontal approach towards Christo and myself ,we are up front to the left hand side of the group. When we blow bubbles (tactically or nervously…?) the shark makes a sudden turn at most two metres away from us into the green haze.
We calmed ourselves and ensured everybody was okay and accounted for. After brief comms Christo and I agree to stay low and take the group back for a shore exit roughly 150 metres away, which was probably the longest swim I have experienced mentally. Staying low on the wreck caused myself and another diver to drop our weight belts due to snagging. Big thank you to Christo for his prompt assistance in getting my weight belt back on. Not exactly the time you want to be floating to the surface.
Tucked up in a huddle formation we headed off , Christo keeping a left lookout whilst I keep a right lookout and both of ensuring the group is in close pursuit . With a 3 metre swell running into the bay there were fair sized shorebreakers on the beach which made shore exit interesting. Once we were all safely ashore we signaled the boat to say we were okay. Tony needed no explanation of what had happened – he had a front row seat to watch the dark shadow circling the group. Big thank you to shore support Clare Lindeque who arrived to transport some excited divers back to the harbour for a repetitive dive at Roman Rock, I think the Clan Stuart had provided its entertainment and blissful memories for the day.
Will definitely be keeping an extra wary eye out when diving the Clan Stuart from now on.
