We did a beautiful May dive on the Brunswick in crystal clear, cold water, and upon rolling off the boat were greeted immediately with a fairly large group of highly structured jelly like animals, pulsing along as if on a mission to somewhere. They were hard to photograph (my best effort is above) so I took a short video of one of them.
The JellyWatch facebook page helped with identification – they do not appear in any of the marine ID books we own. This species is probably Ocyropsis maculata immaculata, a type of comb jelly that is widely and quite abundantly distributed (although WoRMS doesn’t show it as occuring off the Cape). Apparently (says wikipedia) they use their lobes to escape from danger, clapping them together in order to create a water jet that propels them backwards. They are open ocean animals, which suggests that the lovely clean water we were enjoying right at the north western end of False Bay had been brought in by an upwelling from the deep sea outside the bay, driven by the north westerly winds we’d been having.
They are ctenophores, and instead of stinging cells they have sticky cells called colloblasts that they use to catch food. Every website I’ve looked at mentions what “voracious predators” they are! Other ctenophores that we see locally are comb jellies and sea gooseberries. (More pictures of comb jellies around the Cape Peninsula can be seen here, here and here.) All of these species have little disco lights running along their bodies; this is in fact light being refracted off their eight rows of cilia, which are used for locomotion.
I’m not sure why I haven’t written about Roman Rock before. I’ve actually done four dives on the main reef, the first in 2010. The pictures in this post are from more than one of the dives – I’ll group them together, and you’ll be able to see by the water colour which dive is which.
Part of the dive is along high walls that are reminiscent of Atlantis Reef, further south. There are deep dead-end passages in between the rocks, wide enough to swim through (or drive a car through), and the rippled sand looks like a white carpet or a runway. In the middle of nowhere you will come across a ladder; it’s been there since the first time I dived Roman Rock in 2010. Your guess is as good as mine.
Ladder in the middle of nowhere
Sand runway
Craig looks into a gully
Fish in a gully
Looking towards the top of the reef
Craig with the buoy line
Redbait at Roman Rock
The site is suitable for Open Water divers, as the maximum depth one can attain while staying adjacent to the reef is about 18 metres. There are several pinnacles and shallower plateaus that are suitable for deeper safety stops. It goes without saying that each diver must have a surface marker buoy – the site is a relatively short boat ride from False Bay Yacht Club, but offshore nonetheless and there may be boat traffic, depending on where the current takes you.
One Tuesday in early December, Tony escorted some members of the media – Murray Williams of the Cape Argus, and Bruce Hong of Cape Talk radio, on a dive along the inside of the shark exclusion net at Fish Hoek beach. It was just before the start of the school holidays, and since the net has been trialledmultiple times by now and is working well, it’s a good time to raise awareness of the additional beach safety and – importantly – peace of mind that the net offers. I tagged along as photographer.
Over-under view of the exclusion net at Fish Hoek
The net at Fish Hoek beach is a world first. It has a fine mesh that is highly visible underwater, and is designed not to catch anything – unlike the shark gill nets in KwaZulu Natal. The net is put out in the morning and retrieved at the end of the day, but only when sea conditions allow it. The south easterly wind can bring huge quantities of kelp into Fish Hoek bay which would foul the net, so when there is a strong south easter the net cannot be deployed.
If you’re a water person, please educate yourself on how the net works, and its intention, and share it with your friends. Even now, nine months after the trial started, I hear uninformed comments from people who have not bothered to do any reading about the net, and assume it’s the same kind of net as the ones in Durban. It’s not. The whole idea is that nothing – no sharks, no humans, no klipfish – gets hurt. Shark Spotters and the City of Cape Town have been very clear on this from the start. I had a bit of a rant about this late last year.
Murray dives down to check out the exclusion net
I digress. We went to the beach, got suited up, and went to check out the net. It was spring low tide, so at its southernmost end we were in about 2 metres of water. The net is high enough that when the tide comes in and the yellow floats rise with the water level, it simply unfurls further downwards, making an unbroken curtain. The lower portion of the net rests on the sand, with two parallel weighted lines to ensure that it lies flat. You can see that in the photo above Murray is gripping one of these leaded lines, and that there is a fairly large amount of net waiting on the sand for higher tides.
The divemobile ready for action
Entering the water watched by some schoolboys on an outing
Monwa, superhero
Your photographer
Batman on the surface
The net hangs down like a curtain and rests on the sand
Murray and Monwa discuss the net
We stuck close to the net, and didn’t see much marine life on the sandy bottom. I spotted a large sand shark (when I say I “spotted” him, I mean that I almost landed on top of him). We were mutually surprised, and he zipped away into the bay, sliding neatly under the bottom of the net. I also saw a box jelly cruising along the net. Given my recent history with box jellies, I kept clear! The sea floor in the area where the net is deployed is level, sandy and free from rocks. There’s more life on the catwalk side, where beautiful rock pools wait to be snorkelled.
We were accompanied by Monwabisi Sikweyiya, who is the Field Manager of Shark Spotters. He is a hero and I always feel a bit star-struck when I see him (although he has no idea why – he probably just thinks there’s something wrong with me). He swims along the net regularly – someone does each time it is deployed, actually – to make sure that it’s released properly and hanging straight down.
After the dive
Swimming inside the net is completely voluntary. When a shark is seen in Fish Hoek bay the Shark Spotter still sounds the siren and the flag is raised to clear the water. The Shark Spotters team are still waiting to see how a shark will respond to the net when it swims close enough to be aware of it. So far none of the local sharks have come close to the net, as the summer season when sharks move inshore has only just started. Tony was half hoping that we’d be swimming along inside the net, look out through the mesh – and blammo! – see a great white shark. But we had no such luck, if that is the right word.
You can read the article that Murray Williams from the Argus wrote after the dive, here.
It’s not Jellyfish Lake in Palau by any stretch of the imagination, but we had some impressive jellyfish action in False Bay during September and October this year. I filmed these two videos at Outer Photographer’s Reef, at the safety stop.
These purple beauties are compass sea jellies, but we also saw impressive blooms of box jellyfish that lasted for several weeks, right into November. It’s possible that this congregation of sea jellies was caused by a quirk of a current somewhere, that herded them all into False Bay and then prevented their departure. There’s also the possibility that they found something nice to eat in False Bay, perhaps because of the large volume of sewerage that gets pumped out into the ocean all around this special piece of coastline.
Scientists aren’t actually sure what causes jellyfish blooms, but ultimate causes seem to be warmer oceans and increased nutrient loadings in coastal waters as a result of human activities.
Box jellies can deliver a nasty sting – it’s the luck of the draw whether it’s bad or not, but if it is, you can suffer for days. It’s also distinctly possible that with repeated stings you will become more sensitised to their venom. So take care!
Wind, walkers and waves will mean we are diving on Saturday in False Bay starting real early, i.e. 7.00 am at the Yacht club. We plan to dive Atlantis and the Brunswick.
On Sunday there will be way too much traffic and road closures to make an early start possible and I don’t think the wind will allow anything later in the day. I am really keen to do a double tank dive to Justin’s Caves or to dive North and South Paw, but will make that call on Saturday afternoon once we have a better idea of the wind (which looks iffy) and the viz.
Week’s diving
The last week has been spent driving instead of diving as all our cylinders were due for their annual medical examination. We did cancel last weekend’s dives due to the wind being a little stronger than I like to launch and dive in, but the guys that did go out reported really good conditions.
Divers near the jetty in Simon’s Town
We are just home from a really good night dive and all in all we were 19 divers. We dived below and around the jetty in Simon’s Town and had passable viz and a great deal of jellyfish to contend with. Thanks to all those folks from far and wide (including OMSAC!) that joined the fun. The aim with Diversnight International is to have as many divers in the water at 2013 as possible, world wide, and then to eat cake. The numbers since this event started are:
2005: 351 divers in Norway.
2006: 889 divers in Denmark, Norway and Sweden.
2007: 1859 divers in Denmark, Estonia, Finland, Iceland, Norway, Sweden and also Svalbard.
2008: 2183 divers in Denmark, Estonia, Finland, Iceland, Norway, Sweden, Egypt, Indonesia, France, Spain, Faroe Islands and Belgium
2009: 2749 divers, 218 divesites and 20 countries
2010: 1700 divers, 175 dive sites and 22 countries
2011: 2577 divers, 196 dive sites and 24 countries
2012: 2322 divers, 231 dive sites and 25 countries
If you think the water is cold here, you should feel it in Scandinavia in November, where this event started!
Brave jellyfish warriors at Diversnight
Prizes
Congratulations to Bianca, who won two boat dives in the Diversnight lucky draw this evening! Also congratulations to Esti who has won a Nitrox Specialty course in the October boat divers’ lucky draw.
We will have another draw for boat divers in November and one in December. To enter, come for a boat dive. You’ll win a Nitrox course, or, if you’re already Nitrox certified, you’ll win two boat dives!
Gear
Sometimes I have students and former students who want to sell some gear secondhand. If you’re looking for gear, let me know and I might be able to put you in touch with someone. The details of the transaction are up to you! At the moment I know someone with a Suunto D6i dive computer and a regulator set for sale. If you’re interested drop me a mail and I’ll hook you up.
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.
Lately spectacular vehicular disasters seem to follow me around. Hoping for good conditions – there was no real reason why the visibility shouldn’t be good – we set out for a dive with Open Water and Advanced students. Unfortunately the bay was filthy – we looked for clean water at Roman Rock, and found only compass sea jellies. We went south to Shark Alley, where – in desperation – we dived. It was like being in boiling pea soup, only colder. One of my students hung onto the kelp to try and keep position in the water. We had to abort a compass swim because of the surge. It was impossible to keep a heading.
Plane crash!
Meanwhile, on the boat, Kate was watching a large, camouflage-painted radio controlled aircraft circling the boat and the dive site. It crashed into the water just before we surfaced. Its owner was watching frantically from the shore. Brian leaped into the water and retrieved it, and we drove to the slipway at Miller’s Point with it balanced precariously on the pontoon.
Brian gets ready to go overboard
It started to smoke as the batteries short circuited. I told Kate – who was holding it – that if it caught alight she should throw it overboard. There was a small fuel tank that could have caused a problem if the plane started burning! Fortunately we were able to return the plane to its owner. If you recognise the plane, please tell its owner to get in touch because he must have some amazing footage of the boat at Shark Alley on the camera that was mounted on the fuselage!
Brian passes his swim test with flying colours
It turned out to be a good day for fishing (Miller’s Point was packed) but not for diving.
Brian approaching the plane
Starting to tow the plane back to the boat
Brian had to bring the plane quite a distance on the surface
Box sea jellies (Carybdea branchi) are common in Cape waters, and we sometimes see great swarms of them. They are characterised by a roughly cubic bell, with a single tentacle emanating from each lower corner. The tentacles may be retracted at will (if you touch one by accident, the tentacle shortens), and the jellies seem to extend them further at night – possibly for feeding purposes.
Box sea jelly with tentacles of various lengths at Long Beach
It is these trailing tentacles that can, it turns out, deliver a nasty sting. I have swum too close to a box jelly before, and where its tentacles touched my exposed face I felt as though I’d been splashed with hot water (actually not a wholly unpleasant experience on a cold dive). Within a few minutes the sensation was gone, and no marks remained when I came out of the water. On a night dive at Long Beach in July, however, I had a proper experience of how these jellies can sting.
I didn’t even notice the jellyfish as I swam around the wreck, but suddenly became aware of an intense stinging sensation around my neck where the top of my wetsuit meets the edge of my hoodie. We were only ten minutes into the dive, so I put it to the back of my mind and continued swimming. The pain was still there when I exited the water, and became more intense as my skin dried. I rinsed off in fresh water at the beach, and we headed home. The lower half of the front of my neck was an angry red colour with raised white welts. More rinsing in warm fresh water, and then an application of (not joking) some All Stings Considered gel that Tony bought in Durban ages ago did little to dull the pain.
Box jelly sting
It was a full three days before my neck stopped looking and feeling angry, red and lumpy. Tony reluctantly sent me off to the office – wearing a scarf, lest my colleagues think he strangles me in his spare time. As the sting healed it progressed to looking like a severe case of adult onset acne. We washed my hoodie, wetsuit and rash vest thoroughly to make sure that no stinging cells remained on them, because they can retain their stinging power for some time. Unfortunately not thoroughly enough, because the following weekend when I put on my wetsuit I was stung again, quite extensively – in the same spot on the front of my neck, and also around the back. Time to washing machine the wetsuit!
Round two of the jellyfish sting
Fortunately our box jelly is nowhere near as venomous as some of the varieties found in Australia and Indonesia. I very much doubt that anyone has died from a South African box jelly sting. That said, if you’re the sort of person who reacts violently to things and often needs antihistamines, I’d take care to avoid exposure where possible. The NSRI has a fascinating explanation of the stinging mechanism and a run down of some of the treatment options here.
We are actually very fortunate that there are very few ways to get stung in Cape waters. The odds of a sting when one wears so much exposure protection are very small. The other frequent stinging culprit is the bluebottle, which tends to affect swimmers and those strolling on the beach more than it does scuba divers. Don’t hate the jellyfish!
For our last dive we enjoyed lovely drift dive in the fashion of Sodwana. We were aiming to drop in at Doug’s Cave, which is apparently a proper cave in which ragged toothed sharks occasionally lie in repose. Because of the current we missed the cave, and instead of fighting current to get back to it, we continued along the reef at a leisurely pace.
Boxy
I was very excited to find a sort of overhang that seemed to be a meeting place for trumpetfish. There were two or three underneath the rock, and another one hanging about on a patch of sand in front of the little cave. The dive was incredibly colourful (especially when I got my strobe to fire correctly), and Maurice and Craig helpfully found several nudibranchs, and showed them to me.
Branching soft corals
Towards the end of the dive, as we arrived at Birthday Ledges, we once again found the large piece of yellow and red fabric wrapped around part of the reef that we’d seen on our Birthday Ledges dive the previous day. Patrick, our Divemaster (and owner of Calypso) persisted, and managed to unwrap it. Tony confiscated it immediately, and put on quite a show at the safety stop. We’d had a long dive on the Coopers light wreck a couple of hours prior, so we were out of time before we knew it.
East coast rock lobster
Phyllidia varicosa nudibranch
Batman is upside down
Another arch at Birthday Ledges
Thistle corals
Lonely sea star
Sea star and thistle coral
Rock archway at Birthday Ledges
Paperfish (inconveniently positioned)
Phyllidiella zeylanica nudibranch
Moorish idols
Raggy scorpionfish in repose
I thought the Blood Reef complex was amazing, with a lot to see. It’s suitable for drift dives in either direction, depending where the current is going (north-south or south-north), and if there’s no current, that’s also fine. It’s a fairly long boat ride by Cape Town or Sodwana standards (if you’re diving Two Mile), but you’re close to shore.
It’s winter so not as many people dive as they do in summer, but the week’s diving has been good with little or no swell and clean water at around 15 degrees. We had lovely conditions at the infrequently-dived wreck of the Brunswicklast Saturday, before the rain came, and equally good conditions at Long Beach yesterday. There are some photos on facebook here and here. If you haven’t liked our facebook page already, please do – you can keep up to date with what we’re up to. We post photos regularly and try to do a visibility report whenever we dive.
Fish and box jellies at Long Beach
For once the weekend weather and dive plan is an easy call. Both days look exceptionally good and the bay is quite clean and calm right now. We are attending the DAN Cape Town event on Saturday so there will be no diving, but we will launch on Sunday to do qualifying dives for Open Water students. We will launch from the Yacht Club in Simon’s Town and the plan will be to visit Photographer’s Reef and the cowsharks.
Anemone on the Brunswick
Please remember your MPA permits. If you plan to come diving, check that yours is valid. If you don’t have one (or if it’s expired), head down to the post office with your ID book and about R100 and ask for a “scuba diving permit”. We dive a lot inside the marine protected area, for which you need a permit.
Wreckage of the Brunswick
Our Red Sea trip is in October (17-26th). There are still one or two spaces on the liveaboard if you feel like a last minute (almost) holiday, but it’s almost full. We’ll do a local trip (to Sodwana or Durban) again in the new year so don’t worry if you miss out!
