City of Cape Town’s new protocol for cleaning tidal pools

Early in November I attended an information session at the Kalk Bay Community Centre, where the City of Cape Town announced that they will be trialling an environmentally friendly cleaning process on five of the 19 tidal pools on the 260 kilometres of Cape Town’s coastline managed by the City. This coast stretches from Silwerstroom on the West Coast to Kogel Bay on the eastern shores of False Bay.

St James tidal pool
St James tidal pool

The presentation was made by team members from the City’s Recreation and Parks department, which – among other things – is responsible for beaches, outdoor signage, ablutions, lifesaving, environmental education, and administration of Blue Flag status for the beaches and marinas that earn it. This department is also responsible for the tidal pools. (Incidentally the City’s assortment of safe seawater bathing facilities includes two of the largest tidal pools in the southern hemisphere, at Monwabisi and Strand.)

Until now, the City would use chlorine to clean the walls (top and sides) and steps in the tidal pools. The cleaning would be done after draining the pool completely. This year, a supply chain management issue meant that there was no cleaning of the tidal pools between July and November. During this time, regular swimmers (some of them members of the Sea-Change project) noticed that marine life flourished in the pools, and engaged with the City to try to find a way to keep the tidal pools safe but also to preserve the diversity of marine species that had been thriving in the pools during the cleaning hiatus. Safety, of course, is why they are cleaned: slippery, algae-covered steps are dangerous.

The tidal pool at Millers Point
The tidal pool at Millers Point

It was agreed that five of the pools – St James, Dalebrook, Wooley’s Pool, and the two pools at Kalk Bay station – would be subject to a trial of a new, environmentally friendly cleaning regimen. These pools are relatively close together in the north western corner of False Bay. The aim is still to ensure that the tops of the pool’s walls and steps are not slippery, and thus safe for bathers. But a second aim has been added by the City, which is to ensure the environmental integrity of the pools.

Under the new cleaning protocol, the following will be done:

  • the pools will be drained only when necessary, and only as far as is required to reach areas that are covered by water and in need of cleaning (for example, the steps at Dalebrook)
  • animals in harm’s way will be relocated
  • excess kelp and sea urchins will be removed from the pools
  • the tops of the walls and steps will be scraped to remove algae (the sides of the walls used to be scraped too, but this will no longer take place)
  • environmentally friendly chemicals will be used to remove the algal residue after scraping – no more chlorine and no more whitewashing!

All of the above means that the pools will be ready for use by the public immediately after cleaning, in contrast to the old protocol, which renders the pool unusable for a period after the cleaning crew has chlorined it.

I’ve asked the City for more information about the drainage procedure, and for more information about the earth-friendly chemicals that the cleaning contractor will use, but with no response so far. (If I get one I’ll obviously update this post.)

Buffels Bay tidal pool inside the Cape Point section of Table Mountain National Park
Buffels Bay tidal pool inside the Cape Point section of Table Mountain National Park

Many of the City of Cape Town’s tidal pools fall within the Table Mountain National Park Marine Protected Area, and it therefore makes perfect sense to aim to protect the animals living in them while maintaining public safety. Dr Maya Pfaff, another speaker at the information session, even suggested that some of the animals that may now thrive in the pools may actually help to keep the water clean. Mussels and feather duster worms filter the water and improve the clarity, algae take up nutrients, and limpets clean algae off the rocks.

Particularly over the festive season, the beaches and tidal pools around Cape Town are extremely busy. This is a wonderful opportunity for thousands of beach-goers to experience both safe swimming and a little bit more of what the ocean has to offer, instead of a sterile, salt-water pool devoid of healthy marine life. Bringing a snorkel and mask with you when next you go swimming will be well rewarded. To see some pictures of the amazing animals – from nudibranchs to a cuttlefish with eggs – in the St James tidal pool, check out Lisa’s instagram profile.

Do you swim regularly in any of the five pools in which the new cleaning regimen is being tested? What do you think about it? If you think that environmentally gentle cleaning of tidal pools is a good idea, what about letting the city know that you appreciate having tidal pools that are both safe and biodiverse. A short message on the City of Cape Town facebook page to say thank you and keep up the good work (and a request to extend it to the other tidal pools) is a good place to start!

You can read a news article about the new cleaning protocol here.

Newsletter: Magic wand

Hi divers

Weekend dive plans

No weekend dives, but next week looks promising!

A magic wand would be the right tool to fix the weather. The wind has been relentless and despite odd periods of calm, mostly early in the mornings, there has been reasonably good visibility in between the patches of red tide.

Frilled nudibranch
Frilled nudibranch

Sadly this weekend is again going to be dry as the window of light wind is really small early on Saturday, and then it howls again until Tuesday. Wednesday and onwards next week do look like good diving days so if you are up for a weekday dive get in touch.

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog/

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Sea life: Sea swallows

Sea swallow (Glaucus atlanticus)
Sea swallow (Glaucus atlanticus)

The sea swallow, Glaucus atlanticus, is a type of pelagic nudibranch. Pelagic means it lives in the open ocean, and being a nudibranch makes it a member of the phylum Mollusca. They are also called blue dragons, blue sea slugs, and a few other similar names. Because of where they live, these striking creatures are not frequently seen, so we were lucky to encounter a few of them after a dive at Batsata Maze in the south western part of False Bay, just south of Smitswinkel Bay.

Sea swallow
Sea swallow

The blue patterned side of this nudibranch that is visible when viewed from above is actually its underside. The top surface of the animal, which points down, is counter-shaded (like a great white shark). It is a greyish silver colour to blend in with the surface of the sea when viewed from underwater.

Photographing a sea swallow
Photographing a sea swallow

Sea swallows suck air into a gas-filled sack inside their bodies, for buoyancy. They prey on blue bottles (also called Portuguese man o’war) and retain and concentrate the blue bottles’ venom in their bodies for use against their own enemies. This makes them extremely venomous with the potential to sting badly.

Luckily the intrepid Carel leaped into the water to scoop one into a cup and we could all take a closer look (don’t touch!) on the boat and get some photographs. Afterwards, our visitor was returned safely to the ocean.

They are widely distributed through many of the world’s oceans, and sometimes wash up on the beaches in False Bay. They are unusual, but not earth-shatteringly rare. If we were more social media savvy we would have managed to use this sighting to manufacture the kind of hysteria generated by that facebook page whose title expresses an intense and profane love for “science“, or a few other media channels. But we’re not, so you get this blog post!

If you are looking for a marine life reference, first prize for Capetonians is A Field Guide to the Marine Animals of the Cape Peninsula, otherwise the Two Oceans guide.

Newsletter: Smoke on the water

Hi divers

Weekend dive plans

Sunday: Boat or shore dives, conditions dependent!

We have had terrific conditions all week and have been taking full advantage. False Bay is cleanish and warmish. Visibility has varied from site to site but the bay is full of life. On Tueday we spent our surface interval time photographing sea swallows at Batsata Maze. Wednesday’s surface interval was spent filming giant short tail sting rays at Millers Point, and today we were fortunate enough to have two orcas swim by close inshore whilst the divers were on the SAS Pietermaritzburg this morning. Who knows what we will see tomorrow!

Giant short tailed sting ray behind the boat at Millers Point
Giant short tailed sting ray behind the boat at Millers Point

Sadly the diving today was somewhat overshadowed by the raging fire that descended on Simon’s Town with the westerly wind, despite the best efforts of many firefighters. Watching from the water you could see the speed at which the fire traveled and I doubt anything other than a thundershower was going to slow it down. On the run back into Simon’s Town we went through really thick smoke.

Simon's Town fire
Simon’s Town fire

The weekend, however, does not look too rosy. At cowsharks this afternoon the swell was quite noticeable and although it stays at 3 metres for most of tomorrow, the forecast is for 5-6 metres on Saturday. It seldom reaches the height in the forecast but even at 4-5 metres diving becomes less than great. Surge and low viz are on the cards. I think there will be a better than good chance that Sunday will be semi-decent so I will provisionally schedule diving, either from the boat or perhaps a shore dive or two… Text me if you want to join and I’ll keep you posted.

Diarise

Don’t forget the Shark Spotters fundraiser on Sunday – should be fun!

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog/

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Newsletter: Shades of blue

Hi divers

Weekend dive plans

Saturday: launching from Simon’s Town jetty at 8.30 for Omega Reef / 11.00am for Atlantis Reef

Sunday: shore diving at Long Beach or A Frame at 10.00am

Fiery nudibranch at Outer Photographer's Reef
Fiery nudibranch at Outer Photographer’s Reef, picture by Georgina Jones

We had planned not to launch last weekend based on the forecast. The conditions changed dramatically and on Sunday we ventured out for a film project and must admit to being pleasantly surprised by the good visibility. After filming the bits that needed doing, we went to Outer Photographer’s Reef, where Georgina took the picture above.

Dive conditions

The week’s wind has helped improve this and False Bay looks really clean right now despite the 5 metre swell that was forecast for today.

This weekend we should have an acceptable amount of swell, light winds and some sun. Windguru has only used their blue crayons this weekend as opposed to the purples they used a couple of weeks back, and we like the shades of blue. On Saturday we will launch from Simon’s Town jetty at 8.30 and go to Omega Reef, I have been told that it is stunning and have not yet seen it. The second dive at 11.00am will be to Atlantis Reef. If the swell has lingered we will dive the SAS Pietermaritzburg instead.

On Sunday we will shore dive at either Long Beach or A Frame at 10.00am. Text or email me to book a spot on either day.

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog/

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Newsletter: Loose ends

Hi divers

Weekend plans

Saturday: Launching from Hout Bay to the BOS 400 and Tafelberg Reef

Text me or reply to this mail if you want to dive.

We did not manage any diving last weekend as the boat was scheduled to launch in Gordon’s Bay for the Aqualung Fun Day on Saturday but we were cancelled on Friday evening because of bad visibility on that side. Sunday was a howling south easter day so no diving was done.

This weekend has a forecast similar to last weekend but with a few differences. The 3 metre swell that is in every forecast does not appear to be around as the Atlantic wave buoy registers 2 metre swell at the moment and False Bay was relatively flat today. The wind is another matter… There is however less wind on Saturday, so an early launch in Hout Bay is on the cards. We will dive the BOS 400 and Tafelberg Reef. Sunday will be too windy for my kind of diving.

Thanks very much to Jerrel for this week’s photo – taken two weekends ago on a dive to Roman Rock.

Silvertip nudibranch at Roman Rock, by Jerrel van Beek
Silvertip nudibranch at Roman Rock, by Jerrel van Beek

Mozambique trip

There is still space on the Mozambique trip (28 June – 4 July). Remember to book your flights if you’ve decided to join us – get more info from Clare. That is how you will confirm your spot.

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog/

Diving is addictive!

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Newsletter: Making waves

Hi divers

Weekend plans

Friday: Seal Rock (Partridge Point) at 9.30am / Shark Alley at 1.00pm

Saturday or Sunday: Roman Rock at 9.30am / Ark Rock to Photographer’s Reef at 11.30am

Black nudibranch by Georgina Jones
Black nudibranch by Georgina Jones

Dive conditions report

Last Friday we went out in False Bay, and Georgina took this lovely close up of a black nudibranch – thanks for sharing it with us! The visibility wasn’t fantastic, though, and the south easter was a bit strong, which influenced our diving decisions for the rest of the weekend.

We chose to dive out of Hout Bay last Sunday and had really good conditions with 10-12 metre visibility almost everywhere and 15 degree water. We dived below the Sentinel and on the BOS 400, where Christo and Laurine were buzzed by a giant short tailed sting ray. Can you believe it! There were also dolphins just off the harbour wall and they were happy to turn around and say hello as soon as Laurine hit the water with a snorkel. The week has not been all that diver friendly, however, and rain and howling winds have kept us off the water.

Dolphins in Hout Bay
Dolphins in Hout Bay

Weekend plans

This weekend is one of those really hard to call weekends, as the forecasts vary so wildly you would be forgiven for thinking you were looking at the weather in different cities. Most weather and swell forecast sites claim some south easterly wind with a small swell from the south west. Other sites claim slightly more swell but with a 20 second period from the south. A southerly swell rolls straight into False Bay and gives diving in surge a whole new meaning. Tough call.

So my guess is Saturday will be better underwater than Sunday, but Sunday will be better on the surface. I would like to launch both days, but because the forecast is so uncertain I’ll have to make  a call for Saturday late tomorrow afternoon. We will plan to dive Roman Rock at 9.30 and at 11.30 we will drop at Ark Rock and head off towards Photographer’s Reef to see what we can find on the way. You will be very surprised at what there is to see away from the known dive sites.

If we can’t launch on Saturday, I’ll check conditions for Sunday, and we will launch if we can. Sound confusing? Yes. Just email or text me if you feel like a dive this weekend, and I’ll try and make it happen safely and enjoyably.

Other happenings

There is also the possibility that Dungeons will produce a decent wave sometime in the next few days, and that is something to see.

Another option for those at loose ends this weekend is a visit to HMS Iron Duke, a Royal Navy frigate currently visiting Cape Town. This weekend she will be berthed at Jetty 2 in the V&A Waterfront and open to visitors on Friday and Saturday.

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog/

Diving is addictive!

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Sea life: Red sponge nudibranch

Two red sponge nudibranchs at Spaniard Rock
Two red sponge nudibranchs at Spaniard Rock

Last year I did a dive at Spaniard Rock in False Bay. Tami was my buddy, and Georgina Jones of SURG was with us. Georgina is the author of the invaluable Field Guide to the Marine Animals of the Cape Peninsula, and it was during an interlude when Tami had gotten lost that she found and showed me a red sponge nudibranch (Rostanga elandsia). These animals are remarkably well camouflaged – they feed on reddish orange sponges, and get their colouration from the sponge.

I went off hunting after that, and found and photographed another red sponge nudibranch (above) that upon closer examination turned out to be two: there is one just above the top shell near the middle of the photo, and another on the right hand side pointing downwards. You can just see that there are small, darker spots on their bodies.

Next time I spot one I’m interested to see whether they leave marks in the sponge where they’ve been feeding. They are very hard to spot, though!

Dive sites: Roman Rock

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.

Reef life at Roman Rock
Reef life at Roman Rock

Roman Rock reef is a very large collection of boulders separated by sand patches, centred on the Roman Rock lighthouse. Nearby reefs include Castor RockLivingstone ReefRoman’s RestWonder Reef, and Tivoli Pinnacles. The reef is comprised of granite boulders, heavily encrusted with typical Cape Town reef life – feather stars, brittle stars, nudibranchs, sea stars, urchins, sea cucumbers and ascidians – varying with the depth. If the current is strong you will find a lot of fish here, mostly roman and hottentot, enjoying the tasty bounty brought by the tide.

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
Ladder in the middle of nowhere
Redbait at Roman Rock
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.

Dive date: 3 August 2013

Air temperature: 22 degrees

Water temperature: 14 degrees

Maximum depth: 16.5 metres

Visibility: 10 metres

Dive duration: 38 minutes

Newsletter: Good mileage

Hi divers

Weekend launches

The weekend does not look all that rosy. A rather large swell is forecast and a little rain for tomorrow and Saturday, and then a fair amount of south easter for Sunday, but it blows later in the day so this is the plan:

Saturday 9.30 and 12.00, to Outer Photographer’s Reef and Maidstone Rock.

Sunday 8.00 and 10.30, to Spaniard Rock and the Brunswick / Caravan reef

Klipfish at Spaniard Rock
Klipfish at Spaniard Rock

All launches will be from False Bay Yacht Club. As usual, text me if you want to dive. We have Advanced students for Saturday and need to start early on Sunday as the wind picks up after lunch. These launches are subject to a final call early on the day as the swell may or may not affect us. It is always a sign of bad weather to come when big boats seek shelter in False Bay; at present two large ships have come into the bay, presumably to hide from the wind and swell.

Recent dives

Variable dorid at Pyramid Rock
Variable dorid at Pyramid Rock

We have had a good run of late and last weekend we were out on the boat on Sunday, Monday and Tuesday. The weather was not nearly as bad as the forecast so we had some good diving, as well as encountering a large number of extremely frisky whales. It was also good to see some new and old faces on the boat. The viz was not spectacular, but there was not too much wind or swell. Today we had 4-5 metre visibility at Long Beach.

Octopus at Pyramid Rock
Octopus at Pyramid Rock

We had really good mileage out of the white shark encounter two weeks ago and were fortunate to have the story run on a few local blogs, from which the Sunday Times got hold of it, and that led to a short radio interview on Cape Talk on Monday morning. That kind of exposure doesn’t come around very often, so thank you False Bay, Christo, Craig, the Russians and of course the shark. If you haven’t heard what happened, click here.

Two red sponge nudibranchs at Spaniard Rock
Two red sponge nudibranchs at Spaniard Rock

There are two red sponge nudibranchs in the photo above. See if you can see them: a bigger one just above the snail, and a smaller one to the right of the image. They are perfectly camouflaged!

Dates to diarise

The next ScubaPro Day is on Saturday 26 October. On that day we will be spending some time in airports on our way back from the Red Sea, so unfortunately our boat won’t be participating. If you’re keen to do some cheap boat dives and maybe try out some ScubaPro gear, however, diarise the date. More information will be provided in the next few weeks.

The next Cape Town Dive Festival is on 2-3 May 2014. More information on that will be revealed in the coming months, I imagine.

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog/

Diving is addictive!

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