Sponges

Article: The New Yorker on sponges

My favourite science writer, Ed Yong, explores sponges for the New Yorker in an article entitled “Consider the Sponge”. Sponges are deceptively simple creatures with jelly-like interiors and no symmetry. They are, however, covered in microbes which have provided treatments for leukemia, herpes, breast cancer, and a drug that fights HIV/AIDS. Consider the sponge, indeed!

Yong explains that

Last month, in the journal Trends in Ecology & Evolution, a group of scientists published a tub-thumping defense of sponges and other supposedly simple animals. In their paper, Casey Dunn, Sally Leys, and Steve Haddock argue that humans have systematically underestimated these creatures, largely because of our innate bias against organisms outside our taxonomic clique.

… But these creatures, according to Dunn, Leys, and Haddock, are not primitive relics; they are modern animals that excel at their own particular life styles. By ignoring them, we blind ourselves to a wondrous hidden biology and get a misleading view of evolution.

Sponges are wonderful, it turns out, and Yong’s article is wonderfully written. Read the full article here.

Sea life: Red sponge nudibranch

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: Steenbras Deep

On Sunday 11 March, since the Cape Argus Pick n Pay Cycle Tour was going to prohibit access to basically the entire peninsula, we decided to take an expedition out to the eastern side of False Bay to do a boat dive with Indigo Scuba, run by Kate and Deon Jonker. We’ve been meaning to do this for ages and ages, so we were very glad to finally get ourselves over there! The southeaster (which had blown strongly in the few days prior to the 11th) actually cleans up the eastern side of False Bay while it messes up the western side, or at least has some positive effect on visibility. So while we are diving in the Atlantic during the summer, Indigo launches out of Gordon’s Bay and explores local dive sites such as Pinnacles, Cow and Calf, and the Steenbras River Mouth.

Deon Jonker skippering the Indigo Scuba dive boat

We met at Indigo Scuba in the morning, loaded up the boat, and then drove the 5 minutes to Harbour Island in Gordon’s Bay, from where we launched. It’s an extremely civilised launch site and overall experience… The foul-mouthed snoek slinging fishermen crowding Miller’s Point seemed like a bad dream!

It’s about 11 kilometres from Harbour Island to Steenbras Deep, and one has the feeling of being quite far out to sea – although we could see the mountains surrounding False Bay on both sides of us. The wind was stronger than the weather man had predicted, giving rise to some quite serious wind chop and a bumpy and wet boat ride. When we arrived at the reef we could see that there was more wave action on top of the pinnacles than in the deeper water surrounding them. Deon dropped a shot on one of the two pinnacles that comprise the reef (the top of the pinnacle we dropped onto is at about 18 metres, with the sand at about 30 metres). A murky descent (standard for False Bay in summer!) down the shot line led us to the top of the pinnacle, where visibility was only about 2 metres and it was very green.

As we ventured slightly deeper we encountered some invigorating (ahem!) thermoclines (one of them was actually visible as a haze in the water) and improved visibility. There was quite a strong current in places, and lots of surge.

There are many similarities between the reefs we dive on the western side of False Bay, but the overall pattern of the sea life was subtly different. The fish seemed far less skittish than their compatriots to the west, and happily swam within a few tens of centimetres from my mask. Nudibranchs abound, and close inspection of the corals covering the rocks is well rewarded. There seemed to be fewer sea cucumbers, and feather stars were not quite as dominant as they are in some of the other parts of False Bay. The corals, sponges and sea fans are beautiful and very numerous.

The sand around the reef is very coarse and full of shells, and the reef itself abounds with cracks, gullies, small pointy pinnacles, and walls that can be traversed at a variety of depths. The gullies appear to be much beloved by west coast rock lobster, and shysharks were quite common too.

Puffadder shyshark and some lobster friends

This reef is not in a marine protected area (MPA) – none of the eastern False Bay dive sites are. Kate, who regularly dives both sides of the bay, says she can see a distinct difference in the number of fish that they see on “their” side of the bay compared to the western side. So even if I am quite cynical about the competence of the administration and will to police the MPAs, clearly they are having some effect!

Dive date: 11 March 2012

Air temperature: 29 degrees

Water temperature: 12 degrees

Maximum depth: 24.8 metres

Visibility: 2-10 metres

Dive duration: 38 minutes

Dive sites: Caravan Reef

Caravan Reef is an infrequently-dived, simply enormous granite reef that lies very close to the slipway at Miller’s Point. Its northern reaches are close to the SAS Pietermaritzburg, but as can be seen from the map on its wikivoyage page the reef extends far south and has five distinct regions.

Peter Southwood swimming a shallow contour at Caravan Reef (south)

The one we dived (and the only one I’ve visited so far) is Caravan South, which is visible on the right of the map. The top of the reef is shallow, 4-5 metres, and after descending onto the pinnacle we dropped off the southern side. The southern side of the pinnacle, which runs almost west to east, is characterised by a vertical wall that drops down to about 20 metres on the sand. I love vertical reef structures – much easier to take pictures of something next to you rather than below you, but it does require some co-ordination and consideration among the divers to avoid getting in each other’s way.

The reef extending up towards the surface

The rocks at the south eastern edge of the reef

Narrow ridges of rock around the edge of the main reef

One of the sharp-edged slivers of rock beneath the reef

Another of the rocks at the base of the reef

Gullies on the eastern side of the reef extend to the sand

The reef is heavily overgrown with sea fans, bryzoans, corals and invertebrate life

Ascending towards the top of the pinnacle

The top of the pinnacle is overgrown with kelp

A gully leading back up to the top of the pinnacle

Goot and I (after a false start) swam east along the wall at about 15 metres depth, with the current, which was (to put it mildly) howling. At the corner of the reef is a mass of jumbled boulders with small overhangs. Some of these rocks have quite sharp edges, like ancient tree roots or massive parmesan shavings, so there is a lot of surface area for life to grow on relative to the volume of the rock.

A compass sea jelly battling the current around the reef

Compass sea jellies fighting the current

Goot inspects the root-mouthed sea jelly

A small jelly on the top of the pinnacle

Compass sea jellies and fish in the current at Caravan Reef

As we rounded the corner we encountered even more current – it was running roughly north to south, and coming around the reef, hence our difficulty with it whichever way we turned! Large numbers of compass sea jellies were being blown along by the current. We also saw an enormous root-mouthed sea jelly, with a small compass jelly caught in its tentacles (by accident – these creatures eat plankton). The false plum anemones living on the side of the reef were enjoying an unexpected bounty of jellyfish as some of the compass sea jellies had gotten caught on the side of the reef and were being devoured by opportunistic anemones.

False plum anemone slurps in a compass sea jelly

Strawberry sea anemones and sea cucumbers

A sunburst soft coral, with most of its polyps retracted

A false plum anemone lunches a compass sea jelly that got caught on the reef

Knobbly anemone with two urchin assistants

Red sea star cuddling up to a false plum anemone

The eastern edge of the reef has several cracks in it, mostly quite small, but we did see a few large roman taking advantage of the shelter. A small school of hottentot was surfing current on the eastern edge too, enjoying the snacks that it brought directly into their path. We swam into the current a short distance, became distracted by the root-mouthed jelly, and followed it back along the reef for a while. We then ascended to about 10 metres and drifted back down the reef with the current to the corner. By that stage we were getting low on air, so it was time to ascend to the top of the pinnacle. The surface current washed us off the pinnacle in short order, so we inflated an SMB and waited for the boat!

My favourite feature of the southern part of the reef is the vertical wall to the south, which extends along the eastern side as well to some degree. I’d like to explore the northern and western areas of this part of Caravan Reef, but the current prevented us from making much progress into those areas. Peter Southwood is busy mapping this reef, so contours should be added to the existing map on Wikitravel. I think that the current on the day we dived the reef had a lot to do with the extremely strong northwesterly wind that had been blowing for a day or two and dropped slightly on the day of our dive, but I’m not complaining – the visibility was stellar, almost top to bottom!

Dive date: 23 October 2011

Air temperature: 24 degrees

Water temperature: 12 degrees

Maximum depth: 18.0 metres

Visibility: 15 metres

Dive duration: 33 minutes

Sinuous sea fan near the bottom of the reef

Sea fans, featherstars and urchins on the rocky bottom

Abundant invertebrate life on the lower reef

A reticulated sea star resting on some multicoloured sea fans and false coral

Dive sites: Atlantis Reef

One of the pinnacles of Atlantis Reef rises to near the surface

Atlantis Reef was discovered in September 2011 by Steven Benjamin of Animal Ocean. The site was named for the lost city which is (according to legend) submerged now, but was also known as the Pillars of Hercules prior to its rediscovery by Animal Ocean. Atlantis comprises two massive pinnacles that rise to within 4-5 metres of the surface, along with a jumbled collection of enormous boulders strewn about their base. We dived the site in mid-October, in conditions of almost top to bottom visibility. The topography of the site is breathtaking – huge, vertical walls and enormous rocks distinguish it from the lower rocky reef characteristics of the Roman Rock area. The sand lies at about 30 metres on the seaward (eastern) side of the reef, but the average depth is about 20 metres. With a large cylinder full of a nice Nitrox mix, you could dive here for days (water temperature permitting).

Tony over the giant arrowhead (pointing towards the top of the photo)

Fissures in the granite of the reef provide homes for fish

Huge boulders stacked one on top of the other

Massive granite boulders characterise the site

Visibility was almost top to bottom when we dived Atlantis

Lower down on the pinnacle, more sea fans and invertebrates appear

The side of the inshore pinnacle, near the surface

Redbait and urchins cover the tops of the pinnacles

Kelp in the shallow water on top of the pinnacle

Kelp growing on top of the shallower pinnacle

Fish above the redbait that crowns the pinnacles

View from above of the top of the inshore pinnacle

Cape rock crab hiding among the redbait on top of one of the pinnacles

We dropped right on top of the pinnacle closest to shore, and the boat skipper hadn’t used a shot line for fear of damaging the pristine and hardly dived reef. Tony and Justin went down to the sand in order to do a compass swim for Justin’s Deep Specialty course, and I hovered next to one of the pinnacles. The pinnacles are about 3 metres across on their tips, but widen out to a large, roughly rectangular base on the sand. Between the pinnacles is a large overhang, and large cracks in which we saw congregations of janbruin. We spotted some very large (more than 30 centimetre long) zebra and Roman between the pinnacles, as well as some white seacatfish also enjoying one of the cracks in the rock. I discovered some fascinating facts about Roman this week, but they can wait…

Massive school of hottentot, fransmadam and other fish

Fish feeding among the redbait on top of one of the pinnacles

To me, the most spectacular feature of the marine life on the reef is the large schools of fish that assemble around the pinnacles. The reef lies within the Castle Rocks Protected Area and no fishing is allowed there, and it obviously hasn’t been discovered by the fishermen – both commercial and amateur – who don’t care about protected areas and enjoy the fact that they aren’t policed at all. Hottentot, fransmadam, and zebra mill around in their hundreds – I have never seen a school of fish like this in the Cape. The strepies at Long Beach last summer were – until now – the most prolific fish I’ve seen here. The fish are quite relaxed and just reshaped their school around the divers.

Anemones, urchins, corals and sea fans cover the upper reaches of the pinnacles

A knobbly anemone among sea fans, sea cucumbers and other invertebrate bounty

There are also the usual sea fans (plus what looked like a nursery for baby sea fans), massive nudibranchs of several varieties, sea cucumbers, anemones, and a lot of other invertebrate life. The top parts of the pinnacles are covered with huge redbait, interspersed with Cape urchins and several varieties of sea anemone. Lower down on the pinnacles we found orange wall sponges and other sponge species, as well as large klipfish trying to camouflage themselves against the wall.

There was some interesting discussion about whether it is right to have an “exclusive” dive site that only you know the co-ordinates to. An argument was put forward that when one finds a pristine spot like this, it’s natural to want to protect it from careless, ignorant or inexperienced divers. Hopefully the boat charters – all of whom now know where this reef is – will put aside financial considerations when taking divers to this reef, and only allow divers who they know can manage their buoyancy and don’t engage in behaviours that are detrimental to the marine life of the locations they dive. Whether this happens will remain to be seen. (I, for one, am not optimistic… Enjoy it now, while it lasts.)

Dense invertebrate life on the pinnacles

Knobbly anemone (right) on Atlantis Reef

A red sea star among coraline algae and strawberry sea anemones

A sea star gets a grip and holds on tight

Shyshark resting inside an orange wall sponge

I want to go back to this site tomorrow, or yesterday if that’s possible. I’ve been (irritatingly) ranting about it to whoever will listen since we dived it. It’s wonderful to me that we are still finding new places to dive in our local bay of plenty, and so close to shore, too! Also, seeing how healthy and abundant the fish that call this reef home are, I’m thrilled that (it seems) the Marine Protected Areas are working, despite hopelessly inadequate support from the authorities. It made me so, so happy to see this reef. Can’t wait to go back!

Tony swims past the top of one of the pinnacles

Dive date: 15 October 2011

Air temperature: 19 degrees

Water temperature: 13 degrees

Maximum depth: 21.5 metres

Visibility: 15 metres

Dive duration: 40 minutes

Bookshelf: Voyage of the Turtle

The first time I got to observe turtles up close was on our recent (April 2011) trip to Sodwana. We probably encountered ten individual Green turtles on the dives we did. I was amazed by how relaxed and calm they are underwater, and how languid their swimming style is (using the front flippers for propulsion and the rear ones as rudders). They munch at the coral, and allow you to pass by quite close without paying you the slightest bit of attention. When they swim away they look as though they’re hardly exerting themselves, but just try and keep up and you’ll see how fast they are actually moving! Five different species of turtle visit the waters of Kwazulu Natal, and Leatherbacks and Loggerheads actually nest in Sodwana, and during the summer you can go on a Turtle Tour to see the females digging nests and laying eggs on the beach.

So I’ve had turtles on the brain since earlier this year. This book was timely!

Voyage of the Turtle: In Pursuit of the Earth’s Last Dinosaur – Carl Safina

This is the second of Carl Safina’s books that I’ve read. The first, Song for the Blue Ocean, was a revelation to me – he writes beautifully, and covers so much ground that it was quite overwhelming. It was also incredibly depressing and left me feeling that, save for a few brave individuals, humanity was headed to hell in a handbasket.

This book is also beautifully written, with massive scope, mainly dealing with the massive Leatherback turtle but touching on the other six species as well (Hawksbill, Loggerhead, Green, Kemp’s Ridley, Olive Ridley and Flatback). These creatures are reptiles, but amazingly adapted to function in a range of water temperatures. Leatherbacks can swim in water so cold that it would freeze other sea creatures, thanks to special lipids in their blood. They are long distance swimmers of note, spending vast periods of time in the middle of the ocean, moving between feeding and breeding grounds. Seeing their migratory paths plotted on a world map amazed me – they cross entire oceans without a break. At some stages of their life cycle, they spend 97% of their time underwater.

Safina visits most of the primary turtle nesting sites around the world (from Florida to Papua New Guinea), and spends time in spotting planes counting turtles and nests with biologists and conservationists, and on fishing boats looking for these elusive giants out at sea. One section is particularly disturbing – he travels out with some swordfish fishermen, and describes the process of catching and killing these majestic creatures in some detail. Even though Safina is an ardent conservationist and founder of the Blue Ocean Institute, his self-confessed and very obvious enjoyment of recreational fishing – even (or specially) for big game fish – and the relish with which he describes it, is very, very disturbing to me and tends to make his other credentials ring somewhat hollow.

Turtles seem like prolific breeders to us parsimonious (well, some of us) humans. Each female makes several (five or six usually) nests during a breeding season, containing over 100 eggs. The reason for each female laying of the order of 1,000 eggs each time she breeds is because the eggs and tiny hatchlings are incredibly vulnerable to predation from crabs, birds, jackals, fish and other creatures who appreciate a concentrated dose of protein in bite-sized form. Adding to these natural threats are a multitude of dangers posed by humans, who have been on earth for a fraction of the time that these living dinosaurs have.

Human-created threats faced by turtles include entanglement in fishing line or nets, and capture on long lines. In all these instances they drown, as accidental bycatch. The lucky ones lose a flipper, or escape with a hook in their bodies and line entangling their flippers or tangled around their insides. Long lining will hopefully be completely illegal all over the world one day (it’s a brutal and wasteful way to fish), round hooks will become more prevalent, and turtle escape hatches – which are easy to fit and use on most kinds of fishing net – will become more widespread. Safina reports than locations where these hatches are law are reporting a much lower bycatch of turtles. Typically fishermen are fiercely resistant to any kind of change or advice about how to do their jobs, but there are some very persistent people working in this area.

Turtles are also eaten for food in some parts of the world, used for virility potions (can we all say it together… pathetic!) and their eggs are widely used for food as well. Their shells (this doesn’t apply to Leatherbacks, as they have tough skin stretched over bone instead of a hard carapace) are used for jewellery, dishes, and other purposes. It’s easy for poachers to observe the giant female turtles laying in full view on the beach, dig up the nests and remove all the eggs. Other man-made threats include artificial lighting that disorients hatchlings and sends them scurrying inland instead of towards the bright horizon of the ocean when they emerge from the eggs, and interference with beach contours by adding or removing sand. Turtles are particular about what kind of beach they like to nest on, and hatchlings usually return to where they were born in order to breed when their turn comes.

Their presence in the ecosystem keeps certain types of sponges, corals, sea grass and jellyfish (some of their dietary preferences) in check. There is, as Safina points out, a domino effect when the turtle numbers are dimished so much. And we can’t even see all the dominoes.

This is a more hopeful book than Song for the Blue Ocean. It’s made me want to visit Sodwana in summer to see some Leatherback turtles. These creatures have wisdom in their bones – nothing survives on earth for so long by accident. We’ll have to organise a trip there in January.

You can purchase the book here if you’re in South Africa, otherwise click here. If you want to read it on your Kindle, go here.

Dive sites: SS Lusitania

According to Peter Southwood, on the wikivoyage page for the SS Lusitania,

The wreck of the Lusitania is considered by many Cape Town divers to be one of the top wreck dives of the region. It is fairly deep, the wreck is quite broken up, but still interesting, with a number of identifiable components, and the visibility is often quite good. However, it is a physically challenging dive, quite a distance from the launch sites, and conditions are not often suitable, so it is not dived very often. No doubt these factors add to the mystique.

Tony and I had heard about the mystique surrounding this wreck, but because we hadn’t had an opportunity to dive it since he’s been in Cape Town (about two years now) we didn’t know much about it. Beautiful weather in the middle of winter provided an opportunity to take the long boat ride out of False Bay, past Cape Point, and further south to Bellows Rock. Bellows Rock is named for the way in which the water smashes over the top of it, and the break is apparently visible from Macassar – at the northern end of False Bay – when the swell is large.

The ship is now very broken up, after 100 years lying below Bellows Rock

Wreckage lies tumbled among the smooth rocks

Here and there are brass fittings and window frames

Railings (perhaps) from the SS Lusitania

Rocky reef on which the SS Lusitania is lying

The Lusitania was a large Portuguese liner that ran aground on Bellows Rock in late April 1911, carrying about 800 passengers. All but eight survived (a lifeboat capsized), and after a few days the ship slid down the side of Bellows Rock to where it now lies in 37 metres of water. A light Nitrox mix will help increase dive times here. She’s an old wreck – as old as the Clan Stuart – and very broken up. The wreckage is readily discernible, however, because it is not very encrusted with marine life at all. The surrounding reef, made up of granite boulders with a some nice holes, overhangs and places to look underneath, is very colourful and well encrusted with sponges. There are also massive numbers of West coast rock lobster!

Strawberry sea anemones on the SS Lusitania

Sponges and soft corals on the SS Lusitania wreck site

Grant gave us a bone-chilling briefing that had me convinced (if one of the other divers on the boat hadn’t done it already by telling me with dewy eyes that this was “the Mount Everest of diving”) that this is quite a higher grade dive that requires wits, fitness and no small measure of courage for a scaredy-cat like me. The wreck lies right next to Bellows Rock, which is surrounded by a large area of breaking waves and white water. Descents at this site must be rapid – no messing around on the surface doing buddy checks (“PADI stuff”, as Grant called it once) – and descents are equally demanding. There’s usually a current pushing towards the north west, and this will force one onto the rock unless you take care. Grant advised us to swim gently in a north easterly direction (more or less across the current) as we ascended, and to do our safety stops at eight metres instead of the usual five. He warned us not to surface if we saw white water above us. He told us that he has “survived” being washed over Bellows Rock itself, but that it’s not an experience one wants to have unless it’s absolutely necessary.

The ride out to Bellows Rock is magnificent, and takes about 20-25 minutes at the speed Grant drives (very fast). The sea was nice and flat inside False Bay, but outside the bay there was a small swell. Even though it was only 2-3 metres, Bellows Rock and surrounds looked like a terrifying whirlpool to me. Grant couldn’t drop a shot line onto the wreck because it would get washed over the rock (and presumably have to stay there forever, which would be an inconvenience). The plan was for us to enter the water in two groups. The first group kitted up, and Grant drove the boat as close as he dared to the white water around the rock, so that we were right over the wreck. He counted down, slowed the boat to a crawl, and the divers were gone. As soon as they rolled off he drove away so that the second group – me, Tony, Cecil and Ivan – could get ready.

Kitting up on the boat (that's not us!) — Kitting up on the boat (that’s not us!)

Our entry probably looked just as scary, but I wasn’t actually looking at the water! Next time I do this dive I’d take more weight – for deep dives my preferred weighting is marginal and I have to swim down the first 3-5 metres; this wasn’t ideal for this dive, and because I was anxious about getting down quickly, I breathed too fast and struggled to sink! Once we were in, however, everything was fine.

The Lusitania was a 5 557 ton vessel, very large. There are big, complete pieces of wreckage scattered about, but very little actual structure remains. Close to Bellows Rock – which drops off precipitously below the water line – are lots of interesting bits and pieces, but getting there and away is difficult because of the current. We spent some time exploring the edge of the wreck furthest from Bellows Rock, and then swam slightly north over some rocky reef that reminded me a lot of Klein Tafelberg Reef in Hout Bay.

Our ascent was uneventful – we followed instructions, did a deep safety stop, and surfaced a safe distance from Bellows Rock. The water was very clean, and very cold, but as we moved further towards the entrance to False Bay the visibility declined somewhat. I’d like to dive this wreck again, but conditions have to be very special – with almost no swell and no wind – for it to be safe. I feel like a Philistine for admitting that the challenging nature of this dive was not compensated for by the specialness of the dive site itself, although it is without doubt a very interesting and varied dive.

A torch reveals the colours of the soft corals all over the site

The boat ride back past Cape Point and along the eastern shore of the Cape Point Nature Reserve was beautiful. We saw several whales, a sunfish (briefly), seabirds, and – for most of the trip – the ocean floor beneath us, as the water was crystal clear. It was, as Cecil said, an absolute treat and a wonderful way to spend a morning (all of it, even the death-defying leaps from a slow-moving boat!).

Dive date: 16 July 2011

Air temperature: 21 degrees

Water temperature: 14 degrees

Maximum depth: 37.0 metres

Visibility: 12 metres

Dive duration: 36 minutes

Tony managing the reel at the safety stop

Sponges and coral of Malta

I have broken up the invertebrate life into things (mostly) with eyes, and things without. Behold, the things without eyes…

Sponges

The Mediterranean has a history of sponge diving that goes back to antiquity, and we saw quite a variety of sponges, but not vast numbers of them. The Mediterranean bath sponge is the primary target of sponge divers, and comes in a variety of exterior hues. It’s apparently creamy yellow to beige inside.

Bathing sponge (Spongia officinalis) traditionally harvested by Mediterranean sponge divers

Spongia lamella, the elephant ear sponge

Could be the elephant ear sponge... Probably isn't!

Coral

Dive Sites: Pie Rock

Tinus and Lindsay needed to finish their Open Water course, so we visited Pie Rock in False Bay for a boat dive. Pie Rock is so named because someone, once long ago, thought that part of the reef system resembled a slice of pie. I couldn’t see anything pie-shaped, but there are some nice rocks there!

Gap between rocks in the Pie Rock reef system

There’s a spectacular pinnacle that rises to within 5 metres of the surface, but most of the dive we spent at a depth of about 15 metres. The topography is similar to Castor Rock, Partridge Point, and the other rocky reefs on the western side of False Bay. There are abundant overhangs and crevasses, and a large cave with several entrances that was found by other members of our group.

We saw several very large roman, and more magnificent anemones than I thought were possible to exist in one place. The site is entirely within the Castle Rock restricted zone, and the abundance and health of the marine ecosystem attests to the protection that it has received.

A seal beating an octopus on the surface

Dive date: 18 May 2011

Air temperature: 19 degrees

Water temperature: 12 degrees

Maximum depth: 18.5 metres

Visibility: 12 metres

Dive duration: 33 minutes

Ruby Runner, Grant's boat, seen from below

Dive sites (Sodwana): Stringer – part 2

As Sophie and I started our ascent I saw a huge ribbontail ray swimming away from us on the sand. It was surgy and there was lots of sand in the water (as can be seen from the photos), so he disappeared fast.