Reefs – Page 8 – Learn to Dive Today Blog

My fascination with the ocean

This information could possibly used to certify me insane, but I will risk it.

Very little research has been done about this but I (as have many others) have always believed that different creatures begin to warm to divers. There are many stories of specific ocean creatures being named, recognised and often visited by many divers.

Octopus

Several octopus at Long Beach for example live in holes on the pipeline and no matter what if you go by in the day they will be there.

Often, on night dives,there is no one home as they are off feeding, probably close by, but due to the darkness we don’t see them. This is how they move around at night.

[youtube=http://www.youtube.com/watch?v=mAL6Nld69vI&w=540]

Brindle and potato bass

Sodwana Bay had a brindle bass, seen by many divers year after year at the same dive site. This huge creature was very friendly and enjoyed interacting with divers. Many creatures in the ocean are fiercely territorial and once you have found them and discovered their territory it is easy to spot them as they seldom go far.

Whilst working in Mozambique I too visited the same reef sometimes four or five times a day on a busy weekend, showing different groups of divers the same ”locals” on the reef.

[youtube=http://www.youtube.com/watch?v=vyq6qcByx6A&w=540]

This video shows a huge potato bass that I believed was always waiting for us to drop in. This potato bass is easily recognizable by the fact that she has only one eye. You could not just swim past without giving her a tickle as doing so would result in her following the group all down the reef. Ascending to the safety stop you would see her race back to the start of the reef where she knew the next group would be dropped.

I am convinced of this as on the odd occasion that the weather would present us with a reverse current, we would drop down on the opposite end of the reef and there she would be.

Moray eels

“They bite” is what any diver will tell you. Well they do, however I believe this particular black cheeked eel warmed to me. I visited her every day for about six months. The first few weeks I just looked, then the next few weeks I offered my hand, it got bitten, severely several times and the resulting injuries required a few weeks of looking only. From this video clip, heavily edited, its clear the aggression shown in the first few weeks waned, became less severe, and eventually slowed right down to a nibble without breaking the skin… Was she warming, becoming more friendly or just getting so tired of my annoying hand in her face that she didn’t want to bother? You decide.

[youtube=http://www.youtube.com/watch?v=ti4xoPWSztU&w=540]

A rather large honeycomb moray also fond of a chin tickle:

Peanut & Butter

The reason for the preceding information is to justify my fondness for two little fellas I met at Long Beach while Kate was doing her Zero to Hero course. They are called Peanut (a juvenile double sash butterflyfish) and Butter (a juvenile jutjaw).

Peanut the double sash butterflyfish — Peanut the double sash butteflyfish

I first spotted them a couple of months back and every time I go by on a dive I take a peek to see if they are still there. Being as small as they are there is a real risk they may end up as lunch for someone, but for now we will monitor their progress and watch them grow.

Update on the artificial reef: 10 days

Kate and I visiting the reef after ten days

Ten days after installing our artificial reef at Long Beach, we paid it a visit to see how it had held up. The southeaster had been blowing very strongly since we put it in the water, so we were concerned about its effects on the reef.

There was no need to worry. Gobies, starfish, and perhaps even an octopus (check out the shells and other debris at the entrance to the white pot) have moved in.

Feather stars have started to attach themselves. Because of the reef’s triangular shape, several pieces of kelp and sea lettuce got caught inside the triangle, providing shelter to small fish.

The five sponges have lost their colour (except for the green one), and plant life and algae is already colonising the PVC pipes that make up the superstructure. The sea doesn’t waste any time!

Article: The Urban Times – Artificial Reefs

A mash-up of my post on artificial reefs, and Tony’s post on the one we created at Long Beach has appeared in The Urban Times. Check it out here.

Building a small artificial reef

I spend more time diving at Long Beach in Simon’s Town than any other dive site. Considered by many as a training site only it is seldom explored. The Wikivoyage site written by Peter Southwood lists some of the many interesting features of Long Beach.

The northern side of Long Beach is considered ”barren” as it has less to explore than the southern side, but each and every item on the sea bed has been colonised and turned into home for something.

There are several octopus holes there, some of them huge and these creatures seem keen to add odd items to the entrance of their holes. I believe it is an effort to draw other marine life to the spot whilst the octopus waits to devour any tasty bits. I have seen glass bottles, sunglasses, beer cans and golf balls lining their homes.

We decided to build something to see what would be drawn to this spot.

Transporting the components of the artificial reef

We secured three 2 metre lengths of PVC pipe, a piece of chain and a few wooden bits. Attached to this was a glass coffee jar, a plant pot and a few smaller containers.

We had attached five different coloured sponges and a coffee tin as well as some plastic bottles secured on a length of wood. We also added an ice tray to see how much silt would collect in the tray, and from which direction.

The reef, set up with a request to divers not to disturb it

Update on what we found ten days later in a future post!

Artificial reefs

What is an artificial reef?

Most people are familiar with the idea of a reef: it’s an underwater feature, often comprising rocks, sand or coral, that is distinct from and rises out of the sea floor around it. Most reefs are naturally occuring – such as the fossilised sand dune that is Aliwal Shoal, or the coral atolls of the South Pacific.

There is another kind of reef, however. Artificial reefs are man-made reefs. They are most often created by scuttling a ship, whether deliberately or through an act of war, or a sinking in a storm. They can also be created by dumping tyres, rubble, or other materials on the sandy ocean bottom.

Isn’t it just pollution?

The idea seems crazy: isn’t one just dumping garbage into the ocean, and creating a problem where there wasn’t one before? The problem with this thinking is that it neglects to consider the power of the sea to claim and colonise whatever is given to it. On a small scale, think of the bits of glass and other rubbish that sometimes end up on the beach after a storm. The glass is worn smooth by the action of the waves against it and the sand. The bits of garbage often have seaweed growing on them. Ships that traverse the world’s oceans have to be cleaned constantly in order to prevent barnacles, mussels and other sea creatures from making their homes on their hulls and causing structural damage. Marine animals are powerful – even the tiny ones.

If the materials from which artificial reefs are built are carefully chosen, the sea will accept the new reef, and within months change it into something beautiful and much better than it was before. Ships that are deliberately scuttled are specially cleaned to avoid oil spills and polluting the marine ecosystem.

Why make an artificial reef?

Artificial reefs are created for many reasons. Some are pure accidents – think of a ship that sinks in a storm or is holed by enemy fire during a battle. Some are created to enhance the experience of surfers, in order to force a wave to break at a particular spot. Some are created as part of harbour alterations, and others are created to relieve the strain on natural reefs. Reefs are an important breeding ground for fish, as the juveniles have places to hide and shelter from predators. The addition of an artificial reef to a region that is heavily fished can do much to restore fish stocks in the area.

Cape Town artificial reefs

Many of the wrecks around Cape Town are located where they are as a result of the incompetence of the crew (think of the Kakapo on Noordhoek Beach), foul weather (the SS Clan Stuart springs to mind), and hidden rocks and blinders such as Albatross Rock. There are also several deliberately scuttled ships that are much beloved by Cape divers:

the Smitswinkel Bay wrecks, mostly scuttled in the late 1970’s:
SAS Pietermaritzburg in False Bay, scuttled in 1994
MV Aster in Hout Bay, scuttled by divers for divers in 1997, and used for wreck penetration training

All of these wrecks are now heavily overgrown with diverse marine life, much of it found almost nowhere else. They have done much to boost fish stocks – think of how full of fishing boats the area just south of the Smits wrecks is on a busy weekend. And they are a source of immense enjoyment to divers living in and visiting Cape Town.

Bookshelf: A Diver’s Guide to Reef Life

A Diver’s Guide to Reef Life -Andrea & Antonella Ferrari

A colleague has been doing Christmas shopping for the diver in her life, and trying to decide between this book, Reef Fishes and Corals and More Reef Fishes and Nudibranchs.

Tony speaks very highly of this book, but I haven’t looked at it until recently. It covers coral reefs the world over. Densely covered regions include the Red Sea, the Carribean, Indonesia, and the Great Barrier Reef in Australia. Many of the species depicted are found in waters off Southern Africa (further north than Cape Town, alas!).

The pictures are spectacualar – the Ferraris have written several other books, at least one specifically focused on photography, and their standards are high. I cannot over-emphasise how magnificent the photos are. There is a gallery section at the beginning of the book where you can just enjoy the colours and variety of the different kinds of coral for the joy of it.

The Ferraris also include a few pages of advice on reef conduct, and a section explaining the origin and functioning of coral reefs – “the rainforests of the sea”.

The book is arranged according to taxonomy. Each creature is photographed, and brief habitat information is provided. It’s focused on the experience a diver would have – advice about which fish are hard to approach, which are poisonous, and specific behavioural traits.

For each creature the scientific name and a common name are provided. As my colleague discovered, the common names for many fish differ wildly from place to place. What was called the whitespotted boxfish in Reef Fishes and Corals was called the black boxfish in this book… Quite a difference! This is definitely something to bear in mind when ordering fish identification books from overseas.

You can order the book here. It’s about 500 pages, a squarish small-format hardcover. Fairly heavy, but not impossible to take with you in your suitcase on an overseas dive trip.

Sea life: Urchins

I used to love collecting sea urchin shells as a child – we’d go on holiday to Betty’s Bay, and I would collect handfuls of shells from tiny to huge. When we went home, I’d make strings of shells, arranged in size from largest to smallest.

Sea urchins and brittlestar at Fisherman's Beach

The bare, empty shells look green, but at the aquarium we have looked at them under the microscope and they are actually far more detailed than just plain old army green. The live urchin has spines, tube feet, and little pincers, all of which protrude from different holes in its shell. The outer surface of the shell is ribbed, with lots of lumps and bumps and gradations of colour all the way from green to purple. And looking at a live urchin under a microscope is amazing indeed.

Sea urchins tend to like to live on rocks – we don’t see many of them at Long Beach (possibly also because they’ve been eaten by the rock lobsters) but they’re prolific at Fisherman’s Beach, Shark Alley and Sunny Cove. They can be found clustered on the rocky reefs, many of them with a piece of seaweed as a hat.

Juvenile abalone shelter among sea urchins, and disturbing the balance of the sea urchin population can have devastating consequences for abalone. One of the primary predators of sea urchins is the West Coast rock lobster (commonly, and incorrectly, referred to as crayfish). When the population of rock lobster gets out of control, they eat too many urchins, and the juvenile abalone have nowhere to hide. The abalone population can consequently collapse. This has been documented and studied at several sites in the Western Cape. This has implications for fisheries management.

Sea urchin and cushion star at Fisherman's Beach

Sea urchin spines are a pain (literally) if you get them in your foot or other body part. For this reason your buoyancy needs to be good if you plan to swim over urchin country. There are several kinds of urchin found in the Cape, but I’ve only seen the one depicted in these photos so far. Urchin beds are more active than they seem at first glance, and worth a look when you’re diving in a rocky area.

Underwater art: The Silent Evolution

News of a very cool art installation that doubles as an artificial reef off Cancun, Mexico, in what looks like delightfully warm water! Jason de Caires Taylor is an artist who specialises in underwater art. The 400 life size sculptures of people are constructed from a cement mix that encourages coral growth.

There are tons of pictures on the artist’s website. Here’s a video off youtube:

[youtube=http://www.youtube.com/watch?v=6kvaQuXcsVk&w=540]

The visibility is for miles, and the sculptures are installed in water shallow enough to snorkel in. Looks like an awesome place to visit!

Dive sites (Sodwana): Pinnacles

The fourth dive we did (second dive on our second full day in Sodwana) was to Pinnacles, a beautiful site also on Two Mile Reef. The sea was quite rough and kitting up on the boat was not much fun, but dropping down onto the myriad gullies and rocky outcrops covered with coral was a wonderful relief.

The site was full of overhangs and sandy gullies for exploring, and Tony had a blast with his video camera. Several times he almost disappeared into cracks in the rocks in search of elusive sea life.

Tony exploring a sand gully at Pinnacles

The sand did make still photography a bit tricky, and although I did see some lovely fish – including a clown triggerfish, of which I am very fond – I did not get many decent fish photos.

Unicorn fish — A unicorn fish goes about his business at Pinnacles

I did manage to capture some coral polyps retreating into their hard structure after being disturbed (at right in the photo). Compare it to the same kind of coral behind and to the left of it in this photo:

During the dive we passed by a feature called the Anvil – aptly named, as you can see below!

This was a short dive and long wait on the boat for me as I surfaced with Tami when she got low on air, and then was too much of a porridge-head to think to go back down and explore some more (I still had 120 bar in my cylinder), even though I could see the other divers below us. The dive site was gorgeous, but it was the second dive on quite a surgy day and thus both my stomach and my energy levels were giving up the ghost!

Dive date: 9 October 2010

Air temperature: 24 degrees

Water temperature: 22 degrees

Maximum depth: 10.9 metres

Visibility: 20 metres

Dive duration: 34 minutes

Dive sites (Sodwana): Caves & Overhangs

We were feeling a little beaten up after our first dive in Sodwana, what with the rough surface conditions that had had more than one of us (no names mentioned) leaning over the side of the boat feeding the fish before AND after the dive! The focus was on getting into the water as soon as possible, because once we were below the surface everything else melted away.

Caves & Overhangs on Two Mile Reef, Sodwana

The second dive we did was to Caves & Overhangs on Two Mile Reef. The beauty of diving Two Mile Reef is that the longest boat ride you will have to endure is about 10 minutes, and we often spent more time kitting up on the boat than actually locating the dive site!

Justin identifying fish - our underwater naturalist

Justin, Gerard and Tami were doing their Fish Identification dive for their Advanced course, which was a darn good thing because I couldn’t name a single thing I’d seen so far and planned to piggyback off their knowledge! The three of them swanned about with their slates, drawing the things they were seeing. The end results were somewhat hilarious… Compare Justin and Gerard’s slates below (with apologies to both the budding artists for revealing their work in such early stages, and for the water drops – the pictures were taken before I’d removed my camera from its housing):

I was beside myself with excitement – yelled into my regulator – when I spotted a gorgeous moray eel, with his head sticking out of his cave, opening and closing his mouth to breathe. He was a medium-sized guy, and I tried to stick around for as long as possible watching him, before the surge took me away.

Guinea fowl moray eel on Caves & Overhangs

My photos from this dive are uniformly terrible – I took several of my eel, and only the one above was vaguely clear. The one shining light however was this picture of what Tony calls the Colgate nudibranch – Chromodoris hamiltoni – who was an obligingly stationary photographic subject. As I recall, I also managed to find something inanimate to hold onto while I took the picture.

This dive was far easier and more relaxed for me than the first one. I was wearing a dorky little swimcap (thanks Tami!) which made the rest of the group want to disown me, but which controlled the free flowing hair that had made the first dive tricky, and I was more willing to let the surge move me around.

I hadn’t quite got the knack of pressing the camera shutter button in between surges, but even if I didn’t manage to get pretty pictures of everything, I saw some wonderful parrotfish, unicorn fish, goldies, more than one nudibranch, colourful little wrasses, and an anemone fish rubbing himself all over the largest anemone I have EVER seen. I also saw a host of different kinds of butterflyfish and angelfish, a nice little yellow puffer fish, Moorish idols (wow!), and a tiny little domino who I stalked until he emerged for a photo.

Brain coral — I love love love brain coral!

Dive date: 8 October 2010

Air temperature: 23 degrees

Water temperature: 22 degrees

Maximum depth: 15.3 metres

Visibility: 12 metres

Dive duration: 58 minutes