Kelp – Learn to Dive Today Blog

Newsletter: Chin up

Hi divers

Weekend dive plans

No diving

This is a strange time to be alive, and we are all (hopefully) adjusting to being confined to our homes for the next 21 and perhaps more days. This is a challenge, as I don’t need to tell you. Thankfully there are ways to pass the time, whilst not forgetting about the ocean and scuba diving, and I thought I’d share a few of them with you.

Interesting gaps between the rocks and in the kelp are fun for divers!

Free online first aid courses from DAN

DAN Southern Africa has generously made their catalogue of online first aid courses free of charge for the next one month. Pick from the list below:

(Rocking back and forth on your couch contemplating existence and eating popcorn is also ok – don’t feel obliged to try to transform yourself into an intellectual and physical hulk during lockdown.)

Marine Life Identification with Georgina Jones

The City iNaturalist Challenge is rolling around again at the end of April. Georgina’s planned fish ID workshops probably aren’t going to happen in the originally planned face to face format, so she’s preparing daily online posts with information (and photos) on common marine life around Cape Town. You can find these in the Underwater Cape Town facebook group, which you should join if you’re not already a member. Georgina knows what she’s talking about.

The Sea-Change book

We reviewed the incredible Sea Change book a while ago. During the lockdown period, the Sea Change team is making the e-book available free of charge to South Africans. All you need to do is send an email to get a special download code for the Sea Change website. Details here (facebook – may be slow to load thanks to a broken undersea cable).

This is a beautiful offer; you’ll be able to explore the kelp forests from the comfort of your couch, as long as this goes on.

For the kids

Audible is allowing free streaming of a large catalogue of kids’, teens’ and classic books read by awesome narrators: check out stories.audible.com.

Local illustrator Patrick Latimer has created Halfsies, a free print-it-yourself pdf of pictures for kids (or you) to complete, and then colour. Find it here.

Virus information

Much less wonderfully, we’re sure you already know about several of these, but here’s a list of reputable sources for coronavirus updates:

The SA Government’s coronavirus website
The Financial Times has free coronavirus coverage, including this incredible graphical global tracker
Africa Check and Snopes, for myth busting

Finally, to all of you and your families, please do your utmost to stay well, stay at home, and see you on the other side. To the healthcare workers – we cannot thank you enough.

regards

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

Diving is addictive!

To subscribe to receive this newsletter by email, use the form on this page!

Bookshelf: Sea Change

Sea Change: Primal Joy and the Art of Underwater Tracking – Craig Foster & Ross Frylinck

The Sea Change project may be familiar to you from their large format photographic displays, one of which was for a time along the promenade in Sea Point, and is currently in Lamberts Bay. You may have read about the project, or seen its members – ocean-loving filmmakers, journalists, scientists – diving in the cold water of False Bay year round, without wetsuits. You may even have seen the BBC’s Blue Planet II series, in which the filmmakers, guided by Craig Foster and his fellows, captured an incredible octopus sequence filmed on our doorstep in False Bay.

The Sea-Change book has been a long time in the making, and is the product of hours upon hours upon hours spent in the water, observing the animals that call the kelp forests home. The book contains a story of loss and discovery – that of Ross Frylinck – interwoven with large-format photographs of scenes from the kelp forest, taken by filmmaker and naturalist Craig Foster, a co-founder of the Sea-Change project. Foster also provides the captions.

As a diver, it was immediately clear to me that a great deal of patience and close observation was required to gain the deep understanding that Foster has of the smallest creatures living among the kelp. There is no substitute for time in the water. There is no substitute for swimming slowly, deliberately, and for spending extended time looking at one place. The marks that animals leave on rocks, kelp stipes, the sand, and even on each other’s shells, can tell a story.

I learned a huge amount about animal behaviour from this book, and about the interconnectedness of all the elements of the watery, beautiful world around the Cape Peninsula. The photographs are beautiful and striking, capturing moments that one would be extremely lucky to see during the normal course of things. Diving for more than an hour a day, every day of the year, however, makes such things more commonplace.

Sea Change presents a beautiful opportunity for the wider community of ocean lovers to learn from the unique approach taken by the Sea-Change team (this article gives a good sense of it), and to learn how to understand and observe the animals that surround us when we look beneath the surface of the inshore kelp forests. The project also has something to say about how science happens, and the vital connection between science and storytelling. Identifying animals is fun, but – as any veteran twitcher will tell you – the next level is understanding behaviour. This is a challenge I’m happy to take up.

Get a copy here, or directly from the Sea Change team.

Goose barnacles in motion

Ok, so there had to be a video. Here are some of the goose barnacles (Lepas testudinata) that I found on Noordhoek beach last month. Bear in mind that they are out of their natural habitat (which is sea water) and were struggling in the sun. (I did try to drag some of the kelp back to the sea, but the pieces were huge and high up on the sand.) This group of barnacles was quite frisky, and shows you what a raft of kelp colonised by goose barnacles might look like if you swam underneath it.

[youtube=”https://www.youtube.com/watch?v=eqm6ADYhyJw&w=540″]

For more on goose barnacles, visit this post.

Goose barnacles on the beach

A (lovely, rain-bringing) onshore wind left great rafts of kelp all over Noordhoek beach one weekend in mid May. Finding anything of substance on this beach is unusual; it’s on an exposed piece of coastline and all but the most robust objects are dashed to pieces before they arrive on the sand. Seeing all the washed up kelp also reminded me that frequenting the beaches inside False Bay, that are daily cleaned of washed up kelp by the City of Cape Town, is liable to give one a skewed idea of just how much kelp naturally washes up on the sand.

This time, there was kelp, and lots of it. Several of the pieces of kelp had been colonised by goose barnacles. There are several species of goose barnacle that occur off South Africa’s coast, but these ones are Lepas testudinata. They are incredibly strange looking animals, and some of them were still alive and writhing slowly in the drying sun.

In parts of the world (I’m looking at you, Iberian peninsula), goose barnacles are an expensive delicacy. I have nothing to say about that.

Lepas testudinata larvae most often attach to free-floating pieces of kelp (Ecklonia maxima) and plastic debris, which is why you have probably never seen these mesmerisingly gross-looking creatures while on a dive. In the picture below, you can see that they’re attached to the bottom of a kelp holdfast, where it would ordinarily attach to the rock. This shows that they attached after the kelp broke off.

A kelp holdfast encrusted with goose barnacles

Each barnacle is possessed of a long fleshy peduncle, or stalk, which attaches to the kelp holdfast, stipe or fronds. On the end of the peduncle is a carapace (shell) made up of five separate pieces. The large part of the barnacle on the end of the peduncle (what you’d think of as its body), covered by the carapace, is called the capitulum. The apparatus that the barnacle uses for feeding – essentially six pairs of hairy legs – reside inside the carapace, along with the mouth. There’s some more detail and a nice diagram at this link. If you are familiar with other kinds of barnacles – the volcano-shaped ones that live on rocks, ships, whales and piers for example, then most of this (except the peduncle) should sound familiar to you.

Research done around South Africa’s coast (published here) by Otto Whitehead, Aiden Biccard and Charles Griffiths, identified the marked preference of Lepas testudinata for attaching to kelp. The researchers surveyed a selection of beaches around South Africa’s coast, from the west coast of the Cape Peninsula up to northern KwaZulu Natal, between June and October 2009. When they found goose barnacles washed up, they recorded the species of barnacle, the type of material they were attached to, the dimensions of the object, and its location. They also estimated the number of barnacles in each colony they found.

Lepas testudinata was the species they found most commonly, of the six species in total that they identified along the area of coast that was surveyed. (There’s a nice picture of the six species in their paper, which I used to identify the ones I found.) This species of goose barnacle was found to prefer kelp, as mentioned, and also tended to colonise large objects compared to the other species (this could, of course, be because pieces of kelp are usually larger than items such as bits of plastic, glass, feathers, and shells that some other species prefer).

Lepas testudinata was the only species of goose barnacle that the researchers regularly found to form colonies comprising more than 1,000 individuals. It is also the only species of goose barnacle recorded by the survey that is only found in temperate (cooler) waters, which happens to be where kelp is found, too.

The researchers note that the goose barnacles of the Lepas testudinata species that they found on kelp seemed to have exceptionally long peduncles, some more than 25 centimetres long, and that this seems to differ from what has been previously known about them (which is that they have “short, spiny” peduncles). They suggest that perhaps the variety of Lepas testudinata that colonises kelp may even be a separate species from the one previously described (more research obviously required to ascertain this). You can see from my photographs that the peduncles of the washed up Noordhoek beach goose barnacle colonies are also quite long, some easily 20 centimetres in length.

Clusters of goose barnacles on a kelp stipe

They also found that the increasing prevalence of long-lasting and buoyant plastic marine debris and other anthropogenic objects around our coastline, which some species of goose barnacles preferentially attach to, gives these weird little creatures increased opportunities to form colonies, and to spread to new places. This is one of those interesting phenomena to keep in mind, as humans inexorably alter the environment. Some creatures will benefit in strange ways from warming oceans, and others will find new homes in the garbage we leave lying around.

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.

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.

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

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: More purple crayons

Hi divers

Weekend dive plans

No diving

There is little doubt in my mind that diving this weekend will be for the hardcore only. Both Saturday and Sunday will feature howling south easterly winds which will make for rough surface conditions. The forecast seems to imply wind strength capable of affecting both sides of the mountain so there will be very few places to hide.

But wait, there’s more

There are some windless days coming up next week. If you’re a lucky one available for weekday diving next week, let me know your availability and I’ll keep you in the loop regarding plans.

regards

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

Diving is addictive!

To subscribe to receive this newsletter by email, use the form on this page!

A Day on the Bay: Freedom Swim 2016

A day early in April was the date for the annual Freedom Swim, a 7.5 kilometre open ocean cold water swim from Murray’s Bay harbour on Robben Island to Big Bay near Blouberg. As we have in several previous years, we provided boat support for a swimmer.

This entails providing a straight course for the swimmer so as to minimise the distance swum, and keeping an eye on them to ensure that they don’t get too cold or show any other symptoms of hypothermia or distress. It requires communication with race control by radio, and a bit of boat and swimmer dodging in the early stages of the race when the water is thick with activity.

There was a 3.5 metre swell on the day, which made the ride out to the island a bit bumpy. As soon as we were in the shelter of the island, however, the sea was flattened as the swell diverted around the island. The water remained calm until we got quite close to shore, at which point the swell picked up. The final stretch from the rocks at Big Bay to the beach must have been very hairy for the swimmers!

Our swimmer, Maryna, swam in a wetsuit. She was part of the Lighthouse Swim relay team we supported last year. The water was relatively warm (13-16 degrees) clear at the island, and we could see kelp and quite far down into the sea. Great red streaks of water, probably an algae bloom, were filled with sea jellies (which stung Maryna, but she continued strongly). These were replaced by murky green water close to the shore, where the swell had lifted the sand particles into the water column.

It was a good day out, and always a pleasure to see Table Mountain in its majesty from the water.

Weekend dive plans

Free online first aid courses from DAN

Marine Life Identification with Georgina Jones

The Sea-Change book

For the kids

Virus information

Sea Change: Primal Joy and the Art of Underwater Tracking – Craig Foster & Ross Frylinck

Weekend dive plans

Kelp night

Camera housing

Weekend dive plans

Weekend dive plans

But wait, there’s more

Weekend dive plans