Sharks! MOOC videos (part II)

Here is a selection of the videos for weeks three and four of the recent Sharks! MOOC hosted on edX. You can find weeks one and two here. All the videos are available on youtube if you’re really interested – you can check out the channel containing all this year’s videos, or a giant playlist containing all the videos from the 2015 iteration of the course.

Dark shyshark on the sand at Long Beach
Dark shyshark on the sand at Long Beach

Week 3: Thinking like a Shark – Brains and Behavior

Introduction – thinking like a shark

General organisation of the nervous system

Brain regions overview

Brain size

Prey localisation

Seeing underwater

Eyes for deep water

Lateral line system and Ampullae of Lorenzini

Electric snouts

Group hunting – broadnose sevengill sharks – an interview with Dave Ebert on research he did decades ago on the sevengill cowsharks of Millers Point

Week 4: Sharks in the World – Human Interactions, Ecology, and Conservation

Introduction – sharks in the world

What sharks eat

Food webs

What eats sharks?

Deep water communities

Shark struck

The problem with shark nets

Why are aquariums important?

Husbandry

Industrial fishing

The art of Ray Troll

Sawfish DNA

Bookshelf: Sharks

Sharks – Michael Muller

Sharks - Michael Muller
Sharks – Michael Muller

Michael Muller is probably best known for his work as a portrait photographer (focusing on celebrity subjects). He also has, it turns out, a longstanding fascination with sharks. While working as a commercial photographer for Speedo, Muller designed and built a waterproof housing for his 1,200 watt studio strobe lights. Incredibly, he takes these lights underwater – assisted by two to six divers and at least one person on the boat – and has spent a couple of years travelling the world to photograph sharks. 

The resulting photos, of bull, tiger, white, hammerhead and several other species of shark, are fascinating. They are unlike any shark photographs I have seen before, with a cinematic quality and the intensely unusual property – for most underwater photos – of being filled with light. Sharks swim out of bright white light towards the camera, and many of the images are deliberately over-exposed, heightening the dramatic effect. The jump from having professional-quality camera strobes to essentially a full studio lighting rig underwater is enormous, and the results are visually stunning.

Muller’s pictures, to me, emphasise the otherness of sharks. They do not look like cuddly, approachable (although in many cases Muller went very, very close to his subjects) or easy to fathom animals. I like this. Some approaches to conservation try to emphasise how sharks do not intend harm, and attempt to demystify them, with the aim of making them comprehensible and thus worthy of protection. The genre of photography that shows divers and sharks apparently harmoniously inhabiting the watery realm is invariably more about the humans than it is about sharks. That criticism cannot be levelled at these images.

The final sections of the book contain a species guide, essays about shark ecology and conservation, and technical information about the photographic equipment and shot set up. Some of the shark biology and conservation information was contributed by Capetonian shark conservation biologist Alison Kock, who put False Bay’s white sharks on the scientific map.

You can preview some of the images from the book here, and an interview with Muller here. The Washington Post and Wired have image-rich features on this project, too.

This is an enormous book (standard Taschen fare). You’re going to need a bigger bookshelf (a joke about this book which has no doubt been made forty times – I apologise). You can get a copy here (South Africa), here or here.

If you’re a fan of shark photography books, you could also check out Shark and (more substantially) Great White and Eminent Grey.

Bookshelf: Shark

Shark: Fear and Beauty – Jean-Marie Ghislain

Shark
Shark

Jean-Marie Ghislain is a Belgian photographer who has had the privilege to visit far flung places on earth, and to dive with charismatic megafauna of all descriptions. This book is a beautiful collection of images of all kinds of sharks, taken from South Africa to Guadaloupe. The images were taken using natural light only. The level of detail in some of the photographs is almost comparable to the pictures in Beautiful Whale.

There are several images of our local broadnose sevengill cowsharks, and I have enjoyed being able to show them to friends who aren’t familiar with these sharks (my own photos are pretty poor)!

The photos are entirely black and white, which lends a solemnity and luminosity to the sharks’ bodies that is very beautiful. There is almost no text, and one doesn’t miss it. At the back of the book, a mosaic of the photos presents information on the type of shark, the camera settings and a few sentences on the taking of or the motivation for the picture.

The photographs reveal that author is of the school of thought that advocates touching sharks, and some of the photographs even depict illegal dives outside the cage with great white sharks at Isla Guadalupe. This is a great pity and should not be mistaken for an activity that has any conservation benefits for sharks whatsoever.

You can see a couple of the photos from the book, and some information about the author, in this article from the Telegraph.

Get a copy of the book here if you’re in South Africa, otherwise here or here.

Bookshelf: Bay Between the Mountains

Bay Between the Mountains – Arderne Tredgold

Bay Between the Mountains
Bay Between the Mountains

I have an obsession with False Bay; our lives revolve around its moods, and we spend a lot of time around, under or on the waters of the bay. Tony’s business activities are affected by conditions in False Bay, but we also pay attention to the bay because it’s interesting to us. Life lived according to the rhythms of this beautiful body of water to me feels far more authentic and significant than a life lived according to the rhythms of my alarm clock and office hours.

I’ve been reading some things about the history of False Bay, and this book seemed to be the place to start. It was published in 1985 and is written a bit like a Lawrence G. Green book, but with (I think) slightly more attention to detail and accurate sourcing. There is a list of references at the back, but a lot of it is oral history that Tredgold gleaned from interviewing (then) elderly inhabitants of the settlements on the bay’s edge.

It’s essentially a colonial history of False Bay, with a view that history only started when the Dutch arrived in the Cape. There’s a brief section on the very early geological history of the bay, but not enough for my liking, and I would have liked to know more about the Strandlopers who frequented the area before the Dutch and British started stampeding around and shooting cannonballs at each other.

Tredgold devotes most of his attention to the history of Simon’s Town, Fish Hoek, Kalk Bay, St James, Gordon’s Bay and the Strand. False Bay was a very significant fishing resource right from the time of early Dutch settlement at the Cape, and up until about 1900 a significant amount of whaling was done in the bay, most of it from Kalk Bay. By about 1900 it wasn’t economically viable (too few whales) to run a whaling business inside False Bay any more. I found this remarkably sad – that already over 100 years ago humans had practically exhausted some of the marine resources available to them – but also heartening, given the generous numbers of whales that visit False Bay between June and November in the present day.

Despite the importance of the False Bay fishing opportunities, the focus in this book is on human history. The natural history of the bay is only mentioned insofar as it illuminates the activities of the humans in the settlements on its fringes. There are only two or three mentions of the False Bay white shark population: one is made as part of an account of Simon van der Stel’s visit to Seal Island in 1679. The men caught fish around the island, but sharks took many of them before they could be landed. Little did he know what a massive economic powerhouse the False Bay cage diving industry would be over 300 years later!

There are some interesting stories of some of the many wrecks in False Bay, but for more detail on the human aspect of those I’d suggest the Michael Walker books Hard Aground, Forgotten Shipwrecks of the Western Cape and Shipwrecks of the Far South.

This isn’t an easy book to get hold of – it’s out of print – but you can probably find a copy on Bid or Buy, which is where I found mine.

Bookshelf: Demon Fish

Demon Fish – Juliet Eilperin

Demon Fish
Demon Fish

Reading this so close to Thomas Peschak’s book Sharks and People made for an interesting juxtaposition of two books that are both concerned with similar subjects. Peschak makes his interest in the relationship between humans and sharks explicit in the title of his book, and goes on to explore it in a primarily visual manner.

Juliet Eilperin is an environmental reporter for the Washington Post, and despite the singular focus of its title, her concern in Demon Fish seems to be similar to Peschak’s: sharks and people. I’m not sure if this is because, as an outsider to the world of shark research, shark diving, and shark conservation she had couldn’t but focus on the human element of sharks’ existence, or whether it was a deliberate tactic.

Whatever the reason for the book’s focus, this is actually a very good introductory volume to give to someone who doesn’t know much about sharks, and who may not understand the conservation concerns surrounding them. This is not a scientific volume, and may disappoint shark fanatics who purchase it expecting to be enlightened on shark biology. Eilperin provides some facts about a few of the better known (read: more charismatic) species of shark, but the bulk of the book comprises interviews with shark scientists (such as Neil Hammerschlag, Alison Kock, Sarah Fowler, and Barbara Block), fishermen, activists (including seriously legitimate ones like Sonja Fordham), and Asian players in the shark fin trade.

Eilperin dives with sharks in the Bahamas, eats shark fin soup, and travels the world putting together a picture of sharks’ role in local economies – the lucrative fin trade, whale shark tourism in Belize, cage diving in Gansbaai, South Africa – and in human culture. After visiting a shark caller in Papua New Guinea, she traces the history of the 1916 shark attacks along the North Atlantic coast of the USA that did so much to shape our modern perception of sharks, and interviews Jaws author Peter Benchley’s wife (he is deceased). An analysis of efforts to mitigate human shark interactions, lead her to Cape Town’s Shark Spotters program, the Shark Shield device (formerly Shark POD) and the indiscriminate shark mitigation program of the KZN Sharks Board. The acknowledgements at the end of the book read like a who’s who of shark researchers and conservationists (including the venerable Eugenie Clark). Ms Eilperin’s research was thorough!

The book seems to have been reprinted as Sharks: Travels Through a Hidden World in the United Kingdom. I prefer this title, as Demon Fish seems a little bit exploitative and sensational, particularly given the fairly benign nature of the book’s contents. There is a detailed and fascinating review of Demon Fish at the London Review of Books, an interview with Eilperin here, and a very short interview with her here.

Buy the book here if you’re in South Africa, and here if you’re not. If you want to read it on your Kindle, go here.

Christmas gift guide 2013

Ok so this is a bit late, and if you haven’t done your Christmas, Hannukah and Festivus shopping yet, shame on you. Or just shame. Most of these ideas don’t entail going to a mall and having your personal space invaded by ten thousand hormonal adolescents. You can order online, or make a phone call or two. Get going!

Christmas at Sandy Cove
Christmas at Sandy Cove

Books

For the reader, you could check out our book reviews, arranged by topic:

I’m not going to suggest a magazine subscription – I’ve let most of ours lapse as we seem to have entered a long dark teatime of the soul when it comes to South African diving magazines. If the quality picks up, they’ll be back on the gift list at the end of 2014.

Dive gear

Check out What’s in My Dive Bag for some ideas… You can contact Andre for most of these:

Make sure you know the returns/exchanges policy of wherever you make your purchases. Some places can be difficult, and if the mask doesn’t fit it’s no good at all!

For lady divers

For the diving lady in your life (or your man friend with too much hair), what about some rich hair conditioner to apply before going in the water? Suggestions here. A pack of cheap, soft fabric elasticated hairbands is a good stocking filler.

Some high SPF, waterproof sunscreen, or a nice hooded towel for grown ups (available in one or two of the surf shops in Muizenberg) would also not go amiss.

Experiences

Don’t forget to add a memory card for the lucky recipient’s camera if you plan to gift any of these! Contact Tony for prices.

For the non diver, you could inspire a love for our oceans with one of these:

For those who need (or like) to relax

Memberships

Wall art

Clip Clop designs and prints beautiful tide charts for Cape Town and Durban and moon phase charts for the year. You can order online or usually find them at Exclusive Books.

My underwater alphabet is available for R200 in A1 size, fully laminated. Shout if you want a copy.

If you take your own photos, you could print and frame a couple, or experiment with stretched canvas prints if that’s your thing. A digital photo frame pre-loaded with underwater images is also a lovely gift for a diving friend.

Donations

For the person who has everything, or because you’re feeling grateful:

Shark incident map

I love maps (our home is full of them) and have more than a passing interest in sharks. I’ve fooled around with the meeting point of those two subjects during the course of a class I took called Maps and the Geospatial Revolution – you can see the results here. I was therefore delighted and intrigued when Mike (whose blog you should subscribe to – do it now!) posted a link to an ArcGIS map of shark incidents, worldwide.

His take on it was that it shows there is no correlation between shark bites on humans, and locations where sharks are fed or lured with food as part of eco-tourism, suggesting that (as the science also suggests) sharks are not turned into “man eaters” by nearby baited dive or cage diving operations.

Shark incidents worldwide
Shark incidents worldwide

Check out the map here. Click on the Legend text in the left hand sidebar to see what the different coloured dots mean. As it stands the map is not terribly helpful for analysis because it’s hard to discern the different colours of the dots – the types of incidents range in severity. The dots are also clustered most around the most areas that are most heavily populated with sharks and water-using humans. This mostly tells you about population levels, and not so much about sharks. It’s impossible to see any kind of trend because the data is from 1982 to 2012. Conclusions (or hypotheses) such as Mike’s, that are time-independent, are quite appropriate, however.

There’s more information on the source data for the ocean map here (not for the shark incident data – I’d surmise that it came from here or here).

Thanks Mike!

Newsletter: View from the top

Hi divers

Weekend plans

The weekend forecast is for rain on Saturday and partly cloudy weather on Sunday. I am sensitive to water and would prefer not to dive in the rain so our plan is to launch on Sunday, heading to Outer Photographer’s Reef and Phoenix Shoal, launching from False Bay Yacht Club 10 am and 12 am.

Summer is coming but we are not quite there yet so a jacket was still required on the boat today. Despite the south easter that has blown the past week, False Bay is surprisingly clean. I took a trip out today and the further out in the Bay I went the cleaner it got. Estimates at Seal Island from the cage divers was 12 metre visibility.

View of Fish Hoek from Contour Road
View of Fish Hoek from Contour Road

Upcoming events

November 7th is Diversnight International, sign up here. It is an international event with the aim of having as many divers in the water as possible at 8.13pm. We will confirm the dive site once I’ve checked tides and got permission if necessary. There will be cake.

Our long planned Red Sea trip is going ahead next week; we leave on Thursday next week. There will most likely not be a newsletter for a week or two. While we’re away (or technically on our way back), the ScubaPro Day takes place at False Bay Yacht Club. Discounted boat dives and the chance to try some dive gear (tips on that here) – the participating dive charters will take bookings directly.

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, click here or use the form on this page!

Shark cage diving in False Bay (some photos)

Sunrise
Sunrise

We took a trip to Seal Island in False Bay to see the white sharks there, in late July. I’ve already posted my video footage from the cage. We also took some photos – mostly Tony. The trip entailed getting up very early, so as to be at Seal Island by sunrise. Once there, we scanned the horizon for predatory behaviour: typically, the white sharks here attack the juvenile seals from below, often launching their entire bodies out of the water in an explosive burst of energy.

Video still of one of the great white sharks we saw
Video still of one of the great white sharks we saw

It was a very rough day with a swell of about five metres, and from speaking to people who come to Seal Island often, I gather that the sharks tend to be less active on days like this. Their accuracy in striking the seals is reduced by the movement of the water column. Nonetheless we did see a couple of predation events, with the characteristic flock of seabirds waiting to pick up any leftovers, and the slick of “oily seal juices” (to quote Gary!) left on the surface afterwards. The sharks are so quick that if you’re looking the wrong way, it’ll all be over by the time you turn around.

After some time watching natural behaviour, a decoy (surprisingly realistic looking, made to resemble a young seal) is towed behind the boat, to try and elicit breaching behaviour from the sharks. We didn’t have much luck here, again probably because of the surgy seas, but one shark made a few investigations of the decoy before losing interest.

White shark next to the boat
White shark next to the boat

Finally sharks are attracted to the boat using chum, which is mostly fish oils and other fishy substances. A tuna head was splashed in the water near the boat, and when sharks came to investigate it they were visible from the cage. While in the cage we breathed off scuba regulators, which was great. Trying to breath-hold or snorkel while the sea was so choppy would have been next to impossible. The sound of the bubbles emanating from our regulators didn’t bother the sharks at all.

Bernita and some stormy seas
Bernita and some stormy seas

We spent about twenty minutes (or maybe more – I am not sure) in the cage, some of it just waiting for action, and some of it with our full attention focused on the enormous fish swimming by and looking at us with its black eyes. Five minutes of looking at a great white shark, eye to eye, gives sudden perspective on life and the natural world. I’ll recommend this experience to anyone who will listen!

 

Newsletter: Mellow and mild

Hi divers

Mellow and mild aptly describes the weather for the weekend. Day time temperatures of around 17 degrees celcius, water temperatures of around 14 degrees and viz of 5-6 metres or as Facebook will have you believe, anywhere between 3 and 12 metres… There is not much swell, very little wind and more sun than clouds (in the forecast) so the diving should be good.

This week’s dives

We spent some time in the pool (the visibility was good) and yesterday we had 5 metre viz at Long Beach. The bay has patches of clean and dirty water and the cage diving and whale watching boats report clean and dirty water scattered around the bay. This is most likely the rainwater runoff that has not moved too far as there has not been all that much wind. The fishermen report very clean water south of Miller’s Point.

Weekend dives

I have a lot of student dives to get through this weekend for both Open Water and Advanced courses so if you are keen to dive we can slot you in. We are launching tomorrow, Saturday and Sunday and will only decide the sites once out on the bay and we can see where the water is clean. Text me or reply to this email to book a spot.

The rudder of the Brunswick
The rudder of the Brunswick

I’ve had students with me all week so there are no underwater photos this week (no camera allowed), but Clare tracked down the rudder of the Brunswick at the Slave Lodge in town – there’s a photo of it above. It’s huge!

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, click here or use the form on this page!