Newsletter: Warmer and warmer

Hi divers

Weekend dive plans

Friday: Shore diving at Long Beach at 10.00 am

Saturday: Launching from False Bay Yacht Club at 7.00 am for a double tank dive

The days are getting longer and the daytime temperatures are slowly creeping upwards… Well, on some days. Saturday looks like a better bet for False Bay with Hout Bay being an option on Sunday. The water colour off Dungeons has improved slightly today.

Tomorrow I am shore diving students at Long Beach at 10.00 am. On Saturday we will do an early False Bay double tank dive at 7.00 am. Let me know if you’d like to get wet.

 

DAFF octopus fishing gear
DAFF octopus fishing gear

Here’s a little bit of reading on the octopus fishery in False Bay (courtesy of Yvette!). This NSRI blog post, and the comments, are also required reading.

Coming up

As part of First Thursdays, you can attend the opening of the Birdlife Oceans of Life photographic exhibition at the South African Museum on the evening of Thursday 6 October. There’s information here (facebook) – this year’s exhibition includes a retrospective of the last few years’ best images.

Diversnight is on Saturday 7 November, so start charging your torches!

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!

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

A Day on the Bay: Freedom Swim 2016

Maryna and Table Mountain
Maryna and Table Mountain

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.

Be a marine citizen scientist (slash conservationist) in Cape Town

Here are a few ways for Capetonians to save the ocean. Some through direct action, and others through support for scientific research that enables policy makers and conservationists to make good decisions about which species and habitats need protection.

I’ll update this list as new projects are brought to my attention. If you know of an opportunity for ordinary citizens to make a difference for marine science and/or conservation, let me know and I’ll add it here.

Dolphin species distribution

Sea Search would like to map dolphin distribution with the help of citizen scientists (you), partly in order to anticipate what changes may occur in response to climate change. All you need to do is report dolphin sightings and a bit of supporting information via their facebook profile, twitter handle, or iSpot project page. You can read more about their research project here.

Sevengill cowshark sightings

This cowshark appears to have been tagged
This cowshark appears to have been tagged

The Spot the Sevengill Shark project has a facebook page where you can submit images of broadnose sevengill cowsharks taken in False Bay and surrounds. The unique markings on these sharks enable repeat identification from well-composed images. Information about the sex, general appearance and behaviour of these sharks is also useful. There’s some information about the research project here. This is also a great project to follow (on facebook) to keep up to date with the tagging studies that are currently being done on this population of sharks.

For a more global flavour, you can check out the Sevengill Shark Identification Project. It operates mostly in the San Diego area in the USA, but accepts sevengill cowshark sightings from locations around the world, including from South Africa. Their facebook page recently celebrated the first logged sighting from False Bay.

Great white sharks

If you spot a great white shark – while diving, paddling, swimming or surfing for example – please report it to Shark Spotters! This enables the general public to be alerted if necessary, and also provides valuable data for research about white sharks in False Bay and around the peninsula.

You can either report the sighting via the Shark Spotters website, or you can call or text +27 (0) 78 174 4244. Provide as much information as possible, obviously including the location where you saw the shark, and when. If you have a photo or video, that’s a bonus!

Sharks and rays

The ELMO (South African Elasmobranch Monitoring) project collects reports of elasmobranch (shark and ray) sightings along the South African coastline. For the avid beachcomber, their database includes egg cases. The data collected is available to any interested party for their own projects, and can assist conservationists and politicians to make good decisions in order to protect species that need it.

The ELMO website is full of excellent information, including identification guides for egg cases and elasmobranchs, and a handling guide for live animals (aimed at fishermen, not people who are grabby – don’t be like that). You can submit your sightings online.

You can also find ELMO on facebook and twitter.

iSpot

Upload photographs of the marine species you see to the iSpot, SAJellyWatch, or one of the Avian Demography Unit’s project pages. These observations are a help to researchers tracking species distribution – for example, as part of climate change and invasive species research.

More information can be found here.

 Poaching

If you see marine poaching activity in progress, please call to report it. The phone numbers you will need can be found here.

Newsletter: Think again

Hi divers

Weekend diving

No dives planned

Diving has been far from spectacular of late and the weekend looks marginal again. There is a wind window on Saturday morning, but it is under pressure from a chance of rain, and a 3 metre swell with a 15 second period. Sunday looks a little too windy (again).

I don’t think that it’s going to be worthwhile to plan anything. If you choose to dive on Saturday, take your time and check out a few different spots before you decide where to get in.

Balloon offshore of Hout Bay
Balloon offshore of Hout Bay

If you’ve ever considered releasing balloons into the air at a party (or a wedding) because it looks pretty, please think again. We found this balloon far offshore near Tafelberg Reef outside Hout Bay. Unsuspecting marine life could have eaten it, or gotten tangled in the ribbon tied to it.

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: Rescue Warriors

Rescue Warriors: The US Coastguard, America’s Forgotten Heroes – David Helvarg

Rescue Warriors
Rescue Warriors

Much of this book reads like one of the Reader’s Digest “drama in real life” stories that I used to devour from the magazines that my granny brought us when she came to visit. (She’d also bring a packet of Sparkles or Cadbury Eclairs.)

Journalist, activist and former war correspondent David Helvarg (who also wrote Saved by the Sea and 50 Ways to Save the Ocean) spent two years embedded with various branches of the US Coastguard in order to experience their work.

I had naively thought that the US Coastguard, despite being funded by the government, and despite their website having a .mil for military domain name, was just a slightly larger, more financially flush version of South Africa’s National Sea Rescue Institute (NSRI).

I was wrong. The mandate of the US Coastguard is to enforce maritime law (this is its primary difference from the NSRI) as well as to perform search and rescue operations. Viewers of the Deadliest Catch series will be familiar with the rescue work of the Coastguard in extremely challenging conditions. As a result of its law-enforcement mission, the Coastguard uses weapons and provides a lot more military-style training than you’d expect from a pure rescue operation. The Coastguard falls under the department of homeland security and operates cutters (with guns), icebreakers, small boats, helicopters, and other aircraft.

Helvarg’s conservationist tendencies shine through in several parts of Rescue Warriors, and he does not shy away from confronting the aspects of the Coastguard that he finds problematic. His contention is that the Coastguard receives far less publicity than it deserves. This book goes some way towards bringing attention to the individuals who have saved tens of thousands of people during Hurricane Katrina, via water evacuation during the September 11 attacks, and in countless other less well-known emergency situations.

This is a gripping read which I thoroughly enjoyed. I was amazed by the amount of funding and equipment that the Coastguard has at its disposal compared to the NSRI, even though the organisation is actually badly underfunded, especially when considered relative to the rest of the United States war machine. I was also impressed by the egalitarian approach that draws many women to join the Coastguard and enables them to rise in its ranks. The Coastguard made all its jobs available to women in 1977, something which other branches of the military have not yet done.

You can get a copy of the book here (South Africa), here or here.

Bookshelf: The Man Who Ate His Boots

The Man Who Ate His Boots: The Tragic History of the Search for the Northwest Passage – Anthony Brandt

The Man Who Ate His Boots
The Man Who Ate His Boots

The Northwest Passage  is a sea route (routes, actually) running between Canada and Greenland, across the top of the North American continent through the Canadian Arctic Archipelago, and through the Bering Sea between Alaska and Russia. At its end is the Far East, for hundreds of years the destination of the thousands of sea voyages that made their way around the Cape of Good Hope, and later through the Suez Canal. Its existence was an enormously appealing idea to Europeans, because if the east could be reached by sailing along the top of the world, great savings of sailing time and expense would result.

For a long time the existence of the Northwest Passage was merely a hypothesis, and in the 1800s the British expended vast quantities of energy exploring the Canadian Arctic in search of a sea route. The passage was first traversed in 1850-54 by Robert McClure, by ship and sledge. Roald Amundsen traversed it entirely by ship in 1903-1906.  Until this century, the route was not navigable for most of the year owing to the presence of sea ice. Now, thanks (?) to climate change, there is far less ice to contend with.

Sir John Franklin was one of Britain’s most eminent Arctic explorers. He made several trips to the Arctic in search of the Northwest Passage. His final expedition, starting in 1845, ended in the disappearance of his two ships (HMS Erebus and HMS Terror), Franklin himself, and all 128 of the men with him.

The story of his expedition, and the searches for evidence of its fate (upwards of 30 expeditions were mounted to look for him), and the subsequent discovery of what had happened (no spoilers here – it was awful) is related in gripping detail in The Man Who Ate His Boots. Brandt also provides ample historical context, describing prior expeditions which serve to illuminate the British motivations behind their exploration of the Canadian Arctic.

There was a curious mixture of stoic heroism and wild arrogance at work during this period of British history. The rigors endured by early Arctic explorers cannot be overstated – the environment is almost entirely hostile to human survival. The British did not believe that there was anything to be learned from the Inuit, indigenous people who live widely spread across the area, and suffered as a result. As one of the Inuit pointed out when the awful lengths Franklin’s men had gone to in order to try to survive were revealed, his people “know how to starve.”

There is a strong thread throughout this book relating to the colonial attitude towards colonised peoples. A belief prevailed in Britain that, equipped with a shotgun and a good pair of shoes, an Englishman could survive anywhere, and that his Christian piety would serve to protect him and speed his endeavours. (On one of Franklin’s earlier expeditions, which was a complete fiasco largely owing to poor planning, the British officers survived whereas the mixed-race local fur traders – who were doing all the manual work and carrying the supplies – perished. This was attributed to the protective influence of the Christian beliefs of the British men.) It was further reckoned that there was nothing to be gained from studying the techinques of the Inuit. Eyewitness accounts from Inuit turned out to hold the key to the fate of Franklin’s party, although their account was not believed initially (they were dismissed as habitually lying “savages”).

Last year, one of Franklin’s ships, HMS Erebus, was discovered by Canadian archaeologists in Queen Maud gulf, where it sank after being trapped in the ice. They are still studying it (the area is only accessible a few months each summer), and I am watching this story with intense interest. There’s more on the discovery at National Geographic.

You can read reviews of The Man Who Ate His Boots at the New York Times, Washington Post, and The Guardian. If you enjoyed Endurance, then I recommend you investigate this book. In light of the developing findings of the excavation of HMS Erebus, the material has refreshed relevance today.

Get the book here (South Africa), here or here.

Want more Arctic? Check out True North. There’s also this article on what lives under the ice, and this one on what happens on top of it!

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.

Bookshelf: SEALAB

SEALAB – Ben Hellwarth

Sealab
Sealab

In the 1960s the US Navy developed three undersea habitats, in order to experiment with saturation diving and to explore the possibility of humans living on the ocean floor. Of necessity, any group of people engaged in this pursuit would be separated from life on the surface, in some cases by days or weeks of decompression obligations. SEALAB I, II and II were progressively deeper and more complex habitats. Developing them was a technical challenge that led to many advances that we benefit from today. The experiments also provided an opportunity to study the psychological and physiological effects of isolation, and of long periods of breathing mixed gases under pressure.

The SEALAB experiments took place during the same era as the efforts by NASA to put a person on the moon, and received far less attention. Jacques Cousteau was interested in the project, and himself experimented with underwater habitats called ConShelf I, II and II. These habitats were far better publicised than the US Navy’s efforts, even though their aims were more modest.

Author Ben Hellwarth does not confine his attention to the habitats, but also provides a fairly detailed history of decompression theory and diving history. Like Neutral BuoyancySEALAB might provide a relatively painless introduction to dive theory for Divemaster candidates. In fact, this book reads like a thriller at times! Some photographs from the SEALAB projects are available on the US Navy website, and in this slideshow. To our modern eyes, the clunky and primitive appearance of some of the gear is a reminder of how pioneering the now 60 year old work to allow humans to live and work in the sea was.

If you’re interested in the history of saturation diving, I recommend this article, which covers some of the ground that Hellwarth does in SEALAB. If you want to see it in action, check out Pioneer (fictional movie based on actual events) or the series Deep Sea SalvageYou should also check out this article by Hellwarth, entitled The Other Final Frontierand this podcast/radio show. If you are EXTREMELY interested in this subject but don’t want to read a book, try out this hour-long lecture video by Ben Hellwarth.

Experiments with underwater habitats are ongoing.

Get a copy of SEALAB here (South Africa) otherwise here or here.

Movie: Pioneer

Pioneer
Pioneer

In the late 1960s, massive oil and gas deposits were discovered in the North Sea, transforming Norway into one of Europe’s wealthiest nations. Pioneer depicts some of the early, feverish oil-related activity during the 1970s. The Norwegians needed to build a pipeline to bring the oil to land from depths of up to 500 metres. Lacking the technical expertise – particularly with respect to the underwater work that must be done by saturation divers – they bring in American assistance.

Norwegian divers (so-called “pioneer divers“) dived to depths that are now considered unsafe, even for saturation divers, and a group of them have sued the Norwegian government for compensation for damage incurred during their careers in the early days of the oil boom. Pioneer tells the story of Petter, a Norwegian diver who is present during a diving accident and embarks on a search for the cause, believing that human error was involved and that someone must take responsibility.

I enjoyed the film enormously, but most of the reviews I have read found it a bit turgid. The milieu is evoked with incredible attention to detail, including the awful 1970s moustaches and unfortunate hairstyles. The dialogue is in both Norwegian (subtitled) and English. It is beautifully filmed, with clever camera work mimicking the limited view that the divers have while working underwater and in the saturation chamber. The underwater scenes are excellent, reminiscent of those in For Your Eyes Only (I’m joking – they genuinely are extremely convincing and quite magnificent). Tension is maintained throughout, and the action takes places over a fairly short period of time.

You can get the DVD here (South Africa), here or here.