Newsletter: Making a difference

Hi divers

Weekend dive plans

Monday (public holiday): Leaving from  Simons Town at 9.30am and 12.00pm for Atlantis and Photographer’s Reef

We are in  a week long period of practically windless days, not quite winter temperatures and not too much of the dreaded, huge winter swells. You could choose to dive on any of the three days this weekend, or all of them, and I have picked Monday. We will launch from Simons Town at 9.30am and 12.00pm for Atlantis and Photographer’s Reef. Let me know if you’re keen to get out on (and in) False Bay.

Brydes whale showing his head
Brydes whale showing his head

Whale entanglement

It’s been a horrible week. A beautiful Brydes whale became entangled in the ropes of the experimental octopus fishery in False Bay, and drowned. Read about it here (there are some disturbing photos, so take care). In response, there’s a petition to end octopus fishing in False Bay – please sign it.

Can I also encourage you to amplify this issue outside of your usual social networks, who are probably ocean-loving people or friends of ocean lovers, and know about this already. Write an email or call the Department of Environmental Affairs, contact the provincial government, talk to your elected representatives, write to the newspaper. There are some other contact details to be found in one of the links we provided in this newsletter from 2014 that may or may not be useful – sadly this is not a new issue at all.

Beach cleanups

There’s a beach clean up in Cape Town practically every weekend, and it’s fantastic. To find out when they are, follow The Beach Co-Op (facebook / website), and Cape Town Beach Cleanup (facebook / website) to start with. Luckily South Africans are used to doing things themselves, and while the amount of trash recovered is eye-watering, it’s wonderful to see how many people are getting involved with looking after their environment.

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: Octopus

Octopus: The Ocean’s Intelligent Invertebrate – Jennifer Mather, Roland Anderson & James Wood

I think I said I was done with reading about octopus for now, but I wasn’t. I found this book on my Kindle, obscured by more recent purchases, and decided to continue my cephalopod streak. This book distinguishes itself with a raft of beautiful, detailed photographs, and for this reason I’d advise you to try and get hold of a hard copy – pictures on e-readers are terribly unpredictable.

Octopus
Octopus

The authors of this volume are marine biologists, one of whom worked at the Seattle Aquarium. Their focus here is very much on the natural history of the octopus, with each stage of its life history explained in some detail. Their approach is noticeably different from, but complementary to, that of Peter Godfrey-Smith’s in Other MindsGodfrey-Smith is largely concerned with considering octopus cognition from various angles, but in this book the authors are as concerned with the physical properties of the octopus as they are with its congnitive abilities.

You could also quite happily read this book in tandem with Sy Montgomery’s The Soul of an Octopus, which is largely written from the perspective of a volunteer aquarist. Mather et al’s Octopus fills in the scientific insights obtained from studying cephalopods in public aquaria, while Montgomery focuses more on interacting with the animals in a non-scientific context.

Most of the cephalopods used as detailed examples in this book are found only in US and Caribbean waters. The giant Pacific octopus features strongly, but it is hard to remain unmoved by an octopus that can weigh 45 kilograms when fully grown. The behaviour and broad aspects of their life history, however, seem to overlap with what is known about the octopus species we usually see while diving in Cape Town (generally the common octopus, Octopus vulgaris).

There are excellent references at the back of the book, for those who haven’t had enough of cephalopods yet and want to learn more. There is also a chapter on keeping octopus in captivity in a home aquarium, if you’re that way inclined (rather please don’t).

Get a copy here (South Africa), here or here.

Bookshelf: Other Minds

Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness – Peter Godfrey-Smith

THIS is the octopus book you have been waiting for all your life. Philosopher of science (and, importantly, scuba diver) Peter Godfrey-Smith traces the origins of intelligence through the tree of life, pausing at length on the cephalopods. These animals – cuttlefish, octopus, squid – stand out as exceptionally intelligent among animals, but only live for a year or two, the females expiring after they finish nurturing their first and only clutch of eggs (this is called semelparity). Both they and the males undergo a brief and catastrophic period of senescence, during which time they lose limbs, lose pigmentation, and their cognitive functions appear to be in sharp decline. (As an aside, I think that this cuttlefish may have been experiencing this very late-life decline.) Why, speaking evolutionarily, invest the energy required to develop such a complex brain, if its owner is going to live for such a short time?

Other Minds
Other Minds

This is the ultimate question that Godfrey-Smith grapples with. Prior to arriving here, he leads us on wonderful explorations of octopus physiology, the origins of life, and the nature of intelligence. Refreshingly, he takes a nuanced view of intelligence in cephalopods and resists the ever-present temptation to anthropomorphise these fascinating creatures. He points out, for example, that it is easy to mistake dexterity – eight arms and all – for smarts. I read this book while recuperating from a head injury whose degree of seriousness was not yet clear at the time of reading (it was mild, and I’m fine now). This uncertainty as to the state of my own brain made my reading of the sections on intelligence and the nature of minds somewhat poignant. The octopus brain is distributed throughout its body, with neurons in its legs as well as in places you’d be more likely to look for them.

Godfrey-Smith commences this book with a description of giant cuttlefish (the same corgi-sized beings we read about here), and this cements my desire to one day meet such a creature. My favourite chapter, however, deals with how cephalopods change colour. The complexity of this process is incredible, and not yet fully understood. In particular, it seems that they cannot see in colour, and yet they perform feats of camouflage that would seem to be impossible without knowing what colour and pattern to aim for.

The book is beautifully, lyrically written with a gentleness and compassion that I think comes from Godfrey-Smith’s own extensive observation of cephalopods in their natural habitat. He returns compulsively to Octopolis, the first octopus “city” discovered off the coast of Australia. I’ll leave you with this quote:

The chemistry of life is an aquatic chemistry. We can get by on land only by carrying a huge amount of salt water around with us.

You can find a comprehensive list of reviews and interviews on the author’s website. There’s a fetching giant cuttlefish picture in this article from The Guardian. If you are in South Africa, get a copy of the book here. If in the US, here, and for the UK go here.

For an equally awe-struck but completely different take on octopus, written largely from the perspective of an aquarium volunteer, you could also check out Sy Montgomery’s The Soul of an Octopus.

Article: Quartz on octopus cities

I’ve just finished reading another book about octopus (yet to be shared here), and the author talks at length about an octopus “city” off the coast of Australia, discovered in 2009 and dubbed Octopolis. Another, similar location, named Octlantis, has since been found, and scientists have recently published their research on these unusual places. Octopus are not social creatures – at least, they were not thought to be until these two locations, where up to 16 octopus live in close quarters and exhibit complex social behaviours, were discovered.

Octopus at Long Beach
Octopus in his hole at Long Beach. The reddish brown is an angry colour.

Team leader, marine biologist Professor David Scheel, believes that…

… octopus behavior probably hasn’t changed in [the last decade]. Rather, humans’ ability to observe the behavior has. Today more divers are in the water with cameras and better technology to quickly communicate findings amongst divers and scientists.

Once again, the potential for citizen scientists to make discoveries of this nature is highlighted.

Read about the discoveries here. This article, from Citylab, has a map of the most recently discovered octopus aggregation site.

Shrimp news from False Bay

The University of Cape Town has announced that a further three new species of shrimp, all spotted close to shore near Millers Point in False Bay, have been described and named. All three belong to the same genus (Heteromysis), and look similar, with pale bodies marked by red spots and stripes. One of these new (to science) species lives inside octopus dens, and another lives inside the shell of certain types of hermit crab. These three shrimps join the stargazer shrimp that was discovered by and named for Guido Zsilavecz, citizen scientist and author of several books on False Bay’s marine wildlife.

Two of the new species were discovered by local film maker Craig Foster, founder of the Sea-Change project about which we read last week. These types of discoveries are very exciting and should be a great inspiration and encouragement to divers and other water users. Time in the water is rewarded. If you can’t identify something, send an email with its photo to SURG. It is possible to make significant contributions to science while holding down an entirely non-scientific day job!

Read all about the new shrimps here.

Article: The Atlantic on booming cephalopod populations

Let’s not quit our contemplation of the remarkable octopus just yet. For The Atlantic, the wonderful Ed Yong reports on a long-term (since the 1960s) trend of increasing cephalopod populations in the world’s oceans. Cephalopods are octopus, squid, and cuttlefish. The first paragraph of Yong’s article describes cuttlefish in Australian waters that are “the size and weight of a corgi”. I’m hooked (and slightly alarmed).

Octopus at Long Beach
Octopus at Long Beach

Scientists have found that, while there are short-term fluctuations, the overall trend in all kinds of cephalopod populations is up. The populations for which data was collected – largely from fisheries – live in all parts of the ocean, in both hemispheres, suggesting that a global phenomenon is affecting their breeding and survival success rates. Climate change and our overfishing of the ocean’s other inhabitants, as Yong points out, are obvious potential candidates here.

This issue is particularly relevant given the presence of an octopus fishery in False Bay, but unfortunately no one knows how successful that fishery has been (and I don’t buy anecdotal evidence on this – give me data).

Read the full article here.

Bookshelf: The Soul of an Octopus

The Soul of an Octopus: A Surprising Exploration Into the Wonder of Consciousness – Sy Montgomery

The Soul of an Octopus
The Soul of an Octopus

Naturalist and author Sy Montgomery delves deep into the life and times of octopus. The intelligence of these animals is relatively well known, but in The Soul of an Octopus Montgomery chronicles what might be called the “personalities” of several animals that she interacts with at Boston’s New England Aquarium, other aquaria, and reefs in the wild. The idea of an animal as apparently simple as an octopus having a personality may seem to be dangerously renegade. But, as we’ve seen, it may be an idea whose time has come. If you’re interested in this, Carl Safina’s Beyond Words is a good place to go after this book.

In addition to being a love letter to the octopus she meets, Montgomery’s book is a chronicle of the importance of aquariums and the people who work at aquariums: volunteers, in particular. This aspect of the book specially moved me, as I could identify with the ways in which the author and her friends at the aquarium were enriched and changed by their time as volunteers.

The Soul of an Octopus is thus more a speculative meditation and a memoir than a scientific treatise on cephalopods. I loved this book and recommend it to readers whose expectations regarding its content are calibrated appropriately. For a sample of Sy Montgomery’s writing about octopus, this article from Orion magazine is excellent. You could also read The Guardian‘s review.

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

Just want to look at octopus? You could look at this one pretending to be a piece of kelp, this tiny baby one, this one in the warm, clear waters of southern Mozambique, and this one at night.

Octopus playing the imitation game

We saw this octopus on a dive at Long Beach in March. It seemed to be imitating seaweed with its tentacles, but I’m not sure. What do you think?

If you haven’t read it yet, this article from the Daily Maverick illuminates some aspects of the until-now impenetrable octopus fishery in False Bay, while we’re on the subject of octopus. The permit-holder has been on a temporary permit for over 15 years, as the Department of Agriculture, Forestry and Fisheries has been rolled over the five year permit three times so far.

Whales appear to be the by-catch of this fishery – an issue that I don’t think is addressed sufficiently in the article. There is a potential human cost here, too, as the teams that disentangle whales do so at considerable risk to their own lives, and without compensation. The intelligence of octopus is not controversial, and it is interesting to examine the ethics of the fishing method specifically as it relates to this.

Newsletter: Mountain side

Hi divers

Weekend dive plans

Saturday: Boat dives from Hout Bay or False Bay

Last weekend’s dives were pretty good; the visibility was better further south on Sunday. On Saturday we met an octopus at Long Beach, who tried very hard to persuade us he was a piece of kelp.

Octopus imitating kelp
Octopus imitating kelp

This week has had a fair whack of wind on and off, and False Bay currently looks pretty grumpy with very little sign of visibility. Hout Bay also looked a little off this morning, but the wind should have improved that.

I will stick my neck out and say we will launch on Saturday, and it needs to be really early as the wind picks up around midday.

Where we will need to wait for a visual check late tomorrow to decide which side of the mountain we will dive. I don’t think the conditions will be great for training dives and we may end up in the cold Atlantic. Either way we meet at 7.30 am at either Hout Bay slipway or False Bay Yacht Club parking in Simons Town. Text me if you want to join in.

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!

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!