There is not much doubt that the best option for weekend diving activities will need to be from Oceana Powerboat Club in Granger Bay. The next two days of southeasterly wind should clean things up there after the really insane (almost 9 metre) swell that passed through last night.
The swell, if it lingers at 3 metres won’t be great so I will decide late on Saturday whether we launch or not. The water temperature is currently around 16 degrees so some cleaning by the wind is still required.
Octopus at the Two Oceans Aquarium
Diversnight
One more reminder to put Saturday 2 November in your diaries. The dive clubs are hosting this year, and it’s going to be a great event with lucky draw prizes, the works. Here’s the facebook event. Not sure what Diversnight is? Read this.
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
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.
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.
St James tidal pool
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.
The tidal pool at Millers Point
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.
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
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 Minds. Godfrey-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).
I can’t remember how this story crossed my path – I usually only visit Buzzfeed when someone sends me a link containing cat pictures – but it’s definitely worth your time. I thought I’d share it now, before we (hopefully eventually) move on from the cephalopod obsession that I have been nurturing for a while.
The article describes how the curator of molluscs (cool job) at London’s Natural History Museum came into possession of a giant squid, accidentally caught by fishermen in the Falkland Islands, and what it took to preserve it.
She measures 8.62 metres in length and remains the largest wet specimen the Natural History Museum of London has ever preserved. No one has ever captured and preserved a giant squid as complete as this one. That said, she’s missing part of a leg – but it’s not her fault. The fact that she was so fresh meant a section of one of her tentacles could be immediately frozen for DNA research before decay set in.
You, too, can see a giant squid, if you do a behind the scenes tour at London’s Natural History Museum. If you’d like to remind yourself what a giant squid looks like in real life, this talk is a good place to start. Read about giant squid here.
Read the full article here – the accompanying photos are probably even more gripping than the text
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
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.
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 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.
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!
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
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).
The Soul of an Octopus: A Surprising Exploration Into the Wonder of Consciousness – Sy Montgomery
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.
