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We need to talk about chumming

On Thursday a young man in his youthful prime was bitten by a shark in False Bay, and lost his life. Coincidentally, in addition to the usual (limited – three operators only) cage diving activities at Seal Island, an American research vessel had been operating in the bay in the days prior to the attack, using chum to draw sharks closer to the vessel in order to tag them. Naturally, many members of the public – who until last week had been given very little information aside from rumours and gossip on the subject of this highly-funded research cruise – are pointing fingers at the practice of chumming, claiming that it has to be changing the sharks’ behaviour and leading to increased risk to water users in False Bay.

Actual scientific research on the subject

I have read two papers on the subject of chumming (Australians call it berleying) and its effect on shark behaviour, as well as a brief discussion in Thomas Peschak’s excellent book South Africa’s Great White Shark.

The effects of berleying on the distribution and behaviour of white sharks, Carcharodon carcharias, at the Neptune Islands, South Australia – Bruce & Bradford (CSIRO study)

This paper is based on studies in Australian waters on white sharks (summarised here, full paper here), at a seal colony (North Neptune Island in South Australia, 60-70 miles offshore) where shark ecotourism takes place. Over the years the number of days on which the water is chummed, and the number of operators doing so, has increased, and a previous study done in 2001-2003 provided a useful baseline from which to work. A study comparing the movements of sharks tagged in 2010 with sharks tagged in 2001 found that, while no sharks took up residency at North Neptune Island (white sharks are generally highly migratory and only spend short periods in one place), the average amount of time that sharks spend at the island has almost doubled (to 21 days) over the last 10 years.

The study also found that the daily average number of sharks seen by the operators has increased, but rather than indicating increased shark numbers, this reflects the fact that sharks are staying longer at the island. The sharks’ movements around the island also more closely match those of the cage diving operators, as they arrive and depart at around the same time as the boats do each day (regardless of whether there are operators present).

It’s important to note that the Neptune Islands are far offshore, and not much else seems to happen there except for shark viewing.

Don’t bite the hand that feeds: assessing ecological impacts of provisioning ecotourism on an apex marine predator – Hammerschlag, Gallagher, Wester et al (Functional Ecology, March 2012)

The second paper (summary here, full text here) studied two separate populations of tiger sharks, one in Florida, where chumming is banned, and another in the Bahamas where there is a thriving shark diving industry that feeds the sharks to draw them closer to divers. The hypothesis was that if the Bahamas sharks were responding to being fed, their distribution and movements would concentrate far more closely around the feeding areas than the Florida population does around its local area.

The conclusions were surprising: not only did the Bahama sharks range freely, but they did so over distances five times greater than their Florida cousins do, suggesting that they are not affected in a measurable way by being fed on baited shark dives.

A note about methodology

You will notice that both these studies had a sort of a “control group” that was unaffected (or less affected) by the factor (chumming) that they wanted to study. In the Australian one, the authors were able to refer back to a previous study done when there were fewer cage diving operators going out for fewer days a year, to see what had changed, knowing that one environmental variable (frequency and amount of chum) had increased. In the American study, two separate populations of sharks could be studied.

This is good science – in complex systems you cannot draw conclusions without attempting to eliminate the other factors which could influence your observations. While it would have been interesting in and of itself to find out how far the tiger sharks of the Bahamas range, the information would not have enabled any conclusions to be drawn about factors specific to that population (being chummed) without the inclusion of a parallel study on the Florida tiger sharks.

The False Bay chumming question

I’m a mathematician. It’s easy to study numbers and equations: they sit still on the page, they don’t interact with other equations unless I make them do so, and the results of my calculations are (hopefully) unambiguous. It’s this purity and dichotomy between truth and falsehood that atttracted me to the subject in the first place. Studying the natural world seems much harder to me. Sure, you can study sharks, but there are a thousand other variables – many that are specific to the location of the shark population in question – that can affect your study.

Thinking locally, seal populations might rise and fall because of external factors or changes in their food source (or, if you’re Namibian or Canadian, culling). Climate change, ocean warming, or fishing pressure (or something else) might adjust the abundance and type of fish that visit False Bay and how long they do so, thus changing sharks’ movements around Seal Island and inshore. Teasing out the effect of a single activity – chumming, in this case – is far from straightforward. It takes time, and lots and lots of money.

We will never, ever put this question to rest until we can do the science, run the numbers, draw the maps, and get enough observations to draw statistically relevant conclusions. The movements of the sharks both within False Bay and in the open ocean needs to be studied. We can make inferences about the effects of chum in False Bay from the research done in other places (such as the two papers I mention above), but the uniqueness of every location, the pressures exerted on it by the populations along the coastlines nearby, and its own peculiar history means that – in this situation, at least – I don’t think we can stand on the shoulders of others in order to draw hard and fast conclusions.

The sooner we start, the better – in the (probable) absence of an earlier local study such as the one used in the Australian research paper, some clever science will be required to get meaningful results. It’s a great pity and a terrible irony that the very research that could have led us to some answers about the effects of chumming has been suspended – because (it seems) of suspected or perceived culpability in the shark bite incident on Thursday. And no one is in a position to say whether the activities of the research cruise did lead to the incident, because we have no prior research from which to draw conclusions. Thinking about this too much is depressing, and gives me a headache. More tomorrow.

Disclaimer

Tony has been on baited shark dives in the open ocean and at Aliwal Shoal, and we both have been shark cage diving in Gansbaai. We found it a life-altering experience to be with the sharks in these settings, knowing that without the use of chum the chance of seeing any sharks would have been vanishingly small. We are both in two minds, and have been for a long time, as to whether using artificial means to draw the sharks to a boat outweighs the wonder of seeing them in the water, and the effect this can have on one’s view of sharks as something to be protected rather than feared. Perhaps our having been on baited shark dives shows that we feel that the ecotourism and mindset-altering benefits of these dives is more significant than the possible additional risk of changing the sharks’ behaviour with chum… I don’t know, and I can assure you the debate occurs at least once a week in the Lindeque household!

Update

A study has been done on the effects of chumming in False Bay – click here to read about it!

Letter for sharks – follow up

A few months back I wrote to both the Minister of Environmental Affairs (Edna Molewa) and the Minister of Agriculture, Forestry and Fisheries (Tina Joemat-Pettersson) regarding shark finning activity and trade in South African waters, and the protection of broadnose sevengill cowsharks. I received a letter acknowledging receipt of my letter from one of the ministers (it was so exciting I’ve forgotten which one – I think it was from Ms Molelwa’s office).

In a stroke of genius (I think), prompted largely by following Helen Zille on Twitter and seeing how engaged and responsive many of her minions are, I also wrote to the DA Shadow Ministers with the portfolios mentioned above. These Shadow Ministers have no ministerial powers as such, but are assigned to particular portfolios and as opposition MPs generally give their corresponding government ministers a hard time.

Gareth Morgan, the Shadow Minister of Water and Environmental Affairs, was so good as to put my concerns to the minister of agriculture, forestry and fisheries (Ms Joemat-Petterson) in a Q&A in parliament. Her response was the following:

NATIONAL ASSEMBLY

WRITTEN REPLY

QUESTION 3225

DATE OF PUBLICATION: FRIDAY 21 OCTOBER 2011 [IQP No 33 -2011] THIRD SESSION, FOURTH PARLIAMENT

Question 3225 for written reply: National Assembly, Mr G R Morgan (DA) to ask the Minister of Agriculture, Forestry and Fisheries:

(1)   Whether there is any (a) legislation or (b) regulations that prohibit shark finning; if not, why not; if so, what are the relevant details;

(2)   whether she intends to ban the (a) sale, (b) export, (c) import of shark fins and (d) any other products derived from shark fins; if not, why not; if so, what are the relevant details;

(3)   whether her department intends placing Broadnose Sevengill Cow sharks under a similar protection afforded to white sharks; if not, why not; if so, what are the relevant details? NW3837E

REPLY:

(1)   Yes. Shark finning, in other words the removal of fins and discarding of the shark trunks at sea is currently prohibited in fisheries where such practices have occurred or are likely to occur. Due to the high value of pelagic sharks caught by the Large Pelagic Longline Fishery, fishers are encouraged to land sharks with fins attached. If fins are not attached to the trunks then the dressed-weight ration shall not exceed 8% of trunk weight. Conditions attached to the issuing of permits regulate the afore-mentioned.

(2)   Currently there is no intention by the Department to ban the sale, export, or import of shark fins and other products derived from shark fins. The FAO Committee on Fisheries (COFI) developed in 1998 an International Plan of Action for the Conservation and Management of Sharks (IPOA-Sharks) within the framework of the Code of Conduct for Responsible Fisheries to which South Africa is a signatory. The objective of the IPOA-Sharks is to ensure the conservation and management of sharks and their long-term sustainable use, with the following specific aims: The IPOA-Sharks calls for maximum use of dead sharks, therefore whilst sharks are being targeted or caught as by-catch, all products including fillets, cartilage and fins will be utilized.

If research indicates that the finning of sharks is a common occurrence then the legislation regarding finning will be re-examined.

(3)   The department is looking into the feasibility and consequences of placing the Broadnose Sevengill Cow Sharks under similar protection afforded to White Sharks. Currently there is no scientific evidence to suggest that Broadnose Sevengill Cow Sharks are overexploited. However, as the value of the fillets is low it might be argued that a greater usage of Broadnose Sevengill Cow Sharks would be for the eco-tourism market where animals may bring in considerable income if responsibly and safely managed.

Other concerns include the accumulation of mercury and other metals. Mercury is bio-accumulated and concentrated through the aquatic food chain especially in large predatory fish such as Broadnose Sevengill Cow Sharks. Mercury exposure has been linked to neurological diseases and cardiovascular effects in adults, and mental retardation and cerebral palsy-like symptoms in newborn infants exposed to MeHg through the placenta. On the other hand, reported catches of Broadnose Sevengill Cow Sharks are currently low (<5 t per year) and do notappear to be unsustainable. These catches provide consistent data for long-term analysis. If catches of Broadnose Sevengill Cow Sharks are stopped, the ability to monitor the long-term abundance of cow sharks are decreased. All these factors need to be included in such a decision.

This is not particularly encouraging news, and there’s a distinct lack of concern evident here. However. This gives direction to future lobbying (read: harrassing government ministers by mail) efforts. Please feel free to write your own letters on any aspect of this that you feel strongly about. The more pressure that is exerted to obtain protection for sharks in South African waters, the better. You can even put on your bikini while you type your letter… I won’t judge!

Bookshelf: Dive South Africa

Dive South Africa – Al J. Venter & John H. Visser

Veteran war correspondent (and veteran scuba diver) Al J. Venter has written over 35 books – chiefly about the various conflicts and wars he has covered, but also several about diving. Where to Dive, The Ultimate Handbook on Diving in Southern Africa, and The South African Handbook for Divers are long out of print, but his most recent volume, Dive South Africa, was published in 2009 and is available in many dive shops. I have a feeling I picked up my copy at Lightley’s Houseboats in Knysna. I read it just after I started diving, and I fear it gave me a rather skewed view of what scuba diving can be about. I reread it recently, with a little more knowledge and slightly higher expectations of the sport, and humans in general.

This book is basically about overgrown boys shooting stuff and looting things. An aggressive, macho diving culture is portrayed here, and many beautiful reefs are described in terms of what you can find there to kill with your speargun (and, presumably, feel terribly manly afterwards). FIST BUMP! Women are not mentioned without the qualifier “pretty” or “attractive” – no other attribute apparently matters. Sharks are uniformly referred to as “beasts”, “monsters” or “brutes”.

Venter covers dive locations such as Port Elizabeth, Durban, Plettenberg Bay, Knysna, Arniston, East London, Port Alfred, the Mossel Bay area and a number of other destinations with good diving. These destinations sometimes get poor exposure – local diving magazines are particularly guilty of this – at the expense of Sodwana and Aliwal Shoal (which also feature in some detail). A lot of the focus – in the coverage of all these locations – is on where to go to shoot big fish, but these are somewhat useful chapters for divers who want to go off the beaten track a little bit, and experience even more of the diving that South Africa has to offer. Use of this book as a reference – perhaps in conjunction with the Atlas of Dive Sites of Southern Africa and Mozambique is probably ideal for the explorer at heart. It is the chapters on particular destinations – some of them off the beaten track and even lacking dive centres within a hundred kilometres – that are the most useful part of this book. There is even a chapter on diving a wreck in Mozambican waters, with the attendant difficulties of operating in what was then a guerilla state.

A seasoned wreck diver, Venter devotes several chapters to important wrecks in South African waters. An entire chapter – with atmospheric photographs – is dedicated to the wreck of the Maori. Chapters are also devoted to the Colebrooke, the Klipfontein, and the City of Hankow in Saldanha. Much mention is made of the Birkenhead near Arniston. Venter has an interest both in the wrecks as they are now, and the stories behind their sinking and the rescue of their crew and passengers (if that took place). Some of the wrecks are not permitted to be dived any more, so the oral histories recorded here of what the condition of the wrecks are (and even their location) are important. The extensive looting of many of the shipwrecks Venter describes (many in False Bay and Table Bay), however, would make an archaeologist (a proper one) tear his hair out. SAHRA, the body meant to regulate these activities, doesn’t seem to care, and actually didn’t exist when a lot of the plunder and pilfering took place.

There are several chapters about sharks, including a lengthy one about Walter Bernardis of African Watersports, a veteran baited shark dive operator. Bernardis describes in detail the process for doing baited dives with large sharks such as tigers and bull (Zambezi) sharks, as well as an incident in 2006 when he himself was bitten. Strong respect and awe for the sharks is clearly present in both Venter and Bernardis, but the feeling I was left with after reading the chapter on baited tiger shark dives was that it’s a completely stupid idea, and extremely dangerous – both to the divers and to the sharks. Pictures such as the horrible one in this blog post, depicting sharks hurting themselves on the mechanisms used to chum – often involving steel cable and washing machine drums – show that this exploitation cannot be good for the sharks. It is purely a money-making racket and there is very little actual regard for the animals themselves.

Moreover, there are just too many caveats – dive briefings must take HOURS – and the sharks are not in a state that is conducive to calm interaction, which is not good for the divers’ peace of mind either. Venter’s endorsement of Bernardis’ practice of riding the sharks is disappointing, but shouldn’t surprise me I suppose! It has been extremely lucky, thus far, that no one has been badly injured by a shark in – understandably – a frustrated feeding frenzy. There have been incidents, and recently, but the practice continues and is extremely lucrative for the often completely unethical and fame-hungry operators that offer it.

Beautiful colour photographs by Peter Pinnock, Andrew Woodburn and others appear in plates in three sections of the book. Throughout the rest of the book, black and white images taken both above and below the water are featured. There is a brief chapter on underwater photography in which Venter interviews some of the more renowned practitioners of the art, and Thomas Peschak gets a mention.

The book has no index, which makes finding a piece of information after the fact – such as the chapter on diving in Knysna in preparation for our second visit there – completely impossible.

Venter has clearly led a rich, full life and enjoyed a variety of thrilling and hair-raising experiences underwater. His knowledge of our coastline is top notch. For the information on diving conditions and locations around our coast it’s a far more useful reference, however, than The Dive Spots of Southern Africa, for example, even if the information (depths, distances, etc) is slightly less comprehensive. It should NOT be the first book on South African diving that you read (purely from the perspective of the outdated “dive culture” that it presents), but it WILL expand your knowledge – of both facts and the origins of South African diving culture – if you do decide to add it to your library.

You can buy the book at your local dive shop.

Bookshelf: The Living Shores of Southern Africa

The Living Shores of Southern Africa – George & Margo Branch

It took me a while to get my hands on a copy of this classic volume by Margo and George Branch, with photography by Anthony Bannister. It was a staple in the classroom of every biology teacher I ever had, and occupies pride of place behind the microscope display at the Two Oceans Aquarium, where it has helped countless nonplussed volunteers answer sticky questions about jellyfish reproduction or the eating habits of limpets. It was first published in 1983 and is long out of print.

The first half of the book deals with habitats – the rocky shore, beaches, estuaries, the open ocean, coral reefs, and kelp forests. The authors manage to sneak in quite a lot of physical oceanography without one noticing, as it obviously impacts the flora and fauna that can colonise a particular area. Prof Branch has a special interest in limpets, and I was amazed to discover the intricate adaptations that these unassuming little creatures have to life in the highly competitive, high stress intertidal zone. The section on kelp forests was also wonderful to me, as a regular diver in these parts! I found the chapter on estuaries somewhat dispiriting, given that it was written thirty years ago and it seems unlikely that matters have changed since then. Prof Branch used the Richard’s Bay estuary of the Mhlathuze River as an example of how human interference turned a thriving, sensitive ecosystem into a muddy wasteland in a matter of a couple of years. I have not visited Richard’s Bay, and indeed had not heard anything about this particular estuary before encountering it in this book, so I will have to do some research to find out whether it’s still in such a parlous state.

I found the sections on sharks, seals and whales – under the chapter on man and the sea – puzzling and upsetting, but perhaps they are just a reflection on where scientific understanding of ecosystems was in the early 1980s. I would be interested to hear Prof Branch’s views on these three types of animal today.

Sharks

On sharks, the authors mention that the Natal Anti-Shark Measures Board (now renamed to something less obviously brutal, but still with the same ultimate aim of killing sharks) killed 11,700 large sharks in eleven years (presumably the decade to 1980). The authors state that it is not known what the effect of removing so many top predators will be on the ecosystem, but do note that there were an estimated extra 2.8 million dusky sharks – a smaller species that has thrived in the absence of tiger and bull sharks – at the end of the eleven year period in question. I was immediately reminded of the fairly recent shark bite that occurred on a baited dive on Aliwal Shoal a few months ago. The culprit was a dusky shark.

What I found unsettling was that very little concern was expressed about the impact of killing so many sharks – highly migratory creatures, in many cases – along a small region of the coastline. The authors do mention the case of Tasmania, which after a few years of shark nets experienced a population explosion of octopus (traditional shark food), who destroyed the local rock lobster population and the profitable local lobster fishing industry. I know that the authors’ focus has been more on coastal species, but their apparent lack of recognition of the role of sharks in a healthy ocean was strange to me given their obvious awareness of how vital is every link of the food web on the rocky shore (urchins, abalone, kelp, sea otters, rock lobster, etc.).

Seals

The authors describe the economic value of the seal cull (which in the 1980s was a grim reality of South African life, and in Namibia still is the case). Baby seals were (are) valued for their soft pelts and the oil in their bodies, and mature seals just for the oil – their pelts were deemed to be too battle-scarred to make into a fur coat. The method of killing baby seals with a blow to their heads was sanctioned as humane by the NSPCA because their little skulls are still soft when they are young (and, in a happy coincidence, it doesn’t damage the pelts).

Apart from the economic rationale for killing seals, the authors state that seal colonies “attract sharks” – as if this is a reason to destroy them. I found this extremely confusing – why is one creature more important or desirable than another? The fact that fish, limpets, seals and sharks exist in the ocean means that they all have a role to play, and that somehow these populations lived in balance before human intervention.

Another reason provided for the annual seal cull (which at one point left 35 seals on Seal Island, in contrast to the current population of over 75,000 seals) was that their numbers were increasing “unchecked” and threatening the nesting sites of seabirds on the island. Nowhere do the authors acknowledge that the reason for the seal population explosion could be that their natural predator, the white shark, was fished to the brink of disappearance off the South African coast by testosterone-fueled trophy hunters. Fortunately today shark and seal eco-tourism is big business, and I don’t think (I stand to be corrected) that any seals are legally killed in South Africa any more.

Whales

Whaling was an entrenched part of the South African economy from the early 1800s, but was comprehensively banned in 1979, shortly before this book was published. In Blue Water White Death the whaling station in Durban was shown, and whale carcasses were used by the filmmakers to attract sharks. The authors provide a synopsis of the state of whaling in the world’s oceans at the time of writing (depressing – what is the validity of “scientific whaling” when it is conducted by a country that feeds whale meat to school children?) and the population status of various types of whale.

They suggest that, because the small Minke whale competes with blue whales for food, Minke whales should continue to be hunted in order to give blue whales a chance at increasing their numbers. My (admittedly uninformed) view of it is that – what with the population explosion of krill that whaling engendered in the Southern Ocean, the blue whales aren’t even going to notice a few small Minkes dining at the lunch bar with them. Whale populations have been reduced to such a tiny fraction of what they used to be that – for a long time still, everything else being equal – competition for food isn’t going to feature in their population dynamics. My feeling on the matter is that if a Minke whale ever even SEES a blue whale, let alone has the opportunity to argue over a ball of krill with it, it should count itself a lucky little whale and move right along.

The second half of the book deals with specific organisms, their life cycle (beautifully illustrated by Margo Branch), and their habits. The authors focus on invertebrates, as (they say) fishes are extensively dealt with in other volumes. The accompanying photographs were taken by Anthony Bannister, and have not dated at all in terms of quality – they are vivid, clear, and beautiful.

Some of what I learned

I learned a huge amount from this book. It’s clearly provided source material for almost every other South African marine flora and fauna book that has been written, and sentences – that I’ve seen in other books and presentations – kept ringing bells with me (I tend to use my fish ID books quite hard, trying to wring out every last fact from the one-paragraph descriptions accompanying the photos). The authors in fact collaborated on the handy Two Oceans guide, which keeps getting better with each new edition and is indispensible for the travelling South African diver.

I learned that the presence of plough shells on a beach generally indicates that it is safe for swimming – these little snails surf in the waves using their large feet as a sail, and if there were rip currents they would be drawn offshore and lost. Their activities on fish Hoek beach are shown to great effect in the BBC’s The Blue Planet series.
I loved learning how Rocky Bank protects the western side of False Bay to some extent, slowing down the swells as they enter the bay and causing them to focus their power somewhere near the Steenbras River mouth on the opposite side of the bay.
I loved learning about limpets’ “home scars” – the spot on the rock that fits their shell perfectly, and that they somehow return to over and over after foraging for food – and how some species tend little gardens of algae, encouraging its growth by mowing paths in it (and getting fed at the same time). Simple things like the effects of strong or harsh wave action on the slope and sand type of a beach, and as a result the type of life that thrives there, were also fascinating.
I learned that 30 years ago (when this book was published) overfishing was already a serious, serious problem.

You can obtain a copy by scouring secondhand book stores, Amazon.com, and Amazon.co.uk.

Lecture: Sarah Fowler on the challenges & opportunities of shark conservation

Last week Tony and I attended a talk at the Kalk Bay Save Our Seas Shark Centre by Sarah Fowler. Sarah was introduced by Christoper Neff (back in town following the recent shark bite incident in Fish Hoek) and is one of those people who has had such a busy and productive working life that it’s almost futile to try and summarise her qualifications and experience… But she’s a co-author of the fantastic Sharks of the World field guide, founded the European Elasmobranch Society, is a founding trustee of the Shark Trust and has worked in advisory positions to government agencies as well as in an independent capacity as an environmental consultant. She is also the Vice-Chair of International Treaties at the Shark Specialist Group. There’s a better biography of her here – it’s incredibly impressive, and really comforting to know that there are individuals of this calibre involved with shark conservation internationally. Apart from Save Our Seas, our experience of shark conservationists locally has been somewhat dispiriting.

Challenges of shark conservation

Sharks are intrinsically vulnerable animals, perched as they are on the top of the food chain. They are late maturing, long-lived creatures that undergo long (9-18 months – can you imagine!) gestation periods and usually give birth to small litters of well-developed young. They thus have a low population growth rate, and a low resilience to onslaughts by fisheries. Many species of sharks return over and over to the same locations to breed, making them vulnerable to specific habitat threats. Shark populations are also slow to recover, in light of their reproductive characteristics described above.

There is a lack of management of shark fisheries – in many instances, sharks are not the target species but are often bycatch or a byproduct of what the fishery is actually trying to catch. Shark fisheries are low volume, and low value (but the trade in sharks and shark products is high value). From a management perspective, other fisheries have a higher priority to governments and in management treaties.

The IUCN Red List evaluates the global conservation status of plant and animal species. The Shark Specialist Group is responsible for preparing species assessments for elasmobranchs (sharks and rays) for the Red List. There are about 1,040 such species listed on the Red List, of which more than 17% are threatened. The most threatened species are

large bodied coastal species such as sawfish, hammerhead and porbeagle sharks, skates, and spiny dogfish
deep water benthic (bottom-dwelling) species targeted by fisheries or taken as bycatch
freshwater species
oceanic pelagics, which are an unregulated target of bycatch fisheries.

Funnily enough, the white shark is not a typical shark (nor is the whale shark). Both are actually fairly well protected, but they differ from the “average” shark in several other ways. The typical shark – if one were to average across all shark species – is small (about 1 metre long), flat (batoid), with uncertain distrubition, unknown population trends, and largely unknown life history. It is probably endemic to a particular region, making it vulnerable to habitat loss. It is utilised bycatch if not actually targeted by fisheries (in other words, if they’re caught by accident, they are used rather than thrown back into the sea). Its fisheries are unregulated and unrecognised. There is no fisheries management or biodiversity conservation attention being paid to the average shark. The species is probably on the IUCN Redlist as critically endangered, or there is insufficient data on it.

What needs to be done

Urgent conservation and management actions are required. Fisheries management (quotas and Total Allowable Catch or TAC) at a regional and national level is required. Shark finning must be banned.

Since some shark species (such as great whites and bull sharks) are highly migratory and regularly cross international borders, countries must co-operate in the conservation of such species. The Convention on Conservation of Migratory Species (CMS) is one means of cementing co-operation. The CMS Shark Memorandum of Understanding is intended to improve the conservation status of several species of sharks listed in the CMS appendices. South Africa signed this treaty in May 2011, and is one of seven African signatories out of a total of 16 countries.

Who should take action?

National governments – fisheries and environmental ministries
International conventions – CMS, CITES, United Nations Convention on the Law of the Sea
Regional Seas conventions
You and me

How we can take action?

These aren’t complicated, time-consuming or difficult things to do. Most of them require a keyboard and a word processing program, a pen and paper, or firing off an email.

follow codes of conduct for diving and angling
write to elected representatives and government ministers (and shadow ministers)
ask them to follow scientific advice (this is VITAL – scientists are the only ones with no financial or status-related interests in the game) for national fisheries management and biodiversity conservation measures
ask what your government is doing to implement international biodiversity conventions
~~get yourself photographed hanging onto a shark’s dorsal fin, while wearing a bikini~~

(Regarding that last point, if you’ve read my post on the proliferation of ridiculous “shark activists” and conservationists that seem to bedevil us, you’ll be well aware of my views of that sort of exploitative, self-promotional behaviour.) Sarah was extremely diplomatic when I asked her about the sheer number of organisations that claim to be saving sharks, and whether this represents an unneccesary division of labour. Perhaps better results could be achieved by one or two organisations that envelop all the others? In reply, Sarah said that there is a role for every kind of organisation, from pure scientific research groups to those who are in favour of more direct (not illegal) action. She wryly observed that some groups’ only role seems to be to make everyone else look good!

This was a fascinating talk from someone who has been actively involved in shark conservation for many years. It confirmed my long-held suspicions that shark conservation is not glamorous work, and anyone who claims that it is – or is constantly getting themselves photographed with no other outputs in evidence – is not doing what they’re claiming to be doing.

Here’s a video of Sarah Fowler discussing a similar subject (at an event covered here).

[youtube=http://www.youtube.com/watch?v=pdJdZWvzme4&w=540]

I actually don’t know too well what the status of South Africa’s shark conservation action plan is (if there is one), and will do my best to find out and report back when I do.

Diving in an MPA

A couple of weekends ago I picked up a hard copy of this brochure (PDF) at the Paddlers shop in Simons Town. It’s the Marine Recreational Activity Information Brochure published by the Department of Agriculture, Forestry and Fisheries. I wish that more poachers would read it! It has information pertaining to the regulations governing scuba divers, anglers, jet skiers, aquarium keepers, rock lobster, and abalone.

The map at left is from this brochure (PDF), which details all the MPAs along our coastline. Certain areas are restricted zones, which means that NO fishing is allowed there at all. I am always totally delighted when the skipper slows the dive boat to a crawl to inform a clueless (or willfully criminal) kayaker or fishing boat that they’re fishing in a no take zone! This usually happens on the way to Smitswinkel Bay in the Castle Rock restricted zone. Research has shown that restricted zones have dramatically positive impacts on fish populations – the difference between fish and marine life populations just inside and just outside these areas is very dramatic.

I can assure you, from diving in these areas, that even though the policing of restricted zones leaves MUCH to be desired, the experience of diving in one is an absolute pleasure for the most part. Rich dive sites like Partridge Point are testimony to this.

Reading the regulations pertaining to the recreational scuba diving permits that we are required to hold when we dive around the Cape Peninsula (and along much of the South African coast) was enlightening. Most of these are common sense, but it was news to me (for example) that no diving is permitted between 11pm and 4am, anywhere in an MPA! It also put paid to any personal chumming activities… What a pity – I would have loved to have had a great white shark all to myself!

By the way, Bird Island – mentioned below – is near Port Elizabeth. There’s a magnificent lighthouse there.

RECREATIONAL SCUBA DIVING PERMIT CONDITIONS

The holder of a recreational SCUBA diving permit shall:

not remove, unduly disturb or harass any marine organism or habitat, including shells or substrate, marine mammals, seabirds and fish.
not feed fish, practice chumming, or dump any material, or discharge any biological attractants in the MPA.
dive in the Table Mountain, Pondoland, Aliwal Shoal and Stilbaai MPA during daylight hours only (from half an hour before local sunrise to the time of local sunset), unless as part of a group being taken out by an DEA-authorised business operator. A representative of a registered Diving Club or individuals must notify the managing authority of the MPA to their satisfaction if they intend night diving. (Table Mountain (SANParks) – 021-786 5656, Pondoland (Eastern Cape Parks) – 047-387 0451/043-742 4450, Aliwal Shoal (Ezemvelo KZN Wildlife – 0825592848). Stilbaai (CapeNature – 028-754 2234).
not scuba dive in the Bird Island MPA at all.
not dive in any MPA where a scuba diving permit is required between 23:00 and 04:00 at all.
abide by the Diver Code of Conduct (www.environment.gov.za).
note that these conditions will be applicable to any new MPAs that may be declared, regazetted or required to have a permit in the future.
adhere to the condition that boats taking persons diving in an MPA where a permit is required shall only launch from an authorized launching site, and shall not launch earlier than an hour before local sunrise or return later than an hour after local sunset unless night diving in compliance with condition 3.

To obtain your MPA permit, take R100 and your identity document or passport to your nearest post office, and ask for a scuba diving permit form at the counter. It’s a blue and white form, the same one as is used for angling, crayfishing, and some other consumptive marine usage activities.

Sea life: Rock lobster

Many of Tony’s students come to him with extensive skin diving experience. Living in Cape Town, it’s almost obligatory to enjoy at least one lobster braai during the season (and often many more). Sometimes the veteran lobster-divers struggle at first with breathing through a regulator – their instinct while under water is to hold their breath (it’s illegal to take lobster when you’re on scuba). But their comfort in the water (and being used to the cold) stands them in good stead, once Tony’s tapped them on the regulator a few times to remind them to inhale!

We see West Coast rock lobster (not crayfish – those are freshwater creatures) in both False Bay and on the Atlantic side. They are gregarious, and can often be found sheltering in cracks and under overhangs, in quite large groups.

West coast rock lobster on the BOS 400 wreck

It’s a pleasure to do a deep wreck dive such as on the Maori and on the BOS 400, and see hordes of good-sized rock lobster teeming all over the wreck. Some of the shallower sites are definitely over-fished, and we only see really big specimens when we dive beyond the range of your average skin diving lobster hunter. On Gerard’s first deep wreck dive in Smitswinkel Bay, we hadn’t been on the wreck for three minutes when I turned around to see him excitedly waving a MASSIVE lobster at me, the biggest either of us had ever seen. Some finger waggling and head shaking convinced him to replace Mr Lobster in his home, but I think Gerard was heartbroken.

Rock lobster are almost impossible to farm. At the Two Oceans Aquarium on our crash course in marine biology we learned that there are 13 larval stages, during which time the creature drifts hundreds of kilometres offshore through a huge variety of water conditions that it would be impossible to replicate in a mariculture setting. The larval phases can last up to two years. Lobsters grow very, very slowly and can live to the age of 50. There’s some nice detail on the Two Oceans Aquarium website.

They eat crabs, abalone, starfish, snails and sea urchins – this latter fact makes them quite important in the ecosystem as a whole. I’ve mentioned before that juvenile abalone shelter among sea urchins. If there are too many lobsters, they eat too many urchins (and too many abalone) and this leads to a decline in the population of abalone. It’s a fine balance.

Lobsters are incredibly sensitive to the level of oxygen in the water, which sometimes leads to what look like mass walkouts onto the beach when there’s a red tide or similar event leading to (near-)anoxic conditions on our coastline. What actually happens is that they move away from the de-oxygenated water where the red tide has died, and get stranded on the beach by a retreating tide. Once when Tony was landing a dive boat at Miller’s Point, he was waiting for a chance to use the slipway next to a fishing boat that was packed to the gills with lobster. The captain said they’d found a spot where thousands of lobster were strolling together in orderly formation across the ocean floor, and he’d just scooped them up. (He would not share where this magical location was, but the lobster were probably moving to more highly oxygenated waters.) Having substantially exceeded his quota, the fisherman was somewhat twitchy about being pulled over by the authorities!

Poaching of rock lobster is a big problem in South Africa. They’re a very valuable commodity – you just need to go and have a seafood platter at a Camps Bay restaurant to see what damage it can do to your wallet – and easily accessible to anyone who can hold their breath and is prepared to do a bit of rock scrambling. The government Department of Environmental Affairs tries to manage stocks by implementing a closed season, catch and size limits.

Currently, you may only take lobster that measure greater than 8 centimetres from the front of their head to the end of their carapace (NOT to the tip of their tails, as I used to think – fortunately I’m not a lobster fisherman!);
You must have a MPA permit to take lobster (same form at the post office as the scuba diving one);
The season runs from November to April (the dates vary by year);
You may only take lobster during the day – between sunrise and sunset;
You’re not allowed to sell them;
You are not allowed to take females in berry (with eggs), or lobsters with soft shells that have just moulted;
There are also regulations about the number of rock lobster you may transport at once, or have in your possession.

If you’re in doubt as to the utility of this array of regulations, check out the graph in the middle of this page on the Department of Environmental Affairs website. Depressing.