Article: Nautilus on sea lamprey

Nautilus ran an article earlier this year about lampreys, fish that look like something out of the X Files. They are probably close relatives of hagfish; like hagfish, lampreys are jawless. They attach their round mouths to other fish and feed on their bodily fluids. They do not have a reputation as civilised dinner conversationalists.

While hagfish are marine animals, lampreys are anadromous: they return to fresh water (usually rivers) to spawn, in the same way that salmon do. When they’ve spawned, they die, fertilising the rivers and surrounding land with the nutrients from their bodies (in the same way as salmon do, but on a smaller scale).

Rehabilitation of North American rivers, along with the removal of dams, opens the way for fish such as salmon and alewives to return. Lampreys have returned too. Until recently they were viewed as invasive pests:

… the conventional American wisdom on sea lampreys was conceived following the late-19th- and early-20th-century collapse of world-renowned trout populations. The lampreys were invasive, having infiltrated the region through shipping canals; Great Lakes fish could not adapt to their ravages. Historical records describe the ease with which nets could be lowered to lake bottoms, then pulled back up with a cargo of sea lamprey-holed carcasses.

More recent research suggests that lampreys are native to at least Lake Ontario and several other lakes in the region, and were only able to colonise the rest of the Great Lakes when their native fish populations were all but destroyed by removing too many fish and modifying the ecosystem through damming, logging and agriculture.

Although they aren’t pretty, lampreys may be less of an invasive parasite and more of an essential participant in a balanced ecosystem than they were once thought to be. Read the Nautilus article here.

Urgent call to action on the future of seal diving and snorkeling in South Africa

Seal at the slipway
Seal at the slipway

Proposed changes to the National Environmental Management: Biodiversity Act (no. 10 of 2004) will limit scuba divers’ and snorkelers access to Cape fur seal colonies. The proposal was brought to our attention by Georgina Jones (for which we thank her!). Unfortunately the timeline for comments is extremely limited: we must submit written responses to the proposal by 30 April, which is this coming Thursday.

Proposed legislative changes with respect to Cape fur seals

The primary change that will affect us as scuba divers and snorkelers is that we will no longer be allowed within 30 metres of a Cape fur seal colony. This will mean that we cannot approach the colonies at Duiker Island in Hout Bay and at Partridge Point in False Bay. Furthermore, it may mean that we cannot even drive the boat through the gap between Duiker Island and the mainland. Boat routing around the Partridge Point colony will also be affected. Fortunately we don’t do any recreational diving around Seal Island in False Bay, so we don’t need to worry about that!

The Government Gazette outlining the changes is long (288 pages) and you can download it in its entirety here, but I have snipped out the relevant sections. The first is the definition of “harrassment” from page 88, which in point (f) relates to all seal species and states that one may not “approach a colony closer than 30 metres”.

Definition of harrassment
Definition of harrassment (click to enlarge)

The second relevant section is on pages 260-261 as they specifically apply to Cape fur seals. Note that the second last bullet point (on the second page, page 261) prohibits “harassment” of seals, which is defined above.

Cape fur seals regulations
Cape fur seals regulations (click to enlarge)
Cape fur seals regulations continued
Cape fur seals regulations continued (click to enlarge)

Why we object to the proposed legislation

Cape fur seals (Arctocephalus pusillus pusillus) are not endangered. In Namibia they are hunted, but in South Africa hunting of seals was stopped years ago. They are classified as “Least Concern” on the IUCN Redlist, which states that

Due to their large population sizes, the global Cape Fur Seal (Afro-Australian Fur Seal) population appears to be healthy, and the subspecies should both therefore be classified as Least Concern (LC).

The best place to encounter Cape fur seals is in proximity to a breeding colony (such as Duiker Island in Hout Bay) or haul out spot (such as Partridge Point in False Bay). The largest breeding colony is Seal Island in False Bay, and recreational diving and snorkeling is off limits there owing to the white shark population that feeds there, primarily in winter. Restricting access to 30 metre wide areas around these colonies will not improve the lot of the seal populations in any way.

Fishermen frequently have an adversarial relationship with seals (Shaughnessy & Kirkwood). Allowing scuba divers and snorkelers to approach seal colonies in the water enables them to observe any abuses that may be perpetrated on the seals by water users who do not appreciate the seals’ presence. It also provides a means for monitoring and reporting the impact of plastic pollution on the animals, which may be significant. Loops of plastic from bait boxes, shopping bags and from six packs of canned drinks pose a risk to these curious mammals, who get their heads or flippers stuck inside the plastic loops. This causes slow and painful damage to the animals as they grow.

There is no indication that activity by snorkelers and scuba divers causes the seals any distress or leads to harmful behaviour modification that could impact individual seals’ chances of survival (Kirkwood et al 2003). Seals are curious and friendly, and frequently and willingly approach people in the water in order to interact.

If conducted sensitively, trips allowing visitors to experience Cape fur seals have great conservation value, not only encouraging awareness of seal conservation issues, but also of species that prey on and are preyed upon by seals, and of issues of plastic pollution in the marine environment.

The monetary value of Cape fur seals as a tourism resource is also significant and contributes to South Africa’s tourism sector. In addition to snorkeling and scuba diving trips, run by a number of operators, there are seal viewing boats (which sometimes pose a significant danger to snorkelers and divers in the water, but that’s another story…) operating out of Hout Bay, which bring thousands of visitors, mostly tourists, to see the colonies each year.

As both Duiker Island and Partridge Point are located close to shore, restricting boat movements around them may force watermen to use less safe routes up and down the coastline, and force them further out to sea than they would otherwise choose to venture in order to avoid the seals.

(It is in fact not clear to me whether Partridge Point, which is a resting or haul out spot rather than a breeding colony, will fall under the proposed legislation, but Duiker Island in Hout Bay certainly will, as will Seal Island in False Bay.)

How we think seals need to be protected

A more impactful (sorry, hate that word) way to protect seals from perceived harrassment would be to enforce a Code of Conduct for seal tourism operators. This would prohibit landing of people on a seal colony by tourist operators. The use of toys such as bits of rope to attract seals in the water should also be prohibited. Teaching seals to identify human manufactured materials as playthings will only lead to more entanglement of young animals in plastic waste. Strict boat speed limits should be enforced around seal colonies and haul out spots. Finally, no bait or chum should be permitted to be used by operators, even if it is kept on the boat and trickled over the side or held inside a glove and not given to the seals.

How to submit comments

If you enjoy snorkeling and diving with seals and want to be able to share that with friends and family in the future, or have a business that profits from seal trips, or if you like to win photography competitions with pictures of seals chomping at your dome port, this means you have a vested interest in the legislation that has been proposed.

The quickest way to comment is to send an email to with your comments or objections. Feel free to use any or all of the ones we have listed above. Please do this now!

Contact details to submit comments
Contact details to submit comments (click to enlarge)

Operators who do white shark trips and turtle nesting tours in Sodwana should also consult the proposed changes carefully, because they may impact their operations as well.

Article: Phenomena on ocean calamities

The news article/paper that we read yesterday was a serious, yet hopeful assessment of the current and future state of ocean animals. Today’s article is also by Carl Zimmer, writing for Phenomena, and covers an opinion piece that appeared in Bioscience. A group of marine biologists criticises the tendency of scientists to generalise local effects into a supposed global “ocean calamities”. This breeds pessimism and inaction, as the general public is assailed by one apparent disaster scenario after another, and a point of fatigue is reached. The authors contend that

… the marine research community may not have remained sufficiently skeptical in sending and receiving information on the problems caused by human pressures in the ocean and that there is a need to revisit the process by which potential or isolated problems escalate to the status of ocean calamities.

It must be tempting, as a conservation biologist or environmental activist (two different professions) to talk up the dire threats facing coral reefs, or sharks, or whales, in order to attract attention or funding. But it is important to keep things in their proper context and perspective. Furthermore, all of us have a duty to remain skeptical, to investigate claims that seem extreme, and to do a little research beyond the headlines, tweets and facebook status updates. Make no mistake, this is not about being skeptical of science and its capacity to assist us in understanding the world around us; it is about being skeptical about how facts are presented, paraphrased, and – after enough repetition – possibly distorted.

Read Zimmer’s full article here. As an aside, he mentions his New York Times article on the Science paper concerning the health of the world’s oceans that we discussed yesterday. He asked the authors of the ocean calamities paper whether the Science paper was overstating the threats to marine life. Their response was that the paper was balanced and an accurate assessment of the current state of affairs.

I also encourage you to check out the original paper that Zimmer is writing about, which runs through several well-known “ocean calamities” (jellyfish blooms, harmful algal blooms, overfishing, invasive species, etc) and assesses the extent of the evidence for each one to qualify as a global threat to the oceans.

Article: New York Times on the health of the ocean

Humans began adjusting ecosystems on land thousands of years before they were able to do significant damage to the ocean, but in the last five hundred years or so we have been catching up in the marine environment. If you think that five hundred years of significant human impact on the oceans sounds too long and the number should be more like 50 years, read Callum Roberts’s book Ocean of Life – in fact, do that anyway.

In this vein, Carl Zimmer wrote for the New York Times about a recent paper (paywalled on Science) about extinctions and reduction in numbers of animals in the world’s oceans. The article received a large amount of attention and was featured prominently, which is great for science and for the ocean.

When writing about conservation issues it is a challenge to maintain an air of hopefulness, in order to spur the reader on to positive action rather than smothering them in despair. Many books about the health of the world’s oceans struggle to walk this line. Authors sometimes appear unnaturally chirpy about terrible subjects, or to change their minds three quarters of the way through the book, becoming a cheerleader after seven chapters of doom and gloom. Unusually, Zimmer’s article (and, by extension the paper it stems from) are genuinely hopeful, because the paper’s authors sincerely believe there is something that can be done.

(The timeline below is from the paper; click on the image to go to the original on the Science website.)

Timeline of animal loss
Timeline of animal loss

While the paper sounds a warning that “today’s low rates of marine extinction may be the prelude to a major extinction pulse, similar to that observed on land during the industrial revolution, as the footprint of human ocean use widens” and “the terrestrial experience and current trends in ocean use suggest that habitat destruction is likely to become an increasingly dominant threat to ocean wildlife over the next 150 years”, the authors are convinced that prompt and decisive action can make a significant difference. The action would need to be primarily in the form of massive marine protected areas, strategically located, as well as a decrease in carbon emissions.

Zimmer’s full article can be read here. One of the authors of the paper he reviews is Stephen Palumbi, whose Extreme Life of the Sea is an excellent introduction to the entire ocean ecosystem, written in bite sized chunks with the flair of the Guinness Book of Records (but more academic prowess, obviously).



Article: New York Times on the wreck of the Kulluk

We are far enough south that – to me at least – discussions on the subject of oil companies drilling in the Arctic, much of which is now conveniently ice-free in summer, don’t register as viscerally as things that are physically closer to home. But there is a principle at stake here, and a set of risks that corporations have not fully comprehended. The Arctic is a sensitive, valuable ecosystem, and – unlike the populous coast abutting Gulf of Mexico – there are few human settlements and no infrastructure. If something goes wrong with an oil rig or a spill takes place, help is far off and difficult to obtain.

A New York Times article that appeared at the end of last year goes into detail about the consequences of a poorly-planned and executed, premature attempt by Shell to locate oil reserves north of Alaska. The Kulluk was a drill barge, and Shell planned to tow her into the Arcitic so that she could do exploratory drilling for oil.

The emphasis below is mine:

Even with permission, getting to the oil would not be easy. The Alaskan Arctic has no deepwater port. The closest is in the Aleutian Islands at Dutch Harbor, a thousand miles to the south through the Bering Strait. In the Inupiat whaling villages dotting the Chukchi coast, only a handful of airstrips are long enough for anything other than a prop plane. There are few roads; human residents get around in summer by boat, foot or all-terrain vehicle. Shell was trying the logistical equivalent of a mission to the moon. During the short Arctic summer, when the sea ice made its annual retreat, Shell would have to bring not only the Kulluk but everything else: personnel, tankers, icebreakers, worker housing, supply vessels, helicopters, tugboats, spill-cleanup barges and a secondary rig to drill a relief well in case of a blowout. In the wake of Deepwater Horizon, Shell would build a $400 million Arctic-ready containment dome, an extra layer of spill protection that it would also need to drag north.

Predictably, things went badly wrong. The chain of events reads like one of those Reader’s Digest “Drama in Real Life” stories that gripped my sister and me as a child.

Read the full article here.

Seli… gone!

Panorama of the beach at Blouberg where the Seli 1 lies
Panorama of the beach at Blouberg where the Seli 1 lies

Our obsession with shipwrecks that stick out of the water is well documented. We keep a beady eye on the BOS 400, and while the Seli 1 was visible at Blouberg, Tony and I would take a drive out to visit her every few months. We haven’t been out to see her for well over a year, so I was delighted to find myself at Blouberg recently to get an update on her condition.

Look for the orange buoy - the Seli 1 is under it
Look for the orange buoy – the Seli 1 is under it

The wreck had gone from being intact when she ran aground in 2009, to looking a bit ropy, to separating into three pieces (above the surface, at least). After rough winter in 2012, a minor oil spill issued from the wreck, as part of it toppled over. That was the last we’d seen of her, but furious activity was going on behind the scenes as efforts were made to secure her removal.

Divers from the SA Navy were tasked with detonating explosives on the wreck to break her up, which they did in March 2013. This opened a compartment in the wreck from which oil leaked, necessitating a clean up operation. Finally, the remaining wreckage was cut into smaller pieces to expedite its collapse and dispersion on the sea floor.

The Seli 1 is under the orange buoy to the right of this image (hard to see!)
The Seli 1 is under the orange buoy to the right of this image (hard to see!)

Today, the resting place of the Seli 1 is marked by an orange buoy, that is hard to spot from land – let alone in my photographs above. The site has been dived by a group of adventurous locals, and apart from a lengthy surface swim it’s a possibly promising wreck for Open Water divers to dive from shore (these are in short supply in Cape Town – the only others I can think of are the Clan Stuart and the Antipolis, and perhaps the Romelia).

If you’re interested in visible shipwrecks, check out my ebook Cape Town’s Visible Shipwrecks: A Guide for Explorers!

Article(s): Phenomena & The Verge on a sea star wasting virus

Our wedding starfish at Long Beach
Our wedding starfish at Long Beach… see, he is lying in a heart shape!

The starfish in this picture may or may not still be alive (my guess is not), but it looks very much like a starfish in the early stages of Sea Star Wasting Syndrome (SSWS), minus a few legs. (It isn’t sick – I photographed it at Long Beach a few years ago – and it is actually an invasive species on South Africa’s coast.) Sea stars on the Pacific coast of North America began sickening – suppurating and disintegrating – in mid-2013, and scientists have been scrambling to find the cause. Initially it was not clear what was causing the sea stars to die in such grisly ways: pollution, warming oceans, large storms and other possibilities were considered. The clue that told scientists that the cause was “microscopic and biological” (in the words of National Geographic Phenomena blogger Ed Yong, who covers the subject with admirable clarity) was that starfish in aquaria, who were bathed in water pumped from the ocean and filtered, were also dying.

Yong’s post explains how scientists isolated the virus (a process involving blending, filtering, and genetic sequencing), and what scientists are hoping to learn from the work they have done on this subject. Potential parallels between SSWS and viruses that periodically flare up in human populations (Ebola being a recent example) are interesting.

At The Verge, Elizabeth Lopatto writes in more detail about SSWS, its discovery, and consequences. She points out that sea stars are a “keystone species”, and that

Keystone species help maintain an ecosystem by eating quickly-reproducing prey species like urchins and mussels — keeping populations low. Without the sea stars, the urchin population explodes; bad news for the kelp forests and everything in them. Giant kelp can grow to 150 feet underwater at a speed of two feet a day, but their weaknesses are their holdfasts, which are sort of like tree roots. The holdfasts are home to brittle stars, prawns and snails, among other creatures. Urchins like to eat the kelp holdfasts. Without them, the rest of the kelp drifts off in the tides. In this way, urchins can devour forests, which, higher up, are also home to fish, including several types of commercially-important rockfish, according to the National Oceanic and Atmospheric Administration.

Lopatto’s article is an excellent read – find it here.

(As an aside, the ocean is full – full to the gills – of viruses. This was revealed to me by the Palumbis in The Extreme Life of the Sea.)

Bookshelf: Ocean of Life

Ocean of Life – Callum Roberts

Ocean of Life
Ocean of Life

This book is both deeply alarming and relentlessly optimistic. Its author, Callum Roberts, is a professor of marine conservation. He is able to see with clear eyes the damage that we have done to the world’s oceans, but also believes that science has the tools at hand to halt the decline. His optimism is not shared by all of his scientific colleagues, but it makes it bearable to read books like this and gives one a sense that it is still possible to be a positive force for the sea as a private individual. Despite the deliberate tone of optimism and hope, Ocean of Life is a very frightening book.

Roberts’s prior book was of The Unnatural History of the Sea, which explained the extent to which, over the last 1,000 years, humans have been modifying ocean ecosystems by harvesting marine life – to excess. I found it devastating. This book is concerned with other ways in which humans have been tinkering with the sea in addition to overfishing, including but not limited to climate change, industrial pollution, plastic debris, and noise from ships and from other human activities. Huge dead zones from fertiliser runoff and ocean acidification make some parts of the sea an outright hostile place to life.

Not only have we removed countless animals from the sea and added pollutants, but we have also adjusted ocean currents and moved species from one location to others – the lionfish invasion of the Atlantic is an example. Roberts lauds the efforts by recreational divers to control the invasion that are portrayed in Carl Safina’s Saving the Ocean series, but admits that they are ultimately futile except on individual reefs, and lionfish are in the Atlantic for the long haul.

Unlike Paul Greenberg, Roberts believes that initiatives such as SASSI, which encourage consumers to make sustainable seafood choices when shopping and eating out, have value, and he encourages the conservation-minded reader to explore them. He also provides a long list of excellent marine conservation organisations which one can support financially in order to make a difference to the decline of the oceans; he has worked with all of the ones he lists except for Sea Shepherd, and I’d suggest you support those. With the shambles of poseurs mixed in with legitimate conservation organisations, it is sometimes hard for the public to discern who’s a charlatan only interested in raising their own profile, and who’s actually spending the donated funds on conservation strategies that effect change. I’d love to see some guidance on this from a South African perspective – the ratio of fluff to substance here seems very high!

There are excellent reviews of Ocean of Life by the Telegraph, the Guardian, and the Independent. The Economist has an interview with Roberts online, too.

You can get a copy here and here (for overseas readers) or here and here (if you’re in South Africa). The book has appeared under the titles Ocean of Life (in the UK, I suspect) and The Ocean of Life (in the US).

Bookshelf: Shrimp

Shrimp: The Endless Quest for Pink Gold – Jack & Anne Rudloe


Before reading this book it was important to determine the difference between shrimp (which we almost never talk about or eat in South Africa, except for little tins that go into paella when there’s not enough of anything else to make a full meal), and prawns (which are large, and frequently enjoyed). My meanderings around the internet revealed that “shrimp” and “prawn” are common names, not related to any scientific classification, and that by convention shrimp are often small and prawns are large… But it’s not clear cut and no one should be dogmatic about anything in this debate. What Americans call shrimp encompasses our prawns, as well as our tiny shrimps… Hence the term “jumbo shrimp”, which sounds nonsensical to me!

Shrimp capitalises on the popularity of nature books about a single species, often with one word titles, a boom initiated (I think) by Marc Kurlansky’s bestseller CodThe Rudloes are marine biologists and founded the Gulf Specimen Marine Laboratories together (Anne passed away in 2012). Jack Rudloe spent a lot of time on commercial fishing boats, and this book – like Trevor Corson’s book The Secret Life of Lobster – reveals how difficult it is for a writer to remain objective when confronted with the hard working, salt of the earth fisherman archetype.

Despite this, which bothered me slightly, this is a fascinating insight into everything you ever wanted to know about shrimp (slash prawns). Shrimp fisheries and farms worldwide are examined (with a focus on the American Gulf of Mexico fishery), and the dizzying variety of shrimps and prawns is elucidated in some detail. There are diagrams of their bodies, descriptions of their habitats, and details of how they are harvested. The book’s structure is difficult to discern, even chaotic, which throws off a disorganised reader like me (six books on the go, and often fragmentary reading times in elevators and in queues).

I did not find much information in this book about the impact of trawl fisheries, which include horrific bycatch and damage to the ocean floor that is so serious it can be seen from space. It was here that I felt Rudloe’s affinity with the fishermen who do this damage got in the way of a frank assessment of how bad it is. Prawn farming is also not environmentally neutral. The means by which we get prawns onto our plate are actually so bad that the decision whether to eat shrimp and prawns at all should be weighed very carefully.

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

Video (TED): Tanya Streeter on freediving and plastic pollution

If you watched yesterday’s freediving documentary, “No Limits”, you may enjoy this talk by Tanya Streeter, a (now retired) British/Caymanian freediver who features in that film. She gave a talk at TEDxAustin in 2012. In it she talks about the sport of freediving, gas narcosis, motherhood, and plastic pollution in the world’s oceans.