Newsletter: Turtle time

Hi divers

Weekend dive plans

Sunday: Boat dives from Simon’s Town jetty at 10.00 and 12.00, likely to Roman Rock (suitable for Open Water divers)

The weekend looks good for diving. We’ll be boat diving on Sunday. If you want to join us, you know what to do!

Green turtle on the move
Green turtle on the move

Turtles

It’s that time of year when turtle hatchlings get caught up in currents that bring them to Western Cape shores, where it’s too cold for them to survive. If you find one on the beach, please keep it dry and warm, and get it to the Two Oceans Aquarium as soon as possible. Read more about what to do on the aquarium blog here, and here.

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog/

Diving is addictive!

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Article: The New York Times Magazine on animal tagging

Staying with our informal theme of the last few weeks’ (admittedly sporadic) posts, let’s look at a recent article from the New York Times Magazine. Not solely focused on marine animal studies, the article explains how technology has enabled even the general public to directly observe and learn about the migrations of birds, sharks and other animals. The utility of this kind of information is obvious:

By discovering the precise routes animals take during migration, scientists can assess the threats they face, like environments altered by habitat loss and overhunting.

A white shark with a satellite tag
A white shark with a satellite tag

The article’s author is brilliant nature writer Helen MacDonald, who wrote H is for Hawk, and she goes on to muse about the meaning of the relatively few individually tagged and named animals which become icons of their species as they appear to transverse a simplified, borderless planet in solitude. (The OCEARCH sharks on their satellite map refer!) It is easy to lose sight of the rigours of the environments they move through, but easy to become invested in the future of particular individuals.

Erik Vance’s article on great white sharks for National Geographic covers tagging, and he elaborates on his blog about how tags can facilitate population estimates. You can also read about whale tagging, tuna tagging, and the tagging study taking place on False Bay’s cowsharks.

What a time to be alive. Read the full New York Times Magazine article here.

How to help marine wildlife in distress

 

It’s not uncommon to come across marine wildlife – seabirds, seals, turtles – apparently in distress. This is not always the case, so before you mount a complex and dangerous rescue mission, or try to provide help where none is needed, it may be wise to get an expert on the telephone to help you determine whether it really is necessary. Fortunately there is a range of 24-hour wildlife hotlines to choose from, depending on what species you are dealing with.

Seals

Bull seal with plastic around his neck, in Hout Bay
Bull seal with plastic around his neck, in Hout Bay

Seals with plastic or fishing line around their necks should be reported to the Two Oceans Aquarium (if the seal was spotted around Cape Town harbour or the Waterfront), or, more generally to the SPCA Wildlife Unit on +27 (0) 21 700 4158/4159, or +27 (0) 83 326 1604 after hours and on weekends. Unfortunately the odds are your seal is probably not going to get the help it needs if it isn’t in the port of Cape Town or at the Waterfront; this doesn’t mean you shouldn’t do your darndest to advocate on its behalf.

You can help to deal with this problem at its source by retrieving any loops of plastic that you see floating in the water when you’re on a boat. Hout Bay harbour is a particular cesspit of plastic pollution, and with a nearby seal colony it’s a recipe for disaster. Cutting through any closed loops on plastic items (such as beer can holders) that you recycle or dispose of yourself also ensures that should the plastic end up in the wild, it won’t entangle an animal.

Seals found lying on the beach are usually not in trouble. Juvenile seals may rest for long periods – a couple of days at a time – on shore, and the most important thing to do is not to disturb them. They don’t need to be kept wet, they don’t need to be fed, and they can inflict a nasty bite. Encourage other members of the public to give the animal a wide berth, particularly if they have dogs. Lead by example. If the animal appears visibly unwell (fitting, for example) or is bleeding, then call the SPCA Wildlife Unit for a chat about what course of action is best.

Seabirds

Seabirds are most often found entangled in fishing line or plastic, pierced by fishing hooks, or, in the event of an oil spill, with oiled feathers. It is important to get help if possible, particularly for oiled birds.

SANCCOB has a 24 hour rescue centre which can be reached on +27 (0)21 557 6155 or +27 (0) 78 638 3731 (after hours & weekends). Their website provides the following advice to would-be seabird rescuers:

What to do when you have found an injured/sick/oiled seabird:

  • If you are unable to handle the seabird, SANCCOB will send out a unit to collect the bird.
  • If you approach any seabird, please approach with care. Some seabirds such as Cape Gannets and African Penguins have sharp beaks.
  • Have with you a towel, or blanket and wear protection over your hands and eyes. Use a towel/blanket to throw over the bird to catch it, ensuring that the bird is able to breathe.
  • If you have a large box ensure that there are holes for air before you place the injured/sick marine bird.

More information can be found here.

Turtles

During the autumn and winter months, juvenile and sub-adult sea turtles sometimes strand on Western Cape beaches. These animals are often shocked by the cold and in poor shape – they do not typically occur in Cape waters but are washed down in eddies of the Agulhas current.

Do not put the turtle back in the sea or into water. It is probably weak, dehydrated and hypothermic, and is likely to drown. Keep it dry, and call the Two Oceans Aquarium for further instructions and assistance. The aquarium rehabilitates and releases the turtles in warmer water when they are healthy.

Here’s detailed information from the Two Oceans Aquarium on what to do if you find a stranded turtle. Do the right thing!

Whales and dolphins

The City of Cape Town would like ocean users to report whale carcasses before they end up on the beach. This is mostly for public safety and resource allocation purposes, but if we can do anything to keep a whale carcass out at sea (or on a secluded non-swimming beach), it serves a conservation purpose as well. There’s a phone number you can use to do this – read more here.

If you come across a current or imminent live whale or dolphin stranding, contact the NSRI on +27 (0) 21 449 3500 immediately. They will activate the relevant authorities. Try to bear in mind that these events often do not end well for the animals concerned, as they are often sick or disoriented and impossible to assist. Be a help, not a hindrance, and obey whatever instructions you are given by the NSRI, SanParks, or whoever comes to take charge.

A free-swimming but entangled whale should be immediately reported to the NSRI as well – they will activate the South African Whale Disentanglement Network. Do not attempt to assist the whale yourself – this could be fatal for you (not the whale) – rather make a note of the direction it is swimming, and its precise location, and whatever other helpful information you can provide. Whale entanglements seem to be increasing in frequency around False Bay in particular, as more experimental fisheries are approved. (If this worries you, you could write a letter to DAFF about it.)

Turtles at Drop Zone, Ponta do Ouro (southern Mozambique)

One morning while we were in Ponta do Ouro, skipper Mike asked us what we wanted to see that day. Laurine had an answer ready: “A turtle!” So we went to Drop Zone.

Green turtle at Drop Zone
Green turtle at Drop Zone

We had not finished descending when Christo, spotter extraodinaire, noticed a turtle near the surface. We were going in opposite directions, though, so it remained in the distance. When we arrived on the reef, we almost immediately came upon another turtle being cleaned by a group of what I think are lined bristletooths, as well as a bright blue wrasse at the turtle’s right back flipper. The fish are nibbling algae off the turtle’s shell; this went on, peacefully, for some time, while we watched.

We continued the dive, and met a second turtle, who was obligingly friendly and swam alongside us (Laurine in particular – I could see her self-actualising right there) for a while.

Later I returned to the same part of the reef where we’d met the first turtle. The spa session was pretty much over, so I took a little more video. I didn’t want to overstay my welcome or make the turtle feel uncomfortable, so I started trying to withdraw from the area. The turtle, however, had other ideas, and approached me head-on while I back-pedalled slowly. It wasn’t at all hostile (hostile turtle, anyone?) but maybe a little curious or maybe just trying to get somewhere and I was in the way.

Being able to observe these creatures in the water is the most amazing privilege. They can live to 80 years of age. I don’t know how old this one was, but based on its carapace length of about 50 centimetres, work done in California suggests that it is perhaps 5-10 years old.

Newsletter: Winter blue

Hi divers

Weekend dive plans

Saturday: Boat dives out of Simon’s Town, sites to be confirmed

Crescent-tail bigeyes at Creche
Crescent-tail bigeyes at Creche

Mozambique dive trip

We have just returned from a short dive trip to warmer waters. We had five days of really good conditions in Ponta do Ouro, Mozambique, with no swell and almost no wind. The water was 23 degrees most days and on every dive we were amazed by something. Watch the blog for a trip report in the next week or two, and some photos and video from the trip. There’s an album of pictures on facebook already.

A green sea turtle at Drop Zone
A green sea turtle at Drop Zone

Dive conditions and plans

The bay has been treated to winds from all directions in the past week, and there appears to be a huge volume of dirty water swilling around. Some places are really clean and inviting and others not so much.There is some rain in the forecast for Saturday afternoon and a fair amount of wind for Sunday.

I am planning to launch on Saturday but will make a call on where during the course of the day tomorrow as I will take the boat out tomorrow for a good look around. If you’d like to be on board for Saturday’s dives, let me know by email or text message and I’ll keep you in the loop.

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!

Series: Saving the Ocean

Saving the Ocean with Carl Safina
Saving the Ocean with Carl Safina

I know Carl Safina as the author of several wonderful books about the ocean – The View from Lazy Point being the most recent one. I was surprised to discover that he has also ventured into television presenting, and this PBS series (so far a one-off) is the result.

Saving the Ocean showcases, in half hour segments, communities and initiatives that are successfully making a positive difference to ocean environments. Safina visits Baja in Mexico (grey whales are thriving there), Washington State (rivers are being rehabilitated there, for wild salmon), and Trinidad (where leatherback turtles are being protected). An episode where the leaders of the Muslim community on a Tanzanian island are taking the lead in advocating for environmental protection was particularly moving. Tony and I both found it immensely encouraging, and relieving, to see places where a balance is being struck between human requirements – for fish, protein, survival – and the need to take care of the sea.

A few times I felt that an excessive amount of enthusiasm was being displayed for a recovery that isn’t that spectacular – particularly in the episodes on New England cod. After hours of fishing, two or three tiny fish are caught. This in an area where you could lower a bucket and raise it up full of fish a couple of hundred years ago. The cod are still gone – no matter how much you smile about it.

Safina is an enthusiastic fisherman, and devotes two episodes to an artisanal sword fishery on Georges Bank. The fishermen harpoon the swordfish, collecting no bycatch. While I understand that this is a good way in which to target the species, I wasn’t convinced that there were enough swordfish to justify catching them at all, and I think the thrill of the hunt got in the way of telling the real story here.

The final episode in the series is about lionfish, and describes some of the innovative ways that the dive industry in the Atlantic is helping to control numbers of this native Pacific interloper.

Safina is an engaging host, refreshingly natural, like a slightly rumpled professor of an outdoorsy subject. The production values in this series aren’t fantastic, but this is made up for by the sheer good news of the stories told in each episode.

You can get the DVDs here if you’re in South Africa, otherwise here or here. Read a bit more about the show here, if you’re not convinced.

Chasing sunfish

I certainly hope that this isn’t the only time I’ll see an ocean sunfish (Mola mola) underwater, but if it is, I can live with that. During a dive in Maori Bay last weekend, exploring the BOS 400 and SS Oakburn shipwrecks, sharp-eyed Liam spotted a large sunfish swimming alongside us, but some distance away. We had advance warning that there were sunfish about (they’d been spotted from the air near Kommetjie, the previous day), so I was mentally and physically prepared with a strategy that I’ve repeatedly rehearsed in my mind to be ready for underwater encounters with marine megafauna.

I switched my camera to video, pointed it at the sunfish, and took off towards it like (I imagined) a bat out of hell. I figured that if I didn’t get close enough to take a proper photo, I would still have a murky video record of the encounter. (Lo and behold, that is all I do have. See below.)

I swam for what felt like a blistering pace for several kilometres (in reality, a sluggish burst of probably 20-30 metres), and then realised that I’d overbreathed my regulator, was taking in quite a bit of water through a tear in the mouthpiece, and that if I didn’t stop finning I’d pass out. During this time the sunfish gained considerable distance on me, got out of focus and out of frame in my video, and then disappeared.

So I stopped, panting, and watched the animal disappear effortlessly into the blue gloom, waving its fins calmly and slowly but – it was clear – moving at a terrific pace. (The overbreathed regulator situation corrected itself swiftly when I started demanding more reasonable amounts of air again.)

I was reminded of other occasions when I’ve tried to keep up with a fish, or a turtle, in order to take its photo or spend just a few more moments in its company. Perhaps there is no shame in being out swum by a fish weighing over a ton with fins to match, but I’ve been humiliated by 30 centimetre long Red Roman, rejecting my friendly advances and outpacing me with a decidedly less impressive fin-to-body size ratio! Next time I want to enjoy the company of an ocean resident for just a little bit longer I’ll try to remember that I’m not in my natural element, and the decision as to whether we get to be close to one another rests almost not at all with me.

Bookshelf: The Unnatural History of the Sea

The Unnatural History of the Sea – Callum Roberts

The Unnatural History of the Sea
The Unnatural History of the Sea

Conservation biologist Callum Roberts has spent years researching the history of the last 1,000 years’ exploitation of the sea by human beings. The result, The Unnatural History of the Sea, is a stunning and detailed illumination of the scale of destruction we have wrought on our oceans. I had been under the impression that the development of industrial-scale fishing capabilities (factory ships, flash freezing, gill nets and the like) in the mid 20th century was what prompted the most egregious overfishing practices. This, however, is an example of baseline creep, in which successive generations look back at the conditions of nature experienced by the previous generation, and mistake them for pristine.

Humans have been harvesting marine life for over 1,000 years, moving from the freshwater ecosystems of Europe’s rivers and lakes after denuding them of all significant fish life through astonishingly aggressive (and familiar-sounding) fishing practices such as stringing nets across the entire width of rivers when fish returned to spawn. Siltation of the rivers caused by deforestation on their banks, and the development of better fishing equipment, also contributed to the move to marine fishing.

Millions of sea turtles and whales used to roam the oceans. To put that in perspective, there are under 15,000 southern right whales alive today (we think they’re recovering well – haha), and approximately 200,000 breeding green sea turtles. Numerous sea turtle rookeries, where the animals return year after year to lay eggs, are now lost to memory, after their breeding populations were completely wiped out during the 16th and 17th century by explorers and settlers in the New World. Entire seal and otter populations were hunted to extinction for their pelts. Hunters and fishermen often took far more than they needed, killing for amusement, squandering the abundance and leaving carcasses to rot or tossing excess fish – already dead – back overboard. After perusing logbooks, letters, diaries and other documents, Roberts remarks that rarely did the explorers, settlers and merchants remark on any aspect of the natural beauty of the creatures they saw on their travels, and if they did it is immediately followed by instructions on how to kill and prepare the animal, and what it tastes like.

Natural marine spectacles such as the sardine run off the Eastern Cape coast of South Africa were once far less remarkable and unusual than we find them today. The migration of herring from the Arctic down to the latitudes of the United Kingdom between May and October each year drew thousands of basking sharks (now we get a news article when four are seen in one day) and other predators, and their spawning left eggs lying on the sea floor in layers up to two metres thick. Roberts says that great white sharks also feasted on this bounty of fish, and mentions that there are too many detailed reports of white sharks up to nine metres long from the 18th and 19th century to discount all of them as false. (The maximum recorded length of a white shark in modern times is approximately six metres.) Today white sharks are seen so rarely in European waters as to create a great fanfare when one of them is spotted.

The point is that the oceans used to support far, far more life and abundance than we are able to conceive of today. Herring used to be so abundant in the seas around Scandinavia that they held up shipping. Pods of dolphins didn’t number in the thousands; they numbered in the hundreds of thousands. Whales were seen in similar numbers, surrounding boats, rubbing against them, and drenching them with spray from their blowholes. Ships navigated towards land by following the sound of countless sea turtles swimming towards the beaches they laid their eggs on.

This is a crushing, shocking book. While reading it I frequently felt myself assailed with despair and regret at how long the over-exploitation of marine resources has been underway, and how much we have lost. Bottom trawling dates back to the 14th century, and already then there were complaints (to Edward III of England, in 1376) about its indiscriminate destructiveness. Scientists visiting newly-discovered (they think) sea mounts have found their once thriving slopes reduced to fields of rubble, littered with discarded trawl nets and other fishing gear debris.

The sections on fishing in the deep sea and on trawling are devastating. Roberts contends that there is no such thing as a sustainable deep sea fishery, as the target species are so long-lived and slow growing (and unknown to science), with unknown population sizes, that there is no sustainable number of fish that can be removed without risking the species’s ability to survive.

Finally, Roberts offers some solutions to arrest the awful, seemingly inevitable slide towards ocean barrens populated only with sea jellies and urchins. The steps Roberts outlines in order to save and recover the world’s fisheries are simple to state, but will be challenging to implement:

  1. reduce present fishing capacity (i.e. number of boats, level of sophistication – this is not referring to reducing quotas)
  2. eliminate risk-prone decision making (i.e. use science, and act only when you have the facts – don’t use hope or gut feel as a decision making tool)
  3. eliminate catch quotas and instead implement controls on the amount of fishing (i.e. how much effort can be expended)
  4. require people to keep what they catch
  5. require fishers to use gear modified to reduce bycatch
  6. ban or restrict the most damaging catching methods (e.g. trawl fishing)
  7. implement extensive networks of marine reserves that are off limits to fishing

He advocates the use of Marine Protected Areas (MPAs) – scientists estimate that it is necessary to protect 20-40% of the world’s oceans in order to save fisheries for the future. Strangely, to someone who lives here and doesn’t think much of our collective will and ability to police MPAs, especially when fishing is allowed in many of them, South Africa is actually a world leader and has protected a larger proportion of her territorial ocean than many other countries (the world total is about 1.2% of the oceans, with only 0.01% of the world’s oceans designated “no take” zones, according to Wikipedia). The benefits however, even of poorly policed marine parks, are significant.

I am not sure I share Roberts’s optimism that the situation can be reversed or arrested – passages from this book come to me at odd moments, leaving me nauseated at the greed, waste and ignorance that we have displayed as a species, against the life of the sea.

There’s an interview with Roberts that I found interesting, and reviews at American Scientist and the Washington Post.

You can get a copy of the book here or here, otherwise here if you’re in South Africa.

Video (TED): Barbara Block on tagging tuna

Barbara Block is a member of the Tagging of Pacific Predators (ToPP) project, with a focus on tuna. She is based at Stanford University, in partnership with the Monterey Bay Aquarium. ToPP is the project behind the Shark Net smartphone app.

Here Block eloquently explains why bluefin tuna are so wonderful, and how tagging studies can help to identify the seasonal “hope spots” that are critical to tuna, sharks, turtles, seabirds, and other wide-ranging pelagic species.