I completed the edX-hosted Sharks! MOOC, presented by Cornell University and the University of Queensland, and it was excellent. The content was clear and for me, who stupidly quit high school biology at the age of 14 for the sake of a more classical (less useful) education, filled in a large number of gaps in my understanding of sharks and rays.
I’m going to link to some of the most interesting videos below, so you can get a taster of what the course was like. Please sign up next time it gets offered, if you didn’t do so this time!
Broadnose sevengill cowshark at Shark Alley
Week 1: The Big Shark Picture – Biodiversity and Evolution
On our last day in Denmark, after a week-long family visit between Christmas 2015 and new year 2016, we went to Den Blå Planet, Denmark’s national aquarium. (Actually we were wrong about it being our last day in Denmark, but that’s another story involving Turkish Airlines, who seem to innovate in the field of disappointment.) The aquarium is situated in Kastrup, Copenhagen, quite close to the airport, and overlooks the narrow sound called the Øresund, which separates Denmark from Sweden.
The Blue Planet after the mist cleared
We visited on 1 January, after (eventually) sleeping through the sounds of Copenhagen’s residents letting off five hundred metric tons of fireworks, starting at 5.00 pm the day before. We bought tickets online (a small saving in Danish krone that amounted to eleventy million ZAR) and arrived at opening time. The building is surrounded by a reflection pool, and is built in a spiral form inspired by the shape of a vortex. In the larger halls the high ceilings give a tremendous sense of space; at 10,000 square metres, the building is very large. The halls are generally wide and I imagine it could accommodate a very large number of people before feeling crowded.
Tony approaching the entrance to the aquarium
Early morning mist shrouds The Blue Planet
Exiting The Blue Planet
Layout of The Blue Planet
The aquarium is divided into three sections. The first is focused on the life found in the lakes and ocean of Denmark and northern Europe. I particularly enjoyed this first part of the aquarium. The animals are adapted to the cold water, so some of them were very similar what we find around Cape Town, and the displays were creative and interesting. There was also the obligatory “anchor with fish” tank, which was (as always) mesmerising. One of the pictures in the gallery below is of Tony checking it out.
Northern lakes and seas
Touch pool at The Blue Planet
Tony in the northern seas exhibit
Northern seas harbour display
Tony greets the otters
Octopus in the cold water exhibit
Two sea otters live at the aquarium, having been rescued as infants and raised by hand. The male and female otters were found in Alaska when they were four months old with a broken jaw and wounds after a boat strike, and as a 1.5 kg abandoned one day old respectively. As usual, seeing such an intelligent animal in captivity stirs up all sorts of conflicting feelings. That said, you are a stronger person than I am if you could have left these two baby otters to their natural fate (that is, death). The otters spend a lot of time (up to six hours per day) grooming, and in between keep very busy, requiring a lot of enrichment from their four keepers. It was magical to see them.
Also in the northern seas and lakes section is the puffin exhibit, mimicking the cliffs of the Faroe Islands, a Danish territory. Here, also, we found a touch pool (which the Danes call a sensing-aquarium), and a terrifying ambulatory mascot.
The second section of the building is devoted to tropical lakes and rivers, with incredible freshwater exhibits. We saw piranhas, terrapins, frogs, little black rays the size of pancakes, with white polka-dots, and electric eels. The rainforest exhibit is kept at a temperature and humidity level that are impressive in the Scandinavian winter, and I can imagine that this part of the aquarium is popular with expats from warmer climates!
Tropical lakes and rivers
Tony examining piranhas
Piranhas!
Looking dorky in the rainforest
Tony in the Amazon rainforest exhibit
Freshwater lake exhibit
The third part of the aquarium is for the rest of the ocean, and although it’s a big ask to cover (or summarise) so much in the remaining space, it does a fabulous job. The Ocean tank holds four million litres of water, and is home to rays and hammerhead sharks, and other warm water fish. Amongst many other things, there are seahorses, leafy seadragons and coral reef fish to see.
Feeding time in the Ocean tank
We watched feeding time for a while, which was quite funny – the aquarists row out onto the water in a small inflatable boat, and administer the snacks from on board. Standing in the tunnel, we could see the boat from below, with the oars working frantically against what I imagine was a bit of surface current.
The ocean
A ray passing over the tunnel
Life-size model of a white shark
Tony at the plankton wall
The coral reef tank
In the tunnel through the Ocean tank
One of the things that Den Blå Planet does really well is to integrate multimedia, virtual reality and interactive technology into the aquarium experience. This reduces the number of animals required to be on display, and – for the most part – probably takes care of itself, requiring no cleaning and feeding. My favourite such exhibit was the bouncy plankton wall in the ocean section of the aquarium. The photo below is pretty terrible because the display moves all the time, but I put a video on instagram which shows how the plankton clear a space for you when you walk along the wall.
Plankton multimedia display
We finished off our visit with a flæskesteg sandwich at ØST, the restaurant at the back of the aquarium. It was still a bit misty, but the large windows looking out over the sound let in a lot of light. There is a play area outside, and despite the midwinter temperatures, children in snow suits were making the most of it.
The restaurant at the aquarium, ØST
I did not get the same strong conservation message from my visit to The Blue Planet that I think the Two Oceans Aquarium in Cape Town works so hard to propagate. This could be because of different cultural approaches to living a “green” lifestyle; in Scandinavia the government does a lot of the work for you, providing renewable energy, prioritising pedestrian and bicycle traffic, and making it ridiculously easy to recycle, for example. In South Africa it is more of a conscious personal choice and effort to reduce one’s environmental footprint, and there is there is thus perhaps more of a requirement for direct conservation messaging.
Anyway, if you’re in Copenhagen, visit! Next time we’re in Denmark, we’ll check out the little Øresund Aquarium at Helsingor, which is entirely focused on local fauna.
They can be seen fairly reliably year-round, however, near the Millers Point slipway. As with Parrie the ray at Struisbaai harbour, the rays at Millers Point have figured out that the discarded fish guts thrown overboard by the fishermen returning from a day on the bay are a steady source of snacks.
Here’s some fly by traffic coming past the boat one November day near the slipway, where we paused between double tank dives to change cylinders and de-gas.
It is illegal to feed these rays or to bait the water to attract them (or anything, if you don’t have a permit), but a short cruise in amongst the fishing boats queuing for the slipway will cause them to come and investigate. Snorkeling or diving this area is very risky because of the boat traffic, so take care.
Sunday: Boat or shore dives, conditions dependent!
We have had terrific conditions all week and have been taking full advantage. False Bay is cleanish and warmish. Visibility has varied from site to site but the bay is full of life. On Tueday we spent our surface interval time photographing sea swallows at Batsata Maze. Wednesday’s surface interval was spent filming giant short tail sting rays at Millers Point, and today we were fortunate enough to have two orcas swim by close inshore whilst the divers were on the SAS Pietermaritzburg this morning. Who knows what we will see tomorrow!
Giant short tailed sting ray behind the boat at Millers Point
Sadly the diving today was somewhat overshadowed by the raging fire that descended on Simon’s Town with the westerly wind, despite the best efforts of many firefighters. Watching from the water you could see the speed at which the fire traveled and I doubt anything other than a thundershower was going to slow it down. On the run back into Simon’s Town we went through really thick smoke.
Simon’s Town fire
The weekend, however, does not look too rosy. At cowsharks this afternoon the swell was quite noticeable and although it stays at 3 metres for most of tomorrow, the forecast is for 5-6 metres on Saturday. It seldom reaches the height in the forecast but even at 4-5 metres diving becomes less than great. Surge and low viz are on the cards. I think there will be a better than good chance that Sunday will be semi-decent so I will provisionally schedule diving, either from the boat or perhaps a shore dive or two… Text me if you want to join and I’ll keep you posted.
Struisbaai the town is a picturesque little settlement, with deep historical roots, on the way to Cape Agulhas. The town is situated at the western end of Struisbaai the bay. (Struispunt marine beacon is situated at the eastern extremity of the same bay.)
Struisbaai harbour
Struisbaai harbour is home to at least two resident giant short-tail stingrays (Dasyatis brevicaudata). The rays are habituated to the sound of the returning fishing boats’ engines, and come out to investigate whether there are any scraps to be had. We were at the harbour long after the fishing boats had left (and perhaps returned already), and it was quiet, but a sport fishing boat returned while we were there and we saw two large, tell-tale black spots moving across the sandy harbour bottom towards the slip.
Tony stuck his pole camera into the water and got this footage, which is quite lovely. The rays will approach humans on the slipway, but I think some kind of fishy treat (tinned sardines?) is required to get them to come this close. We didn’t give them anything, so they checked out the camera and were on their way.
An information signboard in the harbour
One of the rays that lives at the harbour – the largest one – is called Parrie (possibly short for Paris?). Parrie was, according to legend (I cannot verify this with a reliable source), once captured by the Two Oceans Aquarium team and lived in one of their exhibits for a short while. Intense pressure from the Struisbaai community led to his return to the wilds of Struisbaai harbour.
A private fishing boat enters Struisbaai harbour
You can see a picture of Tony filming the rays from the jetty in the newsletter he sent out when we got home from the trip.
We are back from an exploration trip to De Hoop. We took in Infanta, Arniston and Struisbaai as well as Cape Agulhas. Our aim was to gather info for future dive trips up the coast and we checked out the launch sites, accommodation, eating spots and so on. We went armed with a chart of the wrecks and reefs and chatted to some of the locals who use the areas daily. It was a fantastic trip and one of the highlights was filming the giant short tailed stingrays that are resident in the harbour at Struisbaai. We’ll share that video on Youtube in a day or two, and some photos on our facebook page. Instagram already has some highlights from the trip…
Filming rays at Struisbaai harbour
Dive conditions
The weekend weather does not look all that rosy so we will launch tomorrow at 8.30 and 11.30. Saturday looks really messy and Sunday looks a little wet. We will launch on Sunday if the weather tones down from the current forecast. Either way, let me know if you’d like to be notified of possible Sunday dives, or if you’d like to be on the boat tomorrow.
Just a reminder to make sure your permit to dive in a Marine Protected Area is up to date. Also, if you book a dive please let me know in good time if you can’t take the spot on the boat so that I can give it to someone else.
Collaboration between scientists leads to amazing things, like the massive acoustic tracking system that covers the entire south and east coasts of South Africa.
You can tell a lot about what an animal is doing, without necessarily being right next to the animal all the time, with some clever technology and mathematics (yay maths!)
There are tiger sharks that are partially resident off Ponta do Ouro, Mozambique. They are being tracked and studied. Something to bear in mind next time you visit!
Sharks that cross borders (e.g. tiger sharks, great white sharks) are hard to conserve and face huge risks when they move out of protected areas.
False Bay’s great white sharks are incredibly well understood (great work has been done in the last 5-10 years), and at the same time the more we know, the more questions there are!
We are beginning to get a better understanding of sevengill cowsharks in False Bay and research is ongoing. Plus, did you know there’s a huge sevengill population around Robben Island?
Many of the shark and ray populations around South Africa’s talks are not comprised of separate groups of animals (e.g False Bay’s white sharks, Gansbaai’s white sharks and so on), but interbreed all along their range. This means you can’t protect one aggregation site and expect the species to survive and thrive – you have to think about threats along the entire range of the animal. This was a common theme in the genetics talks (which is a difficult subject to explain to peasants like me).
Juvenile hammerhead sharks aggregate in Mossel Bay at certain times of year! (This wasn’t the point of what was an excellent talk, but I was excited to hear it.)
The view from the top of Red Hill, over Simon’s Town
Earlier this week I had the great privilege of attending the 3rd Southern African Shark and Ray Symposium, which was held from 7-9 September at the Blue Horizon Estate above Simon’s Town. I am not a shark scientist (these days I am probably best described as a lapsed mathematician) but have an interest in the subject so I went to listen. If I had to provide some bite-sized takeaways from the first day of the symposium, jotted down without applying any of the science communication principles I learned at the workshop yesterday, it would be these:
Shark mitigation – avoiding negative interactions between humans and sharks – is HARD and a lot of smart people are working on the problem.
The City of Cape Town is a world leader in shark mitigation efforts, along with Shark Spotters. They really think about the problem, and care about both people and sharks.
If you are not blessed with high coastal terrain and surface-swimming sharks (which would permit a shark spotting program like Cape Town’s one), other shark mitigation measures are in the pipeline… From orca-patterned surfboards (and wetsuits?) to shark exclusion nets to large-scale electrical repellent cables.
The KZN Sharks Board catches a lot of sharks, rays and other animals in their gill nets and drum lines, and this is upsetting and far from ideal. But they facilitate an incredible amount of scientific study, too – their catches do not go to waste.
The KZN Sharks Board is committed to finding measures other than gill nets and drum lines to keep bathers safe, and they are actively working on the problem (refer to the electrical shark repellent cable I mentioned above).
Sometimes scientific research doesn’t look the way you expect or imagine. Ruth Leeney of Protect Africa’s Sawfishes spent months on the ground interviewing Mozambican villagers in the far north of the country to assess the population status of sawfish in Mozambique. She collected data that no one else could have obtained by other means!
Smaller, less charismatic sharks, like catsharks, need more love. There are also whole families of sharks that divers don’t see (such as dogfish) and hence aren’t really aware of. They are caught prolifically as by-catch and not much is known about them. But some smart people are working on this!
There are motivated, talented scientists working hard in South African government departments to protect our marine resources and making recommendations to manage them sustainably. (There’s also many a slip ‘twixt cup and lip, but they are trying very hard.)
Technology – be it cameras, software, or tags – is enabling great leaps in our understanding of what’s out there, which will enable us to protect and conserve things better.
Ocean acidification as a result of climate change could affect sharks directly, by actually wearing away their denticles (tooth-like structures on their skin). Denticles protect sharks and help them to swim faster.
I was tweeting from the symposium twitter account, and along with some of the other attendees we produced a fairly comprehensive summary of each talk, along with some visual media. Here’s a link to the day one compendium on Storify, and it is embedded below:
Diving has been a little on the lean side the past few weeks but that is all set to change tomorrow. The wind dies, the swell is hammering another beach somewhere else, and the forecast is for day time temperatures above 20 degrees. Okay maybe 20.1 degrees, but still, it’s up there. Saturday is going to be best for diving as Sunday looks wild and windy again, so we will launch from Simon’s Town jetty at 10.00am and 12.00pm. I do know there were reports of 15 metre visibility and 4 metre visibility on the same day in the same bay, so I reckon we will go out and look for some clean water and then decide where we dive.
On Monday evening there is a public event at the Bluebird Garage in Muizenberg where a number of speakers will give short illustrated talks about the wonder that is False Bay. There are more details on facebook! We’d love to see you there.
