Series: Shark Men, Season 2

Shark Men, season 2
Shark Men, season 2

 

Season 2 of Shark Men is more of the same as Season 1 – shouting, HOO-HAAing, chest slapping, and manly bleating. It’s not all complete, unmitigated suffering for the patient viewer, however. There is less focus on the manly art of extreme angling than there is in Season 1, which was a welcome relief.

The first two episodes are filmed at the Farallon Islands, a location off California that swarms with white sharks, and with which Tony and I are familiar from reading The Devil’s Teeth (recommended, with reservations). The team has a permit to capture and tag white sharks there, the first time anyone has been allowed to do this kind of work at the Farallons. Not everything goes according to plan, and the team’s research permit is suspended.

Attempting to tease out the entire life cycle of the southern Pacific white shark population, the Ocearch vessel drops anchor off Malibu in southern California. There they fish for juvenile white sharks, in view of the busy beaches. Surfers and swimmers are largely unaware that they are sharing the water with a white shark nursery. The researchers also return to Guadalupe Island off Mexico, and capture and tag more sharks there.

The final few episodes of this season are the most fascinating – a trip is made to the Sea of Cortez, a squid-rich ecosystem teeming with terrifying Humboldt squid, pods of sperm whales, and other cetaceans. There is a long history of white sharks of various sizes being caught in the area, which makes the researchers suspect that it is a pupping area. It is, however, a popular long lining location, which puts the white sharks in danger of being caught by fishermen.

This season of the show was dogged by controversy. The Farallon Islands permit revocation was of serious concern, and repercussions were felt long after filming completed. A shark known as Junior (or Lucky) was badly hooked and spent a long time out of the water on the Farallon Islands trip while the team attempted to remove the hook from deep in his throat. The shark was later filmed with a terrible injury to the side of his face. The Ocearch team were subsequently exonerated from any blame for the wounds, as Junior’s injuries were from another shark (and sharks bite each other frequently and indiscriminately).

There’s an interview with Chris Fischer and Brett McBride about this season of the show, here. Episode guide here. Get the series here, otherwise try here or here. You may have trouble getting them shipped to South Africa.

Series: Shark Men, Season 1

Shark Men, season 1
Shark Men, season 1

After the controversy, drama, self examination, and ultimately very interesting research that came out of the Ocearch expedition to South Africa early in 2012, we had to watch the television show that made Chris Fischer (amongst others) famous for working with white sharks.

Enter Shark Men, a National Geographic series featuring television personality Chris Fischer (who had something to do with getting the funding, or the boat, or both – try to disentangle it here if you’re so inclined) and Dr Michael Domeier, a respected white shark researcher. The researchers fish for white sharks off Guadalupe Island in Mexico, and then lift them out of the water in a specially modified cradle attached to the Ocearch boat. Water is pushed across the shark’s gills while they’re out of the ocean. The team measure and tag the sharks, and take samples for genetic testing. The sharks are released after 15-20 minutes out of the water.

The Ocearch boat also makes a trip to the Shared Offshore Foraging Area, or SOFA, where white sharks are believed to feed. A (giant) squid-rich ecosystem inhabited by sperm whales is found, and Domeier theorises that the sharks subsist on squid while they’re here. I found the two episodes covering the SOFA trip to be fascinating. There’s nothing special demarcating this piece of ocean – just the patterns made by the migrating white sharks, which show evidence that the sharks move between Guadalupe and the SOFA. Domeier believes that their time at Guadalupe is for breeding, and aims to take sperm samples from mature males to verify this theory.

The science is very interesting. During the course of the filming a couple of improvements in the handling of the sharks is made, of which I approved. There is magnificent footage of huge white sharks in crystal clear water. Unfortunately there is also a lot of testosterone-fuelled shouting, posturing, and remarkably inane commentary from a variety of sources. By the end of the series we wanted to watch with the sound off, it was that bad. The only person who comes off well at the end of it all is the captain of the Ocearch vessel and chief angler, Brett McBride, and it seems to be largely because he shuns the limelight and doesn’t say much.

I hate sport fishing. I think it’s pathetic that humans need to prove their mastery of the natural world by shooting or fishing the earth’s most amazingly put together predators. This show is mostly about fishing, and so I found it mostly repugnant. I understand that good television wouldn’t be the expected result from a quiet, respectful treatment of the shark while it’s being brought to the cradle – which leads me to question whether I think that something like this should be televised at all.

If you want the DVDs, get them here. They’ll only ship to the US, so make a plan (mine involved a friend, and a plane). Episode list here.

Article: Smithsonian Magazine on whirlpools

Whirlpools are like giant squid: one feels that they are almost mythical. They have been the subject of stories, legends and poems, and yet they are real and – if you’re lucky – can be seen and visited.

Simon Winchester, author of Atlantic, writes beautifully of a visit to the Corryvreckan whirlpool between the islands of Jura and Scarba, two of the inner Hebridean Islands off Scotland. I’ve read accounts of diving this incredible (and terrifying) water feature in Rod MacDonald’s books, The Darkness Below and Into the Abyss. His interest in this whirlpool was piqued after seeing it marked on a map, and wondering whether it was really a whirlpool, or whether it would be a disillusioning sign that British map making was not all he believed it to be.

He follows this visit with trips to see other whirlpools, and some research into their provenance. The word maelstrom, meaning a large vortex of water, is derived from the name of a whirlpool called Moskstraumen, in the Lofoten archipelago of Norway. This particular system of eddies featured in an Edgar Allan Poe story (A Descent into the Maelstrom).

Whirlpools are the result of winds, tides and currents interacting with underwater topography, generated when great volumes of water are forced over suddenly shallow outcrops of rock. Winchester says:

In other words, whirlpools—the Maelstrom especially, the others most probably—are fluid marine phenomena that have solid submarine causes. There is the pinnacle that rises underneath the Saltstraumen. There is a shelf of rock that rears up in the Corryvreckan. There are shallows that the charts of Norway show south of Lofoten Point. There are ridges of rock under Japan’s Naruto Strait such as to allow a bridge to be built across it. And a number of near-islands loom perilously beneath the keels of such boats as pass beside the international boundary in the tidal estuary that divides the state of Maine from the Canadian province of New Brunswick.

Shallowing, in short, is what it is all about. A narrow passage, a fast-speeding current, howling winds, large tides—and beneath all of these things a sudden, dangerous, confusion-causing shallowing. When these conditions all combine—then the waters begin to eddy and swirl, vortices are formed, immense sounds begin to thunder, spray fills the air, and all around the region notices are posted to warn sailors that to pass through this or that at flood or the ebb is at your direst peril.

Read the full article here. Highly recommended!

Friday poem: The Kraken

What is a kraken? It is a legendary sea monster supposedly found in the seas off Scandinavia and Greenland. The legend probably arose from sightings of giant squid.

Here is an irregular sonnet (it has one extra line, at fifteen) on the subject. Good to read aloud.

The Kraken – Alfred, Lord Tennyson

Below the thunders of the upper deep;
Far, far beneath in the abysmal sea,
His ancient, dreamless, uninvaded sleep
The Kraken sleepeth: faintest sunlights flee
About his shadowy sides: above him swell
Huge sponges of millennial growth and height;
And far away into the sickly light,
From many a wondrous grot and secret cell
Unnumbered and enormous polypi
Winnow with giant arms the slumbering green.
There hath he lain for ages and will lie
Battening upon huge sea-worms in his sleep,
Until the latter fire shall heat the deep;
Then once by man and angels to be seen,
In roaring he shall rise and on the surface die.

Article: Outside on Humboldt squid

The Humboldt (or jumbo) squid is a giant (can be over 1.5 metres long), extremely intelligent, ruthless predator that will not hesitate to engage in cannibalistic behaviour. They are named after the Humboldt Current that flows along the west coast of South America. They exist in huge numbers, can swim at up to 24 kilometres per hour – which is very fast in the water – and move about in large shoals. Their skin colour can change rapidly from white to red and back again, and while they prefer deep (over 200 metres) water, they are found in shallower waters too, particularly at night.

Tim Zimmermann wrote an article for Outside about the slightly lunatic (but awesome) sounding Scott Cassell and his work photographing and diving with Humboldt squid in the Sea of Cortez. Cassell is a number of things – counterterrorist specialist, professional trapeze artist, and experienced diver. He has done some cool stuff  and is a character well worth reading about.

Humboldt squid have been aggressive (or boisterous, if you don’t want to anthropomorphise) towards divers, so various precautions are taken when getting in the water with them. Among these are safety lines clipped to the boat so that divers cannot be dragged deeper by a squid pile-on, and the use of fibreglass body armour to protect against the clinging tentacles of the squid. It sounds absolutely thrilling.

Read the full article here.

White Sharks – Migratory Patterns and Habitat Use

This post follows on from my review of Global Perspectives on the Biology and Life History of the White Shark. That book (a collection of scientific papers) is divided into three sections, and I’m going to highlight papers that I found particularly interesting in each of the sections. Here’s the first series of posts I did, on Biology, Behaviour and Physiology:

There are several known white shark “hotspots” around the world (of which South Africa has a couple) where fairly extensive work has been done to tag and monitor sharks that frequent these locations.

Fine-Scale Habitat Use by White Sharks at Guadalupe Island, Mexico – Domeier, Nasby-Lucas, Lam

Guadalupe Island, about 300 kilometres off the Mexican mainland in the north eastern Pacific Ocean, is one such hotspot. It is a pupping and haul-out (resting!) site for three kinds of seal and sea lion. The seals come and go, fluctuating by species throughout the year. The researchers found that the sharks moved around the island seasonally, positioning themselves near the current aggregation of whatever species of pinniped was peaking. They also noted that during certain months the sharks dived deeper around the island, possibly also corresponding to predation on a different kinds of seal.

Sex-Specific Migration Patterns and Sexual Segregation of Adult White Sharks, Carcharodon carcharias, in the Northeastern Pacific – Domeier, Nasby-Lucas

The Northeastern Pacific White Shark Shared Offshore Foraging Area (SOFA): A First Examination and Description from Ship Observations and Remote Sensing – Domeier, Nasby-Lucas, Palacios

White sharks tagged at both Guadalupe Island and in central California have been shown to spend time each year at a location known as the “shared offshore foraging area”, or SOFA for short. The first of these papers determined the seasonal pattern of shark presence at the SOFA. The males can spend as much as 9-10 months offshore, in a moderately concentrated area (95% of the tagged sharks stayed in an area of diameter 1,000 kilometres, so not THAT concentrated). The SOFA was observed to be a cetacean “dead zone” inhabited only by sperm whales and no other cetaceans. The female sharks did not spend much time in the SOFA, but instead roamed through a very large stretch of ocean that overlapped with it somewhat.

There are fairly extended periods of time when the sexes are completely segregated. The authors propose one or two reasons for this. One is that female white sharks grow much larger than the males, and thus have different energy requirements. This may cause them to forage elsewhere.

The second paper recounts the results gained from sailing a research vessel out to the SOFA, performing transects, scanning for marine animals, and analysing other aspects of the site. The vessel found the area to be characterised by downwelling, no major temperature shifts, very little plankton, and very little horizontal movement. It also found no small cetaceans, but identified sperm whales and three kinds of spawning squid. (White sharks are known to eat squid.) The presence of these apex predators (white sharks, sperm whales, squid) suggests that there’s a lot more biomass supported in the deeper water that wouldn’t be evident from a surface survey.

A New Life-History Hypothesis for White Sharks (Carcharodon carcharias) in the Northeastern Pacific – Domeier

The tagging studies performed at the Farallon Islands and at Guadalupe Island off Mexico have allowed a new hypothesis regarding the life history of white sharks in the north eastern Pacific. Domeier speculates that white sharks may begin their lives in the shallow waters of southern California and may spend their first year in the region. This corresponds to an area where the Monterey Bay Aquarium has acquired juvenile white sharks caught by fishermen for their exhibits.

As the young sharks get larger, they can tolerate cooler water and are thus able to dive deeper and migrate further. Their diet changes from fish and invertebrates to marine mammals such as seals. As they mature, the males begin an annual migration to either Guadalupe Island or to the Farallon Islands and surrounds, off central California. Males from both the aggregation areas visit the SOFA mentioned above, while females range more widely.

The females only visit the aggregation sites every second year, presumably because of an estimated 18 month gestation period during which they spend 15 months at sea. It is believed that mating takes place at these aggregation sites. The females then return to the coastal regions off southern California and Mexico, between May and August, to give birth. They then return to one of the aggregation sites.

This kind of synthesis of previous studies enables the identification of regions where sensitive white shark populations may exist, such as the pupping grounds off California.

~*~

Several papers in this section are devoted to the behaviour and movements of juvenile white sharks off Australia, with a view to better understanding their movements in order to minimise interactions with beach users.

Seasonal Sexual and Size Segregation of White Sharks, Carcharodon carcharias, at the Neptune Islands, South Australia – Robbins, Booth

The sexual and size differences between white sharks present at the Neptune Islands in southern Australia was studied by the authors. They found similar sexual segregation to that observed in the north eastern Pacific studies. They found that larger white sharks visited the islands during the austral winter and spring (June to September). The female sharks seemed to prefer warmer water temperatures, perhaps as an aid to embryonic development when they are pregnant. Far more male sharks than females were identified (for mature sharks, the male:female ratio was 12:1).

The Third Dimension: Vertical Habitat Use by White Sharks (Carcharodon carcharias) in New Zealand and in Oceanic and Tropical Waters of the Southwest Pacific Ocean – Francis, Duffy, Bonfil, Manning

The authors analysed the data from 25 white sharks tagged in New Zealand, as they commenced long-distance migrations across a wide range of habitat types to the south west Pacific Ocean. While on the continental shelf the sharks remained in water less than 50 metres deep (this counts as “shallow” if you’re a marine animal), but during the open ocean migration phases they alternated between being on the surface and doing dives to depths between 200 and 800 metres. One shark went to 1,200 metres. A reminder that it’s pretty much pitch dark down there once you get beyond about 200 metres!

Once they entered the tropical regions, the sharks remained in the top 75 metres of water but coninued to dive deeply. Their dives often corresponded to a 24 hour cycle, with the sharks spending more time diving during the day than at night. The reasons for this could be many, but the sharks may have been navigating at night, or feeding on the creatures that pursue the plankton migrating towards the surface in the darkness.

The behaviour varied widely among the tagged sharks, and more studies in other regions will enable better understanding of why the sharks behave as they do in the various ocean habitats.

Article: How stuff works on marine mammals and more

Here’s some more goodness from Howstuffworks.com… This time something on marine mammals:

And some other marine creatures:

Finally, some links on moving about in the ocean…

Bookshelf: The Search for the Giant Squid

The Search for the Giant Squid – Richard Ellis

The Search for the Giant Squid
The Search for the Giant Squid

Richard Ellis, author and artist of all things oceanic, turns his attention to the giant squid. This creature has never been observed in the wild, which makes this book a frustrating read in some respects (through no fault of Ellis’s). They have washed up with some regularity on beaches around the world, and have been seen on the surface on occasion.

They can grow to epic proportions, and with their grasping tentacles and huge eyes they have captured the imagination of authors and filmmakers with great vigour. Ellis looks at the giant squid in popular culture – chapters which didn’t grip me as much as the biology, behaviour (speculated) and habitat chapters did. He also deals with the mortal enemy of the giant squid, namely the sperm whale.

Unlike other squid, giant squid are neutrally buoyant and thus don’t need to swim all the time. To achieve this their bodies are full of ammonia, which is lighter than water but makes their flesh taste awful. Squid in general have incredibly thick nerves (up to 100 times thicker than humans) which facilitates their almost instantaneous reaction times – and being able to swim in either direction helps. They don’t have a “front” and “back” as such! They are speculated to remain stationary in the ocean depths, waiting to surprise their prey.

Given that his subject is so elusive and that (despite there being many people who study giant squid for a living) much of the material on its lifestyle is speculative, Ellis doesn’t have a lot to work with here, but he does an incredibly good job of illuminating the current state of giant squid research. This is a fascinating read.

You can buy the book here if you’re in South Africa, otherwise buy the book here.

xkcd: Desert Island

Desert Island

James and Claire gave me the xkcd book for my birthday this year. It’s unashamedly geeky humour, and I love this particular cartoon (not in the book) so much that I’d consider getting it tattooed on my back.

Okay, not really, but I do like it very, very much!