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Blue Shark

Blue Shark

An account of photographing blue sharks off Cornwall, Southwest Britain, a few years back, and a link to buying blue shark fine art prints of these amazing hunters of of the oceans at colinmunroimages.com.

On a clear July morning I stumbled out of my bunk (I was living on a boat at the time) at 5.30am, forced out my the insistent buzzing of my phone alarm. One hour, and one strong coffee later, I squeezed my dive bag into the back of Ritchie’s car and we were off. We had over a hundred miles to cover, and a boat to catch.

Blue shark swimming through clear blue water. Cornwall. © Colin Munro Images
A Blue shark, Prionace glauca, swims leisurely through clear blue water off Cornwall, UK.

Charles Hood runs the best, and most successful, blue shark snorkelling operation in the UK. His boat, a large rigid-hulled inflatable (RIB) operates out of Penzance, almost at southwesternmost extremity of the British mainland, so that’s where we were headed. The boat is a fast open boat, perfect for getting us 10 miles offshore quickly, but small and devoid of any shelter from the elements. So we changed in to wetsuits on the quayside, packed our camera gear in dry bags carefully padded with towels and sweatshirts for the bouncy ride out, and we were off.

Blue shark fine art prints. buy fine art prints of a blue shark. Colin Munro Photography www.colinmunroimages.com
Blue shark, Prionace glauca. A female blue shark swimming close to the surface off Southwest Cornwall, UK. Blue sharks are easily recognisable by their slender form, long pectoral fins and vivid blue colour. Like many shark species they are counter-coloured, blue on their backs and white below. Blue sharks are found off Southwest Britain between July and October. For reasons that are still not fully understood it is most females that are seen in British waters. Female blue sharks can be recognised by the absence of of claspers on their belly; sexually mature female blues will often have prominent scars of their head, neck and back. These are mating scars causing by bites from the male blue shark during mating. Blue sharks are found in all major oceans, in temperate and tropical waters.

Each year blue sharks arrive off the coast of Southwest Britain, normally sometime in mid-June and remaining until mid-October. Blues are true oceanic sharks; they inhabit deep water, only infrequently venturing on to shallower, continental shelf waters. They are found in tropical and temperate oceans around the globe. However, in the tropics they tend to stay in deeper, cooler water but are often observed in surface waters in temperate seas. They feed on fast moving prey such as squid and schooling fish. Much of their feeding appears to be done in deeper waters. We know this partly from studies looking at gut contents, identifying the hard tissue remains of the prey species, and knowing where those prey species live, and partly from small data loggers, recording depth profiles, that are attached to sharks and then recovered at a later date. Below 100 metres, it seems they predate mostly on squid, in particular those belonging to the Histioteuthidae family, more commonly known as cock-eyed squid. Cock-eyed squid are bizzare creatures that inhabit the twilight zone of the oceans, so-called because their left eye is around twice the size of their right. Observations with deep water remotely operated vehichles (ROVs) have shown that they swim with the left eye facing upwards, and the right facing down. It’s believe the the huge left eye is used to pick up the faint sunlight coming from far above; the smaller right eye, staring into the depths, serves a quite different purpose. It picks up bioluminecent glows and flashes from prey (or predators below). But blue sharks are not fussy eaters. Studies off the coast of Brazil have found they eat large numbers of oilfish (a deepwater member of the mackerel family) but will also sometimes grab seabirds such as shearwaters. Those off Southern Brazil were found to be mostly scavenging on dead baleen whales. But I have digressed somewhat from our trip. Some ten nautical miles out Charles stopped the RIB and allowed us to drift. Sure we were a fair way from shore, and in pretty deep water, but still well within continental shelf depths, probably 50-70 metres, as we drifted. The 100 depth contour was still over 20 miles distant. So what tempted the blues, normally oceanic species, this close inshore? As we drifted Charles began to prepare the chum bag that hopefully would draw nearby sharks to our boat. A small hessian sack was filled with chunks of mackerel and mackerel guts, including some caught angling off the stern of his RIB. Tied just off the side of the RIB, a slick of fish oil drifted away down current. This is the clue to why blue sharks arrive in coastal waters of southern and western Britain. Mackerel also arrive around British coasts during the summer months, often found in huge shoals numbering thousands of fish. Like their deeper water relatives, the oilfish, mackerel are an oily fish, so a high energy food source for any predator fast enough to catch them. And the blue shark is just that; generally a sedate swimmer it can move with lighting bursts of speed.

Once our bag of chum was positioned, and final checks on cameras completed, all we then had to do was wait. Charles dug out his fishing rod and started supplementing our chum supply with a few extra mackerel. And we waited. There was no wind, and just a slight, rolling swell on the sea. The sun was hot and the sky a clear blue, so it was not extactly a hardship. The sun climbed to its zenith, then slowly fell westward as morning gave way to afternoon. We were woken from our torpor when, around 2pm, a group of three sunfish drifted close. Sunfish are odd-looking disc shaped fish. They feed on There was a flurry of activity as we grabbed cameras and donned fins, but they were skittish and disappeared in seconds. We settled back in to watching and waiting. At around 3.30pm Charles announced that we should start heading back to shore at 4pm. The minutes ticked by; 4pm arrived and still no blues. Charles apologised but, as we were well aware, there is never any guarantee with wildlife. He announced we would give it another 20 minutes. At 4.15 the first blue arrived. Rather than leap in immediately, we gave it time to settle and get used to the boat. A couple of minutes later a second arrived. Charles had been very clear on the safety aspect, wearing gloves, no shiny jewellery. The necessity for this was made abundantly clear when one of the sharks managed to grab to chum bag. Its razor sharp teeth ripped through it like paper, and bits of mackerel guts spilled out into the water. The bag was quickly quisked out of the sea and we gave it a minute for the cloud to disperse. Once Charles was confident the sharks were no longer likely to disappear immediatly, we, one by one, slowly slide over the side of the boat and in to the water.

Richie fires off a couple of snaps as a blue passes beneath him.

Once in the water I dipped my head to check all around me, then slowing finned away from the RIB. Once around 8 metres away I stoppped finning, and started checking around. I could clearly see my three companions at this stage, floating 5-10 metres away from me. Every so often a shark would cruise in, swimming below or between us, to to check out us or the RIB. The water was clear, visibility a good 15-20 metres, but the sun was now low in the sky. When the sun is overhead, and light hits the waters’ surface more or less perpendicular, then much of that light penetrates the surface; but late afternoon, when the sun is low and its rays hit the water at a shallow angle then most of that light bounces off the surface and it becomes markedly darker just below than above. My photographic problems were two-fold. The reduced light levels made focussing a little trickier, and when a blue shark came fast out of the expanse of blue water, the camera would struggle to pick up contrast and focus quickly. I fiddled with the settings, pre-focussed using my colleagues as targets, fired off test shots and again readjusted my settings. All the time keeping looking around me. A RIB, with its large surface area above the water, will drift with wind and tide, but a swimmer, around 90% below the water’s surface, will drift with the tide alone. So as I floated I was aware that the distance between was growing. This was not a concern; conditions were perfect and I knew Charles would be fully aware of our positions. On the contrary, it gave me space around me. As I drifted I also became aware that one of the sharks had become interested in me, and was moving with me, not steadily but zig-zagging. It would pass close, then swim off , to turn and pass close again.

A blue shark checks me out during our dive off Cornwall. © Colin Munro Images
A curious blue checks me out; maybe checking its reflection in my camera dome port?

This was not in a threatening or aggressive manner, but rather one of curiosity. A couple of times it would swim straight towards me, only to stop maybe 18 inches in front of me. Whether it was seeing reflections in the large glass dome port of my camera housing I am not sure. Whatever the reason it provided me with more perfect photo oportunities than I could have hoped for. Thirty minutes passed in what seemed like three, and Charles was recalling us to the RIB. We may have had to wait, but performace at the end far exceeded our expectations.

Fine Art Prints

I have made two of my images from this trip available as fine art prints and wall art. These are available to be purchased in a wide range of media and sizes directly from my Colin Munro Images website. Media available include traditional giclée prints, stretched and flat mounted canvas, metal prints (dye directly infused on sheet aluminium) and acrylic, from 8 inches up to 48 inches across. My prints are produced by Bay Photo Labs in Santa Cruz, California. I choose bay Photo Labs for the excellence of their quality, with over 40 years providing printing services to professional photographers, their constant innovation, combining the latest technology and innovation with the finest traditional techniques, and their committment to the highest environmental standards using green technology. You can buy my prints directly here at www.colinmunroimages.com.

How can I buy fine art photographs if I am not in North America?

I also use excellent printers in the UK, and Bangkok, Thailand. If you are in Europe or Asia, please email me with the photo code, the print style and the size, and I will arrange for it to be delivered from either UK or Bangkok. If you are elsewhere in the World, and would really like to buy one of my images as a fine art print, drop me an email and we’ll see what I can work out. (My www.colinmunrophotography.com site showcases my fine art photographic prints printed in the UK. You can also buy prints directly).

I am slowly moving my marine biology orientated blogs to my other blog site: www.marine-bio-images.com/blog. I may eventually remove them from this site. This article can now be found here.

Blue sharks, graceful sea wolves

Blue shark, Prionace glauca. A female blue shark swimming close to the surface off Southwest Cornwall, UK.

The blue shark, Prionace glauca, is possibly the most beautiful of sharks.  It is a slender, fast and graceful shark, but it is the vivid, almost electric blue colouration that is most striking.

Blue shark, Prionace glauca. A female blue shark swimming close to the surface off Southwest Cornwall, UK.

A blue shark passes close by.

Blues are oceanic sharks, uncommon in shallow coastal waters.  In the tropics they are normally found in deeper, cooler waters, but in temperate seas they are more likely to be found in surface waters (thus are described as being epipelagic).  This does not mean that in temperate waters they occur only in the warmer surface layers.  Recent data from satellite tags have shown that they blues may regularly undertake dives to more than 1000 metres.  One male blue shark, nicknamed Bodi by the researchers, was logged as having dived to 1250 metres off the Bay of Plenty (New Zealand) three weeks after being tagged in 2013.  An earlier joint British- Portuguese study recorded a female blue shark diving to 1160 metres off the coast of Portugal (Queiroz et al, 2012).   This behaviour is probably linked to hunting activity.  Blue sharks are quite catholic in their diet, eating a wide range of mid-water fish and cephalopods,  but appear to be particularly fond of squid, and of course squid will often undertake marked vertical migrations, with many species occurring at considerable depth.  That this deep diving behaviour of blues is primarily foraging for food is supported by a preponderance of deep water quid species found in the gut of contents of blue sharks caught by long-lines, in particular the wonderfully named vampire squid, Vampyroteuthis infernalis, a small deep-water squid those scientific name literally translates as the vampire squid from hell.

In the northern Atlantic at least, they appear to undertake seasonal migrations. They are unusual amongst ocean sharks in that they will sometimes aggregate in groups, often all same sex, as they roam.  This pack-like activity has lead to them being dubbed the wolves of the sea.  Around Southwest Britain blue sharks start to appear in June each year, and hang around until late October or early November.  Although there have been attacks on humans by blue sharks, aggressive behaviour is relatively rare.  Certainly in British waters, where large blues are rarely seen, most are quite timid and easy to scare off accidentally.  The largest blue caught in UK waters was approximately 2.5 metres long and weighed 107kg. This was caught off Penzance, Cornwall, in 2012 (but was also released).  Blues can grow up to 3.5 metres or more (the largest on record was 3.83 metres long) the females being significantly larger than males.

Blue shark, Prionace glauca. A female blue shark swimming close to the surface off Southwest Cornwall, UK.

Blue shark, Prionace glauca. A female blue shark swimming close to the surface off Southwest Cornwall, UK.

An underwater encounter with a blue shark is a wonderful experience, and provided one takes sensible precautions (i.e. wearing gloves, not wearing shiny bits of equipment and NOT trying to feed them) is normally quite safe.  Blue sharks have been one the shark species hardest hit by the practice of shark fining in various parts of the World and there numbers appear to have declined markedly.  Consequently it’s worth remembering that most blue sharks have far more cause to fear us that vice versa.

The above, and more of my blue shark images, can be found on my stock image website www.colinmunroimages.com. They can be licensed for publication, or purchased as fine art prints and canvas wall art.

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References cited: Queiroz N, Humphries NE, Noble LR, Santos AM, Sims DW (2012) Spatial Dynamics and Expanded Vertical Niche of Blue Sharks in Oceanographic Fronts Reveal Habitat Targets for Conservation. PLoS ONE 7(2): e32374. doi:10.1371/journal.pone.0032374

 

Photographing Blue sharks off Cornwall

Blue shark, Prionace glauca. A female blue shark swimming close to the surface off Southwest Cornwall, UK.

A few days ago I was fortunate enough to get in to the water off Cornwall with a couple of blue sharks (Prionace glauca).  Getting some good images of blues had been high on my ‘to do’ list for several years, but for one reason or another it had not happened. In part this was a result of the dreadful summers we have had in the UK for the past few years; wet and windy and severely limiting the number of days when it was possible to spend all day offshore in a small boat (and limiting even more the number of days one would want to). This summer has so far been perfect, high temperates and light winds.

Blue shark, Prionace glauca.  A female blue shark swimming close to the surface off Southwest Cornwall, UK.

Blue sharks are highly migratory, with strong evidence for there being a single well-mixed population within the Atlantic Ocean and seasonal trans-Atlantic migration.  Some studies indicate a crosswise annual migration across the temperate zone of the Atlantic but evidence for this is inconclusive.  What we do know is that blue sharks start to appear off the tip of Cornwall in early July and remain around Southwest England until late September.

Blue shark, Prionace glauca.  A female blue shark swimming close to the surface off Southwest Cornwall, UK.

Off the tip of Cornwall is one of the best areas to see blues; it also has the advantage of exceptionally clear water.  Most are found at least five miles offshore, so with the longish drive an early start was required.  By 10a.m. we were drifting with the current, a nice fish oil slick trailing from our chum bag, cameras ready and waiting.  The sky was blue, the sun hot, the sea ruffled by a light breeze and our spirits were high.  And we waited.  Mid-afternoon a brief flurry of excitement: two sharks arrived within the space of an hour, grabbed our mackerel bait….. and disappeared.  By 4.30pm our hopes were fading and our thoughts turning to when we could schedule the next trip.  Suddenly at 4.45pm a third shark arrived.  A smallish female, probably around 5ft, but most importantly she showed none of the skittishness of the previous two. She was interested in the fishy smell from our chum bag and she was hanging around.  It took a real effort of will to stay calm, remain on the boat and allow her time to settle – what if she also suddenly disappeared?  However, after a few minutes Charles, the boat skipper, gave us the nod and Richie and I slipped gently and quietly in to the water.  As we swum towards her she showed no fear at all, appearing quite curious about us, to the extent that she temporarily lost interest in the chum bag and began cicling us as we drifted slowly from the boat.  Time and again we would swing around to make close passes, to the extent that she occasionally had to be gently pushed away as she came nose to nose.  A more obliging photographic model I could not have wished for.  Around 20 minutes passed in a flash, at which point she became bored with us and disappeared.  Yet no sooner had we climbed back in to the boat than a larger female arrived.  She definately wasn’t timid; before anyone could react she had grabbed the chum bag and was tearing it to pieces.  Within seconds the water around the boat was a murky brown from the contents of the chum bag and the bag itself shredded.

This was too good an opportunity to miss, all four of us hit the water.  She was a real beauty.  Between 6 and 7 ft long, the most dazzling vivid blue on her dorsal surface with deep indigo patches near her dorsal fin, pure white on her underside.  As she passed close the mating scars left by the males teeth could be clearly seen on her head neck and back.  For more than 30 minutes she hung around. circling us.  It was almost 6pm when we finally climbed out of the water.  Tired but very happy.

passing under a snorkeller

Our trip was on board the RIB of Charles Hood (charleshoodphotography.com).  Charles regularly runs basking shark and blue shark trips from Penzance, Cornwall.  I would heartily recommend him.

All my blue shark photographs are available for licence and some as fine art prints along with all my other stock images at http://colinmunro.photoshelter.com. Or you can contact me directly email me

Signed canvas prints and photographs of my work can be bought through my Etsy Store

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