Monthly Archives: July 2016

  • Are Aliens Taking Over Our Oceans?

    OctopusNo, I’m not making a political claim on behalf of some far right political party! I'm talking about cephalopods. Octopus, squid and cuttlefish numbers are on the rise and gradually taking over the oceans. New research published in Cell Biology tells us that global warming, combined with over-fishing, may have caused a boom in cephalopod populations. Besides being an important source food for many animals, including marine mammals and seabirds, they are predators themselves. They are quick to adapt, are relatively short-lived yet very fast-growing and intelligent enough to exploit new opportunities.168-169-7

    Lead author of the scientific report, Dr. Zöe Doubleday, thinks that cephalopods are very responsive to temperature. Warmer seas might accelerate their life cycles, increasing the amount they reproduce. At the same time, over-fishing has reduced competitors and predators of cephalopods.

    Foodies and culinary experts may think they taste delicious, and supplies are plentiful  but remember: octopuses were probably the first intelligent beings on earth, evolving more than 400 million years ago and some 230 million years before mammals. They have three hearts and three-fifths of their neurons are in their arms, which they can regrow. They’re cannibalistic loners that have sex at a distance using a modified tentacle. Masters of camouflage, not only can they change color when mimicking objects and other animals, they may be able to see with their skin.

    114-115-extra5But are they actually aliens? A study published in Nature has pointed to a study that has led researchers to conclude that octopuses have alien DNA. Their genome shows a never-seen-before level of complexity, with no fewer than 33,000 protein-coding genes identified. That’s more than us!

    Dr. Clifton Ragsdale from the University of Chicago said, “The octopus appears to be utterly different from all other animals. The late British zoologist, Martin Wells, said the octopus was an alien. In this sense, then, our [research] paper describes the first sequenced genome from an alien.”_DSC5953

    This has been a ground-shaking claim for the scientific community, which caused an upheaval among marine biologists who seemed both shocked and intrigued.

    If you want to photograph octopuses, you'll need a good underwater flashgun or photographic strobe unit. This is because they are such masters of disguise they can blend quickly into their surroundings under natural light. By using a pulse of white light, the underwater photographer can ambush them photographically and reveal them in both their texture and colour, separated from the surface they are on and have cunningly replicated. They make good subjects for close-focus wide-angle set-ups as long as you are patient and allow the octopus to become confident that you are not going to harm it.

  • How to Photograph Turtles

    _DSC0466The turtle is an iconic reptile that has fortunately started to make a comeback after nearly being wiped out as a general species in the demand for turtle meat and tortoiseshell before the 1950s. Columbus named the islands we now call the Caymans as Las Tortugas because there were so many turtles. He thought that Cayman Brac and Little Cayman were in fact joined together because there were so many turtles punctuating the surface of the water between them.

    There are several different species including the giant leatherback but the turtles you are most likely to encounter whilst scuba diving are the loggerhead, the hawksbill turtle and the green turtle, so called because of the green tinge to the fat of its meat.

    If you chance upon a turtle whilst underwater, it will usually beat a hasty retreat. It’s no good swimming after it. A turtle can swim a lot faster than you can._DSC1180

    So what’s the secret of getting good photographs of turtles? You might unintentionally ambush a turtle that is swimming through open water and if you are calm and appear to offer no threat, you might be lucky enough that it comes close. Just let it come to you. If you have a fish-eye dome port on your camera that might even entice a hawksbill turtle to approach really closely. It might even give your dome port and exploratory bite, which is when you can get a good close-up. That’s because hawksbill turtles will feed on jellyfish and your dome port looks suspiciously like one. Alas, so do plastic bags and these can be a common reason for the demise of turtles.

    Hawksbill turtles also feed on sponges. A feeding turtle takes its food seriously and this is a good opportunity to approach slowly and carefully with your camera. Appear to offer no threat and the turtle will carry on feeding.

    It’s the same with green turtles but these feed on vegetation like seagrasses and algaes. If you come across a feeding green turtle and approach it cautiously it will ignore you and let you get off lots of shots of it.

    A roosting turtle will also let you get close-up photographs if you do not disturb it. Good places to find large numbers of roosting turtles are Sipadan Island off the coast of Malaysian Borneo and Apo Island in the Philippines. The bigger the turtle the less daunted it is by your approach. Turtles have regular favourite roosting sites so if you dive in the same place day after day, you can usually come back to the spot and find the turtle resting where you expect it to be. Never chase a turtle. You can increase its heart-rate by doing so and cause it to go to the surface for a refill of air before would otherwise need to.

    What sort of camera do you need? Turtles are great subjects for close-focus wide-angle shots. Get a wide-angle or fish-eye wet lens for your compact camera or iPhone in its waterproof case, or go into the water equipped with a wide-angle prime lens behind a dome port. Turtles are iconic creatures and everyone will enjoy looking at the pictures you achieve.Oman0039

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