November 17, 2010
It is a little-known fact that Great White sharks can be found in the Mediterranean Sea, and perhaps even less-well known is that they arrived there some 450,000 years ago from Australia, according to new genetic studies.
According to a BBC article published today:
“Researchers writing in Proceedings of the Royal Society B believe the arrival may have been simply a migratory ‘wrong turn’ by a few pregnant females.
A tumultuous climate between ice ages may have been the cause.
The species – Carcharodon carcharias – would have remained in the Med because it returns to spawn where it was born.
It was previously assumed that the great whites in the Mediterranean were most closely related to their nearby cousins in the Atlantic Ocean.
But now, a team led by Les Noble of the University of Aberdeen has examined the several groups of sharks’ mitochondrial DNA – genetic material passed through the maternal line that is particularly suited to tracing lineages.
The team found that the Mediterranean sharks were very different to the Atlantic group and more like sharks from Australia and New Zealand.”
Great White shark attacks in the Mediterranean
The great white shark is most commonly associated with the coasts of Australia, California and South Africa, but there have been occasions when this increasingly rare animal has been spotted in the Mediterranean. Some experts believe that the Mediterranean is a nursery where great white sharks give birth and raise their young. The Sicilian channel, near the Italian island of Lampedusa, is the only location in the Atlantic region where both pregnant females and newly born great whites have been sighted.
A great white shark was caught in Malta by Alfredo Cutajar in April 16, 1987. This shark was also estimated to be around 7.13 m (24 ft).
The map below shows confirmed sightings of great white of great white sharks in the mediterranean sea since the early 20th century:
September 10, 2010
From time to time a glimmer of hope appears as some honorable, committed individuals stand up for what is right, demand a change to human behaviour that, although it may be ‘traditional’, is just downright barbaric and damaging to the environment we live in – thank you Governer Linda Lingle of Hawaii!
Governor of Hawaii, Linda Lingle, has signed into law a ban on shark-fin soup, according to Reuters. The soup is currently served in a number of Chinese restaurants in Hawaii, but the trade has decimated certain shark species due to overfishing.
Between 26 and 73 million sharks are killed annually for their fins to produce the high-end delicacy in Asia. Sharks are brought aboard ships where their fins are cut off then they are thrown back into the water—often still alive—where they succumb to their injuries.
The trade is seen as the primary driver behind drastic declines in many shark species. The scalloped hammered population has dropped by 98 percent in some regions, while the oceanic whitetip shark has declined by 90 percent in the central Pacific Ocean and 99 percent in the Gulf of Mexico. The IUCN Red List has found that 32 percent of open ocean sharks and rays are currently threatened with extinction, a much higher percentage than mammals or birds.
Earlier in the year eight shark species failed to gain international protection at the Convention on International Trade in Endangered Species (CITES). Pressured by Japan, votes to protect sharks and other marine species failed time and again.
Read full article at Mongabay.com
If you’re interested you can contact Linda HERE to show your appreciation.
September 6, 2010
With the exception of a Great White, or possibly an Oceanic White-tip (on a bad day), nothing terrifies me more than the prospect of meeting a 20ft (6m) Saltwater ‘Estuarine’ Crocodile out in the open Ocean. And apparently that’s not as unlikely as I would have hoped for!
Despite being poor swimmers, researchers have discovered that the saltwater crocodile (also known as estuarine) commonly travels long distances over open oceans by riding ocean currents. The discovery, published in Journal of Animal Ecology, solves an unknown mystery of why saltwater crocodiles (Crocodylus porosus) are found across vast distance in the Pacific, yet have not diverged into different species.
Researchers tracked 27 adult saltwater crocodiles for one year using tags and sonar transmitters. The tagging showed that crocodile individuals, both male and female, regularly traveled more than 50 kilometers from their local rivers into the open sea. One crocodile traveled 590 kilometers in 25 days; another traveled 411 kilometers in 20 days.
The saltwater crocodile’s range extends from India to Fiji and from southern China to northern Australia. They are the world’s largest crocodile species.
Oh man, bring out the cello….
Having read this article I decided to read-up on where in the world precisely I might have a chance of bumping in to (or more like becoming a light snack of) one of these huge ocean-going beasts. Here’s what I found:
perhaps not so surprising that they frequent the region of the planet with the largest bio-diversity – and even less surprising that my number 1 must-see diving destination (planned for 2012) is PNG and is a veritable hot spot for the buggers! Great
September 2, 2010
This is an update to an earlier 2008 post about my previous SD equipment setup.
Stepping up to HD
So finally I took the step up to HD video equipment with the Sony PMW EX1, Gates EX1 housing with 2 x 250W Green Force Squid HID lighting rig. Oh yeah, and I just had to go for the Fathom SWP44C Super Wide Port to top it off.
Having spent two years picking up some basic skills with the Panasonic AG-DVX100 and Equinox housing, it wasn’t until I got in the water with the new EX1 rig that I realised just how little about underwater videography I really knew… but also just what can be achieved when you step up the scale with your equipment.
The entire setup set me back around $23,000 which is well-below market value as I managed to get a great deal on some mint-condition used equipment from a great guy called Joe Holley (@ Marine Visions). For me that’s a great deal of cash but then again, now I have the type of rig that documentary professionals use when their main equipment fails…
- Larger format with greater detail (obviously!) – larger market for selling online clips
- Better all-round vision with external HD monitor – beats squinting one-eyed through the housing
- Fantastic manual control positioning and operation – those Gates engineers are incredible
- Up to 60 frames-per-second for slower playback speed (only available with 720 HD format) – for that NatGeo look, well almost
- Record directly to SxS solid-state memory cards – no tape capturing needed!
- Far better low-light sensitivity reducing video noise and giving sharper footage
- Zoom through capability from 120 degree wide angle to full zoom with Fathom SWP44C port
- A LOT! of light with the Green Force 250 HIDs
And that’s just a small sample of the main benefits I’ve found so far – given the EX1′s capability for firmware and software upgrades, the menu feature options just keep expanding with every update.
- Damn its heavy! about 35lbs (16Kg) in total – try freediving with that and not get the jitters before you jump in
- Extra baggage costs – one-way long-haul extra is generally around $400 extra – almost worth flying business class for the extra baggage allowance, almost…
- Limited recording time on expensive SxS cards – about 2hr of footage on $1000 32GB card
- No focus depth bar indicator on external housing monitor – or at least I’m still trying to work it out (let me know if you have!)
- Customs… I’m now starting to attract the attention of customs officers at destination airports…
So far I’ve only an opportunity to get the equipment wet once during a trip to Turks & Caicos. You can see some low-res sample clips here:
Actually to be truthful, I did get the gear in the water during a trip to South Africa for the Sardine run (you can read more about that disaster here: The Truth about the Sardine Run) but only manage to get some semi-decent dry-land nature shoots:
Future gear thoughts
I’m pretty sure that what I’ve got now is going to keep me busy and satisfied for the next few years but if I was to be keeping an eye on developments for the future for my next kit upgrade, I’d be watching these two:
Red Epic: if Gates decide to do a housing for it that is
Canon EOS 5D Mk11: with Full HD video capabilities I think that digital still cameras are going to start getting interesting for underwater video work. It opens an interesting possibility of being able to do video and still with the same kit – if they can work out how to integrate flash strobe and video lighting in one unit. Certainly the lower weight and size looks attractive compared to schlepping my existing gear round the planet…
September 2, 2010
Unbelievable – nature’s defense strategies never cease to amaze…
Photo by INDEX-SATAL/NOAA
“A free-swimming sea cucumber moves through the freezing waters of a 10,515-foot (3,205-meter) abyss.
The 1,250 known species of sea cucumbers—named for their distinctive shapes—live on or near deep ocean floors or dwell in the shallows. (Watch a video of a “hairy” sea cucumber.)
When threatened, some sea cucumbers can mutilate their own bodies as a defense mechanism: The animals violently contract their muscles and jettison some of their internal organs out of their anuses.”
From National Geographic New Deep Sea picture gallery