Category Archives: sharks

Nurse Sharks of Belize — indahs: dive, travel & photography

22nd edition of Marine Life monthly post. Marine Life post published every 19th of the month. It aims to share information on marine life species and to promote their conservation. The Nurse sharks are a common sight when scuba diving in Ambergris Caye (Belize). They usually swim in a group and a chance to meet two […]

via Nurse Sharks of Belize — indahs: dive, travel & photography

Greenland sharks can live to 400 years old, only reach sexual maturity at 150

Researchers using radiocarbon dating have determined that Greenland sharks, slow-moving giants that live in the cold, dark waters of the North Atlantic, are the longest-living vertebrates on Earth, with one recorded as being 400 years old. Which explains the old Greenland shark quip that goes something like: “God must like practical jokes; why would He make […]

via Scientists say Greenland sharks can live for 400 years — The Cotton Boll Conspiracy

Sharks smarter than we think (and probably smarter than the average shark-hater)

Some great UWA research is being reported as showing sharks have better comprehension of their surroundings and are “smarter than we think” – though I presume that means smarter than most clueless people would have thought.

danny green shark

That one time boxer Danny Green next to a dead mako and everyone went crazy. Photo credit: Danny Green

Yes, it’s obvious that scientists are still learning how sharks think, what their motivations are to make long distance swims and even (for any species) their relatively little-known mating and breeding habits. But whenever I see interesting articles in the general media, it still bugs me to read reader comments about how bloodthirsty and stupid sharks are, from people who clearly know nothing about them firsthand.

Anyway, here’s some grabs from the article and I’m sure Dr Yopak is tired of having to always dispel these misconceptions:

University of Western Australia researcher Kara Yopak presented her research into the use of brain anatomy to understand cognitive ability in sharks.

Dr Yopak said it was a common misconception that “sharks are these small-brained pre-programmed eating machines”.

“They are actually relatively large-brained species and they are capable of such an incredible range of complex behaviours,” she said.

Part of her research involved comparing the brains of sharks to mammals, including humans.

“There is a number of similarities that I would say have originated at least as early as sharks and then have been carried through vertebrate evolution to our own brains,” she said.

Dr Yopak said the brains of sharks varied across different species, casting doubt over the effectiveness of one-size-fits-all shark deterrents.

“When we are investigating repellents we probably need to take a species-specific approach,” she said.

Shark Attack 2: Revenge of the Tabloid Headline Writer

Sydney's Daily Telegraph, constant offenders on the 'savage man-killing shark' front

Sydney’s Daily Telegraph, constant offenders on the ‘savage man-killing shark’ front

When I was Sydney last October, preparing for the IUCN World Parks Congress with the French marine protected areas agency, this headline above was splashed in similar formats across several Australian newspapers.

Shark scientists were kept very busy responding to misinformation, stupidity and downright dangerous reporting in the Australian spring and summer – and this headline (and the strapline above it about the ‘4.5m monster’ shark) summed up the challenge they and shark conservationists face. It was absurd for the writer and editor to let this go through:

  • the surfer’s arms were not ‘ripped off’, the writers make it clear in the introduction that he lost parts of both arms
  • a 4.5m shark (if that was even the correct size) is not a monster in size. If it had been a validated sighting of a 6m white shark, I would have been more impressed.

My most popular article from this irregularly-updated blog is another shark attack post that made exactly the same criticisms I can make two years later. I image the people googling that phrase came across the post, saw it was attaching the whole tabloid concept of ‘shark attacks’ and left to find juicy photos of actual shark encounters.

Because that’s what these incidents are: encounters. The increased populations around coastal areas in the warmer months, coupled with overfishing of shark prey species, surfers spending longer in the ocean due to thicker and more comfortable wetsuits, climate change and other unpredictable factors, is leading to more encounters with sharks. And if one in 1000 of those encounters ends in a shark bite, we shouldn’t be surprised every time and call for that shark’s head. This only supports the view of shark fishers that they are removing dangerous animals from the ocean, rather than murdering an endangered animal (in the case of some shark species).

Australian Geographic posted a great article about shark research that revealed we are to blame for shark attacks due to the factors mentioned above. And no matter how big a year we have for shark ‘assaults’, it pales in creation to deaths from car crashes, domestic injuries and even bee stings:

So far in 2011, there have been at least 61 recorded attacks and 10 deaths. However, compared to deaths from smoking, road accidents, lightning strikes or even other animal attacks, the risk is minute, say experts.

So please can we stop with the tabloid shark bashing, stick to the boring but correct title of shark encounters and help target the real villains in this debate: fishing trawlers that are destroying the shark-prey food chain and governments who keep approving shark hunting after each encounter in the misguided view that killing that one ‘manhunter’ shark will end the chance of any further shark bites.

Bull sharks – salinity tolerance little-studied despite river attacks

While putting together a presentation for a Marine Biology subject on lionfish (and throwing in the recent controversy over plagiarised lionfish research), I struggled to find much research on an equivalent marine creature that has developed the same low salinity tolerance.

There were papers on the more well-known euryhaline species (those that tolerate wide ranges of salinities) but surprisingly little on bull sharks (Carcharhinus leucas) and their emergence as key predators in northern Australian rivers and lakes. This is strange given the heavy reporting on shark attacks far upstream in the Brisbane Times, Courier Mail and ABC TV among others.

Juvenile bull sharks have even been found in golf course lakes and unconfirmed reports stated there have been sightings in the Wivenhoe Dam. From what I could find in my research, freshwater bull sharks had a less-developed rectal gland (along with kidnyes, responsible for salt excretion) than their marine cousins and adults were less likely to shift back into marine waters from their freshwater range.

As for competition with longer-term inhabitants of the region:

 

Shark Week snubs scientists, increases fear of sharks

As is becoming common this time of year, my Twitter feed has been swamped with Shark Week vitriol – from swimmers who are now more afraid to go in the water to scientists angry at the lack of consultation that goes into a few of the fake documentaries appearing during the event.

Apart from the fact Discovery Channel ignores the rest of the world when it comes to sharing Shark Week with non-Americans, from what I’ve seen of the clips there seems to be a dearth of well-researched, informative programming.

Christie Wilcox writes for the Discover Magazine and her summaries of the week should be required reading for anyone watching Shark Week, including this post on falling ratings and viewer angst:

“It’s the third day of Shark Week, and Discovery has already come under fire for their programming choices. Their big special on kick-off night—Shark of Darkness: The Wrath of Submarineturned out to be another fake documentary, making up people and events to perpetuate the idea that a 30+ ft long great white patrols the coast of South Africa. The legend of Submarine is a particularly fishy topic choice, as its origin can be traced to the 1970s when some journalists decided to make up a story to see how gullible their readers were.”

As some commenters have noted this week, if the focus was spread from great whites to lesser-known threatened species of sharks, their public profile and survival chances might improve. A great white throwing a seal pup in the air or biting a cage might make for exciting TV but shouldn’t the week be about promoting all sharks, not just the most photogenic ones? 

New year, same attack on the sharks

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Around this time last year, fishermen were hanging up their prize catches in a big annual fishing competition here in Warrnambool.
One of the fish that brought the biggest crowd was a 110kg mako shark- a common enough catch in Southern Australia but still of concern given the huge global exploitation of various shark species.
The Standard newspaper posted this photo yesterday of an 81.3kg mako from the first 2014 competition and it looks like nothing has changed – same happy crew posing with a trophy shark that may win them more praise than competition prizes. Catch and release should be the protocol for fish such as this: get the photo on the boat, have it signed off by judges and leave the fish in the ocean. The article stated that fishers in the competition had caught “several sizable Mako sharks”.
A local fishing group has been criticised lately for its targeting of unnecessary species for competition points, criticism that was definitely warranted. I attended one of their club meetings recently and a few members were complaining about fishing restrictions that stop them racking up points for certain species. Given that one member caught more than 30 fish in two days, some of which were inedible or destined for the closest rubbish bin, their whinging seemed pointless.
These groups may slowly understand the effect of their ‘overfishing’ when they pull in less the next year or have to hunt harder for elusive species (just like the global commercial industry).

Australian Government Scraps Management Plans For New National System Of Marine Reserves

With the international flak over its shark culling programs and threats to the Great Barrier Reef, Australia should be working hard on other fronts to promote its ocean conservation agenda. Sadly, the Coalition Government is intent on making things worse for those who care about the ocean and instead assisting commercial fisheries with its removal of some marine park protections.

Thanks to MPA News for the article below. To view an updated map of global marine protected areas, visit Protect Planet Ocean.

The new Coalition Government in Australia, elected by national vote in September, has scrapped management plans developed by the prior Labor Government for most of the nation’s representative system of MPAs.  The impacted MPAs are the 33 sites that were designated in 2012 by the Labor Government.  The dropped management plans would have taken effect in July 2014.

The impacted sites increased the national MPA system last year from 27 sites to 60, expanding the system to a total of 3 million km2 (MPA News 14:3 and 14:1).

The sites include the 1-million km2 Coral Sea Marine Reserve, of which roughly half would have been no-take under its now-dropped management plan.

Environment Minister Greg Hunt told MPA News in October that the new reserves were “imposed without fair or adequate consultation” of industry, and would unfairly lock out recreational fishermen from large areas of the ocean (MPA News 15:2).  He said the sites’ management must be reviewed and redeveloped before final management plans are adopted by Parliament.

The management plans for the 33 sites were passed by the Australian House of Representatives – one half of Parliament – earlier this year.  Some conservationists anticipated the Senate – the other half of Parliament – would pass the plans, too, in coming months, thus making the plans law.  But the Coalition Government scrapped the plans on 16 December by having the nation’s Governor-General re-proclaim the reserves, effectively restarting the management plan development process.

However, the Coalition Government stopped short of calling for a review of the sites’ boundaries.  The boundaries will remain as designated under the Labor Government, although for the time being they are simply lines on a map.  Their designation one year ago followed a series of six phases of public consultation conducted by the Labor Government, with strong support from conservation organizations and opposition from several fishing industry groups, including commercial and recreational ones.

A review of the management plans, expected to last about six months, will now begin.  The Government will appoint a scientific panel and several Bioregional Advisory Panels to facilitate and improve consultation with stakeholders.  The make-up of the panels will be announced in early 2014.

Environment Minister Greg Hunt’s statement on the MPA management plans:

http://bit.ly/managementplans

Statement by Australian Recreational Fishing Foundation on scrapping of MPA management plans:

www.recreationalfishing.com.au/index.php/rss/31-coalition-government-delivers-on-marine-park-promise-to-australia-s-5-million-recreational-fishers

Statement by Australian Marine Conservation Society on scrapping of MPA management plans:

www.marineconservation.org.au/news.php/153/uncertain-future-for-worlds-largest-network-of-marine-reserves

Reef sharks and aggressive triggerfish: diving on Fiji’s Coral Coast

I’m still sorting through about 200 short videos from my Fiji trip so put together a clip of some highlights from the first week. I could make a Finding Nemo sequel with all the anemonefish footage (though they weren’t the clownfish variety but still very cute). Yes, not all fish in anemones are clownfish – try telling that to kids who grew up watching Nemo and expect to see talking orange and white-striped fish under every rock 🙂

And the fishing shot at the end is from a morning trip with a local villager, who charged tourists FJ$50 to help catch fish for his village. Well worth the (minor) expense and my first chance to see reef sharks up close, though my videos were mainly blurry.

Seal pup all grown up!

20131220-162409.jpgSpotted this seal and his mates a few months ago hanging around the marine sanctuary. It wasn’t long before one of them worked out that begging for fish in front of the pier is an easier way to get snapper carcasses and other tasty leftovers!
Seals in this area don’t have too much to worry about: the larger colony at Lady Julia Percy Island has to contend with a variety of sharks including makos and threshers and the occasional opportunistic orca.

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