Researchers from Cal State University Long Beach have discovered alarmingly high levels of the chemicals DDT and polychlorinated biphenyl in juvenile white sharks off the coast of Southern California. Though the chemicals are toxic, they appear to be having little effect on the young sharks. If you have a minute, swing by and read through their study. It's extremely interesting.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0062886
An independent research guide detailing the migrations and behaviors of the Great White shark. This blog also contains articles on current issues regarding the Great White and other species of shark, as well as information on conservation groups and their efforts to protect sharks and the oceans they live in.
Thursday, August 22, 2013
Monday, August 19, 2013
Greenland shark in the Gulf?
A group of biologists from Florida State University got
quite the surprise while on expedition in the Gulf of Mexico. Dean Grubbs and
his crew were studying species living in the Gulf that may have been affected
by the Deepwater Horizon oil spill of 2010, when they came across a 12-foot
Greenland shark.
For
those who don’t know, Greenland sharks are a deep water species found primarily
in the northern Atlantic Ocean, near the Arctic Circle. They generally range
from depths of up to 1200m and prefer water temperatures from anywhere between
34 and 68 degrees Fahrenheit. A few stragglers have been spotted as far south
as Argentina and in Antarctic waters, but never in the Gulf of Mexico and not
at 6000 ft. So, naturally, when the crew pulled their cabling up to find a
massive shark on the end they were understandably shocked. According to Grubbs,
it took several hours for the shark to be pulled to the surface. Once there,
the shark was loaded on to the boat and the crew began taking samples. Because
the basis of the study was toxicology, the team had to take lethal samplings
from the animal. Grubbs was quoted by NBC saying that the animal probably would
not have lived very much longer in the warmer waters.
This story leaves me conflicted. On the one hand, I'm interested in what the FSU team finds when their reports come back. On the other hand, I wish the shark could've been tagged and tracked. I'm not a scientist (yet), just a student, but I would think the shark would be more beneficial scientifically if it were left alive. That being said, the research crew did find quite a few fascinating bits of information in their examination of the animal. For instance, they found a six-inch stingray barb lodged in the shark's skull, probably the result of a dinner date gone array. They also looked at the stomach contents which included several squid beaks and the egg sac of a skate. Very cool.
Photo credit NBC
Tuesday, August 13, 2013
Friday, August 9, 2013
Alien Sharks
Kudos to Discovery for actually having a good documentary during this Shark Week. Alien Sharks was amazing! In honor of their achievement for having produced and shown something scientific, I've found some footage I'd like to share.
Goblin sharks are awesome!
Goblin sharks are awesome!
Wednesday, August 7, 2013
Murder Down Under
I came across a story tonight that is absolutely shocking to me, and instead of continuing our Endangered Species list I'm going to share this story with you.
Off the coast of Australia, in the HMAS Adelaide marine reserve, a diver found a 6 ft Mako shark. Unfortunately for both parties, this particular Mako was mutilated and left hanging upside down by its tail tied to a buoy. Not only had the shark been tied up, but it also appeared to have been stabbed several times in the chest. As the area is a protected marine reserve, no fishermen (commercial or otherwise) are allowed inside. But according to Robbert Westerdyk, the diver who found the shark, "It can only have been done by fishermen who should not have been anywhere near the site.."
Mr. Westerdyk took photos of the gruesome site and then cut the shark loose. The killing is being investigated by the New South Wales department of fisheries. Below are the photos Mr. Westerdyk shot, and I warn you they are disturbing.
Robbert Westerdyk
Mako sharks, both shortfin and longfin, are listed as Vulnerable to extinction on the IUCN Red List. The fact that someone slaughtered this animal on purpose and then posed it is absolutely barbaric. No living creature, shark or otherwise, deserves to have their life taken and especially not like this. May the person who did this be found and punished to the fullest extent of the law.
Here's something you don't see everyday; the Tasseled Wobbegong. This shark is a master of disguise. The Wobbegong has a squashed body shape and a beautiful design that allows it to blend in with its surroundings. It also has fringed skin flaps on its lips that closely resemble seaweed. The Wobbegong lies motionless on the ledges of the reef and quickly snaps up at unsuspecting fish as they swim by.
Photo courtesy of Arkive
Photo courtesy of Arkive
Tuesday, August 6, 2013
Daggernose Shark (Isogomphodon oxyrhynchus)
For Tuesday’s addition of our “Shark Week Endangered Species
List” let’s take a look at the Daggernose shark. This animal is said to
congregate in the warm coastal waters off South America, namely Brazil,
Venezuela, and Trinidad. The Daggernose, like many other species of shark, is
slow to mature and has few pups. Female sharks mature at around 6-7 years and
can be pregnant for up to 12 months. Because they do not breed annually, the
risk for severe population depletion is great.
Like
many endangered sharks, the Daggernose’ biggest threat is artisanal fisheries
and the use of gillnets. These sharks tend to get caught in floating gillnets
that are targeting mackerel and King Weakfish. Due to their slow reproduction rate,
such high fishing pressure spells disaster for the population and indicates a
high risk for extinction. The IUCN recommends the monitoring of fishing vessels
that use gillnets in the area, and the release of live sharks that are
captured. The website also suggests that the Daggernose be added to the
Brazilian National list of Endangered Species. Restrictions being placed on the
number of sharks that can be caught and enforcement of these rules would help
aid in the conservation of this species.
Photo courtesy of Encyclopedia of Life
Here's a fun fact: Cookie cutter sharks glow in the dark. That's right. They use photophores on their ventral surface to attract prey. Once a larger fish swims up to investigate, the cookie shark uses its lips and upper teeth to suction itself on to the fish. It then spins its body in a tight circle leaving a cookie-shaped hole in the flesh. How great is that? But don't worry, these sharks are so small that they pose little threat to humans.
Mouth of the Cookie cutter shark. Photo courtesy of the FLMNH
Cookie cutter wound. Photo courtesy of FLMNH
Cookie cutter
Mouth of the Cookie cutter shark. Photo courtesy of the FLMNH
Cookie cutter wound. Photo courtesy of FLMNH
Cookie cutter
Monday, August 5, 2013
Pondicherry Shark (Carcharhinus hemiodon)
Alright let’s kick off our “Shark Week Endangered Species
list.” This first shark is extremely rare and has not been seen in the wild
since 1979. As a matter of fact, the only way that this species is known at all
is due in large part to 20 specimens that are housed in museums, none of which
were caught after 1900. It is not actually known whether this shark still exists
in the wild, it may be extinct but more information is needed. It is called the
Pondicherry Shark.
The
Pondicherry Shark is said to be Indo-West Pacific, inhabiting the waters near
China, India, Indonesia, Malaysia, Oman, and Pakistan. It is said to stay
inshore on continental and insular shelves. Due to the fact that this species
is so rare, little is known about its biology or lifespan. What is known is
that the population of Pondicherry Sharks is said to have been severely
depleted due to unregulated artisanal and commercial fisheries, something that,
coincidentally enough, is said for almost every Critically Endangered species
of shark on the IUCN Red List.
The
most important thing that you can do to help with the plight of these
endangered animals is make yourself aware. Get to know these animals and the threats
they’re facing and spread the word. Education is key.
Above is the accepted rendition of the Pondicherry shark by IUCN. Photo courtesy of Encyclopedia of Life
Shark Week
While I am completely disgusted with Discovery Channel and what they've decided to turn Shark Week into this year, I will be posting daily in honor of what Shark Week is supposed to be about; the shark's plight and conservation needs. Each day I will be writing about a different species of shark that is either endangered or critically endangered and ways you can help. This week is supposed to raise the awareness of the masses and make them want to get up and help the cause. If Discovery Channel won't do that, then I will.
Thanks guys,
Heather
Thanks guys,
Heather
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