‘Wicked Tuna’ is food for thought

March 31, 2012 by 2 Comments

Tomorrow the National Geographic Channel (of which approximately over 50% is owned by NewsCorp, a Murdoch Company) is debuting the television show Wicked Tuna. The show is intriguing because the species itself is remarkable.

Atlantic bluefin tuna (Thunnus thynnus) can swim up to 40 miles per hour and can dive up to 3,000 feet. Their body is so remarkably streamlined for efficiently swimming through the ocean that Pentagon-funded scientists have studied the species as a model for Navy torpedoes. They’re also known to travel far and wide (actually, across entire oceans over their lifetime). This causes some challenges when coming together to manage the species.

The dilemma I have in deciding to watch the show is that NatGeo may be glorifying the bluefin tuna as a species of consumption so that people start ordering it more. But, folks need to understand the repercussions and ask one more question, “Is this bluefin tuna caught in the U.S.?”

As I mentioned, there are some challenges with managing a species that spans globe. Bluefin tuna are an internationally managed species, guided by the intergovernmental body the International Commission on Conservation of Atlantic Tunas (ICCAT). Within management plans of the ICCAT, it is irrefutable that the U.S. bluefin fishery is the most sustainably managed in the world. The bluefin tuna caught in Maine, New Hampshire, and Massachusetts is predominantly hand gear (rod and reel or harpoon). This fishery is well regulated and responsible. There is also bluefin tuna caught as bycatch from the longline fisheries targeting other types of tuna. To reduce bycatch, fisheries are now required to use circle hook and weak hooks to reduce the bluefin tuna bycatch, as well as other nontarget species (e.g., sea turtles). The species is slow to mature and catching young bluefin tuna reduces the chance they’ll have the opportunity to reproduce. That is why it is so negligent to eat the bluefin tuna from the poorly regulated European fishery. Many of the bluefin caught there are with purse seines or longlines. In fact, since industrial fishing began in the Mediterranean it is estimated that over 80 percent of bluefin stocks have been fished out.

It’s no help that there is extreme demand for this type of fishing pressure as sushi chefs will pay gobs for the fish. The ‘Wicked Tuna” fishermen can get up to $20,000 for each fish. In January 2012, a Tokyo restaurant paid $736,000 for a bluefin tuna at auction (there’s the ‘first fish phenomenon’ which can bring a lot of publicity to a restaurant for paying a high amount for the first fish).

The Monterey Bay Seafood Guide lists bluefin tuna as a species to avoid. The Center for Biological Diversity encourages the public to boycott any restaurants serving bluefin tuna. Greenpeace has even stated that, “The world needs to see a ban on bluefin tuna fishing until stocks recover”. National Geographic claims this show’s scope includes a “solid conservation message about what’s been going on with the bluefin”. So, if you must ask for ‘Wicked Tuna’, make sure it’s at least from the U.S. Certainly, food for thought.

Filed Under: Biodiversity, Bony Fishes, Fish, Ocean Tagged With: , , , , , ,

New ‘marine life encyclopedia’ launched

September 12, 2011 by Leave a Comment

I think there might be another great bookmark to add to your ocean facts files! Please spend some time reviewing this great new resource, a marine life encyclopedia, compiled by Oceana. Over 500 creatures, places, and concepts can be explored. The pictures are bright and colorful and the information is up-to-date and easy to digest. It seems fantastic if you want a quick answer to a question.

Even if you think you know all the answers, test yourself with this Ocean IQ quiz!

The content on the marine life encyclopedia site has been licensed to Dorling Kindersley, one of the world’s leading educational publishers.

Filed Under: Algae (Seaweeds), Animal Homes, Arthropods, Atlantic Horseshoe Crab, Beach, Biodiversity, Birds, Bivalves, Bony Fishes, Cephalopods, Cnidaria, Coral Reef Ecosystems, Crustaceans, Echinoderms, Egg Cases, Fish, Jellyfish or Jellies, Marine Mammals, Mollusks, Ocean, Penguins, People, Places, Plants, Random Fun!, Reptiles, Sea Turtles, Seashells, Sharks, Skates and Rays, Test Your Knowledge, Univalves, Weather, Wrack Line Tagged With: , ,

5 facts about fish farming

May 24, 2011 by 5 Comments
Fish farming on Lake Titicaca.

Image via Wikipedia

Here are five facts about the glory and challenges of fish farming. Fish farming and aquaculture has really stepped up due to the demand for the world’s fish consumption, but maybe not in the most sustainable manner like Linda Thornton.

1.) It’s polluting our water

It seems as though large fish farm like to cram fish to live in very tight spaces. A large amount of fish would lead to a large amount of waste produced by the fish. Also, the unfavorable conditions often lead to disease. Fish farmers tend to treat the disease and infection with harmful antibiotics which further harm the surrounding waterways.

2.) It brings untested chemicals to your dinner plate

It seems as though many of the antibiotics used to treat diseases on foreign fish farms are commonly made of chemical banned in the US. Since there is no regulation often these harmful chemicals make their way to your dinner table.

3.) It’s tearing apart mangroves

Shrimp farmers are tearing apart the mangroves to make way for their new crop of this popular crustacean. However, this destroys a delicate nursery ground for many local fish species. In turn this depletion in resources severely affects local economies. What makes matters worse is that often these shrimp farms are abandoned in order to find better producing areas.

4.) It’s often counter-productive

Fish farms can be tough to maintain, especially for salmon and other carnivorous species. They tend to eat more food than they actually produce! This is turn leads to a lot of waste that can disturb the balance of the surrounding waterways.

5.) It does good things!

Some fish farms raise species that are actually clear out pollutants from the water. Bivalves (oysters, mussels, etc.) are filter feeders and cleanse their aquatic habitat! Also, tilapia are herbivores and do not require as much input as the carnivorous farmed fish need.

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Test Your Knowledge: NOSB Biology

May 22, 2011 by Leave a Comment

Here are some more sample questions from the Consortium for Ocean Leadership‘s popular National Ocean Science Bowl (NOSB). These questions come from the Biology section.

Good luck!

1.) Northern elephant seals come ashore during the spring and summer to do what? a) Mate b) Eat c) Give birth d) Shed their fur

2.) The habitat of blue whales, tunas and swordfishes is best described as: a) Benthic b) Littoral c) Estuarine d) Pelagic

3.) Intensive aquaculture of which of the following organisms has contributed to loss of mangroves around the world? a) Tilapia b) Cod c) Salmon d) Shrimp

4.) Lophelia (LO-fee-lee-ua) coral reefs in the North Atlantic are being primarily damaged by: a) Pfiesteria b) Poisoning c) Rising temperatures d) Trawling

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Filed Under: Bony Fishes, Marine Mammals, Random Fun!, Test Your Knowledge Tagged With: , , , ,

Arnie ain’t no anglerfish

May 17, 2011 by 1 Comment
The Humpback anglerfish uses a modified dorsal...

Image via Wikipedia

Well, well, well, Arnold Schwarzenegger has a love child. As a newlywed I shook my head when I heard the news and said “surely they’re not all like that.”

I decided to investigate to find out if there are any truly monogamous species out in the blue sea.

Also, I did watch March of the Penguins. As much as I admire the Emperor penguins for staying together to raise their young, they are not lifelong monogamists. Each season they usually procreate with a different partner.

However, one group of anglerfish, from the family Ceratiidae, has a very faithful male (a little to clingy though if you ask me). Highly sensitive olfactory adaptations have evolved in these male anglerfish that allow them to smell out females. This is very useful as they are in the desolate landscape of the deep sea. Once they sniff out a mate, the males basically bite into the flesh of the females and fuse their mouth into her bloodstream. After that, these males will degenerate and simply be a source of sperm for the females.

Without this process the males would not be able to survive. The males of this family do not grow ‘em tall due to the lack of a alimentary canal, essential for feeding. The males are scientifically smaller than the females and several males can be attached to one female. It took researchers some time to uncover the mystery that is the male anglerfish. For the longest time they couldn’t figure out why they were only collecting females specimens. But, unbeknown-st to them, the males were there too.

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Farting on a school bus – bad; Farting as part of a school of herring – ok

May 13, 2011 by Leave a Comment

Recently two Ohio middle school boys were suspended from riding the bus for farting on the bus. If these boys were part of a school of herring they’d have no repercussions. In fact, they’d be making the grade in language arts.

Back in 2003 an article published in the U.K. science journal Biology Letters explained a phenomenon discovered by scientists at the Bamfield Marine Science Centre, British Columbia, Canada, where herring produce high-frequency sound bursts followed by a fine stream of bubbles, dubbed Fast Repetitive Tick (FRT).

The noise can be up 22 kilohertz.

It is suspected that these FRTs are not to be a call to hunger or a call to breed but rather are triggered while the fish are swimming at night while in large densities as a means of communications. According to a National Geographic article on the subject, “It might seem an amusing idea to us that herring communicate using farts. But for herring and the mammals that prey on them, FRTs may signal safety—or the next meal.”

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It’s as easy as A, B, Sea: Y for Yellowfin Tuna

February 27, 2011 by Leave a Comment

Yellowfin tuna are the most commercially sought after of all tunas. They have a football shaped body and can reach up to 450 pounds. Which is very impressive since they can also swim up to 30 miles per hour. Yellowfin tuna prefer to swim in schools in all temperate oceans. They prefer to eat fish any fish smaller than themselves and their biggest predator tend to be sharks.

Image (c) ilovebluesea.com

Filed Under: Bony Fishes, Fish, Sharks Tagged With: , ,

It’s as easy as A, B, Sea: O for Operculum

February 15, 2011 by Leave a Comment

Operculum is the hard scalelike cover of the gills of bony fishes. Cartilaginous fishes (such as sharks, skates and rays) all lack a gill cover.

Image (c) www.webs.lander.ed

Filed Under: Bony Fishes, Fish, Sharks, Skates and Rays

What is the fastest fish in the sea?

October 26, 2010 by 3 Comments

The world’s fastest fish is the Indo-Pacific sailfish, Istiophorus platypterus. This sport fish can swim up to 68 miles per hour by standards (a cheetah can run up to 70 miles per hour).  Check out this incredible video from PBS which aired in August of 2010. Marine biologist, Rick Rosenthal, witnesses a rare moment of a sailfish feeding at night. You’ll also see a baby sailfish drawn into the light by Rick’s flashlight. Enjoy!

Filed Under: Bony Fishes, Fish Tagged With: ,

Whales don’t have scales

October 10, 2010 by Leave a Comment

That’s right. Whales are covered in blubber because they are mammals like you and I. Now the fish in the sea are another story. You might not realize it, but, if you’ve ever had the opportunity to touch a shark they are covered in scales just like other bony fish. There are several main types of scales that cover fish. See if you can figure out which cover sharks.

1.) Ctenoid scales: These scales are comb-like with the ends having small teeth-like structures.

2.) Ganoid scales: These scales are heavy and diamond-shaped.

3.) Cycloid scales: These are round scales with smooth edges.

4.) Cosmoid scales: These scales are very hard and covered in enamel.

5.) Placoid scales: These scales have teeth-like edges. They are different than ctenoid scales because they lack they rounded front.

Scales grow out of the skin and have modified to quite a few different versions over the years. In fact, the feathers of a bird are a type of evolved scale!

Filed Under: Bony Fishes, Fish, Sharks, Skates and Rays