What I know about whale sharks

March 31, 2013 by 1 Comment

Sure, you know that whale sharks are the largest fish in the sea (reaching 33 to 39 feet) and they sieve plankton for nourishment. Being that you’re clever and smart you must know these 10 wicked facts about whales sharks, too – but, I’ll tell you again anyway.

  1. Whale-Shark-03Whales sharks have the thickest skin in the world – just about 10 centimeters thick!
  2. Whale sharks may have wide mouths for gulping plankton, but don’t worry – they can’t swallow a diver as their throats are exceptionally narrow in comparison to their mouths.
  3. Whale sharks don’t just eat plankton, they sometimes wait for fish to lay their eggs so they can eat those, too.
  4. In Vietnam, whale sharks are known as Ca ong, or “Sir Fish”.
  5. The whale shark was once worshiped in Vietnam, and along the coast you can still find ancient shrines along the coast.
  6. Whale sharks are covered with pale stripes and spots (see image).
  7. “What’s that bump?” Whale sharks attempt to get rid of skin parasites by rubbing themselves up against boats.
  8. Whales sharks are loners. They prefer to live, hunt, and travel alone.
  9. Most sharks live to be around 25 to 30 years old, however whales sharks and dogfish sharks can live to be 100 years or more!
  10. Whale sharks are thought to be able to give birth up to 300 pups at one time.

Please feel free to comment below or email questions on this post to Ann McElhatton, Beach Chair Scientist, at info@beachchairscientist.com.

Filed Under: Fish, Sharks

3 truths on the fables about ‘dolphin-safe’ labels

March 20, 2013 by 1 Comment

It all started recently as my 2 year-old showed those tendencies towards becoming a picky eater. I embarked on a supermarket safari for proteins and soon enough I found myself in the canned tuna aisle. Have you been there lately? It’s a little overwhelming with all of the labels. I usually just go for the salmon for the additional omega-3s, but I had a feeling the toddler would turn that down. Also, I am all about rites of passage and isn’t canned tuna with mayonnaise on toast right up there with peanut butter and jelly and macaroni and cheese? Given that I do care, especially with the recent findings of an Oceana report that states 1 in 3 fish are mislabeled,  the nerd in me had to navigate the meaning behind all those ‘eco-safe’ labels found on canned tuna.

Here’s some surprising truths behind the fables about the ‘dolphin-safe’ label you’ll need to know before baking your next casserole:

1) The U.S. wouldn’t sell anything that’s not ‘dolphin-safe’ – label or not. While it’s true that the U.S. has the most restrictive definition of what it means to be ‘dolphin-safe’ it’s also true that canned tuna is the #1 seafood import in the U.S. The internationally accepted definition of ‘dolphin-safe’ is “tuna caught in sets in which dolphins are not killed or seriously injured,” but the U.S. requires that “no tuna were caught on the trip in which such tuna were harvested using a purse seine net intentionally deployed on or to encircle dolphins, and that no dolphins were killed or seriously injured in the sets in which the tuna were caught.” Unfortunately, if we’re rarely eating tuna from the U.S. we can’t say how it’s caught.

2) ‘Dolphin-safe’ labels are designated by the government. I was shocked to realize that its independent observers (i.e., private organizations) making claims to what is ‘dolphin-safe’. But, then I remembered that tuna are an especially difficult species to manage given that they migrate all over the world. The good news on the horizon is that during his State of the Union address in January, President Obama mentioned the U.S. will begin negotiating a free trade agreement (FTA) with the European Union. What does this have to do with tuna fisheries? Well, apparently the talks for the FTA would include discussions on non-tariff barriers. Non-tariff barriers include “things like labels indicating a product’s country-of-origin, whether tuna is dolphin-safe, or whether your breakfast cereal has genetically-modified corn in it.” The need to be more consistent as to how we label tuna was also acknowledged by the World Trade Organization (WTO). The WTO noted that, “while well-intentioned, the ‘dolphin-safe’ labels are deceptive to consumers and quite outdated”. Also, according to the Campaign for Eco-Safe Tuna, “There’s no denying that more than 98% of the tuna in the U.S. market today is sourced from unmonitored and untracked fisheries where thousands of dolphins are killed every year.” That’s a frightening statistic if you’re trying to make the right choice on what can of tuna to purchase.

leatherback_worldwildlifedotorg

Image (c) World Wildlife Fund

3) If it’s ‘dolphin-safe’ it must be safe for all marine life. Let’s cut to the chase here. Canned tuna that is troll or hook-and-line caught is the best choice for a conscious consumer. Other methods of fishing for tuna (e.g., backdown technique, purse seines) have been shown to cause long-term stress to dolphins (leading to their eventual death), including heart and muscle lesions. You might also be disheartened to realize that sharks, billfish, birds, and sea turtles (see image) are often the unintended catch (known as ‘bycatch’) of fishing for tuna. The fish aggregating devices (FAD) commonly used to catch tuna are known as some as the most destructive fishing practices man has ever used.

Where does that leave me in the decision of what type of tuna to purchase for my family? As I mentioned, choosing hook and line (also known as ‘pole-caught’) canned tuna is the most sustainable choice. Fishing for tuna with hook and line 1) enables fish that are too small to be returned to the ocean, 2) practically eradicates any bycatch, and 3) ensures the ocean ecosystem to remain intact eliminating the potential loss of biodiversity. Be careful though since ‘line-caught’ can mean using a longline to catch tuna. However, this method produces ample bycatch as well.

Please feel free to comment below or email questions on this article to Ann McElhatton, Beach Chair Scientist, at info@beachchairscientist.com.

Filed Under: Biodiversity, Bony Fishes, Fish, Marine Mammals, Ocean Conservation, People, Sea Turtles, Sharks

CITES recognizes important marine species

March 11, 2013 by 1 Comment

You might think that sharks are a predator that we want to eradicate, but that’s far from the truth of the matter. For a healthy ocean we need the top predator. For 5 species of sharks – oceanic whitetip, scalloped hammerhead (pictured below), great hammerhead, smooth hammerhead, and porbeagle sharks – there was some inspiring news during the 16th meeting of the Conference of the Parties for the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Proposals were adopted that would give them greater protection and provide them with less risk from overfishing (According to the Guardian, “Those fishing for oceanic whitetip, porbeagle and three species of hammerhead shark will now require strictly controlled permits to export the fins”) for these sharks. However, the move will need to be adopted completely by a final plenary session scheduled for Thursday. It’s a particularly significant move considering CITES meetings take place every three years and that CITES has not traditionally leaned towards protecting marine species due to the intense political and economic issues that are related to fisheries issues. According to the Washington Post, “Elizabeth Wilson, who manages the Pew Environment Group’s global shark campaign, said the broad array of countries backing the proposals this year helped produce success this time around”.

Globally,  sharks are in peril and overexploited due in major part to a voracious demand for shark fins, especially in Asian markets, since it’s the primary ingredient in shark fin soup (more affordable and more popular than ever at Asian weddings). While it might be a difficult culture shift for the expanding Asian middle class (a delegate at CITES stated, “It would be like telling the French not to have champagne at their wedding“), ultimately it’s what has to be done since shark populations have fallen to such low levels. As they saw off the coast of North Carolina once sharks were overfished rays thrived and then destroyed the lucrative bay scallop fishery. Here is another resource outlining the importance of sharks to the ocean ecosystem.

Scalloped hammerhead shark (sphyrna lewini)

Scalloped hammerhead shark (sphyrna lewini) from NatGeoTV

Filed Under: Fish, Ocean Conservation, People, Sharks, Skates and Rays

What’s in your medicine cabinet affects aquatic life

February 25, 2013 by Leave a Comment

Yup, that’s right – what is in your medicine cabinet (e.g., anxiety medication, birth control) affects not only us, but animals in streams, lakes, and even the ocean. As the President’s Cancer Panel noted in a 2010 report, “Pharmaceuticals have become a considerable source of environmental contamination. Drugs of all types enter the water supply when they are excreted or improperly disposed of; the health impact of long-term exposure to varying mixtures of these compounds is unknown”. It might not seem like the most obvious connection. However, as the National Capital Poison Center points out there are many different ways our medications mutate. Here are just a few of the ways drugs enter the water supply:

  1. Drugs that are applied to the skin are washed down the drain.
  2. Drugs can be eliminated through our waste and are then flushed down the toilet (even more direct when it’s from a pet and it’s left on the side of the road).
  3. Healthcare facilities (e.g., mental, dental) that are not legally required to discard drugs as hazardous materials.
  4. There may be ‘straight-piping’ (direct release of untreated sewage into waterways) or overflow of stormwater that bypasses treatment facilities.

Why this matters is incredibly frightening and here are some examples of why:

  1. Anxious Perch: Researchers at the Umeå University in Sweden found that perch exposed to an anxiety medication, Oxazepam, departed from their normal behaviors of hunting in schools by becoming loners and more brave by hunting on their own. They also noticed that the fish seemed to eat more, therefore disturbing the balance of their habitat. (February 2013)
  2. Suicidal Shrimp: Researchers are the University of Portmouth in the U.K. found that through pharmaceutical waste runoff shrimp had been exposed to antidepressants and it was causing an unusual amount of them to die off. (February 2012)
  3. Autistic Fathead Minnows: Researchers from the Idaho State University discovered “psychoactive medications in water affect the gene expression profiles of fathead minnows in a way that mimics the gene expression patterns associated with autism“. (June 2012)
  4. Fish Tissue Fiasco: Researchers from Baylor University studied fish tissue for human drugs and found drugs used to treat high cholesterol, allergies, high blood pressure, bipolar disorder, and depression.  (May 2009)
  5. Infertile and Hermaphroditic Fish: Mother Nature News wrote how birth control pills caused male fish to be less fertile and increased the number of hermaphroditic fish. (September 2009)
  6. and, finally – Did you know, according to the Associated Press, that drinking water of at least 51 million Americans carries low concentrations of many familiar drugs? (2008)
Don’t worry too much though. You’d have to eat tons of the fish affected by the drugs for it to amount to even one pill. But, if you are concerned about how to keep your waterway clean from pharmaceuticals it’s a good idea to never buy the giant bottle of pills (they’ll surely expire before you’ll use them and then you’ll have to toss it), return old drugs to your pharmacy because many often have take-back programs (i.e., don’t flush them down the toilet), ask your doctor for samples before you commit to a prescription that might not work, and clean up pet waste.
From National Geographic Magazine

From National Geographic Magazine

Have you heard of any other ways fish or aquatic life are affected by what we put in our waterways?

Filed Under: Crustaceans, Environmental Education, Fish, Ocean Conservation, People Tagged With: ,

10 brief facts on bioluminescence

February 5, 2013 by Leave a Comment

We all get excited thinking about bioluminescence in nature. Ironically, that excitement is only one of the reasons animals glow like an elf in Middle Earth. Here are some ‘basics on bioluminescence’ you can share with your friends and family the next time you all ogle a firefly and wonder ‘why?’.

    1. Insects (e.g., fireflies, glow worms) and deep sea ocean animals (e.g., squid, hatchetfish) aren’t the only ones that emit light. Many plants (e.g., jack-o’-lantern mushroom, algae) also produce bioluminescence.
    2. Bioluminescence is light emitting from a living organism. Bioluminescence is produced through a chemical reaction, which is what sets is apart from fluorescence or phosphorescence.
    3. Luciferin and luciferase are the two chemicals that must be present for an organism to luminesce. Luciferin produces the light and luciferase is the catalyst. Life in the sea most often use coelenterazine, a type of luciferin.
    4. Sailors commonly saw waves glowing in the wake of ships. This was caused from dinoflagellates, a single-celled algae, which glows when its startled.
    5. Anglerfish use a long illuminated appendage, called a protuberance, to attract young and vulnerable prey. Luring prey is one way bioluminescence is used to an animal’s advantage. They may also use it to stun prey or to attract or recognize a mate.
    6. Conversely, many animals use bioluminescence as a defense mechanism. They’ll cleverly create smoke screens or burglar alarms, as well as counterilluminate or startle predators.
    7. Some animals that luminesce use it defensively and offensively.
    8. Sperm whales, the deepest divers of all the whales, depend on bioluminescence to help locate food. Echolocation is also key to locating food.
    9. The U.S. Navy tapped into the science community for help to develop products that monitor bioluminescence because bioluminescent algae have been known to endanger military missions.
    10. The pulsing light of creatures found in the deep sea is “perhaps the most common form of communication found on our planet”. That phrase was from a video (below) which takes us on a visual journey of what the first deep sea explorer, William Bebe, described in 1934 from his expedition off the coast of Bermuda. This video was produced by National Geographic.

Filed Under: Algae (Seaweeds), Bony Fishes, Fish, Marine Mammals, Marine Science Tagged With: , , , ,

Strike a pose with Shark Stanley for shark conservation

January 3, 2013 by Leave a Comment

Surely you’ve taken pictures with Flat Stanley, a tool used to advance children’s literacy – But, did you know that you can now take a shark on your adventures? Grab a Shark Stanley printout and show your support for shark conservation by participating in this initiative of the Shark Defenders. Help them reach their goal of collecting at least 5,000 photos! It’s important to gather these photos in time for the upcoming Convention on International Trade in Endangered Species (CITES) meeting in March. Check out all the places Shark Stanley has been on the Instagram and Facebook pages!

Why is shark conservation important?

Sharks are in peril and overexploited due in major part to a voracious demand for shark fins, especially in Asian markets. Shark finning is the removal and retention of shark fins and  discarding the body at sea (The animal is often alive when tossed back into the water!). The Pew Environment Group estimates that “Up to 73 million sharks are killed every year to primarily support the global shark fin industry”. The underlying problem is that sharks grow slow, mature late, and produce few young over their long lifetime – meaning their populations recover slowly once depleted. Depleted populations affect the health of the entire ocean ecosystem. Here are some examples on how it’s all connected:

  • Sharks help maintain healthy fish stocks because they prey on vulnerable sick, diseased, or old animals – thereby, preventing disease or sickness from spreading.
  • Sharks have the ability to ensure we always have vital seagrass beds by controlling their prey, dugongs and green sea turtles – which forage in these beds. Healthy seagrass beds are essential for maintaining good water quality in our estuaries.
  • Sharks are the #1 draw for many divers providing a booming tourism industry to remote places that might not otherwise have a good economy.
Print Shark Stanley and take a picture with him showing your support. Don't forget to tag @SharkDefenders, #SharkStanley, and the country you live (i.e., #USA).

Print Shark Stanley and take a picture with him showing your support. Don’t forget to tag @SharkDefenders, #SharkStanley, and the country you live (i.e., #USA).

 

Filed Under: Inspiration, Ocean Conservation, Sharks Tagged With: , , ,

If you gooble, gooble the turkeyfish know your source

November 22, 2012 by Leave a Comment

The extravagant fins of the lionfish, native to the the Indo-Pacific, resemble the plumage of turkeys and have thus earned the additional common name of ‘turkeyfish’. What is so ironic about that particular nickname is that scientists and fisheries managers have urged us to ‘gooble’ up this exotic looking creature. What’s happened over time is a gradual introduction of the lionfish along the southeast coast of the U.S., the Caribbean, and in parts of the Gulf of Mexico by way of too many releases from fish tanks in the late 1980′s and early 1990s. Unfortunately, these fish have become quite a nuisance in their new neighborhood. In 2010, Juliet Eilperin wrote this on how the lionfish are destroying the reefs along the southeastern Atlantic coast, “As a top predator, it consumes juvenile snapper and grouper along with algae-eating parrotfish, all of which help keep reefs healthy. Between 2004 and 2008, local densities of lionfish increased by roughly 700 percent in some areas; there are now 1,000 lionfish per acre on certain reefs”. As part of the plan for recovering the reefs, in 2010 a campaign was launched to catch lionfish and deep fry, blacken, sautée, or even turn it into an ingredient in sushi. Although, it is imperative that your know you’re source. This past summer, the FDA tested almost 200 lionfish and found there was a high level of the toxin that causes ciguatera in nearly a quarter of the fish. However, according to Michael Dimin, founder of Sea to Table, sautéeing them is still the best way to regain a more natural balance.

Not interested in eating them? You can even help to control the population by becoming a lionfish hunter yourself!

Filed Under: Biodiversity, Environmental Education, Fish, Marine Science

Do you know your seafood?

November 8, 2012 by 3 Comments

With the holidays right around the corner there will no doubt be plenty of indulgences. It is important to keep in mind that seafood can also be considered an extravagance if you’re choosing an unsustainable option to serve or taste. Did you know that the global fishing fleet can catch up to twoo and a half times what the ocean produces? 80% of fish stocks are harvested at or above maximum sustainable yield? Check out this infographic by One World One Ocean that was released last month for National Seafood Month  for those facts and a whole lot more, including 1) fish on the red list (not good) and green list (good), 2) reasons why these fish are on these lists, 3) chefs and grocers to support, and 4) important guides to download.

From ‘One World One Ocean’

Filed Under: Bony Fishes, Conservation, Environmental Education, Fish, Ocean Conservation, People, Sharks Tagged With: , , ,

Finned foliage

October 1, 2012 by 2 Comments

I wanted to share this image of anthias swimming in the Red Sea to usher in the briskness of autumn! As you know it’s my favorite time to beachcomb, but it’s also my favorite time to be surrounded by the brilliant-colored leaves of trees. The reds, yellows, and oranges are as vibrant as a coral reef.

These schooling anthias are interesting because they are born one sex, but then change to another. In fact, all anthias are born female and only change to male if the male in their school dies. Most anthias remain female their entire life. This type of hermaphrodite is known as protogynous (proh-TAH-guh-nus). If it were the other way (beginning their life as male and changing to female) it would be known as protandrous (pro–TAN-dur-us).

The image is from Free Underwater Images, a new favorite resource. This website “promotes increased awareness of the marine environment by allowing users to download free, high quality underwater photos.  All images are in the public domain and free for any use without prior written permission and without fee or obligation. Images can be used for any non commercial purpose”.

Filed Under: Animal Homes, Coral Reef Ecosystems, Fish Tagged With: , , , ,

Myth debunked: Delaware Bay not an annual pit stop for all shark species

September 26, 2012 by Leave a Comment

A fan of Beach Chair Scientist on Facebook recently asked me to demystify a rumor she had heard. This is what she wanted to know: “I was told that over the course of a year, at least one of every species of shark can be found in the Delaware Bay. Do you know if this is true?” I asked Jim Wharton, frequent BCS guest blogger and shark expert, to tackle this one. This is his response.

Sadly, it is not true. There are at least 500 species of sharks in the ocean. They range in size from six inches to sixty feet. They can be found in water ankle deep to the abyssal depths … from the tropics to polar ice caps. To find a nexus point like this anywhere in the ocean would miraculous. Sharks are just too diverse.

Still, there are sharks in Delaware Bay. Anglers might encounter sand tigers, sandbar (brown) sharks, smooth dogfish, and spiny dogfish with other occasional visitors (including at least one record of a juvenile white shark). In fact, the National Marine Fisheries Service has identified the Bay as ‘Essential Fish Habitat’ for several species of Federally protected ‘Highly Migratory Species’ including sandbar sharks, sand tigers, and smooth dogfish. This designation recognizes the critical foraging and nursery habitat the Bay provides for these important species.

Sand tiger shark at the Georgia Aquarium. Image (c) Underwater Times

Dr Dewayne Fox’s lab at Delaware State University is working to create a conservation plan for the sand tiger sharks in the Bay. These distinctive, snaggletoothed sharks are very popular in public aquariums. Despite their fearsome appearance, they rarely interact with people. Sand tigers are top predators and represent a critical keystone species in the ecology of Delaware Bay. Dr. Fox and his students are implanting passive acoustic transmitters inside sharks to better understand their movement patterns. The transmitters emit an identifiable ‘ping’ that is collected by strategically located listening stations to help researchers track the animals in the Bay. Understanding how the sharks use the Delaware Bay is essential to identifying critical habitat for protection. You can learn more about Dr. Fox’s work here.

Sand tigers, by way, are freakish and fantastic creatures that are well-worth saving. No sharks have swim bladders, but sand tigers gulp air at the surface to make themselves neutrally buoyant. Sand tigers are one of many species that explode the myth of the shark in constant motion, frequently found lying near-motionless on the sandy bottom. Sand tigers are fish-specialists, with more-than-a-mouthful of narrow, prong-shaped teeth for grabbing slippery prey. They like to hang-out in large aggregations and may actively cooperate to herd schools of fish. Most fantastic of all…baby sand tigers are “embryonic cannibals.” Sand tiger embryos quickly exhaust their meager yolk sacs and start in on the undeveloped eggs…but they don’t stop there. The largest embryo in each uterus (yes, sharks have two) attacks and consumes its brothers and sisters in the ultimate form of sibling rivalry.

Good references for more on sand tigers:

  • Castro, J. I. (2011). The sharks of North America. Oxford: Oxford University Press.
  • Compagno, L. J. V., Dando, M., & Fowler, S. L. (2005). Sharks of the world. Princeton: Princeton University Press.

Thanks for sharing you knowledge, Jim! Check out his other BCS posts on sharks here.

Filed Under: Animal Homes, Conservation, Sharks Tagged With: , , , , , ,