Science – Page 68 – Southern Fried Science

Maximum (un)Sustainable Yield

September 8, 2010December 20, 2011 Bluegrass Blue Crab 10 Comments

Science

In 1954 and 1957 Gordon and Schaefer respectively described the idea of maximum sustainable yield (MSY) – that is, the amount of fish that could be taken by commercial fishing operations to maximize reproduction by the system year after year. Since then, it has been heralded as the mathematical panacea to fisheries management.

Gordon and Schaefer also described the maximum economic yield which threw price relations into the mix. It describes the point at which the fishers will make the most money, accounting for revenue and their expenses. Note in the graph below the fold that the maximum economic yield (MEY) is below the MSY in terms of effort. Gordon and Schaefer imagined a private manager or government overseer that could calculate the MEY and regulate fisher behavior in order to meet it. The idea was meant to be win-win for the fishers and the fish.

Biodiversity Wednesday – Ancient Sea Monsters Triple Feature

September 8, 2010September 5, 2010 Andrew Thaler

Science

Bone-eating worms and contorted creationist thinking

September 7, 2010January 12, 2012 Andrew Thaler 10 Comments

Science

I tend to avoid the creationist blogs. Every time I get sucked into that vortex of pseudoscience, I find the exact same debunked claims that were bunk when I was 12. There are better bloggers out there who have the energy and patience to systematically dissect the same tired old rubbish day after day, but I’m not one of them.

This claim, however, is special. There’s nothing new in the rhetoric behind it, it’s just another “how could this commensalism/symbiosis/mutualism evolve? It must be magic!” mantra. And the analysis isn’t terribly sophisticated, anyone could do the basic googling to find out why every argument in it is either wrong or deceptive. What’s special is that it’s about one of my favorite critters, Osedax – the bone eating worm.

Chemistry of the Great Big Blue: Nutrients

September 7, 2010September 7, 2010 Bluegrass Blue Crab 1 Comment

Science

The Great Big Blue looks like it contains nothing but water and maybe a little salt, especially out in the open ocean. However, this kind of sparse environment is exactly where the chemistry matters the most – it’s a fine line between not enough, too much, and just right. Given this, there’s no distinct myth here but an underlying unresolved question: what is the limiting factor that keeps the open ocean at low productivity?

Ocean of Pseudoscience Shorty – Sharks and Cancer

September 6, 2010September 7, 2010 David Shiffman 1 Comment

Science

One of the most prevalent shark myths is “sharks don’t get cancer”. This is associated with the more troubling myth that consuming shark cartilage will cure humans of cancer. Despite the success of books with titles like “Sharks don’t get cancer: How shark cartilage could save your life” and “Sharks still don’t get cancer: The … Read More “Ocean of Pseudoscience Shorty – Sharks and Cancer” »

Greenwashing – Is there really a sustainable Orange Roughy fishery?

September 6, 2010September 13, 2010 Andrew Thaler 9 Comments

Conservation, Science

Wandering through the grocery store the other day, I noticed something strange in the fish bin. Now, in general I’m pretty conscious of where my fish comes from, how it was caught, whether the fishery as a whole or the specific population is sustainable. I pay attention to those details and I can usually tell when a company’s branding is legitimate and when it’s just greenwashing.

Imagine my shock when I found a packet of Orange Roughy, sold by the Full Circle brand, and marketed as sustainable.

Chemistry of the Great Big Blue: Metals

August 31, 2010August 31, 2010 Bluegrass Blue Crab 1 Comment

Science

The ocean is full of metals and minerals that naturally occur such as zinc, copper, and cobalt and many marine organisms therefore depend upon access to those metals in small concentrations. However, inshore marine systems receive inputs from industrial, mining, and stormwater runoff that far exceed what these organisms can use. So what’s the effect? There was recently a good review article by Mayer-Pinto et al describings the effects of these metals at the assemblage level that basically did my job for me, research-wise, covering both marine and freshwater systems.

Death of a dinosaur: WhySharksMatter attends a loggerhead sea turtle necropsy

August 27, 2010 David Shiffman 5 Comments

Science

Those of you who follow me on Twitter know that I recently was allowed to participate in a unique scientific and educational opportunity- my Tetrapod Biology class and I attended the necropsy of a large Loggerhead Sea Turtle. For those of you unfamiliar with the term, a necropsy is basically an autopsy for animals. The goal is to figure out why the animal died, information which can hopefully be used to protect the rest of the species in the future. Since this species is considered “Threatened” under the Endangered Species Act, this information is particularly valuable.

Many factors contributed to population declines among Loggerheads. Like sharks, they are slow growing, which makes it difficult for their numbers to quickly rebound. I’ve heard a range of numbers, but according to the National Marine Fisheries Service, they reach reproductive maturity around 35 years of age. Turtle populations have historically taken a big beating from shrimp trawling (the turtles used to get caught in the nets and drown), but the invention of the Turtle Excluder Device has helped on this front. These animals use the beach to lay their eggs, which are vulnerable to anthropogenic disturbance (beach nourishment, riding ATV’s on beaches, poaching, etc). Artificial lighting along the beach can also distract hatchlings, which are used to crawling in the direction of the light to reach the relative safety of the oceans. Since the temperature of the beach determines what sex the turtle will become, they are also threatened by global climate change.

It is extremely important to put the photos you are about to see into their proper context- they show a team of trained professionals who care very deeply about sea turtles using the latest scientific and medical techniques to figure out what happened to an already-dead turtle. They do not show animal abuse of any kind. Some are quite graphic and if such things bother you I’d advise against reading further.

Note: All photos were taken by me

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The Sierra Club Presents: WhySharksMatter!

August 24, 2010 David Shiffman 2 Comments

Science

On Thursday, September 2nd at 7:00 P.M., I will be the South Carolina Sierra Club’s Speaker of the Month! The event will be held at MUSC’s Baruch Auditorium, which is 284 Calhoun Street. I have prepared a 45 minute multimedia presentation on shark conservation, followed by a question and answer session. If any of our … Read More “The Sierra Club Presents: WhySharksMatter!” »

Chemistry of the Great Big Blue: Petroleum Byproducts

August 24, 2010August 31, 2010 Bluegrass Blue Crab 2 Comments

Science

In light of the BP oil spill, this week’s installment of Chemistry of the Great Big Blue will be particularly relevant to current events and hopefully already on the minds of everyone reading. Where do petrochemicals in the marine environment come from other than oil spills? Road runoff, refineries, plastic production, plastic degradation, atmospheric deposition and ocean circulation from other parts of the world, natural seeps, and the list goes on and on. It is important to note, however, that oil spills are not necessarily the predominant source of petrochemicals. So what exactly is a petrochemical and what does it do?