shark overfishing – Southern Fried Science

28 quotes, facts and graphs from the new UN global use of shark products report

August 2, 2015August 27, 2015 David Shiffman

The United Nations Food and Agriculture organization just released fisheries and agriculture technical paper number 590, “the state of the global market for shark products.” Coauthored by legendary shark conservation researcher Shelley Clarke, this 196 page document is a comprehensive look at, um, the state of the global market for shark products.

It includes an updated review of threats to sharks and the conservation and management mechanisms that governments are used to protect them. If you’re interested in shark conservation, you should read it. If you’re interested in shark conservation but don’t want to read a 196 page technical document, I’ve selected 28 important quotes, facts, and graphs from the report. These are organized into the following four categories (categories which can be used as a TL;DR summary of the entire report):

A) The global trade in shark meat is growing and is significantly different from the fin trade (despite not getting anywhere near the same attention from conservation activists and the media as the fin trade).

B) Many, many countries other than China are involved in the global trade in shark and ray products (despite not getting anywhere near the same attention from conservation activists and the media as China).

C) Many species and populations of skates, rays, and smaller sharks are highly traded (despite not getting anywhere near the same attention from conservation activists and the media as larger, charismatic species).

D) Global trade is complex, and we need a lot more data from governments of shark fishing and trading nations to effectively track trends in shark product use (i.e. science and record-keeping are critical for conservation, and not all important conservation work is glamorous or exciting).

Does Shark Week portrayal of sharks matter?

June 29, 2015July 3, 2015 David Shiffman 6 Comments

Blogging, Popular Culture, Science

I’ve been critical of factual inaccuracy and fearmongering on Shark Week documentaries for years. But how big of a problem is this, and how do we know? I asked some of the authors of three recent scientific studies* to summarize the evidence.

Many species of sharks are in desperate need of conservation. Twenty-four percent of all known species of sharks, skates and rays are considered Threatened with extinction by the IUCN Red List. Using a variety of different methods, scientists have documented rapid and severe population declines in many species of sharks all over the world.

Conservation requires public support. In a participatory democracy, new policies and regulations require some public support to pass. It’s easy to get public support to conserve cute and cuddly animals, but ugly animals need protection too. So do animals that scare people, like sharks.

First systematic threat analysis reveals that 1/4 of sharks, rays, and chimaeras are threatened with extinction

January 21, 2014 David Shiffman

Conservation, Science

It took a team of over 300 scientists nearly two decades, but the first systematic analysis of the conservation status of chondrichthyans (sharks, rays and chimaeras) has been completed. The results, published today (open access) in a paper titled “Extinction risk and conservation of the world’s sharks and rays,” are chilling.

“Our unprecedented analysis shows that sharks and their relatives – which make up one of the earth’s oldest and most ecologically diverse groups of animals — are facing an alarmingly elevated risk of extinction,” said Dr. Nick Dulvy, IUCN SSG Co-Chair and Professor at Simon Fraser University in British Columbia.

As of the writing of this paper, the IUCN Shark Specialist Group recognized 1,041 species of chondrichthyans. However, a new species is described, on average, every two or three weeks! Out of these 1,041 species of chondrichthyans, approximately one in four are considered “Threatened” by IUCN Red List criteria; 113 species are Vulnerable, 43 are Endangered, and 25 species are Critically Endangered. 487 species are considered Data Deficient, but the IUCN Shark Specialist Group estimates that 68 of them are likely to be Threatened as well! Most alarmingly, only 23% of known chondrichthyan species are considered Least Concern, the lowest percentage out of any group of vertebrates on land or sea!

A hierarchy of IUCN Red List categories. Note that "Threatened" includes Vulnerable, Endangered, and Critically Endangered — A hierarchy of IUCN Red List categories. Note that “Threatened” includes Vulnerable, Endangered, and Critically Endangered

One of the two main factors influencing Threatened status is the size of the animal. Larger bodied species are sensitive to overfishing because they typically have a life history with slow growth, late age at maturity, and relatively few offspring. Additionally, living in coastal habitats (in other words, close to humans) makes a species more likely to be Threatened.

13 amazing things scientists discovered about sharks in 2013

December 28, 2013December 30, 2013 David Shiffman 5 Comments

Conservation, Science

Other than a certain week in August whose name we shall not speak here, 2013 was a great year for both shark science and the communication of that shark science. There were many important and fascinating discoveries, and many of the world’s top media outlets covered them. Presented here is a list of 13 amazing scientific discoveries made in 2013, in no particular ranking order. To make the list, research must have been published in a peer-reviewed scientific journal in 2013, and someone else other than me must have also thought it was awesome (i.e. it received mainstream media or blog coverage). In the interest of objectivity, I did not include any papers that I or my lab were directly involved with. Whenever possible, I’ve linked to an accessible version of the paper.

1) A two-headed bull shark!

Citation: Wagner, CM, Rice, PH, and Pease, AP 2013. First record of dicephalia in a bull shark Carcharhinus leucas foetus from the Gulf of Mexico. Journal of Fish Biology 82: 1419-1422.

Brief description: Researchers presented the first case of a bull shark embryo with 2 heads (the mother was caught by a Florida fishermen). In response to the most common question I received about this study, no, this animal would not have survived to adulthood. While this is a cool discovery, the broader significance is somewhat minimal. As I told science writer Douglas Main in an interview about a similar study, “There have been a number of reports of deformed shark and ray embryos in recent years— two heads, one eye, etc. There’s no evidence to suggest these defects represent a new phenomenon or that they are harmful to shark populations as a whole.”

Media coverage highlights: A figure from this study was named one of the coolest science photos of the year by the International Science Times. It was also covered by National Geographic, the Guardian, and TIME magazine.

Breaking News! “Most Comprehensive Estimate of Mortality”: Between 63 and 273 Million Sharks Killed Each Year

March 1, 2013March 1, 2013 David Shiffman 10 Comments

Conservation, Science

A new study* has estimated that the total number of sharks killed by fisheries each year is between 63 and 273 million, with a average of approximately 100 million.In an interview, lead author Dr. Boris Worm explains the importance of this estimate:

“This is by far the most comprehensive estimate of shark mortality yet,” he said, “because we consider all sources of mortality, from direct fishing, finning, and discard mortality. the estimate was derived by crunching numbers from almost 100 publications on the catches and mortality of sharks.”

Of all the numbers this team crunched, the most important thing to consider is whether the exploitation rate is greater than the rebound rate. In other words, is this level of exploitation more than the populations can recover from? Though many estimates and approximations went into calculating these figures, it seems quite clear that sharks are being harvested at an unsustainable rate.

The ten best and worst events in shark fisheries management of 2012

January 4, 2013October 27, 2013 Guest Writer 1 Comment

Conservation, Science

Sonja FordhamPresident, Shark Advocates International — Sonja Fordham
President, Shark Advocates International

Sonja Fordham founded Shark Advocates International as a project of The Ocean Foundation in 2010 based on her two decades of shark conservation experience at Ocean Conservancy. She is Deputy Chair of the IUCN Shark Specialist Group and Conservation Committee Chair for the American Elasmobranch Society, has co-authored numerous publications on shark fisheries management, and serves on most of the U.S. federal and state government advisory panels relevant to sharks and rays. Her awards include the U.S. Department of Commerce Environmental Hero Award, the Peter Benchley Shark Conservation Award, and the IUCN Harry Messel Award for Conservation Leadership.

The last twelve months added up to another exciting year in shark and ray conservation policy. We certainly saw and should herald a lot of great progress in 2012. I think it’s also important to acknowledge what went wrong so we know where we stand and how best to move forward. I’ve taken a look back and compiled a top ten list of what I see as the best and worst events in shark fisheries management for 2012, based on my work at Shark Advocates International. I’m starting with the low points, but keep reading! It ends on a high note.