One-Quarter of Sharks and Rays Face Extinction

[GoLeft TV]

From Ring of Fire:

A quarter of sharks and rays are threatened with extinction due to overfishing, according to the first-ever global analysis of these species by the International Union for Conservation of Nature (IUCN). The most recent edition of the IUCN’s “Red List” of threatened and endangered species assessed the conservation status of 1,041 shark, ray, and chimaera species, Live Science reports.

According to the Red List, sharks, rays, and chimeras – cartilaginous fishes (Chondrichthyans) – are at higher risk of extinction than most other species on the list. Only 23 percent of shark, ray, and chimera species are categorized as being of “least concern,” or relatively unthreatened.

The cartilaginous fishes are mainly threatened by overfishing. Reported catches of sharks, rays, and chimeras peaked in 2003, although researchers say catches are likely greatly under-reported. Many catches are unintentional, although there are developing markets for sharks and rays that are adding stress to the species, according to IUCN.

You can read the full article here at Ring of Fire.

[Common Sense Party]

1. The Sharks are gonna have their way Tonight.

[byronius]

2. Great post.

[LeftyMom]

3. Part of the problem is that they're slow to reach maturity and mostly reproduce slowly.

Apologies, this is a slightly complicated explanation because sharks have several different methods of reproduction:

Unlike bony fish who pop out some eggs and spray some semen on them and take off, sharks have internal reproduction and give birth to significantly fewer young. Some of them give birth much like mammals do, with one or two young living off of a placenta and then being born when they're fully equipped to feed and care for themselves- white sharks are a good example of this. Sharks don't parent but they do appear to have a biological mechanism that prevents the mother from feeling hunger until the young have had time to get away. Other shark species grow their young internally for some period and then release rubbery egg cases that develop the rest of the way on their own- these are the most fecund species but many of the egg cases will be eaten before they develop. The final group split the difference between the two- the young develop internally but are fed by an egg sac. Some of these species engage in intrauterine cannibalism, and the fastest developing embryo on each side of the mother's divided uterus will eat it's siblings, so an initial litter of dozens will result in two pups, no more and no less.

So long story short, with variations for different types of reproduction most shark species take a very long time to become sexually mature and reproduce slowly: usually only one or two pups every other year for live-bearing species.

[flvegan]

4. That's because some people are selfish and stupid.

Sharkfin soup consumers, I'm looking at you first. Ignorant and selfish is no way to go through life, consumers.

Yet you do. Why?

[stuntcat]

5. I wonder how many shark species will make it to the end of this century.

Well I wonder if any of them will.
Like a lot of the animals we'll be wiping out in the next few decades, their species has lived on Earth much longer than humans have.

[LeftyMom]

6. Since plants started moving onto land.