Tag Archives: Extinction

What 415 million year old fossil plankton tells us about heavy metal pollution and extinction

These weird looking things are plankton – from the genus Ancyrochitina to be a little more precise.  They are also fossils – approximately 415 million old, from a period known as the late Silurian.  That’s pretty cool in itself (at least I think so), but what makes this really interesting is that the individual on the left is malformed, whilst the one on the right is ‘normal’.  What is even more interesting than that, is that these malformations coincide with the initial stages of extinction events.

Led by Thijs Vandenbroucke (researcher at the French CNRS and invited professor at Universiteit Gent | Ghent University) and Poul Emsbo (US Geological Survey), an international team of researchers have taken a look at these malformed (known as ‘teratological’) fossil plankton.  They wanted to find out what was causing these malformations. Continue reading What 415 million year old fossil plankton tells us about heavy metal pollution and extinction

How to hunt a species to extinction

Overexploitation is regarded as one of the main threats to biodiversity, with a number of species extinctions directly linked to our ability to efficiently hunt and capture (or in the case of plants remove) a whole range of different taxa.

But wait a minute – surely if a species becomes too rare, it will eventually become uneconomical to hunt – even if they are worth a lot of money….so exploitation will stop?  Not so say the authors of a new paper published in TREE last month.  In a scenario which they have coined ‘opportunistic extinction’, species that are no longer targeted for exploitation can still be caught if we stumble across them in our search for something more common.  In this situation, the rare species is whisked up, providing a tidy profit.

The authors Trevor A Branch, Steven Purcell and Aaron Lobo have provided a great overview of their paper and crucially its implications.

If you have access to the journal Trends in Ecology and Evolution, you can have a look at the paper http://dx.doi.org/10.1016/j.tree.2013.03.003

Image: The sperm whale was heavily hunted from the 18th to 20th century, primarily for its  spermaceti which had many applications including soap, candles, lamp oil, and pencils.  Credit: Peter G. Allinson, M.D. 2009/Marine Photobank