Half a century of global decline in oceanic sharks and rays

[Greg Bernhardt]

TL;DR

We find that, since 1970, the global abundance of oceanic sharks and rays has declined by 71% owing to an 18-fold increase in relative fishing pressure.

Overfishing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difficult to measure, particularly for the largest predators found in the high seas1–3. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goals4,5: the Living Planet Index (a measure of changes in abundance aggregated from 57 abundance time-series datasets for 18 oceanic shark and ray species) and the Red List Index (a measure of change in extinction risk calculated for all 31 oceanic species of sharks and rays). We find that, since 1970, the global abundance of oceanic sharks and rays has declined by 71% owing to an 18-fold increase in relative fishing pressure.

https://www.nature.com/articles/s41586-020-03173-9

 

[BillTre]

Similar to the decline in insects we have been hearing about for several years.

 

[jim mcnamara]

Birds as well. Some like passenger pigeons are extinct. Audubon has a list of once more common species, species that have become rare. Here is one list:

http://focusonnature.com/BirdListRareBirdsNorthAmerica.htm

 

[256bits]

Birds as well. Some like passenger pigeons are extinct. Audubon has a list of once more common species, species that have become rare. Here is one list:

http://focusonnature.com/BirdListRareBirdsNorthAmerica.htm

Any in there that are warm, cuddly and cute?

Besides the sharks and scary insects, that is.

 

[jim mcnamara]

John Terborgh 'Where have all the birds gone' 1989 -- discusses the impact of deforestation of Cuba and the steep decline of North American songbirds that used to overwinter there.
https://www.amazon.com/dp/0691024286/?tag=pfamazon01-20

It is not like we have been unaware of an impending problem.

 

[Ygggdrasil]

Observations like the ones cited in the posts above are why some scientists argue that we are in the midst of the sixth mass extinction event Earth's history:

https://www.pnas.org/content/114/30/E6089
https://www.theguardian.com/environ...nction-event-already-underway-scientists-warn