The population of Oceanic sharks and rays has fallen by 71%3 min readReading Time: 3 minutes
A recent study, published in the journal called Nature, reveals that the population of oceanic sharks and rays from all over the world has taken a drastic plummet by 71% in the last 50 years. This has placed some species that were earlier found in abundance, like the Oceanic Whitetip and the Great Hammerhead, in the critically endangered list.
Closer home, in the Indian Ocean, the population of ocean sharks and rays has fallen continually since 1970, with a total decline by 84.7%.
The reason for this decline is relative fishing pressure. This means that the existing stock of fish is being exploited or being overused with respect to the number of fish left.
Other reasons as given in the study are listed in the following figure:
Since 1970, the fishing pressure has increased 18-fold. As such, there is an immediate need to impose catch limits to curtail this increasing graph of decline.
The research shows that 24 of the 31 species of oceanic shark and ray species now fall under the categories of vulnerable, endangered or critically endangered in the International Union for Conservation of Nature (IUCN) Red List.
Refer to the table below to know how species are characterised on the scale of endangerment:
Sourced from National Geographic
The researchers mentioned that the species under review are some of the “ocean’s apex predators”. They remain far from the land and as such appear to be immune to the human action on the environment. However, the numbers prove the opposite! The team of researchers have warned that an extinction of this species will adverse effect the entire ocean ecosystem, and food security in developing nations.
Owliver’s Obscure Observations:
POSITIVE NEWS FROM THE STUDY
The brightside of the research is that with the appropriate fishing limits, these species can recover their lost population!
One of the longest lived species that usually show a decline rate faster than its younger contemporaries, the “Great” White Shark, has shown signs of rebuilding since early 2000s.
Courtesy Terry Goss
Before you go, find out who sharks are scared of (and surprise yourself) by decoding this Merry-time Jigsaw! Find out the reason and let Owliver know in the comments, below.