Shark Numbers Along The Great Barrier Reef Have Dropped By 92% In Just 50 Years

World 02:19 15.12.2018

Shark populations have been declining steadily around the world for decades. It feels like every other week a shocking new report reveals the dire straits of these vulnerable creatures. This time it is the turn of the apex predators of Australia’s east coast, whose numbers have plummeted alarmingly in the last half a decade.

A new study has revealed that the numbers of iconic species such as hammerheads, tiger sharks, and great whites that live in the waters off the coast of Queensland have dropped by as much as 92 percent in just 50 years.

Researchers from the University of Queensland (UQ) used data from a shark control program, which was first instigated to minimize shark-human interactions in 1962, that now stretches over 1,100 miles (1,760 kilometers) and includes the Great Barrier Reef.

Before that there are no official records, so researchers have used the shark control data to reconstruct historical records of shark numbers and shark catches over the last half a century to understand the changes that have taken place between then and now.

“Explorers in the 19th century once described Australian coastlines as being ‘chock-full of sharks,’ yet we don’t have a clear idea of how many sharks there used to be on Queensland beaches,” Dr. George Roff of UQ, who led the study, explained in a statement.

“We will never know the exact numbers of sharks in our oceans more than half a century ago, but the data points to radical changes in our coastal ecosystems since the 1960s.”

The shark control program uses baited drumlines to bring down local populations, making shark encounters with humans less likely. According to the study, published in Communications Biology, nearly 50,000 sharks have been caught by this method. Though the range of species caught has been diverse, proper species identification in the recordings only began in the 1990s, so the earliest records grouped them all into five categories: hammerheads, tigers sharks, great whites, whaler sharks, and “other”.

“What we found is that large apex sharks such as hammerheads, tigers and white sharks, have declined by 74 to 92 percent along Queensland’s coast,” Dr Roff said.

“And the chance of zero catch – catching no sharks at any given beach per year – has increased by as much as seven-fold.”

That’s not all. The decades of data revealed another trend, most likely a result of fewer sharks reaching reproductive age.

“The average size of sharks has also declined – tiger sharks and hammerhead sharks are getting smaller,” Roff said.

While human-shark interactions are not desirable, it’s the shark that usually comes off worst. Around 100 million sharks are killed each year globally by humans, while sharks kill on average six humans a year.

However, the researchers concluded that while the shark control program certainly contributed to the diminishing numbers, the likely culprit is commercial fishing, both for the Asian market and as bycatch thanks to large fishing nets.

Azerbaijan Defense Minister informs NATO chief on situation in Azerbaijan-Armenia conditional border -VIDEO

News line

Pakistan restricts foreign travels of ministers, government officials
Pakistan restricts foreign travels of ministers, government officials
20:39 18.03.2024
EU to boost military support fund for Ukraine by EUR 5 bln — Hungarian foreign minister
20:00 18.03.2024
Industrial zones to be created in Azerbaijan’s Zangilan, Jabrayil, and Gubadli
19:16 18.03.2024
Reuters: Only an oil slump can stop Russia
19:00 18.03.2024
Top Hamas operative killed in hospital raid, IDF says
Top Hamas operative killed in hospital raid, IDF says
18:33 18.03.2024
President Ilham Aliyev congratulates people of Azerbaijan on occasion of Novruz holiday - UPDATED
18:00 18.03.2024
Jens Stoltenberg: We fully support Georgia's sovereignty and territorial integrity
Jens Stoltenberg: We fully support Georgia's sovereignty and territorial integrity
17:47 18.03.2024
2 dead, 6 injured in Türkiye factory explosion
2 dead, 6 injured in Türkiye factory explosion
17:28 18.03.2024
Armenia’s anti-Russian policy reaches new level
17:11 18.03.2024
"The Middle Corridor plays a key role for Green Energy" - Expert Ali Pasha
16:45 18.03.2024
Central square of Khankandi named “Victory Square”
16:22 18.03.2024
President: We demonstrated tremendous heroism during the II Karabakh War and the anti-terror operation
16:16 18.03.2024
Nobel Peace Prize Laureate Muhammad Yunus visited IEPF - PHOTOS - VIDEO
16:00 18.03.2024
Historic opportunity emerged to advance the Azerbaijani-Armenian peace agenda - FM Bayramov
15:21 18.03.2024
Bayramov and Stoltenberg discuss normalization process between Azerbaijan and Armenia
15:03 18.03.2024
Azerbaijan Defense Minister informs NATO chief on situation in Azerbaijan-Armenia conditional border -VIDEO
14:58 18.03.2024
Stoltenberg's visit to the Caucasus: "NATO is in panic" - OPİNİON
14:29 18.03.2024
Hikmat Hajiyev holds discussions for upcoming COP29 with Chinese Vice FM
Hikmat Hajiyev holds discussions for upcoming COP29 with Chinese Vice FM
14:00 18.03.2024
Stoltenberg concludes his official visit to Azerbaijan
13:42 18.03.2024
Geomagnetic storm expected on March 20
13:33 18.03.2024
Mbappe celebrates his 250th goal in PSG
Mbappe celebrates his 250th goal in PSG
13:19 18.03.2024
President Ilham Aliyev makes a phone call to Vladimir Putin
13:00 18.03.2024
President Ilham Aliyev lit Novruz bonfire in Khankandi and congratulated Azerbaijani people
12:34 18.03.2024
Foreign students attacked in India over Ramadan prayers
12:30 18.03.2024
Spring comes to Northern Hemisphere
Spring comes to Northern Hemisphere
12:17 18.03.2024
Why does Azerbaijan matter to the European Union? - OPINION
12:00 18.03.2024
Number of human remains found in mass grave in Khojaly reaches 19
11:45 18.03.2024
Hikmat Hajiyev meets Pakistani envoy to China
Hikmat Hajiyev meets Pakistani envoy to China
11:33 18.03.2024
EU Council to discuss Armenian-Azerbaijani normalization
11:23 18.03.2024
Global Terrorism Index: Azerbaijan among countries with highest anti-terror rating worldwide
10:56 18.03.2024
Oil prices keep rising
Oil prices keep rising
10:40 18.03.2024
Stoltenberg: NATO looking forward to further strengthening partnership with Azerbaijan
10:23 18.03.2024
Azerbaijani police found numerous weapons and ammunition in Khankandi
10:10 18.03.2024
President Ilham Aliyev: There is a good chance for settlement of Azerbaijan-Armenia relations
09:57 18.03.2024
Putin warns about possible war between Russia and NATO
09:40 18.03.2024
Hikmat Hajiyev meets with Vice Minister of Ecology and Environment of China
09:23 18.03.2024
Azerbaijan relocates 123 more residents to Fuzuli city
08:53 18.03.2024
President Ilham Aliyev held expanded meeting over dinner with Jens Stoltenberg
23:07 17.03.2024
Putin wins the presidential elections for fifth term, exit poll shows
22:43 17.03.2024
COP29 will be turning point, says NATO Secretary-General
21:54 17.03.2024
Hamısı