Australia Shark Safety Nets Can’t Catch One Key Species, Researchers Say

The bull shark prefers shallow water, so encounters with people can be frequent. Photo: Shutterstock

According to experts, a shark monitoring program administered by the government of New South Wales (NSW), Australia has one critical flaw: Bull sharks are slipping through the cracks.

The Shark Management Alert in Real Time (SMART) system is a catch and release based method of tracking sharks near Australia’s eastern beaches. This amounts to drum lines that catch sharks and alert nearby wildlife officers, who then attach tracking beacons to the animals and release them.

Those tags, placed on the fins, can then send alerts to beachgoers or lifeguards if the shark swims near a busy beach.

The SMART system went live on a long stretch of eastern Australian coastline in March 2022, thanks to more than $85 million in government funding. The program has just completed its first calendar year, and it is funded through 2026. SMART drumlines are now in place at 19 locations along New South Wales’ more than 1,300 miles of coastline.

A January article published in the journal Fisheries Research documented findings from SMART during a period before it became a government program: December 2019 to May 2021. Their research, based in two beach towns in the northeastern corner of the state, showed remarkably low bull shark catches. While 67% of the system’s total catch was split between white and tiger sharks, bull sharks accounted for just 3%.

Only eight bull sharks hit the monitored drum lines during the 18 months, compared to 137 great whites and 65 tiger sharks.

This contradicted regional observations. Documented sightings of large bull shark bites and bites have been on record, including two fatal attacks in the past 15 years.

No bull sharks?

Of all sharks, bull sharks are of the greatest concern to swimmers and surfers. Because they prefer shallow water, encounters are plentiful.

So if the New South Wales government’s program is aimed at preventing shark attacks, how effective can it be if it lets bulls go largely undetected? The answer may be that it still works quite well.

SMART lines are obviously in their infancy, so data from one season only explains so much. But Australia reported just nine unprovoked shark bite incidents in 2022 – a significant drop from its five-year average of 15 and well below the US’s 41 confirmed cases.

Nevertheless, the authors of the Fisheries Research paper think that the SMART system lacks bull sharks for one important reason. The article noted that “[h]Higher catch rates and increased activity associated with bull sharks have been reported during periods of low light (night, dawn and dusk), but the SMART drumlines are deployed during daylight hours.”

According to Australia’s ABC News, this is accurate. The SMART lines deploy between sunrise and 8 a.m., and crews retrieve them “at least two hours before sunset,” a summary of the paper said.

Whether or not SMART needs to catch more bull sharks to keep beachgoers safe, the species isn’t the only variety of shark to benefit from the officials’ methods. Harm reduction is the methodology behind SMART – the fewer unprovoked attacks, the fewer sharks suffer fatal consequences at the hands of the authorities.

But because the bait hooks hang at a certain depth below the surface, the study authors found, critically endangered gray nurse sharks are generally safe from bycatch. The 3.2 meter depth also reduces false alarms, the study said.

“The standard tracks effectively caught target shark species, while reducing gray shark catches and false alarm events, highlighting that the track length currently used for NSW SMART drumline deployments is optimal,” the paper concluded.

Nothing like a win-win on a Friday.

Learn how to reduce the chances of an adverse shark encounter, as well as essential information about shark behavior, shark personalities, shark language, what to do if a shark bites you, and more during over 20 video lessons in Ocean Ramsey’s Guide to Sharks and Safety.