Sharks and Rays Belong on Australia’s Protected Species Lists

A Leopard shark glides over the bottom of the big tank at the Cairns Aquarium. (Photo by David Clode on Unsplash)

The Australian government has incorporated marine life into its Threatened Species Action Plan for the first time ever, but experts warn that the government's failure to address marine species and aquatic predators, such as rays and sharks, could threaten the entire ecosystem. 

Over 45,000 marine animals in Australia face endangerment and vulnerability due to factors such as climate change, pollution, and fishing, according to the University of Queensland. But, despite marine species' inaugural inclusion, amongst the 100 new species added to the Threatened Species Action Plan released in October 2022, only a quarter or less are marine animals, and only nine are fish. 

According to Australia's Minister for the Environment and Water, Hon Tanya Plibersek, the “priority species” are chosen based on ecological standards of high densities, significance to cultural values for Indigenous groups, and benefit to other species. The plan sets targets, such as preventing any new extinctions of protected fauna, and conserving an additional 50 million hectares of their habitats. 

However, the imbalance in the plan's protected ecosystems fails to reckon with escalating threats posed to marine life, including increased pressure on aquatic animals from extreme weather events in the region. It has also called into question the Australian government's commitment to comprehensive wildlife conservation. 

Overlooked: Rays and Sharks 

Notably absent from the action plan are a number of Australia's ray and shark species, like the hammerhead shark, the great white shark, the bow-mouth guitarfish, and others. 

The Humane Society International and Australian Marine Conservation Society report that there are 62 species of sharks and rays found in Australian waters that are listed as Endangered, Threatened, or Vulnerable under the IUCN Red List, but despite this data, only 15 of those species are considered protected under Australian laws.

In a 2021 assessment of extinction risk for all Australian sharks and rays, conservation biologist Peter Kyne with the Marine Biodiversity Hub found that Australia was home to more than a quarter of the world's sharks and rays. While he reported that overall risks to Australia's species were lower than global levels, the number that faced an elevated risk was concerning.

"While we should celebrate the secure status of many species, we urgently need to increase our research and management efforts for Australia's threatened sharks and rays," Kyne said in a 2021 National Environmental Science Programme media release. Yet, Kyne added that many of Australia's threatened sharks and rays are kept largely "out of sight, out of mind" due to a lack of commercial importance. 

Mammals steal the spotlight

Marine biologist Lawrence Chleback with Humane Society International said in a 2022 memo that "shark protection and shark conservation require the cooperation of governments, industry, and fishing management organizations," but explained that "there are rarely any voices to speak for the sharks." 

This dynamic is apparent in the list of organizations that contributed to the construction of Australia's Threatened Species Action Plan, all of which appear to have a primary focus on terrestrial ecosystems rather than on marine life. 

Moreover, out of the five governmental conservation organizations that make decisions within the Department of Climate Change, Energy, the Environment, and Water, none appear to specifically focus on marine ecosystems. 

One reason for this lack of attention could be that marine animals are deemed to be less important or in less dire situations than Australia's vast amount of terrestrial mammal species. 

Built for speed like a torpedo, a blacktip reef shark glides past at the Cairns aquarium, while the photographer struggles to pan at the same speed. (Photo by David Clode on Unsplash)

In a press conference regarding the Threatened Species Action Plan last year, Plibersek told local reporters that Australia was the "mammal extinction capital of the world." This moniker has long been associated with Australia due to the extinction of at least thirty-nine native mammals dating back to the region’s colonization. 

The action plan makes sure to highlight that Australia has lost more mammal species to extinction than any other continent. Speaking at the National Press Club in Canberra in July 2022, Plibersek noted the effects of the Australian bushfires of 2019-2020 on local terrestrial ecology and the government's protection priorities. 

However, marine mammals in Australia have also faced their own environmental related threat in the past few years: an oceanic and atmospheric phenomenon called La Niña. 

La Niña poses new threats 

The weather phenomenon known as La Niña is a cooling event of the central equatorial Pacific that can impact global wind and weather patterns. 

For Australia, this means a build-up of warm water and humid air off the northern coastline. The subsequent rising water temperature and heat waves resulting from La Niña can pose severe threats to aquatic life and fisheries, according to experts. 

The last La Niña event was the third to be declared by the National Oceanic and Atmospheric Administration (NOAA) over three years, constituting the first 'Triple La Niña' of this century. NOAA announced the La Niña streak officially ended in March of this year, but its effects on the environment could linger. 

In 2011, Australia experienced a La Niña event which coincided with a major marine heatwave, according to records from Australia's National Environmental Science Programme (NESP). The agency said in a 2021 report that the heat wave "caused widespread impacts to the local environment, ecology, and ocean-dependent industries." 

NESP added that La Niña brings significant troubles in marine communities like rays and sharks. According to the agency, "even several years after the heatwave, from 2011, only parts of the ecosystem have shown reasonable recovery, indicating that the marine heatwave had a lasting effect on the region." 

The latest La Niña adds pressure to the survival of top predators like tiger sharks, snubfin dolphins, dugongs, and hammerhead sharks that have already struggled with endangerment following the 2011 ocean heating event. Additionally, increased rainfall from La Niña can increase sea levels, causing top predators to interact with humans and toxic chemicals more so than ever. 

However, despite its seeming relevance, the Australian government does not mention the present threat of La Niña in the Threatened Species Action Plan. 

Predators are needed 

While marine predators such as rays and sharks tend to stay 'out of sight, out of mind,' the failure to adequately conserve them could have unforeseen consequences throughout the rest of the food chain. 

According to research published in the peer-reviewed ecology journal Oecologia in 2017, decreases in top predators in aquatic ecosystems can trigger an ecological event known as a "trophic cascade." A trophic cascade is an ecological phenomenon in which the addition or removal of top predators has a powerful effect on the rest of the ecosystem.

The Oecologia paper headed by Jordan M. Casey, formerly a Ph.D. at James Cook University, claims that given sharks' position at the top of the food chain, it would be reasonable to expect strong repercussions from decreases in shark biomass.

At first glance, removing a top predator may be seen as beneficial to food supplies for the greater Australian population. But, predators like rays and sharks play an important role by stopping any one species group from growing too abundant and thus upsetting delicate ecosystem balances. 

Conservationists say the effects of a trophic cascade can spiral to irreparable damage ​​to marine environments, ultimately tampering with the quality and ability of local communities to fish them for produce. 

Increasing environmental threats from climate change and extreme weather events could increase the likelihood of a trophic cascade from the loss of  sharks and rays in Australia. Once a key habitat for many rays and sharks in the region, The Great Barrier Reef was said to have deteriorated from "poor to very poor" in a United Nations Educational, Scientific and Cultural Organization committee report in 2022. 

While the government has recognized and named past failures by allowing terrestrial mammal species to go extinct, Australian aquatic life may be following down the same path right under their noses. 

Recent research indicates that shark and ray populations are estimated to have declined by over 70% globally since 1970. According to a statement by marine conservationist Peter Kyne, "no country has a higher diversity of sharks than Australia... that means we have a special responsibility to protect them from threats such as fishing and damage to their marine habitat."