The decline of Australian coastal sharks

What is sharks conservation in the Australian coastal areas? Especially in the eastern coastal areas of the country?

by Lorenzo Ciotti
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The decline of Australian coastal sharks
© Carl Court / Staff Getty Images

Important threats to the survival of sharks include severe alterations to their natural habitat, damage due to urban development on the coasts, pollution and the impact of fishing on the seabed species that are typically prey to these fish. The violent practice of fin cutting, linked to the preparation of shark fin soup and mentioned in the previous paragraph, has given rise to much discussion and regulation aimed at preventing it. The acclaimed 2007 documentary Sharkwater explained how several species were driven to near extinction following the huge demand in some Asian states for fin soup.

Sharks are found all over the globe, from north to south in all major oceans and seas. They generally live in sea water, but there are known exceptions of the Zambezi shark and the so-called river sharks which can live in both salt water and fresh water. They are common up to depths of 2,000 meters and some species even live below this threshold. However, a December 10, 2006 report by the Census of Marine Life group reveals that 70% of ocean waters in their volumetric sense are free of sharks. This research has also highlighted the fact that sharks are practically absent in waters deeper than 3,000 metres, and this habit exposes them even more easily to the dangers deriving from fishing. However, the shark found at the greatest depth ever was a Centroscymnus coelolepis observed at 3,700 metres.

Shark
Shark© Dan Kitwood / Staff Getty Images
 

But what is their conservation in the Australian coastal areas? Especially in the eastern coastal areas of the country?

The study Long term declines in the functional diversity of sharks in the coastal oceans of eastern Australia, published in Communications biology, explained:

“We illustrate the steady decline in functional richness of sharks quantified using both ecological aspects and morphological traits, and this corresponds to declines in ecological functioning. We demonstrate a community shift from apically targeted sharks to increased functional richness of non-target species. The decline of functional richness of apical sharks and corresponding changes in non-target species can lead to a human-induced trophic cascade. We believe that remediating declining shark populations is crucial for the stability of coastal ecosystems. abundance, diversity and characteristics of shark assemblages, altering the functioning of coastal ecosystems. The functional consequences of shark decline are often poorly understood due to the absence of empirical data describing long-term changes Queensland Shark Control Program in eastern Australia, which has deployed mesh nets and baited hooks at 80 beaches using standardized methodologies since 1962.”