Guest essay by Eric Worrall
In Australia a fierce debate is raging, between people who want to reduce the rising risk of shark attack on swimmers, by culling dangerous sharks, and greens, who often give the impression that losing a few people to shark attacks every year is acceptable. Now Professor Rod Connolly has added a new argument to the debate – he claims culling sharks exacerbates climate change.
According to the Brisbane Times;
As debate over shark culling continues along Australia’s coastline, a Queensland researcher has thrown another consideration into the mix – climate change.
Gold Coast-based marine scientist Professor Rod Connolly looked at data from coastal wetlands around the world and found those with fewer predators were less effective at storing carbon.
Simplistically, this meant less greenhouse gas locked away in plants and more floating free in the atmosphere contributing to warming and climate change.
The findings, published Tuesday in journal Nature Climate Change, came a few days after a seven-year-old girl was apparently bitten by a shark off Russell Island, near Cairns.
The abstract of the study;
Predators continue to be harvested unsustainably throughout most of the Earth’s ecosystems. Recent research demonstrates that the functional loss of predators could have far-reaching consequences on carbon cycling and, by implication, our ability to ameliorate climate change impacts. Yet the influence of predators on carbon accumulation and preservation in vegetated coastal habitats (that is, salt marshes, seagrass meadows and mangroves) is poorly understood, despite these being some of the Earth’s most vulnerable and carbon-rich ecosystems. Here we discuss potential pathways by which trophic downgrading affects carbon capture, accumulation and preservation in vegetated coastal habitats. We identify an urgent need for further research on the influence of predators on carbon cycling in vegetated coastal habitats, and ultimately the role that these systems play in climate change mitigation. There is, however, sufficient evidence to suggest that intact predator populations are critical to maintaining or growing reserves of ‘blue carbon’ (carbon stored in coastal or marine ecosystems), and policy and management need to be improved to reflect these realities.
I’m personally disgusted that anyone could put the welfare of a few sharks, even an entire species of sharks, ahead of the safety of Australia’s children. As for the alleged “climate risk” associated with shark culling – lets just say I’m prepared to take that chance.