A recent study published in the journal Nature has uncovered a significant decline in more than 500 common species of fish, seaweed, coral, and invertebrates inhabiting reefs around Australia. The research, conducted by a collaborative team of approximately 35 researchers from various institutions, warns of the detrimental impacts of increasing ocean temperatures, labelling it an “existential threat” with far-reaching consequences for ecosystems and commercial fisheries.
The study focused on monitoring 1,057 species, revealing that a staggering 57% of them have experienced declines, with nearly 300 species at a rate that could categorize them as threatened. A concerning 28% of the species analysed showed drops of 30% or more within just a decade, with those dwelling in cooler waters being particularly hard-hit by the adverse effects of global heating.
Lead author Prof Graham Edgar, a marine ecologist at the University of Tasmania, expressed deep concern over the declines, emphasizing that the most pronounced effects were observed in the rocky kelp-dominated reefs of Australia’s cooler southern waters, collectively known as the Great Southern Reef.
Edgar underscored the urgency of the issue, noting that the declines are occurring with little public attention, and the situation could be even more critical as many unmonitored species are likely facing similar threats. He warned, “Species could be going extinct now,” emphasizing the severity of the situation and the urgency for action.
The loss of kelp is identified as a particularly crucial factor, as these species serve as the cornerstone for various habitats in the cooler waters around the continent. Larger fish were found to be declining at a faster rate than smaller ones, a trend attributed to the dual pressures of rising temperatures and increased fishing activities exacerbating the challenges faced by marine life.
The study heavily relied on existing data from the Australian Institute of Marine Science, as well as the contributions of volunteer divers participating in the Reef Live Survey. Prof Edgar acknowledged the vital role of these volunteers, stating, “Without the volunteer efforts of Reef Live Survey divers, we couldn’t have done this work.”
As marine species face unprecedented threats due to global warming, the study concludes that the repercussions extend beyond the immediate decline of individual species, posing a significant risk to entire ecosystems and the livelihoods of those dependent on commercial fisheries. The findings underscore the urgent need for comprehensive conservation measures to address the escalating challenges faced by marine life in Australian waters.
