A report from Catlin Group Limited explains that its Seaview Survey, “using specially developed underwater imaging techniques,” is revealing how Tropical Cyclone Ita impacted exposed parts of the Great Barrier Reef earlier this year.
The Catlin sponsored Seaview Survey is now in its third year, and has carried out a series of scientific expeditions to study changes occurring to coral reefs, one of the most distinctive features of our oceans.
A team of divers and scientists from the Global Change Institute at The University of Queensland went to the Great Barrier Reef “to get an initial assessment of the impact of Tropical Cyclone Ita, a Category 5 storm that crossed the Great Barrier Reef in January 2014,” Catlin said. “Equipped with a new, highly portable model of the SVII survey camera kit, the team was able to deploy quickly to make an initial assessment and observations. A full scientific survey will be carried out by the team later this year.
“Tropical Cyclone Ita was the second Category 5 storm in three years to hit the Great Barrier Reef and Coral Sea off the North East Australian coast, following Tropical Cyclone Yasi in February 2011.”
The team reported that the “Ribbon Reef region of the Great Barrier Reef suffered most as Cyclone Ita passed directly overhead. By contrast, there was less impact at Osprey Reef in the Coral Sea because the center of the storm passed about 90 kilometers away.
“The impact cyclones have on the health of coral reefs is quite unpredictable and still relatively unknown.” In this case, however, the team had “photographed reefs in the region during 2012 and has been able to revisit some of those areas to make comparisons. The most striking observation was the huge variance of storm impact, with no uniform pattern of damage in the wake of the storm.
“On Osprey Reef it was evident that some areas are more robust, with some parts naturally protected from storms. Whilst the outer walls of the reef lying closer to the path of the cyclone were damaged, these corals are relatively hardy and can be expected to recover.
“Acting as a breakwater, the reefs themselves seem to have reduced the power of the storm’s impact on their leeward side and, as a result, Cyclone Ita left those areas mostly intact. There were more pockets of intense damage found in the shallower Ribbon Reefs on the Great Barrier Reef closer to the coastline.”
Richard Vevers, the Catlin Seaview Survey’s Project Director, who dived with the team, said: “We found areas with extensive damage next to perfectly healthy reefs that appeared virtually unaffected by the storm. There were differences not just between the sheltered and exposed parts of reefs, but also differing levels of damage to areas immediately adjacent to one another.
“What’s so significant about this work is that we now have the capability, for the first time, to deploy our cutting-edge survey technology quickly to compare information over time.”
Later this year the team will investigate how the overall structures of the reefs may have channeled the force of wave action, creating the varied pattern of damage. Professor Ove Hoegh-Guldberg, the Catlin Seaview Survey’s Chief Scientist and Director of the Global Change Institute, explained: “There is a myriad of increasing and cumulative impacts on the Great Barrier Reef. We can control impacts such as fishing, coastal development and marine debris. However, we do not have the same control over storms and cyclones.
“Ensuring that coral can bounce back from these disturbances is at the heart of the matter. The more we reduce other stressors on the reef (factors such as water quality), the better the chance that coral can bounce back. Given the steep decline of coral on the reef, it’s clear we have a lot of work to do.”
As company founder Stephen Catlin explained at in an interview at the Reinsurance Rendezvous last year, the Seaview Survey is an example of the kind of response insurers can make to understand the impacts of climate change more clearly.
Earlier this month, the international think tank Geneva Association, supported by the insurance industry, expressed concern about the prospect of extreme climate change and its potentially devastating economic and social consequences. It committed to better research to boost evaluation and management of climate risks and to “play a major and concerted role in the global efforts to counter climate risks.
Mark Newman, CEO of Catlin Group Limited’s Asia-Pacific underwriting hub, warned: “Extreme weather increases economic threats such as damage to property, compromising food security and the livelihoods of coastal populations.
“At the heart of the Catlin Seaview Survey work is a need to determine if tropical cyclones are causing long-term damage to coral reefs and reducing their effectiveness as protecting barriers for the coastline, its people and their businesses. Clearly, there is a potential risk which we need to understand better.”
Source: Catlin Group Limited