Shoreline defences are being placed at Vanguard Cave in a bid to protect the UNESCO World Heritage Site from the medium-term threat of sea levels rising due to climate change.
The defences consist of gabions, cage-like structures filled with rocks and used to absorb the impact of waves before they break on the shoreline.
The placement is part of the Gibraltar’s Government commitment to the UNESCO site and it is hoped that the gabions will protect the sensitive archaeological deposits from the action of waves during storms.
Yesterday morning, the Director of the Gibraltar Museum Professor Clive Finlayson and the managing director at the Gibraltar Museum Dr Geraldine Finlayson were at the caves viewing point to see the works commence.
“One of the things identified in the UNESCO management plan was that one of the medium term risks to the site was sea levels rising,” said Professor Finlayson, explaining further that they had already placed gabions at Gorham’s Cave and monitored their effectiveness.
“We have seen recently in the really bad storms that sometimes the water goes right up, obviously it’s a surge not waves breaking so it is not a dangerous thing, but the gabions protected it very well.”
“We felt that Vanguard needed the same treatment, not because there is an immediate risk but if you carry on having storms and surges coming close there might be risks eventually.”
“What you do see in Gorham’s and Vanguard that the surge gets very close and we do not want it to get worse and worse, so rather than wait until there is a problem it is better to take preventive actions,” he added.
“The projection is that there is going to be a slight sea level change so that means the water will start to go in if we do not do something about it.”
The gabions will also serve as walkways for visitors.
The medium risk factor of sea levels rising is hard to predict but based on current information 30 years is an estimated figure.
However, Professor Finlayson points out: “I know this site very well and so does Geraldine. We have been coming for decades and to be honest the storms of two weeks ago and the one we had last winter we have not seen anything like it before.”
“This means that in spite of the average being 30 years, you do not know what the actual timeline is.”
“It is better to be safe and protected and do as much as you can,” he added.
The works will see the deployment of equipment by sea aimed at bringing in quantities of broken limestone rock that will fill the gabions and create the sea wall.
The design, the Government states, is aimed at reducing the visual impact on the site. It also noted that the remoteness of the site and the difficulty of access make the operation a difficult one which needed careful planning.
The Minister for Education, Heritage, Environment, Energy and Climate Change, Dr John Cortes, said: “This is essential work to protect the integrity of our World Heritage Site, and shows the Government’s commitment to this. It is an example of work that we needed to do particularly as the threat of increasing sea levels due to climate change becomes more and more apparent. We are the custodians of this unique site, and will ensure it is well looked after.”