What is behind barrier number 3?

February 14, 2018

 

Fact-seals fear sharks. Seems common sense, right? Well as silly as it seems scientists have done entire and likely costly study to determine this to be true. The results … it is true.

 

What was interesting to me about the study though is the way they measured the seals’ fear. In this three-year study, researchers tested the stress levels in seal colonies that have varied exposure to great white sharks hunting them. The cortisol stress hormone glucocorticoid released when they experience stress can be found in seal feces. Scientists chose six islands in South Africa's Western Cape home to the Cape Fur seal colonies and gathered up droppings then compared the hormone levels to seals that lived without the threat of sharks.

 

 

The question for me was how are there any seals free from the apex predator? One island Geyser Rock apparently hosts seals living free from fear. Comparing the stress hormone level of samples revealed that indeed the seals on this island did not show comparable signs of stress to those living on other islands. The reason: Geyser Rock’s kelp bed and reefs allow seals a natural safe passageway from sharks.  Apparently sharks will not venture into a place where they are not able to swim freely mainly because they can’t swim backward.

 

What does this all have to do with shark conservation you may wonder? Well shortly after reading about this study, I came across yet another ‘new’ shark deterrent method that has been developed and proven to deter sharks 100 percent of the time. Basically building a barrier that resembles the kelp bed and reef like the one in Geyser Rock. No nets just a natural barrier that has proven to be 100 percent effective. The new Sharksafe Barrier mimics Mother Nature. It was designed by scientists after marine biologists observed seals in South Africa swimming into forests of kelp to avoid being killed by great white sharks. Observations revealed that time after time, upon approaching the kelp, the great white shark would turn away from these areas. In the six year testing not a single great white breached the Sharksafe Barrier. These are incredible numbers. 

 

So why aren’t the governments of high risk countries adopting it? Apparently they are entertaining it as it was a topic among shark experts at the 2015 Shark Summit. The NSW government was watching to see if the technology had progressed to a stage of readiness for testing off NSW beaches. Unfortunately in the meantime, they continue to use shark nets and drumlins which have proven to kill sea life. As we enter 2018, my hope is that alternative shark deterrent methods are no longer entertained but actually put in place so that humans and sharks can safely co-exist.   

 

Please reload

Recent Posts

April 12, 2019

January 24, 2019

Please reload

Archive
Please reload

Search By Tags