In conjunction with the upcoming North American release of Disney’s “Oceans” (on DVD and Blu-ray October 19), Disneynature hosted a virtual roundtable discussion with Dr. Sylvia Earle that I was fortunate enough to be a part of.

Dr. Earle, who worked as a consultant on “Oceans,” has logged over 7,000 hours of underwater time and has authored over 125 publications on marine science and technology. She was the first recipient of Time magazine’s “hero for the planet” in 1998, and won the TED prize in 2009.

I had the opportunity to ask Dr. Earle for her perspective on the declining number of shark populations in the world’s oceans.

There is no doubt that sharks, especially large species, are greatly depleted. The best numbers come from a 2003 study that reviewed 50 years of global data and concluded that about 90 per cent are gone. Those of us who have been diving in places such as the Galapagos, Cocos, Gulf of Mexico, Seychelles, Hawaii, the Bahamas, Bermuda and elsewhere since the 1960s where sharks were once very abundant can attest to the greatly diminished numbers. Sharks reproduce slowly and live a long time, making them especially vulnerable to overfishing.
-Dr. Sylvia Earle

Additionally, Dr. Earle was asked for her opinion on the greatest threat to the world’s oceans today.

Obvious threats include what we are putting into the sea (millions of tons of pollutants) and what we are taking out (millions of tons of ocean wildlife), as well as profound disturbance to natural shoreline systems — mangroves, marshes, sea grass meadows, kelp forests, coral reefs and even healthy, natural sandy beaches. But far and away the biggest problem is ignorance, something that OCEANS helps to solve. When people understand how important the ocean is to their lives, and how much damage we are causing, they can respond with action. If people don’t know, they can’t care . . .-Dr. Sylvia Earle

In addition to the issues above, Dr. Earle discussed other topics such as memories of her first dive, advice for children who want to explore ocean-based careers, and what species she has yet to personally encounter but would like to dive with (she mentioned giant squid and narwhals in her response).

Many thanks to Dr. Earle for sharing her insight!