When National Geographic approached with an opportunity to swim with sharks to kick off its it was an easy yes for the Marvel star who is the new Captain America.

The water, says Mackie, is a 鈥渟afe space鈥� where he 鈥渃an just tune everybody and everything else out.鈥�

Mackie has been a certified scuba diver for nearly two decades. 鈥淚鈥檝e swam with some crazy stuff, and I鈥檝e swam with sharks before. I just swam with Great Whites in South Africa. I did whale sharks in Mexico. I swam with a blue whale off the coast of Cape Town.鈥�

For debuting Thursday, he wanted cameras to visit the waters near where he is a regular boater and fisherman. An increase of sharks in the area are swarming boats and eating fishermen鈥檚 catches, leading to a greater risk of hungry sharks becoming aggressive. This points to a larger environmental issue that the ecosystem is off-kilter.

鈥淚f we eat all the fish, the sharks have nothing to eat,鈥� said Mackie. 鈥淪harks have babies in Lake Pontchartrain and Lake Catherine. When their babies come out, they鈥檙e full-grown pups. They鈥檙e three-foot sharks鈥� They鈥檙e not predators, but they also need a substantial food source.鈥�

Mackie says he was in the water for about four hours and 鈥渋t鈥檚 not that hard to find a multitude of sharks in the Atlantic Ocean.鈥� Seeing the sharks up-close reminded him 鈥渉ow majestic and powerful they are, but also you just see how beautiful they are.鈥� He was accompanied by marine biologist Jasmine Graham, whom Mackie says was his 鈥渟ecurity blanket鈥� if it got too intense.

鈥淓very time it would get to be too much, I would grab her. I鈥檓 like, 鈥楾hey鈥檝e got to pick one. So if one of us getting eaten, it better be you,鈥欌�� he laughed. 鈥淪he really looked out for me and gave me a lot of information that really opened my eyes to the community that we鈥檙e in and explaining the sharks鈥� behavior.鈥�

Mackie, whose show will be followed soon by Discovery鈥檚 Shark Week programing, also hopes to highlight the effects of global climate change on the coastline of New Orleans where . Global warming has both caused snow and ice to melt and it鈥檚 led to more storms that cause flooding. Also, activity from the oil and gas industry weakens the soil.

鈥淭he area around New Orleans is slowly going away. You know, the water is starting to eat away at our habitat, our home,鈥� said Mackie. 鈥淭here are certain areas where I used to go as a kid, and those areas are gone now, like oyster farms,鈥� said Mackie.

鈥淲e used to go fishing when I was little and my uncle would put me in the water. I would walk around and field for oysters with my feet, put them in a boat, and we would eat those oysters for lunch. Whole oyster beds are gone.鈥�

For someone whose career has afforded him the opportunity to travel the globe both for work and pleasure, Mackie says there truly is no place like New Orleans.

鈥淭here鈥檚 nothing more beautiful than seeing the sun come up over the Gulf of Mexico. It鈥檚 literally breathtaking and I鈥檝e seen the sun come up over everything. When you鈥檙e in a boat, going out to the Gulf or even Lake Catherine and you see the sun come up over that marsh and wetland, there鈥檚 nothing like it.鈥�