Hi N2G,
This is my spin on the your article...

Derek voiced concerns about the future survival of various species of sharks, which are being captured and for their fins for shark fin soup, considered(comma),a rare delicacy in Asia and in the United States  (in the U.S.? really! I never knew that)

"It's very difficult to know how many there are left in the world," Derek said. "Some studies show that in the past 20 years, the number of sharks were  they're down 90 percent. They Sharks reproduce very slowly. I believe I think that unless people just stop killing the sharks for the fins which is a highly sought delicacy for certain cultures, I don't think the species has a chance."



"There" would be incorrect to use.