. >> they may be here gestai ng or giving birth. >> they tagged sharks and 11 were pregnant females.ou can see a pup's two eyes and mouth. this place seems particularly important for pregnant tiger sharks. why do you think that is? >> i think what's happening is sharks are spending their 10 to 15 months of gestati on periods in warm waters. >> but pregnant females is hard to come by. meanwhile the crew has another innovation to try out. it's an experiment that he hopes will make research easier on the sharks and the true. >> the reason why i like the platform is because it's bigger. you can walk all around it. the positive thing, and you'll >> the very positive thing, and jim, you'll be happy about this, it's underwater. that's really good. >> this is a tiger shark. >> it's not long before the platform is put to the test by an 11. 11.5-foot tiger shark. [ yelling ] >> since the shark is dorsal finish up, tissue samples are taken first. and then blood is drawn. it will provide a wealth of information, the kind that scientists used to get only by sacrificing the shark. >> in the past i