00:00:11regularity here in the world’s largest
00:00:22mangrove swamp in the Bay of Bengal
00:00:25villagers trudged through a murky river
00:00:28to net shrimp larvae locals speak of a
00:00:33monster that attacks underwater without
00:00:36warning it happened to sumitra mystery
00:00:45barcelona Cabo sorry it was an ordinary
00:00:49day I woke up and then I went for
00:00:52fishing in the river I was pulling my
00:00:58net in the water for three hours when
00:01:00the animal bit me it was like a sharp
00:01:04razor cut
00:01:05I pushed the animal and it immediately
00:01:08took off my hand
00:01:11I swam to the shore and saw the blood
00:01:13running from my hand
00:01:19many here bear the scars of these
00:01:21frightening encounters National
00:01:30Geographic biologist rocky strong an
00:01:32adventurer Fabien Cousteau have come to
00:01:35investigate rocky believes the culprit
00:01:41might be a bull shark
00:01:49they set the bait
00:01:52why this spot versus any other this is a
00:01:55place where two major rivers converge
00:01:59and even more importantly all the locals
00:02:03say this is a good spot for sharks
00:02:20something is biting
00:02:23but the researchers can’t make a catch
00:02:40well no no really even good good bites I
00:02:45have to say it’s the longest time I’ve
00:02:47spent fishing without any results at all
00:02:53later they’re led to a market were two
00:02:56small sharks are for sale so in here all
00:03:02yours
00:03:04goodness gracious ah this is this is a
00:03:08brand new pup by the look of the
00:03:12umbilical marks these pups were newborns
00:03:14to determine the species the researchers
00:03:20count T five six seven eight nine and
00:03:27ten
00:03:28that’s our fish it’s conclusive these
00:03:32are bull sharks as rocky suspected this
00:03:36sometimes aggressive species has been
00:03:38documented in rivers throughout the
00:03:39world
00:03:43Rocky’s theory is that bull sharks
00:03:45developed the ability to live
00:03:47temporarily in freshwater so that
00:03:49females can give birth where their young
00:03:51are safest from other sharks but maybe
00:03:56it’s after giving birth that the females
00:03:58had further upriver in search of food
00:04:00sometimes encountering people why Upper
00:04:05River versus say further down the coast
00:04:07or deeper into the ocean because they
00:04:11can because they can leave all their
00:04:13competitors behind and be king of the
00:04:16hill up inside a an environment that
00:04:20they’re very good at dealing with and
00:04:22other sharks just aren’t
00:04:31both shark and human are seeking food in
00:04:33these waters to help them survive
00:04:39and that competition can sometimes lead
00:04:42to dangerous clashes
”