CONTROL AND THEN WASH UP DEAD. HERE’S MARISSA PARRA.
>> Reporter: IN THE
SHIMMERING BLUE WATERS
OF THE FLORIDA KEYS,
LONG THE JEWEL OF
THAT’S SOUTHERN COAST,
A MYSTERY LURKS
BENEATH THE SURFACE.
FISH WITH THE SPINS,
FLIPPING AND SPINNING
WITHOUT STOP.
>> IN MY LIFETIME OF
DIVES, I’VE NEVER SEEN
ANY BEHAVIOR FROM FISH
LIKE THIS AT ALL.
>> Reporter: THIS
DIVER FIRST OBSERVED
IT LAST YEAR AND SOON
LEARNED THE FISH,
INCLUDING THESE SMALL
TOOTH SAWFISH
WHICH CAN GROW UP TO
16 FEET WERE DYING.
SCIENTISTS ARE
STRUGGLING TO
UNDERSTAND WHY.
>> IT’S UNPRECEDENTED.
THEY DO NOT SPIN LIKE
THIS.
THEY DO NOT BEHAVE
LIKE THIS.
THIS IS NOT NORMAL
BEHAVIOR AT ALL.
>> Reporter: THAT
HIGHLY UNUSUAL
BEHAVIOR HAS BEEN SEEN
IN MORE THAN 40
SPECIES ACCORDING TO
FISH AND WILDLIFE.
IT HAS REVEALED NO
SIGN OF A PATHOGEN OR
BACTERIAL INFECTION.
OXYGEN LEVELS, WATER
SALINITY, pH AND
TEMPERATURE ARE NOT
BELIEVED TO BE THE
CAUSE BEWILDERING
RESEARCHERS.
>> IT’S A MYSTERY.
THERE’S SO MANY
DIFFERENT
POSSIBILITIES, THAT
IT’S REALLY DIFFICULT
TO ISOLATE WHICH ONE
IT COULD BE.
>> Reporter: 28
SAWFISH HAVE BEEN
FOUND DEAD, BUT THE
ACTUAL NUMBER BELIEVED
TO BE HIGHER.
A BLOW TO THIS SPECIES
EARLY ON ITS ROAD TO
RECOVERY.
>> SO, TO SEE THESE
ANIMALS DYING COULD BE
A MAJOR SETBACK.
WE WANT TO GET TO THE
BOTTOM OF IT AND
FIGURE OUT A WAY, A
WAY TO COME BACK FROM
THIS.
>> Reporter: FISHERIES
IN THE FLORIDA KEYS
REMAIN OPEN, THOUGH
STATE OFFICIALS SAY
SWIMMING WHERE DEAD
FISH ARE OBSERVED
ISN’T RECOMMENDED.
WHY DO WE NEED TO
PROTECT THE ECOSYSTEM
AND THE FISH THAT LIVE
HERE?
>> IT’S VERY SPECIAL.
FUTURE GENERATIONS
NEED TO BE ABLE TO
APPRECIATE IT THE SAME
WAY I DID.
>> Reporter: MARISSA