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IT'S SHARK WEEK,
AND THIS IS YOUR "DAILY BITE."
THERE HAVE BEEN
SOME INCREDIBLE DISCOVERIES
IN THE DEEP BLUE SEA
SINCE LAST YEAR,
AND GREAT WHITE SHARKS
HAVE BROUGHT US
SOME OF THE MOST JAW-DROPPING,
FROM MILLIONS OF YEARS AGO,
RUBBING FINS WITH THE MEG...
TO BREACHING ALL NEW HEIGHTS
THIS YEAR.
THIS APEX SPECIES
IS A FORMIDABLE PREDATOR,
AND WE'RE NOW OBSERVING
NEW STRATEGIES
IN THEIR ATTACK ARSENAL.
ONE OF THEIR MOST RECENTLY
DISCOVERED TACTICS IS KELP.
SEALS TEND TO FEEL SAFE HANGING
AROUND A PROTECTIVE KELP FOREST,
BUT RECENT RESEARCH
FROM THE UNIVERSITY OF MIAMI
ACTUALLY SHOWS THEY HAVE
REDUCED CORTISOL LEVELS
WHEN THEY AREN'T WORRIED
ABOUT BECOMING LUNCH.
BUT RESEARCHERS INSIDE AFRICA
HAVE SPOTTED WHITE SHARKS
LURKING IN KELP.
WITH THE SEALS' GUARDS DOWN,
THESE HUNTERS CAN USE IT
AS A SORT OF CAMOUFLAGE
AS THEY STALK OUT
THEIR UNSUSPECTING PREY.
AND THERE'S EVEN NEW PROOF
THAT SUGGESTS THE GREAT WHITE'S
HUNTING ABILITIES
HAVE BEEN SPOT-ON
FOR A GOOD 11 MILLION YEARS
OR SO.
NEW FOSSIL DATING
RECENTLY REVISED THE DATE
OF MEGALODON'S EXTINCTION
FROM 2.6 MILLION YEARS AGO
TO 3.6 MILLION YEARS AGO --
RIGHT BACK TO WHEN
GREAT WHITE SHARKS
WERE ALSO ROAMING THE OCEANS.
IT'S POSSIBLE
THAT GREAT WHITE SHARKS
LITERALLY STARVED THE MEG
INTO EXTINCTION
BY OUT-HUNTING IT.
NOW, THE ABSOLUTE COOLEST
HUNTING TACTICS
PROBABLY GO TO THE BREACHING
GREAT WHITE SHARKS
OF SOUTH AFRICA.
THE WORLD GOT ITS FIRST GLIMPSE
OF THE JAW-INSPIRING BEASTS
BACK IN 2001
WHEN "SHARK WEEK" DIRECTOR
JEFF KURR
CAPTURED THE PHENOMENON
IN SOUTH AFRICA'S SEAL ISLAND.
WHAT'S REALLY INCREDIBLE
IS THE SHEER SPEED
THAT GREAT WHITES
ARE ABLE TO ACHIEVE
TO PROPEL THEIR ONE-TON BODIES
THROUGH THE SURFACE
AND SNATCH UP THE SEALS.
THE RESULTS ARE JUST
TERRIFYINGLY BEAUTIFUL.
UNFORTUNATELY,
THE TWO-DECADE-LONG STUDY
THAT BROUGHT US YEARS
OF AIR JAWS
HAS DISCOVERED
THOSE ACROBATIC SHARKS
ARE DISAPPEARING
FROM SOUTH AFRICA.
DR. NEIL HAMMERSCHLAG
AND CHRIS FALLOWS
HAVE DOCUMENTED
OVER 8,000 SIGHTINGS
SINCE THE YEAR 2000.
AND SOMEWHERE AROUND 2015,
THE NUMBERS DROPPED OFF
DRAMATICALLY.
THINGS GOT EVEN QUIETER
ON THE SURFACE IN 2017
WHEN THEY BEGAN DISAPPEARING
ENTIRELY FOR MONTHS AT A TIME.
MY FRIEND
DR. NEIL HAMMERSCHLAG
EXPLAINED HIS FINDINGS
IN A NEWLY PUBLISHED PAPER
WITH AN EXCITING TWIST
AT THE END.
WE KNOW THAT MANY SHARK
POPULATIONS ACROSS THE GLOBE
ARE DECLINING, WHICH RAISES
A REALLY IMPORTANT QUESTION.
WHAT ARE THE ECOSYSTEM
CONSEQUENCES?
WHAT HAPPENS
WHEN AN APEX PREDATOR
DISAPPEARS FROM AN AREA?
AND UNFORTUNATELY, TO THIS DAY,
TRYING TO OBTAIN THAT TYPE OF
DATA HAS BEEN REALLY DIFFICULT
BECAUSE MOST STUDIES
ARE SHORT-TERM.
HOWEVER, A LONG-TERM STUDY
AND COLLABORATION BETWEEN
CHRIS FALLOWS AND I
REVEALED SOME
REALLY NEW, EXCITING DATA
THAT'S HELPED PROVIDE INSIGHTS
INTO HOW AN ECOSYSTEM
MIGHT CHANGE
FOLLOWING THE LOSS
OF AN APEX PREDATORY SHARK.
IT'S CRAZY TO THINK THIS PLACE
THAT WAS FAMOUS FOR
BREACHING GREAT WHITE SHARKS
NOW IS VOID OF GREAT WHITES.
BUT IN THE ABSENCE
OF GREAT WHITE SHARKS,
WE DOCUMENTED SOMETHING
THAT WE COULDN'T PREDICT --
ANOTHER APEX PREDATOR MOVING IN.
THE SEVENGILL SHARKS.
SEVENGILL SHARKS RESEMBLE
PREHISTORIC SHARKS,
HAVING SEVEN GILLS
INSTEAD OF THE NORMAL FIVE
THAT MANY MODERN-DAY SHARKS
HAVE.
IN THAT PART OF THE WORLD,
IN FALSE BAY,
SEVENGILLS WERE KNOWN
TO AGGREGATE
NEARLY 20 KILOMETERS AWAY
IN KELP FORESTS.
WE HAD THOUGHT THAT ONE OF
THE REASONS THAT THE SEVENGILLS
WERE HANGING OUT
IN THESE KELP FORESTS
IS BECAUSE THEY PROVIDED
A REFUGE TO GREAT WHITES,
BECAUSE OTHER THAN
GREAT WHITE SHARKS,
THESE SEVENGILLS DON'T ACTUALLY
HAVE ANY NATURAL PREDATORS.
AND THE THOUGHT IS WHEN
THE WHITE SHARKS HAVE LEFT,
THESE SEVENGILLS ARE ABLE
TO MOVE TO SEAL ISLAND
AND TAKE ADVANTAGE
OF THE VOID LEFT BEHIND
BY THE ABSENCE AND DISAPPEARANCE
OF WHITE SHARKS.
WHAT THIS LONG-TERM STUDY
REALLY SHOWED
IS THAT ECOSYSTEMS ARE COMPLEX,
AND WITHOUT AN APEX PREDATOR
LIKE THE GREAT WHITE,
THE SYSTEM CHANGES.
AND FOR THE FIRST TIME
IN 20 YEARS,
WE SAW THE EMERGENCE
OF THIS OTHER APEX PREDATOR
MOVE INTO THE AREA -- SOMETHING
THAT WE COULDN'T HAVE PREDICTED.
WE DON'T KNOW WHY THE
GREAT WHITE SHARKS DISAPPEARED
OR WHERE THEY'VE GONE,
HOWEVER, WHAT I CAN TELL YOU
IS WE'VE DOCUMENTED
A NEW SPOT IN SOUTH AFRICA
THAT IS A GREAT WHITE SHARK
HUNTING HOT SPOT.
WE WERE ABLE TO GO THERE
AND FILM FOR THIS YEAR'S
"SHARK WEEK"
IN A SHOW CALLED
"AIR JAWS STRIKES BACK."
AND AT THIS SITE,
WE'VE SEEN SOME INCREDIBLE,
NEW HUNTING BEHAVIORS
OF WHITE SHARKS
THAT HAVE CHANGED THE WAY WE
LOOK AT SHARK/SEAL INTERACTIONS.
THE GREAT WHITE SHARK
DISCOVERIES THIS YEAR
HAVE ONLY JUST
TAPPED THE SURFACE
OF WHAT WE KNOW
ABOUT THESE LIVING DINOSAURS.
"SHARK WEEK" SCIENTISTS
HAVE UNCOVERED SO MUCH MORE,
LIKE THE REAPPEARANCE OF
THE LARGEST GREAT WHITE SHARK
ON RECORD -- "DEEP BLUE"...
[ INDISTINCT SHOUTING ]
...AND SOME NEVER-BEFORE-SEEN
PREDATION
IN SECRET HUNTING GROUNDS
AROUND GUADALUPE.
STICK WITH US
ALL "SHARK WEEK" LONG
AS WE CONTINUE TO BRING YOU THE
COOLEST DISCOVERIES IN SHARK.
IN THE NEXT EPISODE
OF THE "DAILY BITE,"
WE'RE GONNA CATCH UP WITH
THE FASTEST SHARKS IN THE OCEAN
AND THEIR RACE
AGAINST EXTINCTION.
