Transcript: Vilified Beasts: All About Eels | Aug 05, 2020

Nam sits in the studio. She's in her early forties, with shoulder length curly brown hair. She's wearing glasses, a green blazer over a black blouse, and a golden pendant necklace.

A caption on screen reads "Vilified beasts: All about eels. Nam Kiwanuka, @namshine, @theagenda."

Nam says THEY'RE NOT EXACTLY FISH, AND THEY'RE CERTAINLY NOT SNAKES THAT LIVE IN WATER. WHAT THEY ARE - IF YOU CAN GET OVER THE SLITHERY, DARTING WEIRDNESS OF EELS - IS FASCINATING: TRULY EVER-CHANGING, VERSATILE, AND RESILIENT. WITH US TO WIN YOU OVER TO THE REMARKABLE CHARACTERISTICS OF EELS: IN MALMO, SWEDEN: PATRIK SVENSSON, JOURNALIST AND AUTHOR OF "THE BOOK OF EELS: OUR ENDURING FASCINATION WITH THE MOST MYSTERIOUS CREATURE IN THE NATURAL WORLD..."

Patrik is in his forties, bald, with a stubble. He's wearing a white shirt.
A picture of his book appears briefly on screen. The cover is pale blue and features a drawing of two eels facing each other.

Nam continues AND IN OUR NATION'S CAPITAL: STEVEN COOKE, PROFESSOR AND CANADA RESEARCH CHAIR OF ENVIRONMENTAL SCIENCE AND BIOLOGY AT CARLETON UNIVERSITY.

Steven is in his forties, clean-shaven, with short gray hair. He's wearing a blue suit and a white shirt.

Nam continues WELCOME TO YOU BOTH.

Steven says THANK YOU.

Patrik says THANK YOU VERY MUCH.

Nam says I'M JUST GOING TO START WITH THE MOST BASIC OF QUESTIONS AND, STEVEN, I'D LIKE TO START WITH YOU. WHAT IS AN EEL?

The caption changes to "Steven Cooke. Canada Research Chair."

Steven says SURE. SO AN EEL IS A FISH. THERE'S ACTUALLY 800 OR SO SPECIES OF EEL IN THE WORLD SO IT'S NOT LIKE THERE'S JUST ONE OF THEM, THERE'S MANY OF THEM AROUND THE WORLD. THE EEL THAT WE HAVE IN ONTARIO IS CALLED THE AMERICAN EEL. IT EXISTS ALL THE WAY... ITS RANGE IS FROM VENEZUELA ALL THE WAY UP TO THE EASTERN ARCTIC. IT'S IN FACT THIS FISH SPECIES WITH THE GREATEST GEOGRAPHIC RANGE THAT INCLUDES CANADA WITHIN THAT HOME RANGE. THEY'RE INCREDIBLE BEASTS. THEY'RE LONG AND SKINNY. THEY DO LOOK LIKE A SNAKE. THEY'RE QUITE SLIPPERY, BUT THEY DO HAVE SCALES. THEY HAVE TINY LITTLE SCALES. THEY'RE COVERED IN A FAIR AMOUNT OF MUCUS, BUT ESSENTIALLY THEY ARE ELONGATED, THEY DO LOOK VERY MUCH LIKE A SNAKE WHEN THEY'RE SWIMMING IN THE WATER.

Nam says ALL I HEARD IS MUCUS. (LAUGHING) BUT TO US THEY LOOK LIKE SNAKES. SO WHAT MAKES THEM FISH?

Steven says RIGHT. SO THEY HAVE GILLS AND THEY OBTAIN THEIR OXYGEN FROM THE WATER. THEY ARE ENTIRELY DIFFERENT FROM REPTILES IN THAT WAY. AND WHAT'S REMARKABLE ABOUT THEM IS THEIR LIFE CYCLE. IT'S REALLY UNIQUE. THERE ARE NOT MANY BEASTS THAT ARE LIKE THEM.

Nam says WE'RE GOING TO TALK ABOUT THE LIFE CYCLE IN JUST A MOMENT. BUT IN ONTARIO HERE, WHAT MAKES AN EEL DIFFERENT FROM A LAMPREY?

Steven says RIGHT. IN THE GREAT LAKES PEOPLE MIGHT BE FAMILIAR WITH LAMPREY. LAMPREY ARE A PARASITE, THEY'RE SORT OF LIKE A VAMPIRE FISH THAT JUMPS ON BOARD SAY A NATIVE LAKE TROUT AND ESSENTIALLY DERIVES ITS NOURISHMENT FROM EATING THAT ANIMAL, FROM BLOOD AND OTHER TISSUE THAT IT EATS FROM THAT ANIMAL. SO IT'S PARASITIC. AND IN FACT WE SPEND MANY MILLIONS OF DOLLARS A YEAR TRYING TO ERADICATE OR CONTROL THE POPULATION OF INVASIVE SEA LAMPREY IN THE GREAT LAKES. ON THE OTHER HAND, EEL ARE ACTUALLY ENDANGERED. EEL ARE IN AN ENTIRELY DIFFERENT FAMILY, DIFFERENT GROUP OF FISH, AND IN FACT THEY ARE IMPERILLED. SO WE ARE ACTUALLY GOING TO GREAT LENGTHS TO TRY TO RESTORE THOSE POPULATIONS.

Nam says WE'LL TALK ABOUT SOME OF THE CONSERVATION EFFORTS THAT ARE BEING MADE. A MOMENT AGO YOU MENTIONED THE LIFE CYCLE OF AN EEL. WE'RE GOING TO HAVE A GRAPHIC UP HERE ON THE SCREEN. CAN YOU EXPLAIN TO US WHAT THE EEL LIFE CYCLE IS?

A graph pops up showing the life cycle of eels, starting as rice-shaped eggs.

Steven says RIGHT. SO THE EEL IS catadromous WHICH IS A FANCY SCIENTIFIC WORD FOR MEANING THAT THEY SPAWN IN THE OCEAN IN SALT WATER. SO THAT'S WHERE THE MALES AND FEMALES COME TOGETHER. AND THEN THE EGGS ARE FERTILIZED. THEN THEY END UP WITH A LEPTOCEPHALUS STAGE, WHICH IS MOVES ABOUT IN THE GULF STREAM FOR A NUMBER OF WEEKS AND THEN THERE'S A METAMORPHOSIS THAT OCCURS AND THEY BECOME GLASS EELS.

A picture shows dozens of yellowish semi-transparent eels with dark eyes.

Steven continues THEY SPEND UPWARDS OF A YEAR IN THAT PHASE AND THEN MOVE ON TO THE NEXT PHASE, WHICH ARE ELVERS, AT WHICH POINT THEY'RE STARTING TO MOVE, ACTIVELY MOVE, UPSTREAM INTO FRESH WATERS.

A picture shows two reddish elvers next to a coin.

Steven continues WHEN THEY'RE FULLY IN FRESH WATER, THEN THEY BECOME YELLOW EELS. AND THAT'S THE PART WHERE THEY SPEND THE MAJORITY OF THEIR LIFE. SO THEY MIGHT SPEND 10 OR 15 YEARS AS YELLOW EELS.

Two pictures show yellow eels in water. Another picture shows a greenish eel on mud as a researcher measures its length.

Steven continues THAT'S WHERE THEY'RE GROWING. THAT'S WHERE THEY WOULD BE IN PLACES LIKE LAKE ONTARIO. AND THEN WHEN THEY MATURE, THEY BECOME SILVER AGAIN AND HEAD BACK TO SEA. THEY'RE KIND OF THE OPPOSITE OF PACIFIC SALMON. EVERYBODY THINKS ABOUT HOW SALMON ARE BORN IN FRESHWATER, GO TO THE SEA AND COME BACK. THESE ANIMALS ARE OPPOSITE WHERE THEY'RE BORN IN THE SEA, COME TO FRESHWATER TO GROW, AND THEN GO BACK TO THE SEA TO REPRODUCE. THEY'RE ALSO SIMILAR TO PACIFIC SALMON IN THAT THEY DIE AFTER THEY SPAWN. SO THEY HAVE REALLY ONLY GOT ONE SHOT AT REPRODUCTION.

Nam says PATRIK, YOU'VE WRITTEN THIS INCREDIBLE BOOK THAT'S RESONATED WITH A LOT OF PEOPLE. IT'S PART MEMOIR AND NATURAL HISTORY. HOW DID YOU BECOME INTERESTED IN EELS?

The caption changes to "Patrik Svensson. Author, 'The book of eels.'"

Patrik says WELL, FIRST OF ALL, IT'S A REMARKABLE ANIMAL, I THINK. THE LIFE CYCLE THAT STEVE JUST EXPLAINED IS JUST A GREAT STORY, YOU KNOW. BUT MY FASCINATION FOR EELS STARTED ALREADY WHEN I WAS A CHILD AND I WENT FISHING WITH MY FATHER. THAT'S WHAT WE DID TOGETHER, ME AND MY FATHER, LATE SUMMER NIGHTS DOWN BY A SMALL STREAM AND IT WAS JUST ME AND HIM AND HE TOLD ME ABOUT THE EEL. HE TOLD ME ABOUT THIS INCREDIBLE JOURNEY TO THE SEA AND ALL THESE STRANGE DETAILS THAT SURROUND THE EEL. SO I HAD THIS FASCINATION WITH THIS FISH SINCE I WAS A SMALL CHILD.

Nam says ARE YOU SURPRISED BY HOW IT'S RESONATED WITH PEOPLE? BECAUSE WHEN YOU DO THINK ABOUT EELS, I DON'T KNOW IF YOU THINK ABOUT A BEST SELLING BOOK OR AN AWARD-WINNING BOOK.

Patrik says NO. I'M A LITTLE BIT SURPRISED, I HAVE TO SAY, BECAUSE ALSO A LOT OF PEOPLE HAVE THIS IMAGE OF EELS, THAT THEY ARE SCARY AND DISGUSTING, YOU KNOW, THEY ARE SNAKE-LIKE AND SLIMY. SO I'VE BEEN SURPRISED ABOUT... I MET A LOT OF PEOPLE WHO READ THE BOOK WHO SAID THAT I HAD NO IDEA I WOULD EVER READ A BOOK ABOUT THIS SUBJECT AND ACTUALLY ENJOY IT. BUT THAT'S THE BEST THING YOU CAN ACCOMPLISH, I THINK.

Nam says AND IN YOUR BOOK TOO, YOU REVEAL THAT THERE'S A LOT OF HISTORICAL FIGURES WHO WERE ALSO FASCINATED, MAYBE OBSESSED WITH THE EEL, ARISTOTLE, SIGMUND FREUD. WHY DO YOU THINK THESE MEN WERE SO FASCINATED WITH EELS?

Patrik says YES. I WAS ACTUALLY ALSO SURPRISED ABOUT THE TIME AND EFFORT THAT PEOPLE HAVE PUT DOWN TO UNDERSTAND THE EEL, FOR SEVERAL HUNDRED OF YEARS, FROM ARISTOTLE TO RACHEL CARSON. AND FOR HUNDREDS OF YEARS THEY HAVE TALKED ABOUT THE EEL QUESTION AS A SPECIFIC QUESTION THAT'S BEEN VERY, VERY HARD TO SOLVE, TO ANSWER, TO UNDERSTAND WHAT THE EEL IS AND HOW THEY BREED AND WHERE THEY BREED, ALL THESE QUESTIONS THAT HAVE BEEN SURROUNDING THE EEL. AND I THINK THAT'S ALSO WHAT MAKES THE EEL FASCINATING, FOR ME AND ALSO FOR ALL THESE SCIENTISTS, THAT THEY ARE MYSTERIOUS, THAT THEY ARE VERY HARD TO UNDERSTAND AND TO EXPLAIN.

Nam says WHY IS IT IMPORTANT FOR US TO UNDERSTAND HOW THEY LIVE AND HOW THEY FUNCTION? WHY IS IT IMPORTANT?

Patrik says I THINK THAT'S ACTUALLY THE WRONG QUESTION. I THINK WHAT THE SCIENTIFIC HISTORY OF THE EEL TELLS US IS THAT THERE'S A HUMAN FORCE TO UNDERSTAND THE WORLD AND TO UNDERSTAND NATURE AND TO UNDERSTAND LIFE AROUND US. AND THERE'S NO GAINING BY UNDERSTANDING HOW THE EELS REPRODUCE BUT THERE'S A HUMAN FORCE THAT WANTS TO KNOW, AND THIS FORCE IS VERY STRONG AND I THINK IT'S A VERY INTERESTING STORY ALSO ABOUT HUMAN... ABOUT SCIENCE AND ABOUT HOW SCIENCE WORKS AND HOW WE KNOW THE THINGS WE KNOW.

Nam says WE KNOW FREUD NOW FOR ANOTHER REASON BUT BACK IN THE DAY HE SPENT TIME DISSECTING HUNDREDS OF EELS. WHAT WAS HE TRYING TO FIGURE OUT?

Patrik says THIS WAS IN 1876 AND FREUD, HE WAS 19 YEARS OLD AND THIS WAS HIS FIRST SCIENTIFIC WORK, AND HE WAS TRYING TO PROVE THAT EELS HAVE SEXUAL DIFFERENCES BECAUSE THEY HADN'T BEEN ABLE TO PROVE THAT AT THAT POINT. SO SPECIFICALLY HE WAS TRYING TO FIND A MALE EEL WITH SEXUAL ORGANS. HE WAS TRYING TO FIND AN EEL TESTICLE. AND HE WENT TO TRISTE, IN ITALY, AND HE DISSECTED 400 EELS TRYING TO FIND THESE MAGICAL EEL TESTICLES. AND HE FAILED. HE WASN'T ABLE TO FIND ONE. AND MAYBE THAT HAS SOMETHING TO DO WITH HIS LATER CAREER, YOU KNOW, GOING INTO THE HUMAN MIND INSTEAD OF TRYING TO UNDERSTAND THE EEL AND ALL THIS THEORY ABOUT PENIS AND THE CASTRATION COMPLEX.

Nam says WHEN YOU WROTE THIS BOOK, PART OF IT WAS... YOU SAID THAT YOU STARTED BECOMING FASCINATING WITH EELS BECAUSE IT'S SOMETHING THAT YOU DID WITH YOUR FATHER. WHEN YOU FINISHED THE RESEARCH AND YOU WROTE THE BOOK, IS THERE ANYTHING THAT YOU DIDN'T KNOW BEFORE YOU STARTED RESEARCHING THAT YOU DISCOVERED ALONG THE WAY THAT SURPRISED YOU?

Patrik says THERE ARE A LOT OF THINGS I DIDN'T KNOW ABOUT THE SCIENTIFIC HISTORY AND ABOUT ALL THOSE GREAT SCIENTISTS WHO HAVE TRIED TO UNDERSTAND THE EEL. AND I WAS ACTUALLY SURPRISED ABOUT HOW BIG A PART THE EEL QUESTION HAS PLAYED IN THE SCIENTIFIC HISTORY AND THE NUMBER OF SCIENTISTS WHO HAVE REALLY TRIED TO ANSWER THIS QUESTION.

Nam says AND PART OF THIS EEL QUESTION, STEVEN, IS FIGURING OUT WHERE EELS LIVE. WHERE DO THEY LIVE?

The caption changes to "Steven Cooke, @SJC_fishy."

Steven says RIGHT. SO THEY OBVIOUSLY ARE SPREAD BETWEEN THE OCEAN AND FRESHWATER, BUT THERE ARE MANY MYSTERIES THAT REMAIN. SO LET'S TAKE SOMETHING LIKE A YELLOW EEL, SO AN ADULT EEL THAT'S GETTING NEAR THE POINT WHERE IT'S GOING TO REPRODUCE AND LET'S PRETEND IT'S BEEN HANGING AROUND HAMILTON HARBOUR, SO IN THE WEST END OF LAKE ONTARIO. THAT EEL WILL HAVE TO UNDERTAKE A 5,500-KILOMETRE JOURNEY THROUGH LAKE ONTARIO, DOWNSTREAM IN THE ST. LAWRENCE AND OUT TO THE SEA. THE SARGASSO SEA, WHERE IS THAT? IT'S ESSENTIALLY THE BERMUDA TRIANGLE. THE EELS DISAPPEAR. NOBODY HAS EVER SEEN AN AMERICAN EEL REPRODUCE IN THE WILD. WE ACTUALLY DON'T KNOW WHAT THAT LOOKS LIKE.

A world map pops up highlighting the location of the Sargasso Sea, in the Atlantic Ocean.

Steven continues WE JUST KNOW GENERALLY IT'S IN A BIG SWATH OF THE OCEAN BETWEEN BERMUDA AND THE BAHAMAS. BUT BEYOND THAT, THERE'S MANY UNKNOWNS. IN FRESHWATER WHEN THEY'RE ADULTS, THEY'RE ACTIVE MOSTLY AT NIGHT. THEY'RE NOCTURNAL ANIMALS, WHEN THEY'LL MOVE AROUND AND THEY'LL FEED ON INVERTEBRATES AND SMALL FISH AND FROGS AND SUCH. BUT DURING THE DAY, THEY BURROW IN THE MUD. SO THEIR HABITAT INCLUDES SOFT BOTTOM, SAND, SOME GRAVEL, AND IN THE WINTER IN FACT THEY SPEND MUCH OF THEIR TIME BURIED. IN FACT, SOME FOLKS HAVE ESTIMATED THAT OVER THE COURSE OF THE LIFE OF AN EEL, THEY SPEND THREE-QUARTERS OF THEIR LIFE BURIED IN SUBSTRATE. SO IN MANY CASES, YES, THEY'RE IN THE WATER COLUMN, BUT THEIR HABITAT IS ALSO IN THE SUBSTRATE, IN THE BOTTOM OF RIVERS AND LAKES.

Nam says WHAT'S THE DIFFERENCE BETWEEN AN EEL THAT CAN BE FOUND IN THE GREAT LAKES AND SAY ONE THAT CAN BE FOUND IN EUROPE?

Steven says RIGHT. SO THEY ALL, TO OUR KNOWLEDGE, REPRODUCE IN AND AROUND THE SARGASSO SEA. SO THAT PART IS NOT ENTIRELY DIFFERENT. BUT WHEN THEY'RE HEADING TO DIFFERENT PARTS OF THE WORLD AS A JUVENILE, SOME HEAD TOWARDS NORTH AMERICA, AND THE EUROPEAN EELS HEAD TOWARDS EUROPE. THE EUROPEAN EELS TEND TO LIVE A LITTLE BIT LONGER, BUT OTHERWISE THERE'S NOT REALLY A WHOLE LOT OF DIFFERENCE. THEY'RE PRETTY SIMILAR BEASTS. AND THEY CERTAINLY TASTE QUITE SIMILAR.

Nam says AND HOW DO THEY KNOW WHERE TO GO? CAN YOU TELL US MORE ABOUT THE MIGRATION OF EELS?

Steven says RIGHT. SO CERTAINLY THERE'S SOME LEVEL OF MAGNETIC SENTRY CAPABILITY. THEY CERTAINLY PAY ATTENTION TO LIGHT AS WELL. SO SCIENTISTS DO EXPERIMENTS WHERE THEY COVER THE EYES, WHERE THEY GLUE MAGNETS ON THE FOREHEAD OF THESE ANIMALS AND SUCH, AND IT SEEMS THAT THEY USE A VARIETY OF CUES. THERE'S NOT ONE SINGLE CUE THEY USE TO NAVIGATE DURING THEIR JOURNEY.

Nam says IS IT TRUE THAT EELS CAN WALK ON LAND?

Steven says NOT WALK, BUT THEY CERTAINLY CAN MOVE ON LAND FOR SHORT PERIODS OF TIME. SO THERE ARE DAMS THAT ARE IN THE WAY SOMETIMES FOR MIGRATIONS AND SOMETIMES IF IT'S... REMEMBER, THESE ANIMALS ARE ACTIVE AT NIGHT. AND IF IT'S A WET NIGHT AND THERE'S SOME GRASS AND DEW OR RAIN, THESE ANIMALS WILL EMERGE FROM THE WATER AND ACTUALLY MAKE THEIR WAY ON LAND AROUND THESE BARRIERS IN AN ATTEMPT TO GET UPSTREAM. IT'S PRETTY UNCOMMON. YOU'RE NOT GOING TO GO FOR A WALK AT YOUR LOCAL PARK IN THE EVENING AND SEE A BUNCH OF EELS UP ON THE LAWN, BUT IT IS A PHENOMENON THAT HAS BEEN DOCUMENTED.

Nam says WOULDN'T THAT BE A SIGHT TO SEE? (LAUGHING) PATRIK, IN YOUR BOOK YOU WRITE ABOUT JOHANNES SCHMIDT. WHO WAS HE AND WHAT ROLE DID HE PLAY IN OUR UNDERSTANDING OF THE EEL?

Patrik says EXACTLY. I'M INTERESTED IN TELLING STORIES, AND THE SCIENTISTS WITH THE EEL IS A GREAT STORY. IF YOU DON'T JUST ASK WHAT DO WE KNOW ABOUT THE EEL BUT ALSO ASK HOW DO WE KNOW IT. FOR EXAMPLE, HOW DO WE KNOW THAT THE EEL BREEDS IN THE SARGASSO SEA. WE KNOW THAT BECAUSE THERE WAS A DANISH BIOLOGIST CALLED JOHANNES SCHMIDT WHO WENT OUT ON THE ATLANTIC OCEAN AND TRIED TO FIND THE BIRTHPLACE OF THE EEL, AND HIS METHOD WAS TO FIND THOSE SMALL LARVAE, THE LEPTOCEPHALUS LARVAE, AND THE THEORY WAS, THE PLACE WHERE THEY WERE AT THE SMALLEST SIZE, THAT'S THE PLACE WHERE THE EEL IS BORN. SO HE SPENT ALMOST 20 YEARS. HE SPENT 18 YEARS IN THE ATLANTIC, SAILING AROUND, CATCHING SMALL LARVAE, MEASURING THEM. IN 18 YEARS HE FOUND THE PLACE WHERE THERE WAS JUST TINY, TINY LARVAE THAT OBVIOUSLY HAD BEEN NEWLY HATCHED AND HE COULD SAY THIS IS THE BIRTHPLACE OF THE EEL. BUT AS STEVEN SAID, NO ONE HAS EVER SEEN EELS BREED. THEY WANT TO IN CAPTIVITY AND NO ONE HAS SEEN IN THE SARGASSOSEA, LIVE OR DEAD, ONLY THE NEWLY HATCHED LARVA.

Nam says WHY IS THAT?

Patrik says THAT IS PART OF THE MYSTERY. PEOPLE HAVE CERTAINLY TRIED. THEY HAVE TRIED TO PUT TRANSMITTERS ON EELS GOING TO THE SARGASSO SEA AND THEY HAVE TRIED TO CATCH EELS THERE, BUT IT'S ALMOST LIKE THE EEL IS HIDING FROM US, IN A SENSE, AND THAT'S ALSO WHAT MAKES IT FASCINATING.

Nam says AND I'M THINKING TOO, YOU KNOW, FOR... WE HAVE FARMED FISH NOW, AND IF YOU DON'T KNOW HOW EELS MATE, I GUESS YOU CAN'T FARM THEM; IS THAT RIGHT, STEVEN?

Steven says YEAH, SO THERE ARE FARMED EELS, BUT THE WAY IT WORKS IS THAT PEOPLE GO OUT AND THEY CAPTURE THE GLASS EELS, THEY BRING THEM INTO CAPTIVITY OR PUT THEM IN SEA CAGES OR CAGES IN FRESHWATER AND RAISE THEM THERE. SO THERE STILL IS AN IMPACT WITH THE CULTURE SIDE OF THINGS. IT REQUIRES TAKING THE SMALL FISH THAT ARE CAUGHT IN THE WILD, BRINGING THEM INTO CAPTIVITY, AND JUST GROWING THEM. WHEN ONE DOES THAT, THEN THAT ALLOWS YOU TO HARVEST THAT PROTEIN AND THERE'S LESS MORTALITY AND SO ON. THERE ARE RESEARCHERS IN JAPAN WORKING ON A JAPANESE EEL SPECIES, AND THEY'VE HAD SOME SUCCESS WITH TRYING TO GET THESE ANIMALS TO REPRODUCE IN CAPTIVITY AND TRYING TO FIGURE OUT THOSE EARLY PHASES OF THE LIFE CYCLE IN PARTICULAR, THE LEPTOCEPHALUS STAGE AND HOW TO MAINTAIN IT IN THE LABORATORY BUT THERE'S STILL SO MUCH TO LEARN.

Nam says FOR ME, JUST LEARNING ABOUT EELS, I'M SURPRISED THAT THEY DON'T KNOW HOW THEY MATE. I'M ASSUMING THAT SCIENTISTS HAVE TRIED MANY WAYS TO DISCOVER THAT INFORMATION. ARE YOU SURPRISED THAT WE STILL DON'T KNOW THAT, STEVEN?

Steven says YES AND NO. BUT THE OCEAN IS A BIG PLACE. AND SOME OF THE TELEMETRY DATA THAT PATRIK TALKED ABOUT BEFORE, SOME OF THE SATELLITE TAGS TELL US IN THE ANIMALS ARE IN THE DAY AT 500 METRES OF DEPTH. AT NIGHT THEY COME UP TO RELATIVELY SHALLOW WATERS, 200 METRES. THAT'S STILL REALLY DEEP. YOU'RE NOT GOING TO BE OUT THERE SNORKELING OR SCUBA DIVING AND COMING UPON THOSE ANIMALS. AS I MENTIONED, THE SARGASSO SEA, IT'S REALLY DIFFICULT TO PUT YOUR THUMB ON A PLACE. YES, THE SARGASSUM, WHICH IS A KIND OF ALGAE WHICH IS IN THAT REGION, BUT THAT'S IT. IT'S NOT LIKE, YOU KNOW, IN FRESHWATER WHERE WE CAN POINT AT THE PILE OF ROCKS AND SAY THAT'S WHERE THE ANIMALS REPRODUCE AND WE CAN GO AND JUST STARE AT THAT UNTIL THEY COME. THAT DOESN'T HAPPEN IN THE OPEN OCEAN IN THE SAME WAY.

Nam says PATRIK, HAVING WRITTEN A BOOK THAT'S RESONATED WITH PEOPLE AND WHEN WE TALK ABOUT THE CONSERVATION EFFORTS OF EELS, DO YOU HOPE THAT MAYBE PEOPLE WILL LOOK AT EELS IN A DIFFERENT WAY AND MAYBE HAVE A LITTLE BIT OF OWNERSHIP AND WORRY ABOUT WHAT HAPPENS TO THE EEL MOVING FORWARD?

Patrik says YES, I CERTAINLY HOPE THAT, NOT ONLY THE EEL. THE EEL IS JUST ONE EXAMPLE OF A MUCH BIGGER THING THAT IS HAPPENING RIGHT NOW. SCIENTISTS CALCULATE THAT THE POPULATION OF THE EUROPEAN EEL THAT I'M MOSTLY WRITING ABOUT HAS GONE DOWN BY MORE THAN 95 percent SINCE THE '70S, AND THAT'S A VERY DRASTIC CHANGE.

Nam says THAT'S SHOCKING.

Patrik says YEAH, THAT IS SHOCKING. BUT THE EEL IS JUST ONE EXAMPLE OF THE MANY, MANY SPECIES THAT ARE THREATENED RIGHT NOW. A LOT OF SCIENTISTS ARE ACTUALLY TALKING ABOUT WE'RE GOING INTO THE SIXTH MASS EXTINCTION, WHICH MEANS THIS IS A PERIOD WHERE A LOT OF SPECIES WILL DISAPPEAR IN A RELATIVELY SHORT TIME. YOU KNOW, THE LAST MASS EXTINCTION WAS THE FIFTH ONE, WAS AROUND 65 MILLION YEARS AGO WHEN ALL THE DINOSAURS DISAPPEARED. NOW THIS IS HAPPENING AGAIN. FOR THE FIRST TIME IN HISTORY, IT'S ONE SPECIES THAT IS A THREAT TO EVERY OTHER SPECIES. THAT'S ACTUALLY A REMARKABLE THING AND VERY SCARY THING HAPPENING.

Nam says STEVEN, I WANT TO ASK YOU THE SAME QUESTION, YOU KNOW: HOW IMPORTANT IS IT FOR US TO KNOW ABOUT THESE CREATURES SO WE DO HAVE A SENSE OF OWNERSHIP AND WE BECOME INVESTED IN WHAT HAPPENS TO THEM?

Steven says ABSOLUTELY. GETTING THE PUBLIC AND POLITICAL WILL TO PROTECT OUR RIVERS, TO PROTECT OUR FISH IS KEY. I WAS PART OF A TEAM THAT LAST WEEK PUBLISHED A LIVING PLANET INDEX REPORT ON THE STATE OF FRESHWATER MIGRATORY FISH. AND ON A GLOBAL BASIS, POPULATIONS ARE DOWN 73 percent FOR FISH THAT MIGRATE IN FRESHWATER, INCLUDING EELS. SO THAT CERTAINLY... YOU KNOW, WE CAN TALK ABOUT EEL TODAY, BUT WE'RE REALLY TALKING ABOUT ALL FISH THAT UNDERTAKE FRESHWATER MIGRATIONS. AND THERE'S MANY CHALLENGES THEY FACE. YOU KNOW, DAMS ARE CERTAINLY A BIG ONE. WHEN YOU'RE A MIGRATORY ANIMAL, YOU NEED TO MOVE UP AND DOWNSTREAM IN RIVERS. AND THESE ANIMALS HAVE CHALLENGES THAT THEY FACE ON THE WAY TO THEIR FRESHWATER FEEDING GROUNDS, SO WHEN THEY'RE ELVERS ABOUT YEA LONG, ABOUT 15 TO 30 CENTIMETRES LONG, THEY NEED TO MAKE THEIR WAY UPSTREAM AND THEY ENCOUNTER LARGE DAMS. THINK ABOUT THINGS LIKE THE MOSES SAUNDERS DAM ON THE ST. LAWRENCE RIVER. FORTUNATELY IT'S EQUIPPED WITH AN UPSTREAM EEL LADDER THAT ALLOWS THOSE ANIMALS TO MOVE PAST, BUT THEN THEY ALSO HAVE TO MAKE THEIR WAY BACK DOWNSTREAM. AND AT THAT POINT THEY'RE LONG ANIMALS AND THEY HAVE TO GO THROUGH HYDRO POWERED TURBINES. SO WE KNOW THAT ON THE ST. LAWRENCE, THE CUMULATIVE MORTALITY BETWEEN THE TWO MAIN DAMS ON THE WAY DOWNSTREAM IS ABOUT 40 percent. IN FACT WE THINK BASED ON MODELLING WORK THAT EEL THAT MOVE DOWN THROUGH THE OTTAWA RIVER MAY IN FACT EXPERIENCE 95 percent MORTALITY FROM TURBINES. SO HYDRO POWER IS CERTAINLY A PART OF THE PROBLEM BUT THEY'RE WORKING QUITE HARD ON SOLUTIONS, TRYING TO GUIDE FISH TO SAFE PATHS USING THINGS LIKE LIGHTS. I MENTIONED THAT THESE ANIMALS ARE NOCTURNAL. SO IF WE CAN USE LIGHT TO GUIDE THEM, TO REPEL THEM ESSENTIALLY, WE CAN PUSH THEM INTO SAFE PATHS AND USE THAT TO HELP THEM STAY AWAY FROM THE TURBINES AND TAKE SAFE PATHS BACK TO THE OCEAN.

Nam says YOU MENTION A FEW THREATS TO THEIR HABITATS. BUT WHAT IS THE BIGGEST THREAT TO THE EEL HABITAT, WOULD YOU SAY?

Steven says YEAH. IN GENERAL, IT'S HABITAT LOSS AND DAMS ARE A BIG PART OF THAT. IN THE NATIVE RANGE OF AMERICAN EEL IN THE GREAT LAKES WATERSHED, SO THINKING ABOUT LAKE ONTARIO AND THE ST. LAWRENCE, OTTAWA RIVER AND SO ON, THERE ARE OVER 950 DAMS. AND SO, YES, THERE ARE THE BIG DAMS I REFERENCED BEFORE BUT THERE ARE ALL SORTS OF SMALL DAMS AS WELL. AND THAT LIMITS ACCESS UP TO FEEDING GROUNDS THAT ARE UPSTREAM OF THOSE DAMS, AND THEN THERE'S FISHING AS WELL. THERE WAS HISTORIC COMMERCIAL FISHING RIGHT THROUGH TILL THE 2000S. THERE WAS THE ONTARIO ENDANGERED SPECIES ACT ENDED UP COMING INTO FORCE AND AMERICAN EEL WERE CLASSIFIED AS ENDANGERED AND AT THAT POINT THE COMMERCIAL FISHERY AND THE RECREATIONAL FISHERY CEASED. BUT THERE'S A LEGACY FROM THAT. THESE ARE LONG-LIVED ANIMALS. SO WHEN YOU PUSH POPULATIONS DOWN, IT REALLY TAKES QUITE A LONG TIME FOR THEM TO COME BACK, AND THEN JUST LAYER ON EVERYTHING ELSE, INVASIVE SPECIES, CLIMATE CHANGE, CONTAMINANTS. THESE ANIMALS BURROW IN THE SUBSTRATE, AND THAT'S WHERE A LOT OF THESE CONTAMINANTS HAVE ACCUMULATED OVER THE YEARS. SO BASICALLY ANY STRESSOR YOU CAN THINK OF THAT FRESHWATER FISH HAVE TO DEAL WITH, AMERICAN EEL HAVE TO DEAL WITH IT THROUGHOUT THEIR LIFE.

Nam says YOU KNOW, WE CALLED THIS SEGMENT, IT'S PART OF OUR VILIFIED BEASTS SHOW FOR THE WEEK, AND, PATRIK, HAVING WRITTEN THIS INCREDIBLE BOOK THAT NOT ONLY LOOKS AT HISTORY BUT ALSO TALKS ABOUT YOUR FAMILY'S LIFE, AND I KNOW THAT YOUR FATHER PASSED AWAY... OUR CONDOLENCES. WHAT DO YOU THINK YOUR DAD WOULD SAY ABOUT YOUR BOOK THAT'S BEEN ABLE TO CONNECT PEOPLE, SO MANY PEOPLE, OVER SOMETHING LIKE THE EEL?

Patrik says I THINK HE WOULD BE EXCITED. HE WAS VERY INTERESTED IN NATURE AND ANIMALS AND FISH. HE WAS A WORKING MAN. HE NEVER WENT TO UNIVERSITY. BUT HE WAS INTERESTED IN THIS. BUT I ALSO THINK HE WOULD BE VERY SURPRISED THAT PEOPLE ALL OVER THE WORLD ARE ACTUALLY READING A BOOK THAT'S ALSO ABOUT HIM BECAUSE I THINK HE WOULD FIND THAT VERY HARD TO BELIEVE.

Nam says AND, STEVEN, BEFORE WE GO, ONE QUESTION I DIDN'T ASK YOU, THAT I MEANT TO ASK YOU, IS HOW LONG DO EELS LIVE FOR?

Steven says RIGHT. SO IN THE GREAT LAKES BETWEEN 12 AND 22 YEARS OR SO IS WHAT'S BEEN DOCUMENTED IN TERMS OF THEIR FRESHWATER RESIDENCY. THEN ADD IN A COUPLE MORE YEARS FOR THEM TO FIND THEIR WAY TO FRESHWATER AND FIND THEIR WAY BACK. WE THINK MAXIMUM FOR AMERICAN EEL, SOMEWHERE IN THE VICINITY OF 24 YEARS.

Nam says PATRIK, I'LL LET YOU HAVE THE LAST WORD. WHAT DO YOU THINK IS THE MOST IMPORTANT THING THAT PEOPLE SHOULD KNOW ABOUT EELS THAT THEY PROBABLY DON'T KNOW?

Patrik says ACTUALLY, YOU KNOW, ABOUT THE AGE OF THE EEL, THE EUROPEAN EEL, WE HAVE IN SWEDEN DOCUMENTED AN EEL BEING OVER 85 YEARS OLD, AND THERE ARE STORIES ABOUT EELS BEING OVER 150 YEARS OLD. SO IT CAN BECOME VERY, VERY OLD. I THINK THE IMPORTANT THING TO UNDERSTAND THAT THE EEL IS PART OF A MUCH BIGGER NATURAL SYSTEM, AND ALL SPECIES HAVE A ROLE IN THIS SYSTEM. WHETHER YOU THINK THE EEL IS KIND OF SCARY OR DISGUSTING, IT'S IMPORTANT TO UNDERSTAND THAT EVERY SPECIES IS IMPORTANT IN THE WHOLE NATURAL SYSTEM.

The caption changes to "Producer: Meredith Martin, @MeredithMartin."

Nam says GENTLEMEN, THANK YOU SO MUCH. I'VE REALLY ENJOYED THIS CONVERSATION AND I'VE LEARNED A LOT. WE APPRECIATE YOUR TIME AND YOUR INSIGHT.

Patrik says THANK YOU.

Steven says THANK YOU SO MUCH.

Watch: Vilified Beasts: All About Eels