The American Eel Magical Mystery Tour

A moody grey roadside picture in Labrador. Photo courtesy of Sarafina Henderson.

It was a misty cold Monday morning in October when myself and 3 researchers from the Department of Fisheries and Oceans set off on a 14-hour journey from St. John’s, Newfoundland to Cartwright, Labrador. Our main objective: assess the population status of the elusive American eel (Anguilla rostrata).

With numbers dwindling since the late 1980s, uncovering the major threats to eel survival is becoming an increasingly daunting task for scientists, locals and Indigenous peoples. Unlike salmon that spawn in rivers, American eels spawn in the Sargasso Sea and have puzzled humans for centuries with their complex life history patterns. To this day, we know little about how and where specifically American eels spawn. There is also much to learn about how they interact with the distinct but related European eel species that share breeding grounds. What we do know is that eels play an important role as generalists in ecosystems and are culturally significant to many communities. For the Mi’kmaq First Nation, eels are woven into multiple aspects of daily life such as their food, social, and ceremonial practices. 

As a masters student just starting my program in Marine Biology, I was eager to join this trip and aid in the conservation of a threatened species. Prior to chatting with the lead researcher last September, my idea of eels consisted mostly of mythical-electric-snake-looking-things that I am afraid to say I mildly shuddered at. I now realize what I was picturing was a knife fish (Apteronotus albifrons), or electric eel, which are electric but are not eels at all despite the confusing name. True eels on the other hand, could be thought of as slimy, tube puppies of the sea as they are known to be quite curious and have a playful spirit. 

The American eel (Anguilla rostrata) captured using electrofishing techniques from a river in southern Labrador. Animals were euthanized humanely using clove oil. Picture courtesy of Dr. Tom Bird.

Lead researcher, Dr. Tom Bird, collecting environmental DNA. Picture courtesy of Sarafina Henderson.

Our fieldwork took place in approximately 25 rivers; some tame and shallow, and some so swollen I tried to convince myself an autumn Labrador swim would be refreshing. I was primarily responsible for collecting benthic macroinvertebrates. This consisted mostly of dragonfly larvae, shrimp-like amphipods, caddis-fly larvae, and my least favourite, midge larvae or blood worms. We also collected environmental DNA samples, a method that provides indication of species presence through the detection of genetic information that’s expelled from animals via feces, urine, hair, or fish scales. Simply, this involved pumping water through a fine filter. Less simply, this required balancing a long tube on a fibreglass tripod which connected to the 30 pound backpack holding the pump. 

After much persistence in electrofishing efforts, we found eels in just one river. The researchers and I are still puzzled by our findings. It could be that some of the populations have already been extirpated from the region. Though, according to one local, rivers in the area are overflowing with eels in the summer; so perhaps our timing for fieldwork was off. While finding so few befuddling creatures could have dampened my spirits, I believe that turning over a rock and finding nothing (or next to nothing) is still progress. 

As we drove home through the endless scenery of rolling hills, sandy beaches, and windy coastal roads of Big Country, it left me wondering: how do we protect a species that we can’t find? The mystery of the eel lingers on and with it, a hope that we will have enough time to solve it. 

A swollen river that was deemed unsampleable in our search for American eels. Picture courtesy of Dr. Tom Bird.

References:

Haro, A., Richkus, W., Whalen, K., Hoar, A., Busch, W.D., Lary, S., Brush, T. and Dixon, D. 2000. Population decline of the American eel: implications for research and management. Fisheries. 25:7-16.

COSEWIC. 2006. COSEWIC assessment and status report on the American eel Anguilla rostrata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 71 pp. (www.sararegistry.gc.ca/status/status_e.cfm).

Mi’kmaq, M.N.S. 2011. Mi’kmaq and the American Eel: Traditional Knowledge Relating to the American Eel by Mainland Nova Scotia Mi’kmaq. Report to Environment Canada & Fisheries & Oceans.

Jarvis, B. 2020 Where Do Eels Come From? There is much to be learned from how little we know about them. The New Yorker.

Sarafina Henderson
WISE GSS Director of Social Media
MSc Student, Bates Laboratory
Department of Ocean Sciences
Memorial University of Newfoundland