A Note from the Animal Husbandry Team – Nov. 2016

Just last week we were asked, where are the eels? In the wild their numbers are certainly diminished compared to several decades ago throughout the St. Lawrence. Dams are the biggest culprit to the success of the eels. And while we can’t just tear down all of the dams and barriers in the area, there are ways that many researchers and companies are employing to help the population of eels in our area succeed. At the Aquatarium, we actually have a few adult eels. They are not ready for exhibit yet, so very few people have seen them. They are still getting used to their surroundings and we hope they will be ready soon.


I’m not quite sure if people are going to be fascinated by eels or freaked out when they see them. They look like snakes, but really they are a fish. If we search the internet we will see that “The American eel (Anguilla rostrata) is a facultative catadromous fish found on the eastern coast of North America”. Simply put, it means that eels are born in salt water and swim up stream to fresh water to live their lives. They return to the sea to spawn and die. Yeah that is backwards to what we think about when we talk about salmon, but like salmon their bodies undergo a huge change to allow them to take the long trip out to the breeding area. Where in the ocean do eels go to spawn? Scientists surmise that they go to the Sargasso Sea to spawn, but no one knows for sure. The Sargasso Sea is not really a sea at all but rather an area in the Atlantic Ocean that contains large sargassum algae mats. I have visited this area and it is fascinating. These mats are habitat to a huge variety of juvenile aquatic animals. This area has lots of food, good places to hide, and is rich in nutrients. How does an eel know where to go? Recent research has shown that eels are able to navigate such long migrations because they have an internal compass. They are literally able to follow the magnetic waves of the earth to discern their locations.

It is this journey to and from the ocean that is so problematic for the eels in the St. Lawrence. Even if you know where you’re going, navigating a boat is hard enough with locks, dams, boats, islands, dead ends…. Try swimming it! Eels have an almost impossible journey to make it up river. This is why OPG (Ontario Power Generation) is working hard to install eel ladders and scientists, at facilities like the St. Lawrence River Institute and Queens University, are studying eels and looking at other ways for the eels to make their way up and down stream successfully.


What is an eel ladder? Just like the name implies, eel ladders are plastic trays that are installed next to a dam that allow an eel to climb up and over a dam. We have a small eel ladder setup in the Aquatarium, and we should have some small eels (donated by the River Institute) to test it out very soon. Small eels only migrate in the early spring, and can’t easily be caught at other times during the year. We are lucky to be getting some! So, I hope you can swing by and check out the eels soon. We are looking forward to working with them and sharing them with you. Oh, one last fun fact! My friend Matt Windle (an eel researcher from the River Institute) told me that all of the eels in the St. Lawrence are female. No one knows why!

The Husbandry Team

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