Rainbow Smelt


The rainbow smelt (Osmerus mordax) is a small schooling fish that is native to watersheds of the northwest Atlantic ocean.  They are anadromous (ie. adults live in saltwater, migrating to freshwater to spawn), however some populations live permanently in lakes due to human introduction (ex. The Great Lakes).  Rainbow smelt are predatory, consuming mainly zooplankton and even young fishes.  They live for 5-6 years and survive in various environments, including waters from -1.8ºC to 20ºC!


If you observe rainbow smelt please consider reporting your sightings to https://www.inaturalist.org/ or use our smelt data form. 

Additional data from sightings helps wildlife managers monitor the health of the population.

SAWIG Smelt Data Form 2023.pdf

Life Cycle

Rainbow smelt are sexually dimorphic; this means that females grow larger and live longer than males.  Smelt migrate into freshwater streams right after ice out (around mid-April) and usually spawn at night.  

Once the eggs hatch, the young smelt, who are only ¼ inch long and are translucent, rely on the stream's current to carry them back to sea, where they will grow and mature.  They will return to freshwater streams after 1-2 years, repeating the spawning cycle.

Fun Facts

Why Monitor Rainbow Smelt?

Smelt are an important food source for larger predatory species like Atlantic salmon and Atlantic cod. They’re also a popular recreational fish on PEI, being eaten by humans and also used as bait.

Rainbow smelt populations face a number of threats.  Habitat degradation, acid precipitation, and blocked culverts can lead to poor water quality, which can negatively impact their reproduction and survival.  Smelt are also poor swimmers, meaning they can't easily use fish ladders to access upstream habitats.  This can impact their spawning success.

How To Monitor Smelt

The easiest way to monitor for the presence of smelt is to locate the first culvert up from a stream’s connection to the ocean.  Smelts are most likely to spawn in the first area of freshwater they come across.  Checking both upstream and downstream of the culvert will give you a good indication of smelt abundance in the stream.  Look for dark patches near the stream’s bottom; smelts congregate in schools, so they’ll be tightly packed together.

Another great way to protect smelt populations is by protecting their habitat.  This means doing what you can to minimize runoff of pollutants, fertilizers, and sediments into your local stream.  This will help to maintain a good water quality and ideal bottom substrate.

Check out this video to learn how to identify smelts from the riverside!

Catching Smelt on PEI

Did you know that you don’t need a license to fish rainbow smelt on PEI? 

The smelt fishery is regulated to ensure that this important species isn't overfished.  Smelts are relatively vulnerable to this, especially since they're weak swimmers and are easy to catch.