Eulachon Monitoring

The Skeena River is pulsing with life each year as the return of the Eulachon ushers spring into the valley. Thousands of gulls dip and dive above the river filling their bellies with glistening Eulachon. It is a reminder of the rich history of travel and trade that connects people from the Skeena to the Nass, and the stories of long canoe trips to transport grease to other coastal and upper Skeena communities.

Why monitor the eulachon run?

Once abundant, eulachon is now a species at risk of extinction.

Scientists estimate the Skeena River eulachon population has decreased by 90% since the 1960s. This decrease has greatly affected Kitselas nutrition and cultural practices. It has also reduced a vital food source for many birds, mammals, and larger fish. We don’t understand all of the reasons for the population declines. Habitat degradation, bycatch from commercial fishing operations, and climate change could impact the eulachon. Many First Nations are trying to understand why this has happened and bring the fish back to historic levels. We are collecting data on the Skeena River eulachon to track how the eulachon run is changing. This research will help us identify the causes of low (and high) returns. With this information our nation can make well-informed fisheries management decisions so that this resource can remain a part of Kitselas culture for generations to come!

How is the eulachon monitored in the Skeena River?

We collect data on the eulachon run size and timing in several ways.

eDNA

eDNA refers to “environmental DNA” or tiny particles of DNA that organisms shed. We can find these particles in the environment around that organism. Many scientists now use eDNA in ecological studies to determine if a species is nearby and estimate its numbers.

eDNA is a powerful and reliable tool for finding both common species and elusive or rare species.

Recently, eDNA has helped determine the run timing and numbers of eulachon in several areas. eDNA has been used in Southeast Alaska to monitor eulachon. The Haisla Nation is using eDNA to monitor eulachon on the Kemano River and other rivers in British Columbia. Because the eDNA technology is non-invasive and does not harm the fish, it is an ideal technology for detecting eulachon in the Skeena River.

In 2022, the Kitselas Lands and Resources Department began a pilot study to test whether we could use eDNA to monitor eulachon in the Skeena River. This study is the first time eulachon eDNA has been collected from the Skeena River to examine the abundance and location of the species. The study sampled the lower Skeena River, mostly between the Khyex River confluence and the Exchamsiks River confluence. Scientists identified a series of key sites to sample eDNA to find eulachon and determine their migration timing.

Our study confirmed that there was eulachon eDNA in the water samples. The data from the samples shows that eulachon entered the lower Skeena River and Khyex River in low numbers in early February 2022. The eulachon eDNA peaked at the Khyex River sampling site at the end of February. There was a peak at all upstream sites in early March, and then a steady decline at all sites by mid-March. We observed the highest peak of eulachon eDNA at Kwinitsa fishing location in early March.

eDNA and Eulachon

eDNA or “environmental DNA” is tiny particles of DNA that exist in the environment. For example, eulachon DNA can be found floating in water where eulachon are swimming.

Everything that lives in or near the water adds eDNA to the water

Scientists can sample the water to find traces of eulachon

Eulachon DNA enters the water from:

Spawning Shedding and waste Decomposition Predators

Our researchers collect water samples from different places and at different times. The eDNA can show there are eulachon nearby even if we can’t see the fish.

Fish were being harvested at this location when eDNA was sampled. To our surprise, we detected eulachon eDNA as far up the Skeena River as the Exchamsiks confluence.

Right now, we don’t know how early eulachon arrive in the lower Skeena River. We also don’t know what affects the timing of the eulachon entering the river. But the Kitselas Lands and Resources Department has secured funding to continue the eDNA work and uncover answers to these questions.

Predator Abundance

Eulachon are an essential part of the food web, both in the river and at sea. Eulachon feed on plant and animal plankton (e.g., krill), other invertebrates, larvae, and fish eggs. In return, eulachon provide a food source for a wide variety of animals. At sea, eulachon are eaten by deep-water fish, porpoises, seals, sea lions, and a few species of whale. Eulachon in the river are eaten by many birds and mammals. Common bird predators include gulls, terns, ducks, eagles, ravens, crows, and cormorants. Common mammal predators include otters, seals, sea lions, and wolves. A gathering of predators is a good sign eulachon are nearby.

Since 2018, the Kitselas Lands and Resources Department has been monitoring predator numbers in the Skeena River. We conduct yearround, monthly land- and vessel-based surveys of marine mammals and birds. We increase the number of our surveys in February and March alongside the eulachon run. The survey data will help us track how mammal and bird numbers change over time.

A scientist uses an eDNA sampler backpack. The backpack pumps water from the river through a small filter. After the sampling is finished, the filters are removed from the backpack and packed up. Then these filters are shipped to a laboratory for eDNA analysis.

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0 year-round average number of seagulls

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The bar chart shows the 2019 predatory bird survey results, which covers 12 days between February and March. We gathered the data at 13 land-based locations along the Skeena River. The horizontal line represents the average gull numbers over the entire survey period. The number of gulls varied in February but showed a gradual increase over time. Gull numbers peaked on March 5th. After this, there was a gradual decrease. The observations of gull activity might be linked to eulachon run timing and abundance.

Watching gull activity during the 2019 predatory bird survey Eulachon Catch Monitoring Catch monitoring for eulachon is very important to gather information on how the species is doing. Here’s how you can help:

1. Pick up Eulachon Monitoring Tool booklet from our offices for free. 2. Record the number of totes/buckets you caught, along with the time, place, weather and water conditions. 3. Return the data cards to the Kitselas Lands and Resources Department. You may also give your catch information to our Kitselas Fisheries Technicians when you see them monitoring the run!

The data you provide will be used to inform national and provincial fisheries policy and help guide future research in the Traditional Territory. We will communicate all results back to the community so everyone can better understand the trends in the eulachon population. Our monitoring program will help us more effectively manage the species for the future.

Our future monitoring goals The Kitselas Lands and Resources Department plans to conduct a coordinated and ongoing data collection program. This will give us specific details about how eulachon are doing right now, and what the conditions are in the estuary and instream waters within the Kitselas Traditional Territory. This information will be our “baseline dataset” which we will enhance with eDNA sampling to confirm eulachon abundance, distribution, run timing, and spawning. Our goal with this program is to improve our understanding of eulachon migration and habitat use.

All results will be communicated back to the community so everyone can better understand the trends in the Eulachon population.

Eulachon Monitoring Tool

You can participate in monitoring the run, and help protect and sustain this important species!

Last year the Kitselas Lands and Resources Department launched a new Eulachon Monitoring Tool for community members. This is a short booklet with two sections: an educational section and a monitoring section.

The first section has information on eulachon’s biological, cultural, and ecological importance and provides a guide to eulachon predators. The second section has a field guide, maps of important monitoring locations, and tearaway monitoring cards.

We encourage you to bring your Eulachon Monitoring Tool when you go out fishing, or just to observe the run! Complete the included cards with your catch information and/or observation of predators.