Tales of a Grass Carp Capture

In the spring of 2024, five Grass Carp were captured in Canadian waters. Three were in Lac des Deux Montagnes in the Baie de Vaudreuil (Québec), one was in Rondeau Bay in Lake Erie (Ontario) and the most recent capture was in Jordan Harbour in Lake Ontario. Despite individual captures, there continues to be no evidence of an established population in Canadian waters. Grass Carp is one of the four species of Asians carps and pose the most imminent risk to Canadian waters as a result of their established populations in nearby U.S. tributaries to Lake Erie. If they were to establish in Canadian waters, they could have devastating impacts on the environment and could impact key economic industries such as commercial and recreational fishing.

Anglers play a huge role in the early detection of aquatic invasive species, so we decided to reach out to local angler Darian Savage (@dariansavage.fishing) who helped catch the three Grass Carp in Québec this spring. In our interview we talked about how to identify Grass Carp, what it means to him as an angler for them to have been discovered in this region and all about his experience working alongside the Ministère de l'Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP) in Québec.

Darian is a fishing guide, so he spends a lot of time out on the water. One of our first questions for him was what were you going fishing for originally in the Baie de Vaudreuil?

“I was fishing for Longnose Gar; in the summer they are found in super shallow weedy bays near the surface and the body of water where I was fishing is loaded with tons of them.

A friend of mine was visiting from Toronto, and we were trying to get video footage of how many Longnose Gar were in the bay and to get some strikes on film as they are a very aggressive fish that likes to eat on the surface. We were using a drone, which is able to fly high and straight up over the water reducing the glare from the sun which makes it ideal to film this type of event”. These would be the first documented Grass Carp captures in this region, and the fourth confirmed capture in the wild in Quebec since 2016. The Grass Carp’s preferred habitats are slow-flowing, vegetated waterbodies (i.e., backwaters, lagoons, and shallow lakes) when recruiting and grazing and large rivers with moderate currents when spawning. They feed primarily on aquatic plants but will also consume detritus, small fish, and benthic invertebrates in the absence of aquatic vegetation. Grass Carp can eat up to 40% of their body weight in aquatic vegetation in a single day! To put this into perspective, this would be like a person eating 40 large pizzas, 430 cups of lettuce or 180 burgers! Only half of that

gets digested and the rest gets expelled back into the water, enriching it with nutrients which can promote algal blooms.

So where did Darian first learn about Grass Carp and how to identify them?

“I’ve been hearing about them for a few years. I’ve stumbled across Facebook posts from the government with information on Grass Carp. I think there have been a few caught in Québec, which I had heard about.

Most avid anglers know about Asian carps and the four species we’re really worried about in Canadian waters. In terms of identifying them it’s a really interesting story. Two weeks before I filmed the video, I was looking for Bowfin and I came up behind what I thought was the biggest Common Carp I’d ever seen. You can hear the excitement in my voice as I am recording on my phone. I quickly realized it wasn’t a Common Carp; the eyes were level with the mouth, and I knew it was one of the Asian carps, but I wasn’t sure which one. I texted a friend who is really good at fish identification and they suggested Grass Carp. At this point I didn’t think too much of it. I was like wow, ok so there’s one in our system but it’s probably only one. I didn’t reach out to the government or anything since I didn’t have any good visual proof.

Fast forward two weeks and I am flying the drone again getting video footage. When I was looking at the footage the next day these fish stood out to me because there were also

Common Carp in the frame. These fish were much bigger, shaped completely different and way darker in colour. If it hadn’t been for the encounter two weeks prior, I am not sure if I would have thought of Grass Carp. I started posting on fish species identification groups on Facebook and reached out to people that work with the species. A lot of them told me yes, it’s a Grass Carp 100%.”

There are many native (and naturalized) fish species that may be mistaken for Grass Carp, Common Carp being the one it is most often confused with. One of the easiest ways to distinguish any of the four Asian carps from a Common Carp is by the lack of barbels at the corners of the mouth, which Common Carp have. Grass Carp will also have a terminal mouth that sits in line with the eye, a short dorsal fin and large overlapping scales outlined in dark pigment. For more information you can visit the Grass Carp Identification and Reporting Guide and the Confused with Carp series.

How did Darian react when he realized he had spotted Grass Carp?

“I was in shock. I was in disbelief. I didn’t really know what to think. I was really excited; I wanted to see it again. I was in a sanctuary so I couldn’t fish for it, but I wanted to try and capture it on film. I tried again, but I never ended up seeing it so it all just flew over my

head, and I told people and forgot about it. Then when I saw them again, I got excited. I mean, obviously it’s a bad thing, but I was excited about the possibilities of being the first one to discover and catch them in this region. I was thinking about what this could mean for our fisheries, because it’s a big discovery whether you spot them or catch them, confirming their presence is a big thing because of the negative impacts they can have.”

Grass Carp pose a massive threat to wetlands, an important part of the Great Lakes ecosystem. Wetlands provide nursery areas for fishes, support a variety of wildlife, control flooding, filter nutrients and harmful pollutants, and provide food and habitat for native fishes, birds, amphibians and reptiles. It is estimated that just 10 Grass Carp per hectare can reduce wetland vegetation by up to 50%. This would have serious negative impacts on many native Great Lakes fish populations relying on these environments and could reduce opportunities for both commercial and recreational fishing.

Now what happens after there is a confirmed report of a Grass Carp? In most cases, an on-the-water response operation is conducted where the fish was found. For Darian and the MELCCFP, this meant teaming up to go try and catch them.

“That was a really incredible experience. I never thought I'd ever get a chance like that, but it was super cool. It's something I've always wanted to do ever since I've seen electrofishing.

I thought that electrofishing would be a lot more effective than it seemed to be. Like I was so excited when the government was coming down. I was like, oh, it's going to take us like 30 minutes and we're going to have all the fish, you know. And they even came up a day early and we started electrofishing on the first day. I was so excited, and we had perfect conditions. When we went back the next day it was windy, rainy, and the water was all murky from us driving around the day before. As the experience went on, I got less and less hopeful that we were going to get them. Even though I knew they were in there and I was confirming every day that they were still there. We were having trouble catching them with both the net and electrofishing. They're enclosed in this tiny little Bay, and we were still having a hard time catching them. I didn’t think we were going to get them. When everything came together, it was one of the happiest moments of my life. It was really amazing. I'm so glad I got to be a part of that. The Québec government was great. I liked the whole team I was working with. They were really cool people, really easy to get along with, and they listened to my advice. I was surprised. I thought I was going to be more of a visitor, but I was involved and helpful. So yeah, that felt really good.”

The MELCCFP electrofishing boat was damaged during this operation, resulting in poor performance. Though electrofishing remains the most effective method of catching Grass Carp, Darian’s ability to spot them using a drone has shed light on its potential as a new method that could be used for future on the water operations. The MELCCFP will be testing the use of drones for spotting Grass Carp in the 2025 field season.

If you suspect you have caught a Grass Carp, the first step is to keep the specimen and report the capture by calling the Invading Species Hotline at 1 (800) 563-7711 (or by emailing info@invadingspecies.com and uploading a photo to EDDMapS.org. Your report will be sent directly to experts in the field, who will then review the report and verify the identification. In the case of a positive Grass Carp detection, you will be contacted for more information and plans to transfer the specimen to Fisheries and Oceans Canada will be organized. Once you have reported your sighting, record your exact location (e.g., longitude and latitude) and take photographs of the fish from multiple angles with adequate lighting. A handy tool for determining your geographic location is the Google Maps mobile app, where you can drop a pin by tapping and holding the location you caught the fish. If you were unable to reach someone directly in the first step (reporting), avoid unintentionally killing native fishes by being certain of your identification before killing a

suspected Grass Carp. If you are confident in your identification, do not release the Grass Crap! Keep the fish alive in a livewell or euthanize it (without damaging the head or eyes) and store it in a cooler on ice while waiting for it to be picked up. The head needs to be kept above the ice and the eyes protected with a damp cloth to prevent freezing. Fluid samples from the eyes are needed to check whether the fish is fertile or sterile. Frozen eyes prevent an accurate test! For more information, check out the Ontario Recreational Fishing Regulations Summary and download the Grass Carp Identification and Reporting Guide here: https://www.asiancarp.ca/grass-carp-identification-and-reporting-guide/

Lastly, Darian had some words of wisdom and calls to actions to share with other anglers.

“If you catch a fish and you don’t know what it is, definitely do not keep it. A lot of people keep fish, bring it home, and then they post on a Facebook group asking what it is. You need

to know what you’re keeping if you keep a fish. If you think you’ve caught a Grass Carp or have seen a Grass Carp, make sure you know what it is because to the untrained eye it looks similar to Common Carp. So, know what you’re catching, know what you’re targeting, and if you do catch something you don’t know there are a few apps that you can use to help you identify them. My favourite app is iNaturalist, it works for plants, turtles, fish, anything and everything that is nature related if you can’t ID, even if it’s a tree. With this app you take a picture of it and as long as you have your location, it’ll give you a very good idea of what it is based on the information provided. I use this a lot when I’m catching little minnows and species I can’t identify.”

If you are interested in watching the full video of Darian’s experience this spring catching Grass Carp with the MELCCFP, tune in on Fishing OD’s Youtube channel using this link: https://www.youtube.com/watch?v=3ljOYBqjQhA

You can also follow Darian on various social media platforms.

Instagram: @dariansavage.fishing

Facebook: Darian Savage www.savagefishingguideservice.com

Additional Resources:

Grass Carp Identification and Reporting Guide https://www.asiancarp.ca/grass-carp-identification-and-reporting-guide/

Confused with Carp https://www.asiancarp.ca/asian-carps/confused-with-carp/

Confused with Carp: Baitfish https://www.asiancarp.ca/asian-carps/confused-with-carp-baitfish/?fbclid=IwY2xjawFfuZpleHRuA2FlbQIxMAABHSftOMjBDPEMLLj35G0Pc6yvAcKLedHdTjuqp73FPHPwao19CTDhV916lg_aem_S4ek5TyYBesi0IQ0Ph7cxg

The Baitfish Primer https://www.dfo-mpo.gc.ca/species-especes/publications/baitfish-poissons-appats/index-eng.html

Grass Carp Info Videos https://www.asiancarp.ca/resources/video-gallery/ Report invasive species to EDDMapS (https://www.eddmaps.org/ ) or call the Invading Species Hotline: 1 (800) 563-7711