New Zealand is a dream country for all trout. I was lucky enough to spend over a year there on work, holiday and tourist visas. During my stay, I saw several giant eels chasing the trout I hooked. I also landed a few trout with visible eel jaw marks. COVID stopped all travel for a while; however, in November 2022, I finally returned to the North Island for some fishing.
Returning to this river, it is just as I remembered it. I took a short walk to the river, prepared my nymph rig and started working the water upstream. After approximately 2 hours of fishing, I landed five nice rainbows and hit some big rapids. Few people fish these rapids so there was a great opportunity to get into some bigger fish. After a few casts, I hooked another beautiful rainbow.
The fight lasted a few minutes and I managed to put it in the net! After landing successfully, I decided to take some photos. I set up a tripod with my phone, and when I reached into the net to catch the trout, I almost messed up my waders. A tall black shape quickly came from the side and tried to grab my rainbow. Not one but two eels together were chasing this fish while I had it in the net. I moved towards the Eels trying to scare them off. The eels moved back a little, but began to follow again. I have never seen Eels so aggressive before. Suddenly I lifted the net from the water, but the Eels continued to follow, with one of them biting the trout in my net.
I finally tried to shoo the eels away to get them to stop harassing my beautiful rainbow. The eels were crazy – they seemed to want a good meal of the trout I was landing.
I didn’t want to torture the trout any more with pictures, so I released it in the hope that it would escape the jaws of the Eels. At the end of the day, I saw three more eels, something I had never seen or experienced when fishing this majestic river.
Fish: native vs. “invasive”
It is well known that trout is not the native fish of New Zealand. Eels, on the other hand, are local, so let’s take a closer look.
Long eel (Anguilla dieffenbachii) is locally known as “tuna”. The Long Eel, endemic to New Zealand, so named because its dorsal (upper) fin is longer than the lower, is one of the largest Eels in the world. Some females can reach up to 2 meters in length and weigh up to 40 kg.
During the day, Eels are secretive, hiding under logs and rocks or cut riverbanks. They hunt mainly at night, using their excellent sense of smell. Juvenile long eels feed on insect larvae, worms and water snails. As they grow, they start feeding on fish. They will also eat freshwater crayfish and even small birds like ducks.
When eels begin life, they are microscopic, reaching only one millimeter in length. Eels are slow growing compared to many other fish – a long thread can grow only 15-25 mm per year. They can also live for many years. Big Longarms are estimated to be at least 60 years old.
Long eels have a unique life cycle. They live in rivers, lakes and wetlands for most of their lives. Then, after 25-80 years, they travel 5,000 km to the South Pacific near Tonga to breed. After laying eggs, they die. The tiny fertilized eggs float in ocean currents for about 15 months until they reach New Zealand. They then travel inland, swimming rivers and waterfalls and even crawling over dams! They turn into glass eels and then elvers before becoming adults. However, Long Eels are now considered endangered and their numbers are still declining.
Angler Story of the Week by Martin Dvořák, be sure to follow his fly fishing adventures on Instagram @mdx_flyfishing.
Check out the articles below:
Pure Fly New Zealand: Behind the Scenes
Fly Eel Fishing