Burbot-ology 101
A deep dive into the biology of a misunderstood icon
EDITORS NOTE: more and more anglers in this part of the world are realizing what a great sportfish burbot are. Not only that but there are a fantastic eating fish. This time of the year is probably the most productive angling time so we at Hooked thought we should do a deep dive into this mysterious fish. Hooked Contributor and fisheries biologist and manager Eric Mullen unlocks some of the mysteries in this three part series on the Mighty Burbot.
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Burbot (Lota lota) are commonly caught by anglers across Canada, yet have not garnered widespread popularity as a sportfish when compared to other species like walleye, lake trout, or northern pike. Historically, burbot have suffered from negative reputations for their eel-like appearance, slimy skin, or from misinformed views about their negative impacts on more popular species. In some extreme cases, adverse perceptions of burbot have led to their persecution and wastage by some who regard burbot as ‘trash fish’. Despite these tragic instances, burbot are rapidly gaining acceptance amongst anglers who are enlightened to their mysterious world. Understanding the biology of this incredible fish can help anglers plan their next burbot pursuit, and to share their passion for this misunderstood fish with others.
Burbot famously go by many names – ling, mariah, eelpout, and even lawyers – often dictated by regional preference. Burbot are taxonomic members of the order Gadiformes, which include cods, pollock, haddock, rockling, and mora. Of the more than 600 Gadiforme species worldwide, most are marine. While some species occasionally use freshwater habitats, burbot are the only fully freshwater species in this order. The root name of burbot is the latin word barba, meaning beard, referencing the single barbel that sits below the fish’s chin that is used for food detection.
Ecology
Burbot are one of two freshwater species with the widest native range on the planet (northern pike are the other) and are found circumpolar around the globe in the northern hemisphere. Burbot are widespread across much of their native range, especially in North American lakes, rivers, and streams from above the arctic circle down to the Missouri river drainage. However, there are several populations that are endangered or have disappeared entirely. For example, burbot can no longer be found in many native habitats in the United Kingdom and Western Europe due to extensive habitat loss.
Burbot love deep water
Adult burbot occupy the deepest basins of lakes for much of the open water season. In an extreme example, burbot in Lake Superior have been recorded in 300m (984 ft) of water. Their activity levels tend to be low in the summertime and increase steadily as water temperatures decrease in the fall and winter. One study conducted on Bad Medicine Lake, Minnesota installed acoustic tags into 32 burbot to track their seasonal movements. The researchers found that females held larger home ranges than males, and that home range size increased sharply in the winter until March, presumably during peak spawn. This was followed by the lowest recorded home range size in April, possibly a result of the post-spawn ‘resting’ period.
Taking the Night Shift!
Burbot are incredible predators, which may not seem intuitive given they are not the fastest fish with the greatest burst striking abilities. However, burbot are specialists at taking the ‘night shift’ when other predators are getting some much-needed rest. As nocturnal predators, burbot have incredible dexterity and powerful senses of smell and touch that assist in the pursuit of resting and unsuspecting prey that are typically more active in the day. Studies have evaluated food web dynamics in sub-arctic boreal lakes and found that burbot are apex predators, occupying food web positions like that of lake trout and northern pike. Therefore, burbot serve a critical role in their ecosystems by keeping the populations of animals in the lower food web levels in check. The loss of apex predators can often have complex and sometimes unpredictable consequences to the stability and diversity of freshwater fisheries.
Burbot are not picky eaters!
Burbot diets vary considerably and include numerous potential prey fish species. However, crayfish are a common component to their stomach contents in Manitoba. Underwater footage of burbot fishing validates the burbots superior ability to tackle prey taking shelter amongst rocks or in the sediment. When approaching a baited spoon or jig pounding on bottom, burbot will often overshoot the target without connecting with the bait, seemingly wanting a quick smell or feel with their barbel. However, they can quickly reverse back over the bait and strike it ferociously. You can imagine this would be an effective tactic for burbot seeking crayfish, which when spooked, back themselves into rocks, where burbot can re-orient themselves to find an angle of attack. On the other hand, young burbot (i.e. up to 40 cm) are an important prey species themselves. During stock assessments, we frequently observe burbot in the stomachs of trophy-sized walleye and northern pike in the Winnipeg River, suggesting their importance to the production of large predators with immense recreational value.
Reproduction
Burbot are winter spawners, reproducing in temperatures ranging from 1 – 4 °C, and are among the very few species that spawn under the ice. The timing of the spawn varies considerably between waterbodies; one study examined gonad condition from burbot in 24 lake-populations across Canada and suggested spawning occurred in most populations within the first 3 weeks of February. Nevertheless, anglers observe spawning burbot as late as the last week of March in Northern Manitoba, and there are likely unique spawning windows for most lakes between late January and late March. Anglers keen enough to determine the timing and location of burbot spawning activities on their local lake are rewarded with some of the best and most unique fishing action of the winter.
