Details on the walleye

Technical data on the yellow walleye

The reason that this species of fish is sought after is without a doubt its savoury flesh. The James Bay area is covered in water surfaces favourable for fishing the yellow walleye (Stizostedion vitreum). It is a lucifugeous fish, meaning that it avoids light as mush as possible. Its eyes have a glassy appearance that reminds us of big glass marbles. These eyes are adapted to low luminous intensities and conditions. It is one of the reasons why the adults stay during the daylight hours in deeper waters or protect themselves from light intensity near great rocks, fallen trees or aquatic vegetation. The degree of turbidity of the water therefore influences its feeding behaviours. At sunrise and sunset, it feeds near the surface and during the day it swims deeper or moves amongst its natural shelters. If the water is troubled enough, the walleye will feed all day. Another of its characteristics is to live amongst others; therefore it lives in schools or shoals.

Its body (or if you prefer the color of its skin) is golden of course, with some darker area of dark green, brown, yellow, even blue depending on its habitat; its abdomen is white and the extremity of the inferior lobe of its tail has a white spot. It is a beautiful mixture of colors. Its fins are particular to the great family of the percidae, to which it belongs. The dorsal fin, mainly, is equipped of 12 to 16 thorns or prickles and the sports fisherman must be prudent when handling a walleye.

The further north we go, the slower the growth of the walleye and its sexual maturity is stunted so that in the area, a walleye of 15 inches (37,5 cm) is usually approximately 8 years old. Those who are smaller of equal to 15 inches have not yet reproduced since sexual maturity has not been yet in the spawn. The spawn occurs at the end of May or early June in our area. The male arrives first in the lake fry but he does not establish his territory and does not build a nest. Shallow, well oxygenated areas having a rocky substrate seem to be the favourite of this species for its reproduction. The spawn occurs at night and the female will be accompanied by 2 to 3 males. The female usually deposits its eggs in one night and we estimate the relative fertility to 40 000 eggs/kg.

The eggs deposited in shallow water, are not protected by the adult and take 20 to 25 days to hatch. Afterwards, the hatchings concentrate near the surface where they remain for several weeks. It is recognized that the wind and waves may be an important cause of mortality but it is the predation that is probably the main factor of regulation of the survival of the young and annual recruitment since, between the moment the eggs are deposited and that a lenght of one half inch is reached, the mortality rate generally exceeds 99,5%. This makes it a species sensitive to its environment.

Fish consuming and its benefits on health

Contrary to meat, fish has generally a low content in cholesterol and fat, particularily in saturated fat, keeping altogether a comparable source of high quality proteins. We find approximately 19 g of proteins in a portion of walleye where a daily recommended nutritional intake is , according to age and sex of individuals, around 50 to 64 g of proteins. Fish is a noticeable source of vitamins and minerals, among which we find vitamin D and selenium. It seems that this last one would have an antagonistic effect on the toxicity of mercury. As for vitamin D, a daily supply is essencial to keep calcium in the serum to insure mineralisation of bones. For the walleye, a portion is equivalent to a 394 u.i. of vitamin D where the daily recommanded nutritional intake should be between 100 and 200 u.i.


According to several studies, Omega-3 polyinsaturated fat acids contained in the fish meat could represent a protection against cardiovascular diseases. Other preventive and therapeutic properties are also attributed to Omega-3 polyinsaturated fat acids, notably for pregnant or breastfeeding women. Furthermore, a supplement of fish oil taken while pregnancy would allow substantial reduction of risk for premature birth or low weight babies. A portion of walleye gives a supply of 320mg of Omega-3 polyinsaturated fat acid where a daily recommanded nutritional intake should be in between 500 to 1000mg.


Although the fish is considered as an healty food, environmental pollution has a negative impact on the quality of the meat of predatory fishes such as walleye. Of course, the actions taken by the environmental protection authorities in place have helped to reduce contamination. However, predatory species such as walleye, northern pike, black bass, and maskinongé, in fact those fishes that eat other fishes, have a tendency to accumulate more contaminant like mercury. They are so called “risky” but contamination is lesser important on younger catches. The better reason why trophy specimens should be returned in water.

On the other hand, there is no restriction for fishes like lake whitefish, brook trout, and other trouts as well as most species living in salted waters. It is however recommanded to reduce fishes intake such as walleye, northern pike, black bass, maskinongé and grey trout to no more than twice a month. If within a year you eat those fishes only occasionnaly, for example on a fishing trip, the risk of contamination is so weak that no restriction is applied since no frequent nor usual absorbtion is made on a long extension of time. It is however suggested for pregnant and breastfeeding women to avoid such species and replace them by non restricted fishes.

Bon appétit!


Sources

Plan de gestion du DORÉ en Abitibi-Témiscamingue 1999-2003

Le doré et l’omble de fontaine : deux grandes vedettes, Société de la faune et des parcs du Québec Région Nord-du-Québec, Gouvernement du Québec.

Chronique nature… Le doré jaune : l’adoré du Nord-du-Québec, Justine Desmeules, biologiste pour FaunENord, Tribune Chapaisienne, 2002.

BEAUDET Sylvie, biologiste responsable de la faune aquatique du territoire de la Baie-James et responsable des dossiers des espèces de petites faunes de la région Nord-du-Québec, à la Direction Nord-du-Québec de la Société de la faune et des parcs à Chibougamau.

Connaissez-vous les Oméga-3? Moi, oui … Et je suis bon pour la santé!, Ministère de l’Agriculture, des pêcheries et de l’Alimentation, Ministère de l’Environnement et de la Faune, Ministère de la Santé et des Services sociaux, Gouvernement du Québec, 97-212-1.

Site Internet : www.inspq.qc.ca/cse/bise/1999/bise_10_2.htm