Ecology of a northern pike (Esox Iucius) population in a small, oligotrophic Lake : with comparisons to other northwestern Ontario populations / by Arnold Laine
Notice bibliographique
Résumé
The life history and population dynamics of the northern pike \n(Esox lucius) within Squeers Lake, Ontario were studied in order \nto provide information on pike found within oligotrophic lakes. \nResults clearly demonstrate the Squeers Lake northern pike \npopulation is relatively stable but small in size, has a very low \nproduction rate, exhibits rapid growth, an early age of maturity \nand an intermediate life span. The low availability of spawning \n(and to a lesser extent nursery) habitat apparently regulates \npopulation size. The rapid growth may be the result of abundant \nfood, lack of serious competition for food resources and presence \nof favourable environmental conditions. Epilimnetic summer \ntemperatures 16-21?C) within the main lake basin were very near \noptimal for "adult" pike (ie 18-20?C, Casselman, 1978), whereas \nsummer temperatures within the Western Arm (which formed the main \nspawning and nursery area within the lake) were near optimum for \nyoung-of-the-year and yearling pike (ie 26?C, Hokansen et al 1973). \nTo assess accuracy in age and growth assessment for the \nSqueers Lake northern pike population, the validity of using scales \nand cleithra was examined. The high percent frequency of \nagreement, low index of average error (Beamish and Fournier 1981) \nand index of precision (Chang 1982) indicate both scales and \ncleithra are equally suitable tissues for assigning age structure \nto Squeers Lake northern pike provided that marks interpreted as \nannuli are in fact annually formed. An examination of the accuracy \nof age estimates through the use of partly known aged fish (via iii \ntetracycline labelling and mark-recapture methods) confirmed that \nthe checks identified on both aging tissues were in fact annuli. \nCleithra, were, however, more accurate for northern pike > age 10. \nTherefore, when age estimates are required without killing the \nfish, the use of scales can be recommended provided that the \npopulation is relatively fast growing and precision levels between \nthe two tissues do not exceed 5%. \nIn order to further determine what factors may influence \nnorthern pike growth and population size, the influences of lake \nmorphometry and chemistry on 14 northwestern Ontario populations \n(including Squeers Lake) were investigated. Northern pike \npopulations found within deep-oligotrophic lakes exhibited low \npopulation densities, a superior growth rate, piscivory and were \nspawning and nursery habitat limited. Northern pike populations \nfrom meso-eutrophic lakes had much greater population densities, \nexhibited much poorer growth rates, were generally opportunistic \npredators and appeared to be food limited. Northern pike from \nmesotrophic and shallow-oligotrophic lakes exhibited intermediate \npopulation size and growth rates with the maximal individual size \nof fish from these populations approaching that of northern pike \nfrom deep-oligotrophic lakes. With the increased acceptance of \nindividual lake management, a number of management alternatives are \nproposed.
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».