1. Investigating fish migration, mortality, and physiology to improve conservation planning of anadromous salmonids: a case study on the endangered North Sea houting (Coregonus oxyrinchus)
- Author
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Hertz, M., Jensen, L.F., Pertoldi, C., Aarestrup, K., Thomsen, S.N., Alstrup, A.K.O., Asmus, H., Madsen, S.S., and Svendsen, J.C.
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Animal behavior -- Case studies -- Physiological aspects -- Investigations -- Protection and preservation ,Fishes -- Case studies -- Physiological aspects -- Investigations -- Protection and preservation ,Adenosine triphosphatase -- Case studies -- Physiological aspects -- Investigations -- Protection and preservation ,Wildlife conservation -- Case studies -- Physiological aspects -- Investigations -- Protection and preservation ,Lakes -- Case studies -- Physiological aspects -- Investigations -- Protection and preservation ,Company legal issue ,Zoology and wildlife conservation - Abstract
Understanding migratory behavior, mortality, and physiology is essential for conservation of many species, particularly anadromous fish. In this study, freshwater and marine migrations of the endangered salmonid North Sea houting (Coregonus oxyrinchus (Linnaeus, 1758)) were investigated using telemetry. Furthermore, physiological samples were collected from North Sea houting and from resident and anadromous populations of the closely related European whitefish (Coregonus lavaretus (Linnaeus, 1758)) to compare hypo-osmotic tolerances. On average, North Sea houting spent 193 days at sea where the mortality was 36%. Most fish returned from sea in the autumn, and river entry correlated inversely with river temperature and positively with discharge. Fish spent an average of 49 days in the estuarine area. Artificial lakes negatively affected migration speeds. Migration speeds did not differ consistently between individuals (i.e., not a repeatable trait) but correlated positively with water temperature. Fish arrived at spawning areas in November. In the post-spawning state, [Na.sup.+]/[K.sup.+]-ATPase activities were elevated in North Sea houting and anadromous whitefish compared with resident whitefish, while osmolality was elevated only in North Sea houting. Our study provides important information for conservation planning related to the Habitat Directive of the European Union that lists the North Sea houting as critically endangered. Key words: acoustic telemetry, Bern Convention, Coregonus oxyrinchus, fish, Habitat Directive of the European Union, [Na.sup.+]/[K.sup.+] ATPase, North Sea houting, osmolality, repeatability, spawning migration. La comprehension du comportement de migration, de la mortalite et de la physiologie est d'importance centrale pour la conservation de nombreuses especes, en particulier celle des poissons anadromes. Les migrations en mer et en eau douce du coregone oxyrhynque (Coregonus oxyrinchus (Linnaeus, 1758)), un salmonide en danger, ont ete etudiees a l'aide de la telemetrie. Des echantillons physiologiques ont en outre ete preleves de coregones oxyrhynques et de populations residentes et anadromes de coregone lavaret (Coregonus lavaretus (Linnaeus, 1758)), une espece etroitement reliee, pour comparer leurs tolerances a des conditions hypoosmotiques. Les coregones oxyrhynques passaient en moyenne 193 jours en mer, ou le taux de mortalite etait de 36 %. La plupart des poissons revenaient de la mer en automne, et l'entree en riviere etait inversement correlee a la temperature de la riviere et positivement correlee au debit. Les poissons passaient une moyenne de 49 jours dans la zone estuarienne. Les lacs artificiels avaient une incidence negative sur les vitesses de migration. Ces dernieres ne variaient pas de maniere coherente entre individus (c.-a-d. pas un caractere reproductible), mais etaient positivement correlees a la temperature de l'eau. Les poissons arrivaient dans les lieux de frai en novembre. A l'etat post-frai, les valeurs d'activite de la [Na.sup.+]/[K.sup.+]-ATPase etaient elevees chez les coregones oxyrhynques et les coregones lavarets anadromes par rapport a celles des coregones lavarets residents, alors que l'osmolalite n'etait elevee que chez les coregones oxyrhynques. L'etude fournit d'importants renseignements pour la planification de la conservation associee a la Directive de l'Union europeenne concernant la conservation des habitats naturels, dans laquelle le coregone oxyrhynque est designe comme etant une espece en danger grave. [Traduit par la Redaction] Mots-cles: telemetrie acoustique, Convention de Berne, Coregonus oxyrinchus, poisson, Directive de l'Union europeenne concernant la conservation des habitats naturels, [Na.sup.+]/[K.sup.+]-ATPase, coregone oxyrhynque, osmolalite, reproductibilite, migration de frai., Introduction Knowledge of habitat use and movements between habitats is essential for conservation of threatened species (Simpson and Mapleston 2002; Ebner and Thiem 2009) because diversity in habitat use and [...]
- Published
- 2019
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