Investigating fish migration, mortality and physiology to improve conservation planning of anadromous salmonids: a case study on the endangered North Sea houting (Coregonus oxyrinchus)

Morten Hertz*, Lasse Fast Jensen, Cino Pertoldi, Kim Aarestrup, Søren Nøhr Thomsen, Aage Kristian Olsen Alstrup, Harald Asmus, Søren Madsen, Jon Christian Svendsen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

127 Downloads (Pure)

Abstract

Understanding migratory behavior, mortality and physiology is essential for conservation of many species, in particular 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+/K+-ATPase activities were elevated in North Sea houting and anadromous whitefish compared to 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.
Original languageEnglish
JournalCanadian Journal of Zoology
Volume97
Pages (from-to)1126-1136
Number of pages11
ISSN0008-4301
DOIs
Publication statusPublished - 2019

Keywords

  • Acoustic telemetry
  • Bern Convention
  • Coregonus oxyrinchus
  • Fish
  • Habitat Directive of the European Union
  • Na+
  • K+-ATPase
  • North Sea houting
  • Osmolality
  • Repeatability
  • Spawning migration

Fingerprint Dive into the research topics of 'Investigating fish migration, mortality and physiology to improve conservation planning of anadromous salmonids: a case study on the endangered North Sea houting (Coregonus oxyrinchus)'. Together they form a unique fingerprint.

Cite this