The influence of initial developmental status on the life-history of sea trout (Salmo trutta)

Diego Del Villar-Guerra, Martin H Larsen, Henrik Baktoft*, Anders Koed, Kim Aarestrup

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

Spring migrating sea trout juveniles can be classified as parr, pre-smolt or smolt based on body morphology and osmoregulatory capacity. In this respect, parr are assumed to be less prepared for a marine life and to have lower survival at sea than pre-smolts and smolts. However, the behaviour and survival of these trout phenotypes upon entering the sea is not well known. Using passive integrated transponder telemetry, this study found that the return rate from the sea to the natal river was higher for parr compared to pre-smolts and smolts. Additionally, trout classified as parr generally migrated earlier to the sea and a larger proportion returned to the river after less than one year at sea. The daily mortality rate at sea was comparable among the different phenotypes of trout, suggesting that the higher proportion of returning parr to the river was linked to their shorter duration at sea. These results provide evidence of different life-history strategies for seaward-migrating juvenile sea trout, ultimately affecting their return rate to the natal river. Investigations failing to consider downstream migrating parr and pre-smolts risks neglecting a large part of the anadromous population and may result in inaccurate assessments of sea trout stocks in rivers.
Original languageEnglish
Article number13468
JournalScientific Reports
Volume9
ISSN2045-2322
DOIs
Publication statusPublished - 2019

Keywords

  • Animal migration
  • Behavioural ecology

Cite this

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title = "The influence of initial developmental status on the life-history of sea trout (Salmo trutta)",
abstract = "Spring migrating sea trout juveniles can be classified as parr, pre-smolt or smolt based on body morphology and osmoregulatory capacity. In this respect, parr are assumed to be less prepared for a marine life and to have lower survival at sea than pre-smolts and smolts. However, the behaviour and survival of these trout phenotypes upon entering the sea is not well known. Using passive integrated transponder telemetry, this study found that the return rate from the sea to the natal river was higher for parr compared to pre-smolts and smolts. Additionally, trout classified as parr generally migrated earlier to the sea and a larger proportion returned to the river after less than one year at sea. The daily mortality rate at sea was comparable among the different phenotypes of trout, suggesting that the higher proportion of returning parr to the river was linked to their shorter duration at sea. These results provide evidence of different life-history strategies for seaward-migrating juvenile sea trout, ultimately affecting their return rate to the natal river. Investigations failing to consider downstream migrating parr and pre-smolts risks neglecting a large part of the anadromous population and may result in inaccurate assessments of sea trout stocks in rivers.",
keywords = "Animal migration, Behavioural ecology",
author = "{Del Villar-Guerra}, Diego and Larsen, {Martin H} and Henrik Baktoft and Anders Koed and Kim Aarestrup",
year = "2019",
doi = "10.1038/s41598-019-49175-0",
language = "English",
volume = "9",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",

}

The influence of initial developmental status on the life-history of sea trout (Salmo trutta). / Del Villar-Guerra, Diego; Larsen, Martin H; Baktoft, Henrik; Koed, Anders; Aarestrup, Kim.

In: Scientific Reports, Vol. 9, 13468, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - The influence of initial developmental status on the life-history of sea trout (Salmo trutta)

AU - Del Villar-Guerra, Diego

AU - Larsen, Martin H

AU - Baktoft, Henrik

AU - Koed, Anders

AU - Aarestrup, Kim

PY - 2019

Y1 - 2019

N2 - Spring migrating sea trout juveniles can be classified as parr, pre-smolt or smolt based on body morphology and osmoregulatory capacity. In this respect, parr are assumed to be less prepared for a marine life and to have lower survival at sea than pre-smolts and smolts. However, the behaviour and survival of these trout phenotypes upon entering the sea is not well known. Using passive integrated transponder telemetry, this study found that the return rate from the sea to the natal river was higher for parr compared to pre-smolts and smolts. Additionally, trout classified as parr generally migrated earlier to the sea and a larger proportion returned to the river after less than one year at sea. The daily mortality rate at sea was comparable among the different phenotypes of trout, suggesting that the higher proportion of returning parr to the river was linked to their shorter duration at sea. These results provide evidence of different life-history strategies for seaward-migrating juvenile sea trout, ultimately affecting their return rate to the natal river. Investigations failing to consider downstream migrating parr and pre-smolts risks neglecting a large part of the anadromous population and may result in inaccurate assessments of sea trout stocks in rivers.

AB - Spring migrating sea trout juveniles can be classified as parr, pre-smolt or smolt based on body morphology and osmoregulatory capacity. In this respect, parr are assumed to be less prepared for a marine life and to have lower survival at sea than pre-smolts and smolts. However, the behaviour and survival of these trout phenotypes upon entering the sea is not well known. Using passive integrated transponder telemetry, this study found that the return rate from the sea to the natal river was higher for parr compared to pre-smolts and smolts. Additionally, trout classified as parr generally migrated earlier to the sea and a larger proportion returned to the river after less than one year at sea. The daily mortality rate at sea was comparable among the different phenotypes of trout, suggesting that the higher proportion of returning parr to the river was linked to their shorter duration at sea. These results provide evidence of different life-history strategies for seaward-migrating juvenile sea trout, ultimately affecting their return rate to the natal river. Investigations failing to consider downstream migrating parr and pre-smolts risks neglecting a large part of the anadromous population and may result in inaccurate assessments of sea trout stocks in rivers.

KW - Animal migration

KW - Behavioural ecology

U2 - 10.1038/s41598-019-49175-0

DO - 10.1038/s41598-019-49175-0

M3 - Journal article

VL - 9

JO - Scientific Reports

JF - Scientific Reports

SN - 2045-2322

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ER -