Oceanographic flow regime and fish recruitment: reversed circulation in the North Sea coincides with unusual strong sandeel recruitment

Ole Henriksen, Asbjørn Christensen, Sigrun Jonasdottir, Brian R. MacKenzie, Kristian Ege Nielsen, Henrik Mosegaard, Mikael van Deurs*

*Corresponding author for this work

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Abstract

The chase for environmental descriptors of fish stock production is ongoing. Although, numerous correlations between environmental variables such as food abundance or sea surface temperature have been proposed in the past, few are operational in a fisheries management context today. Reasons for this may be many, but spurious correlations, the use of higher level climate-change indicators, and wrong perception of causal relationships has been pointed out. In the present study, we demonstrate how modelled oceanographic data, describing local conditions, combined with a simple probabilistic risk assessment can be used to forecast fish recruitment. We used the lesser sandeel (Ammodytes marinus) in the North Sea as an example and focused on the circulation patterns experienced by the first feeding larvae on the Dogger Bank. A strong link between the net-direction of the water transport in the surface and unusual strong year-classes of sandeel were found. For example, the most extreme recruitments only took place in years with a particular type of flow-regime in February, which may be associated with the occasional reversals of the North Sea circulation. Using risk-ratios, we put forward the potential for using flow-regime in probabilistic short-term forecasts of unusual strong year-classes. Lastly, we propose a hypothesis for recruitment in sandeel, which could be extended to other species, and thereby contribute in future pursues for predictors in recruitment forecasting.
Original languageEnglish
JournalMarine Ecology - Progress Series
Volume607
Pages (from-to)187-205
ISSN0171-8630
DOIs
Publication statusPublished - 2018

Keywords

  • Recruitment
  • Flow
  • First feeding
  • Match−mismatch
  • Short-term forecast
  • North Sea
  • Sandeel
  • Ammodytes marinus
  • Circulation

Cite this

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title = "Oceanographic flow regime and fish recruitment: reversed circulation in the North Sea coincides with unusual strong sandeel recruitment",
abstract = "The chase for environmental descriptors of fish stock production is ongoing. Although, numerous correlations between environmental variables such as food abundance or sea surface temperature have been proposed in the past, few are operational in a fisheries management context today. Reasons for this may be many, but spurious correlations, the use of higher level climate-change indicators, and wrong perception of causal relationships has been pointed out. In the present study, we demonstrate how modelled oceanographic data, describing local conditions, combined with a simple probabilistic risk assessment can be used to forecast fish recruitment. We used the lesser sandeel (Ammodytes marinus) in the North Sea as an example and focused on the circulation patterns experienced by the first feeding larvae on the Dogger Bank. A strong link between the net-direction of the water transport in the surface and unusual strong year-classes of sandeel were found. For example, the most extreme recruitments only took place in years with a particular type of flow-regime in February, which may be associated with the occasional reversals of the North Sea circulation. Using risk-ratios, we put forward the potential for using flow-regime in probabilistic short-term forecasts of unusual strong year-classes. Lastly, we propose a hypothesis for recruitment in sandeel, which could be extended to other species, and thereby contribute in future pursues for predictors in recruitment forecasting.",
keywords = "Recruitment, Flow, First feeding, Match−mismatch, Short-term forecast, North Sea, Sandeel, Ammodytes marinus, Circulation",
author = "Ole Henriksen and Asbj{\o}rn Christensen and Sigrun Jonasdottir and MacKenzie, {Brian R.} and Nielsen, {Kristian Ege} and Henrik Mosegaard and {van Deurs}, Mikael",
year = "2018",
doi = "10.3354/meps12786",
language = "English",
volume = "607",
pages = "187--205",
journal = "Marine Ecology - Progress Series",
issn = "0171-8630",
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TY - JOUR

T1 - Oceanographic flow regime and fish recruitment: reversed circulation in the North Sea coincides with unusual strong sandeel recruitment

AU - Henriksen, Ole

AU - Christensen, Asbjørn

AU - Jonasdottir, Sigrun

AU - MacKenzie, Brian R.

AU - Nielsen, Kristian Ege

AU - Mosegaard, Henrik

AU - van Deurs, Mikael

PY - 2018

Y1 - 2018

N2 - The chase for environmental descriptors of fish stock production is ongoing. Although, numerous correlations between environmental variables such as food abundance or sea surface temperature have been proposed in the past, few are operational in a fisheries management context today. Reasons for this may be many, but spurious correlations, the use of higher level climate-change indicators, and wrong perception of causal relationships has been pointed out. In the present study, we demonstrate how modelled oceanographic data, describing local conditions, combined with a simple probabilistic risk assessment can be used to forecast fish recruitment. We used the lesser sandeel (Ammodytes marinus) in the North Sea as an example and focused on the circulation patterns experienced by the first feeding larvae on the Dogger Bank. A strong link between the net-direction of the water transport in the surface and unusual strong year-classes of sandeel were found. For example, the most extreme recruitments only took place in years with a particular type of flow-regime in February, which may be associated with the occasional reversals of the North Sea circulation. Using risk-ratios, we put forward the potential for using flow-regime in probabilistic short-term forecasts of unusual strong year-classes. Lastly, we propose a hypothesis for recruitment in sandeel, which could be extended to other species, and thereby contribute in future pursues for predictors in recruitment forecasting.

AB - The chase for environmental descriptors of fish stock production is ongoing. Although, numerous correlations between environmental variables such as food abundance or sea surface temperature have been proposed in the past, few are operational in a fisheries management context today. Reasons for this may be many, but spurious correlations, the use of higher level climate-change indicators, and wrong perception of causal relationships has been pointed out. In the present study, we demonstrate how modelled oceanographic data, describing local conditions, combined with a simple probabilistic risk assessment can be used to forecast fish recruitment. We used the lesser sandeel (Ammodytes marinus) in the North Sea as an example and focused on the circulation patterns experienced by the first feeding larvae on the Dogger Bank. A strong link between the net-direction of the water transport in the surface and unusual strong year-classes of sandeel were found. For example, the most extreme recruitments only took place in years with a particular type of flow-regime in February, which may be associated with the occasional reversals of the North Sea circulation. Using risk-ratios, we put forward the potential for using flow-regime in probabilistic short-term forecasts of unusual strong year-classes. Lastly, we propose a hypothesis for recruitment in sandeel, which could be extended to other species, and thereby contribute in future pursues for predictors in recruitment forecasting.

KW - Recruitment

KW - Flow

KW - First feeding

KW - Match−mismatch

KW - Short-term forecast

KW - North Sea

KW - Sandeel

KW - Ammodytes marinus

KW - Circulation

U2 - 10.3354/meps12786

DO - 10.3354/meps12786

M3 - Journal article

VL - 607

SP - 187

EP - 205

JO - Marine Ecology - Progress Series

JF - Marine Ecology - Progress Series

SN - 0171-8630

ER -