Abstract
Based on GIS-mapping and semi-parametric modelling of recaptures from
PIT-tag experiments in the North Sea nursery area (September 2011), the Celtic
Seas spawning area (May-June 2014-2021) and the Icelandic Waters feeding
area (August 2015-2019), we argue that the distribution of Northeast Atlantic
(NEA) mackerel is influenced by a size-dependent migratory behaviour. The
time-space recapture dynamics revealed that larger mackerel tended to
migrate a longer distance between spawning and feeding areas, either
through a western route from the Celtic Seas into the Icelandic Waters and
the Greenland Sea or by following the main route northwards through the
Faroe-Shetland Channel into the Norwegian Sea. This long-distance travel
resulted in turn in delayed arrival in the North Sea wintering area. During the
return spawning migration into the Celtic Seas, larger individuals remained in
the front, likely heading to spawning grounds farther south than smaller
conspecifics. Migration patterns also evolved with time at liberty as the
mackerel grew older and larger, while possibly covering a progressively wider
area over its annual migration cycle as suggested from the tagging data.
However, the study also showed large inter-annual variability in the
recapture patterns which likely reflect changes in environmental condition
(prey availability and ocean current), NEA mackerel population demographics,
and the spatial fishery dynamics.
PIT-tag experiments in the North Sea nursery area (September 2011), the Celtic
Seas spawning area (May-June 2014-2021) and the Icelandic Waters feeding
area (August 2015-2019), we argue that the distribution of Northeast Atlantic
(NEA) mackerel is influenced by a size-dependent migratory behaviour. The
time-space recapture dynamics revealed that larger mackerel tended to
migrate a longer distance between spawning and feeding areas, either
through a western route from the Celtic Seas into the Icelandic Waters and
the Greenland Sea or by following the main route northwards through the
Faroe-Shetland Channel into the Norwegian Sea. This long-distance travel
resulted in turn in delayed arrival in the North Sea wintering area. During the
return spawning migration into the Celtic Seas, larger individuals remained in
the front, likely heading to spawning grounds farther south than smaller
conspecifics. Migration patterns also evolved with time at liberty as the
mackerel grew older and larger, while possibly covering a progressively wider
area over its annual migration cycle as suggested from the tagging data.
However, the study also showed large inter-annual variability in the
recapture patterns which likely reflect changes in environmental condition
(prey availability and ocean current), NEA mackerel population demographics,
and the spatial fishery dynamics.
| Original language | English |
|---|---|
| Article number | 983962 |
| Pages (from-to) | 1-18 |
| Number of pages | 18 |
| Journal | Frontiers in Marine Science |
| Volume | 9 |
| DOIs | |
| Publication status | Published - 11 Nov 2022 |
Keywords
- Atlantic mackerel
- size-dependent migration
- GIS
- semi-parametric model
- PIT tag
- tag-recapture
