TY - JOUR
T1 - Nutrient-driven poleward expansion of the Northeast Atlantic mackerel (Scomber scombrus) stock
T2 - A new hypothesis
AU - Pacariz, S.V.
AU - Hátún, H.
AU - Jacobsen, J.A.
AU - Johnson, C.
AU - Eliasen, S.
AU - Rey, F.
PY - 2016
Y1 - 2016
N2 - The Northeast Atlantic mackerel (Scomber scombrus) stock has increased and expanded its summer feeding migration west- and northwards since 2006, entailing large geopolitical challenges for the countries harvesting this species. A common perspective is that climatic warming opens up new regions for biota in the north. It has also been suggested that the presently large pelagic fish stocks deplete prey resources in the eastern North Atlantic during their summer feeding phase, forcing the stocks west towards the Irminger Sea in their search for food. Here, we suggest that the declining nutrient (silicate) concentrations observed along the northern European continental slope reduce primary and thus secondary production, exacerbating food scarceness in the east and adding to the incentive to migrate westward. The new westward feeding route requires that the fish cross the Iceland Basin, which during the summer season quickly becomes nutrient-depleted and thus might act as a barrier to migration after the spring bloom. Using mackerel and zooplankton abundance data from the International Ecosystem Summer Surveys in the Nordic Seas, we suggest that the oligotrophic waters in the central Iceland Basin force the fish to migrate through a narrow ‘corridor’ along the south Iceland shelf, where nutrients are replenished and both primary and secondary production are higher.
AB - The Northeast Atlantic mackerel (Scomber scombrus) stock has increased and expanded its summer feeding migration west- and northwards since 2006, entailing large geopolitical challenges for the countries harvesting this species. A common perspective is that climatic warming opens up new regions for biota in the north. It has also been suggested that the presently large pelagic fish stocks deplete prey resources in the eastern North Atlantic during their summer feeding phase, forcing the stocks west towards the Irminger Sea in their search for food. Here, we suggest that the declining nutrient (silicate) concentrations observed along the northern European continental slope reduce primary and thus secondary production, exacerbating food scarceness in the east and adding to the incentive to migrate westward. The new westward feeding route requires that the fish cross the Iceland Basin, which during the summer season quickly becomes nutrient-depleted and thus might act as a barrier to migration after the spring bloom. Using mackerel and zooplankton abundance data from the International Ecosystem Summer Surveys in the Nordic Seas, we suggest that the oligotrophic waters in the central Iceland Basin force the fish to migrate through a narrow ‘corridor’ along the south Iceland shelf, where nutrients are replenished and both primary and secondary production are higher.
KW - Northeast Atlantic mackere stock
KW - scomber scombrus
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84986254010&partnerID=MN8TOARS
U2 - 10.12952/journal.elementa.000105
DO - 10.12952/journal.elementa.000105
M3 - Article
SN - 2325-1026
VL - 4
SP - 1
EP - 13
JO - Elementa: Science of the Anthropocene
JF - Elementa: Science of the Anthropocene
M1 - 000105
ER -