Behaviour of mackerel schools during summer feeding migration in the Norwegian Sea, as observed from fishing vessel sonars

Abstract In July 2002, two commercial vessels were used to study the distribution of Northeast Atlantic mackerel (Scomber scombrus L.) during their feeding migration in the eastern part of the Norwegian Sea between 62°N and 70°N. Pelagic trawling and school tracking with SIMRAD 24–36 kHz sonar demonstrated that the stock was distributed throughout the study area. Information about time, geographic position, size, depth, speed, and direction was stored for each school during tracking. This study reports analyses of data from 63 schools that were tracked for 30 s or longer. All schools were recorded at depths of less than 100 m, and the majority (65%) were found between the surface and 40 m. The direction of migration (north 0° ± 22.5°, northeast 45° ± 22.5°, etc.) was non-random, with east and west as dominant swimming directions. School size and migration speed varied from 1 to 7000 tonnes and 0 to 6 m s−1, respectively. Methodological improvements are discussed.

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Anisakis species composition and infection characteristics in Atlantic mackerel, Scomber scombrus , from major European fishing grounds — reflecting changing fish host distribution and migration pattern

Fisheries Research ◽

10.1016/j.fishres.2017.07.030 ◽

2018 ◽

Vol 202 ◽

pp. 112-121 ◽

Cited By ~ 12

Author(s):

Arne Levsen ◽

Paolo Cipriani ◽

Simonetta Mattiucci ◽

Melanie Gay ◽

Lee C. Hastie ◽

...

Keyword(s):

Species Composition ◽

Fish Host ◽

Migration Pattern ◽

Atlantic Mackerel ◽

Scomber Scombrus ◽

Host Distribution ◽

And Migration

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Mackerel predation on herring larvae during summer feeding in the Norwegian Sea

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv087 ◽

2015 ◽

Vol 72 (8) ◽

pp. 2313-2321 ◽

Cited By ~ 20

Author(s):

Georg Skaret ◽

Eneko Bachiller ◽

Herdis Langøy ◽

Erling K. Stenevik

Keyword(s):

Clupea Harengus ◽

Distribution Area ◽

Calanoid Copepods ◽

Norwegian Sea ◽

Atlantic Mackerel ◽

Investigation Area ◽

Pelagic Larvae ◽

Coastal Shelf ◽

Regulatory Effects ◽

Summer Feeding

Abstract In the course of the past two decades, Atlantic mackerel, Scomber scombrus, have expanded their summer feeding distribution in the Norwegian Sea substantially, and now potentially overlap with pelagic larvae of Norwegian spring-spawning herring, Clupea harengus, as these drift northwards. Mackerel are known to be opportunistic predators, and the aim of this study was to evaluate mackerel predation in an area of overlap between mackerel and herring larvae, with particular focus on predation on herring larvae. In early June 2013, we followed a predefined transect in the expected core larvae distribution area on the Norwegian coastal shelf between about 66°N and 69°N. The transect was repeated twice, and samples of mackerel for stomach analyses and subsequent herring larvae samples were obtained at pre-defined stations. Mackerel were caught in all but one of the trawl hauls, but were hardly ever observed acoustically, suggesting that they were dispersed close to the surface throughout the study area. Herring larvae were caught in all samples. Calanoid copepods were the dominant prey of the mackerel, but 45% of the mackerel guts contained herring larvae, with a maximum of 225 larvae counted in a single gut. Both the frequency of guts containing herring larvae and the average amount of herring larvae increased in line with increasing abundance of larvae. On the other hand, no spatial correlation between mackerel abundance and herring larvae abundance was found at the station level. The results suggest that mackerel fed opportunistically on herring larvae, and that predation pressure therefore largely depends on the degree of overlap in time and space. Rough areal projections suggest that the mackerel would be capable of consuming the herring larvae present in the investigation area in 6–7 d, and that such predation therefore could have regulatory effects on stocks of Norwegian spring-spawning herring.

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Changes in weight-at-length and size-at-age of mature Northeast Atlantic mackerel (Scomber scombrus) from 1984 to 2013: effects of mackerel stock size and herring (Clupea harengus) stock size

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv142 ◽

2015 ◽

Vol 73 (4) ◽

pp. 1255-1265 ◽

Cited By ~ 16

Author(s):

Anna H. Olafsdottir ◽

Aril Slotte ◽

Jan Arge Jacobsen ◽

Guðmundur J. Oskarsson ◽

Kjell R. Utne ◽

...

Keyword(s):

Prey Availability ◽

Somatic Growth ◽

Recent Decade ◽

Clupea Harengus ◽

Negative Effects ◽

Norwegian Sea ◽

Stock Size ◽

Northeast Atlantic ◽

Atlantic Mackerel ◽

Scomber Scombrus

Abstract Weight-at-length and length-/weight-at-age were analysed for mature 3- to 8-year-old Northeast Atlantic mackerel (Scomber scombrus; n= 26 084) collected annually in autumn (September and October) at the end of the annual feeding season during 1984–2013 in the northern North Sea. The age range represented 92% of the mackerel stock size (age 3+). During the most recent decade, mackerel length- and weight-at-age continually declined. In 2013, the average mackerel was 3.7 cm shorter and weighed 175 g less than the average individual in 2002. Individual weight-at-length, demonstrating annual summer feeding success, continually declined during the most recent 5 years, whereas somatic growth of cohorts aged 3–8 continually declined for the last 11 of 25 cohorts investigated. Growth of the latest cohort was 34% of the maximum cohort growth recorded. Both weight-at-length and cohort growth were negatively affected by mackerel stock size and Norwegian spring-spawning herring (Clupea harengus) stock size (weight-at-length: r2 = 0.89; growth (length): r2 = 0.68; growth (weight): r2 = 0.78), while temperature was not significant. Conspecific density-dependence was most likely mediated via intensified competition associated with greater mackerel density. Negative effects of herring were likely mediated by exploitative competition for shared food resources rather than direct competition due to limited spatio-temporal overlap between mackerel and herring during the feeding season. Herring begin their seasonal feeding migration at least a month before mackerel; therefore, herring consumption influences prey availability for the later-arriving mackerel. Record low mackerel growth and negative effects of mackerel and herring stock size suggest that the carrying capacity of the Norwegian Sea and adjacent areas for plankton-feeding fish stocks have been reached. However, compounding effects of a less productive Norwegian Sea during the 30-year period cannot be excluded.

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Temperature constraints shaped the migration routes of mackerel (Scomber scombrus) in the Black Sea

Acta Adriatica ◽

10.32582/aa.58.2.12 ◽

2017 ◽

Vol 58 (2) ◽

pp. 337-344 ◽

Cited By ~ 1

Author(s):

Daniel Pauly ◽

Çetin Keskin

Keyword(s):

Black Sea ◽

North Atlantic ◽

The Black Sea ◽

Seasonal Temperature ◽

Migration Routes ◽

Atlantic Mackerel ◽

Scomber Scombrus ◽

The North ◽

And Migration ◽

Induced Changes

Conventional narratives explain fish migrations in term of requirements (food, mates, habitats, etc.), with adequate temperatures being optional. Here, using the example of a (commercially extinct) stock of Black Sea mackerel (Scomber scombrus), we suggest that seasonal migrations are driven by seasonal temperature cycles. Therein, temperature acts as a constraint determining where the fish can be at any given time, and not a one of several factors which they would consider when choosing between alternative migration routes. Generalizing, we suggest that temperature should generally be an explicit part of hypotheses about the migratory behaviours of marine fishes. For illustration of what may occur when this is not the case, it is suggested that the non-consideration of temperature in a model of North Atlantic mackerel migration may have led, among the researchers concerned, to a sense of complacency with respect to the climate change-induced changes in the phenology of this fish in the North Atlantic, whose distribution and migration are misleadingly seen as “stochastic”.

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Overlap in distribution and diets of Atlantic mackerel (Scomber scombrus), Norwegian spring-spawning herring (Clupea harengus) and blue whiting (Micromesistius poutassou) in the Norwegian Sea during late summer

Marine Biology Research ◽

10.1080/17451000.2011.642803 ◽

2012 ◽

Vol 8 (5-6) ◽

pp. 442-460 ◽

Cited By ~ 46

Author(s):

Herdis Langøy ◽

Leif Nøttestad ◽

Georg Skaret ◽

Cecilie Broms ◽

Anders Fernö

Keyword(s):

Late Summer ◽

Clupea Harengus ◽

Norwegian Sea ◽

Blue Whiting ◽

Atlantic Mackerel ◽

Scomber Scombrus

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Early growth and recruitment in Atlantic mackerel Scomber scombrus: discriminating the effects of fast growth and selection for fast growth

Marine Ecology Progress Series ◽

10.3354/meps337209 ◽

2007 ◽

Vol 337 ◽

pp. 209-219 ◽

Cited By ~ 74

Author(s):

D Robert ◽

M Castonguay ◽

L Fortier

Keyword(s):

Early Growth ◽

Fast Growth ◽

Atlantic Mackerel ◽

Scomber Scombrus ◽

Selection For

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Selectivity of square mesh codends of pelagic trawls for Atlantic mackerel (Scomber scombrus L.)

Fisheries Research ◽

10.1016/0165-7836(92)90081-4 ◽

1992 ◽

Vol 13 (3) ◽

pp. 267-279 ◽

Cited By ~ 4

Author(s):

J. Casey ◽

M.D. Nicholson ◽

S. Warnes

Keyword(s):

Atlantic Mackerel ◽

Scomber Scombrus

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Feeding strategy of mackerel in the Norwegian Sea relative to currents, temperature, and prey

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv239 ◽

2015 ◽

Vol 73 (4) ◽

pp. 1127-1137 ◽

Cited By ~ 17

Author(s):

Leif Nøttestad ◽

Justine Diaz ◽

Hector Penã ◽

Henrik Søiland ◽

Geir Huse ◽

...

Keyword(s):

Swimming Speed ◽

Swimming Performance ◽

Feeding Strategy ◽

Near Field ◽

Norwegian Sea ◽

Swimming Direction ◽

Atlantic Mackerel ◽

The North ◽

Foraging Rate ◽

Feeding Resources

Abstract High abundance of Northeast Atlantic mackerel (Scomber scombrus L.), combined with limited food resources, may now force mackerel to enter new and productive regions in the northern Norwegian Sea. However, it is not known how mackerel exploit the spatially varying feeding resources, and their vertical distribution and swimming behaviour are also largely unknown. During an ecosystem survey in the Norwegian Sea during the summer feeding season, swimming direction, and speed of mackerel schools were recorded with high-frequency omnidirectional sonar in four different regions relative to currents, ambient temperature, and zooplankton. A total of 251 schools were tracked, and fish and zooplankton were sampled with pelagic trawl and WP-2 plankton net. Except for the southwest region, swimming direction of the tracked schools coincided with the prevailing northerly Atlantic current direction in the Norwegian Sea. Swimming with the current saves energy, and the current also provides a directional cue towards the most productive areas in the northern Norwegian Sea. Average mean swimming speed in all regions combined was ∼3.8 body lengths s−1. However, fish did not swim in a straight course, but often changed direction, suggesting active feeding in the near field. Fish were largest and swimming speed lowest in the northwest region which had the highest plankton concentrations and lowest temperature. Mackerel swam close to the surface at a depth of 8–39 m, with all schools staying above the thermocline in waters of at least 6°C. In surface waters, mackerel encounter improved foraging rate and swimming performance. Going with the flow until temperature is too low, based on an expectation of increasing foraging rate towards the north while utilizing available prey under way, could be a simple and robust feeding strategy for mackerel in the Norwegian Sea.

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