Multi‐decadal variations in spawning ground use in Northeast Arctic haddock (Melanogrammus aeglefinus) |
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| Authors: | Øystein Langangen Leif Christian Stige Kristina Ø. Kvile Natalia A. Yaragina Jon Egil Skjæraasen Frode B. Vikebø Geir Ottersen |
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| Affiliation: | 1. Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway;2. Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, USA;3. Polar Research Institute of Marine Fisheries and Oceanography, Murmansk, Russia;4. Institute of Marine Research, Bergen, Norway |
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| Abstract: | Despite the importance both in an ecological and management context, much uncertainty remains about the underlying factors controlling spawning ground use in marine fish. Here, we investigate how spawning ground use of Northeast Arctic (NEA) haddock (Melanogrammus aeglefinus) has changed over time. By combining data from a Soviet‐Russian egg survey conducted over a 35 year period (1959–1993) with a biophysical drift model, we estimate annual median spawning latitudes of NEA haddock. Furthermore, we test for statistical association between the median latitude of spawning and covariates that are candidates for shaping the spawning distribution of haddock. The results indicate no association with temperature, as measured at the Kola transect, or demographic structure, as measured by the mean weight of spawners. However, we find a positive and significant association between spawning latitude and spawning stock biomass, indicating that density‐dependence may be more important in shaping spawning location than other factors such as temperature and demographic structure. A potential mechanism for the reported effect of spawning stock biomass may act through the distribution at the feeding grounds, which is reported to expand north‐ and eastwards at high population density. |
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| Keywords: | biophysical model egg survey haddock spatial distribution spawning |
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