Fun with Fish 3: Consequences of spawning locations for fish in the Barents Sea.

This project is quantitative and will focus on analysis of existing data.

Recently it has been shown that both Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) have shifted spawning locations northwards^1,2. At the same time, both populations have experienced a recent decline in biomass (tables 3.18 and 4.15 in the IMR/PINRO report³). One mechanism that is known to affect the population productivity, is the size of juvenile cod and haddock in the fall preceding the first winter⁴. The spawning location has been linked to the size of offspring, e.g. through ambient temperatures and growth⁵. To shed further light on the link between spawning location, offspring size, and population productivity, this master project will investigate the link between the spawning locations in cod and haddock. The annual differences in spawning locations can be quantified using fisheries statistics¹ and will be compared with the observations of juveniles in the fall (0-group cod and haddock as quantified in BESS⁶). The link can also potentially be explored using a coupled-physical biological drift model. The details of the project will be developed by the student and the supervisor(s).

Refs.

1.        Langangen, Ø. et al. Ticket to spawn: Combining economic and genetic data to evaluate the effect of climate and demographic structure on spawning distribution in Atlantic cod. Glob. Chang. Biol. 25, 134–143 (2019).

2.        Langangen, Ø. et al. Multi-decadal variations in spawning ground use in Northeast Arctic haddock (Melanogrammus aeglefinus). Fish. Oceanogr. 27, 435–444 (2018).

3.        Howell, D. et al. Report of the Joint Russian- Norwegian Working Group on Arctic Fisheries (JRN-AFWG) 2023. IMR/PINRO Jt. Rep. Ser. 7, 189 (2023).

4.        Stige et al. Density‐ and size‐dependent mortality in fish early life stages. Fish Fish. 18, 615–656 (2019).

5.        Langangen, Ø., Ottersen, G., Ciannelli, L., Vikebø, F. B. & Stige, L. C. Reproductive strategy of a migratory fish stock: Implications of spatial variations in natural mortality. Can. J. Fish. Aquat. Sci. 73, (2016).

6.        Skjoldal, H. R. et al. Recruitment variability of fish stocks in the Barents Sea: Spatial and temporal variation in 0-group fish length of six commercial species during recent decades of warming (1980–2017). Prog. Oceanogr. 206, 102845 (2022).