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Data and reports from the Freshwater Laboratory in Marine Scotland.

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UK Open Government Licence (OGL)

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Girnock and Baddoch: Ova to Ova Stock-Recruitment Dataset

The Girnock and Baddoch catchments are long-term monitoring sites where the population dynamics of spring salmon have been assessed since 1966 and 1988 respectively. These long-term monitoring sites consist of a pair of fixed traps designed to catch emigrating juvenile salmon and returning adults. Trap protocols were similar, although not identical, over the monitoring period.

Glover, R. & Malcolm, I. 2018. Girnock and Baddoch: Ova to Ova Stock-Recruitment Dataset. doi: 10.7489/12085-1

Data and Resources

Release Date
Spatial / Geographical Coverage Area
POLYGON ((-3.0617000581697 57.066079405196, -3.4586051758379 57.022539882985, -3.5348991025239 56.881078091725, -3.4280875045806 56.872740106637, -3.0527214054018 56.980989208195))
Temporal Coverage
English (United Kingdom)
UK Open Government Licence (OGL)
Data Dictionary

• Ova deposition from individual females was estimated using the length-fecundity relationship reported by Bacon et al. (2012) for upland early running salmon.
• Female salmon were considered to have contributed ova to in-stream production provided they were not spent on arrival at the traps and did not leave the stream unspent (i.e. they had successfully spawned).
• The dataset does not differentiate between stocked and unstocked ova as previous work suggests no difference in outcomes by smolt life-stage.
• Total ova deposition (stock) was estimated by summing the ova content of individual females in each year that contributed to spawning.
• A single female had no recorded length, so a mean length was estimated from females of the same age returning in the same year.
• The year of spawning for returning females (recruits) was calculated from scale read ages as follows: year spawned=return year-sea age-freshwater age-1.
• Where sea age, freshwater age, or both are unknown, ages were assigned based on the proportions of freshwater / sea age combinations for returning females in each year.
• Total ova recruitment was estimated by summing the ova content of individual females lagged to the year they were spawned (regardless of whether they subsequently contributed to spawning or not).
• No fish were allowed to spawn naturally above the trap in 1978. As such, there are no data available for this year.
• The dataset is constrained to spawning year 2009 to allow for adult returns aged 3.3.
• The dataset contains some repeat spawning females (n = 37) and it is assumed that the length-fecundity relationship is the same as for first spawning fish.

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Marine Scotland
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