Temperature & Parental Influences on the Early Life History of Sockeye Salmon
In the context of climate change, it is becoming increasingly important to predict how temperature changes may affect fish reproduction and development. Will populations be able to adapt? Addressing this theme, my thesis consisted of 1) a literature review that synthesized the importance of parental influences in assessing temperature effects in fish early development, and 2) laboratory experiments that assessed how individual spawners influence progeny responses to developmental temperature stress in sockeye salmon.
The question: Within a population, how much does individual variation (genotype and phenotype of male and female spawners) influence the way developing salmon respond to temperature stress (warmer water during egg development)?
Key findings: I found that exposure to high temperatures during egg development can have persistent effects in later life stages: reduced fry size, survivorship and swimming endurance. I also found that different offspring ‘families’ had substantially different survival success at different temperatures (a significant genotype-by-temperature interaction) and that parental identity (ie. female or male spawner) had a significant influence on egg and alevin survival, alevin size, hatching duration, and how well fry could sprint when they emerged! These interactions demonstrate there are genetic differences in how phenotypes respond to thermal change, and they are likely what allows successful early development each year as environmental conditions vary. This observed ‘plasticity’ in phenotypic response to temperature will play an essential role in determining whether populations can persist or evolve with continued temperature change.
Collaborative Salmon Research
Within the Pacific Salmon Ecology Lab (UBC), many of our projects require a team effort. As a result, during my masters program I was part of many different types of research and assisted with a number of field experiments:
– adult thermal holding studies examining how maturing adult sockeye respond physiologically to temperature stress during their final maturation stages (Researcher: Ken Jeffries)
– a capture stress experiment examining how sockeye respond to both ‘exhaustive exercise’ (capture simulation) and increasing river temperatures (Researcher: Marika Gale)
– a juvenile tagging validation study examining how juvenile sockeye cope with different tag burdens (does it affect their survival, swimming ability and smoltification?) (Researcher: Alison Collins)
I also worked a short contract with L.G.L. Environmental Research Associates, assisting with a catch-and-release radio-tagging project on returning Fraser River sockeye. I spent 1 month aboard a commercial trolling vessel in Johnstone Straight, where I was in charge of collecting and processing physiological samples, data recording and radio-tagging live individual sockeye.
Burt, J.M., S.G. Hinch, and D.A. Patterson (2012) Parental identity influences progeny responses to incubation thermal stress in sockeye salmon (Oncorhynchus nerka). Journal of Fish Biology 80: 444-462.
Burt, J.M., S.G. Hinch, and D.A. Patterson (2012) Developmental temperature stress and parental identity shape offspring burst swimming performance in sockeye salmon (Oncorhynchus nerka) Ecology of Freshwater Fish 21: 176-188.
Jeffries K.M., S.G. Hinch, M.R. Donaldson, M.K. Gale, J.M. Burt, L.A. Thompson, A.P. Farrell, D.A. Patterson, and K.M. Miller (2011) Temporal changes in blood variables during final maturation and senescence in male sockeye salmon Oncorhynchus nerka: reduced osmoregulatory ability can predict mortality. Journal of Fish Biology 79: 449-465
Burt, J.M., S.G. Hinch, and D.A. Patterson (2011) The importance of parentage in assessing temperature effects on fish early life history: a review of the experimental literature. Reviews in Fish Biology and Fisheries 21: 377-406