Rapidly changing life history during invasion

• Published in: Oikos
• Main Authors: Bøhn, Thomas, Terje Sandlund, Odd, Amundsen, Per‐Arne, Primicerio, Raul
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2004
• Subjects: Pasvik
• Online Access: http://dx.doi.org/10.1111/j.0030-1299.2004.13022.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0030-1299.2004.13022.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0030-1299.2004.13022.x

The fish species vendace ( Coregonus albula ) invaded the sub‐arctic Pasvik watercourse during the second half of the 1980s, and became the dominant pelagic species in the upstream part of the watercourse within a few years. Life history traits of the pioneer population of vendace in Pasvik were recorded from 1991–2000. A rapid increase in population density in the upstream part of the watercourse was accompanied by decreased growth rates, decreased fecundity and a reduced size at first maturation. The downstream part of the watercourse showed a similar, but delayed, change in life history traits compared to the upstream part. The study documents great life history variability of a non‐native fish species entering a new environment. We discuss two co‐acting explanations for the observed patterns: (i) a density dependent response mediated by food depletion; and (ii) a pioneer strategy that allocates resources to favour reproduction at early developmental stages with a high number of offspring, trading off growth and size of offspring.