The Logic of Skipped Spawning in Fish

That sexually mature fish skip reproduction has been documented in many species especially in response to poor condition. We present results from an energy-allocation life- history model that shed light on the underlying logic of skipped spawning, based on the Northeast Arctic stock of Atlantic cod...

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Bibliographic Details
Main Authors: Joergensen, C., Ernande, B., Fiksen, O., Dieckmann, U.
Format: Book
Language:English
Published: IR-05-066 2005
Subjects:
Online Access:https://pure.iiasa.ac.at/id/eprint/7776/
https://pure.iiasa.ac.at/id/eprint/7776/1/IR-05-066.pdf
Description
Summary:That sexually mature fish skip reproduction has been documented in many species especially in response to poor condition. We present results from an energy-allocation life- history model that shed light on the underlying logic of skipped spawning, based on the Northeast Arctic stock of Atlantic cod (Gadus morhua). The model predicts that skipped spawning is a regular phenomenon, with up to 30% of the sexually mature biomass skipping spawning. Spawning should be skipped if the expected future gain in reproductive output, discounted by survival, more than balances the expected reproductive success the current year. Skipped spawning was most common 1) among potential second-time spawners and 2) early in life, 3) when fishing mortality at the spawning grounds was high, 4) when fishing mortality at the feeding grounds was low, 5) when natural mortality was low, and 6) when the energetic and mortality costs associated with migration and spawning were high. Cod skipped spawning more often both when food availability was increased (opportunities for better growth) and decreased (too little energy for gonad development), and this pattern interacted with mortality rate. We conclude that skipped spawning may be more widespread than appreciated, and highlight potential consequences for the understanding of stock-recruitment relationships.