| HJORT'S HYPOTHESIS UNDER THE QUANTITATIVE MICROSCOPE |
| BEYER, J.E., National Institute of Aquatic Resources (DTU-Aqua), Technical University of Denmark, Charlottenlund Castle, DK-2929 Charlottenlund, Denmark, jeb@aqua.dtu.dk |
| 100 years ago Hjort developed the famous Critical Period Hypothesis, which has generated a multitude of hypotheses to explain recruitment variability and produced 100s of process studies to understand the dynamics of early life. This reflects the complexity of the whole issue. Does fishery science need new generic, quantitative, mechanistic, probabilistic and analytical modeling platforms for being able at least for some species to predict recruitment in a not so distant future? With this question respectfully in mind, the aim of this paper is to suggest one way forward by using available models and concepts in combining three starting points. First, the point of departure is not the observed recruitment variability but the opposite, i.e. the apparent stability of recruitment. Second, Hjorts and all subsequent hypotheses are considered within a generalised concept of patchiness. Third, modeling the very start of first feeding is demonstrated to produce an amazing degree of stability in the probability of initiating successful first feeding at the completely different patchy food situations the individual larvae will experience at the microscale during that day. Implications of the results are exemplified with a view towards future research needs for improved understanding of recruitment at large spatial and temporal scales. |
| back |
|
