One of the most conspicuous features over much of the world’s oceans is the seasonal variation in environmental conditions (e.g. light, temperature, nutrients, food). In this new article from a large team of Ocean Life members (past and present), we seek to uncover patterns in life history strategies that marine organisms adopt to deal with these annual variations.
We use a simple mechanistic model to determine the optimal strategy of different sized organisms subject to varying degrees of seasonal fluctuations in their resource availability. The model generates several general hypotheses: (i) small organisms (bacteria to small copepods) should cope with winters by making resting stages or by dormancy; (ii) medium-sized organisms (large copepods) should build reserves and perform seasonal vertical migration to reduce predation; (iii) large organisms (forage fish to whales) should primarily employ latitudinal migrations to follow seasonal peaks in production. In parallel to these model results, we compile, collate and analyze a large set of observational data on seasonal variations in dormancy, energy storage and migration across many different taxa and habitats. In general, the observations support model predictions. This article provides a theoretical framework to explain and predict how seasonality challenges marine organisms and shapes their varied life history strategies.
Visser AW, Brun P, Chakraborty S, Dencker TS, van Denderen PD, van Gemert R, van Someren Gréve H, Irene Heilmann, Holm MW, Jónasdóttir SH, Kenitz KM, Kiørboe T, Lindegren M, Mariani P, Nielsen LT, Pancic M, Payne M, Pécuchet L, Azaña Schnedler-Meyer N, Uffe Thygesen UH, Törnroos A, Andersen KH. (2020) Seasonal strategies in the world’s oceans. Progress in Oceanography doi: 10.1016/j.pocean.2020.102466.