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Laboratory experiments were used to determine effects of long-and short-term food limitation on birth, growth, and death rates in Centropages typicus (Copepoda, Calanoida), a species previously reported to be sensitive to patchy food resources. Life-history parameters were measured in cohorts from hatching to senescence in a range of constant food treatments (0.2-7 pg Chl a liter-') and in two pulsed treatments that cycled between 0.5 and 2.0 pg Chl a liter-I at periods of -0.5 and 1.0 d. A flow-through culture system minimized biochemical and grazing-induced changes in food supply and allowed automated measurement of food levels (fluorescence). Particulate carbon, nitrogen, lipid, carbohydrate, and protein were measured also. Results show that even the "foodsensitive" copepod, C. typicus, can integrate daily fluctuations in food supply at amplitudes comparable to patchiness levels observed in the field. This finding has important implications for field and laboratory studies that relate zooplankton growth and fertility to ambient food supply. Additional new findings include exponential growth in body length, sustained high fertility with age, ingestion of large algal and animal prey, and low contribution of camivory to the diet. Comparisons with field data suggest that C. typicus is restricted to shelf regions due to food limitation, but that on the shelf it is a major contributor to total copepod production in the fall.

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The Atlantic sea scallop supports one of the most lucrative fisheries on the Northeast U.S. shelf. Understanding the interannual variability of sea scallop size structure and associated drivers is critically important for projecting the response of population dynamics to climate change and designing coherent fishery management strategies. In this study, we constructed time series of sea scallop size structures in three rotationally closed areas in the Mid-Atlantic Bight (MAB) and decomposed their total variances using the variance partitioning method. The results suggested that the interannual variances in sea scallop size structures were associated more with thermal stress in regions shallower than 60 m but more with fishing mortality in regions deeper than 60 m. The percentages of small (large) size groups increased (decreased) with elevated thermal stress and fishing pressure. We adopted a scope for growth model to build a mechanistic link between temperature and sea scallop size. Model results suggested a gradual decrease in maximum shell height and habitat contraction under warming. This study quantified the relative contributions of thermal stress and fishing mortality to the variance of scallop size structure and discussed the need for adaptive management plans to mitigate potential socioeconomic impacts caused by size structure changes.