TY - JOUR

T1 - Variation in diatom biochemical composition during a simulated bloom and its effect on copepod production

A1 - Berenike,A.

A1 - Diekmann,S.

A1 - Peck,M.A.

A1 - Holste,L.

A1 - St. John,Michael

A1 - Campbell,R.W.

AU - Berenike,A.

AU - Diekmann,S.

AU - Peck,M.A.

AU - Holste,L.

AU - St. John,Michael

AU - Campbell,R.W.

PB - Oxford University Press

PY - 2011

Y1 - 2011

N2 - The biochemical quality of phytoplankton depends in part upon nutrient availability, which has implications for the population dynamics of grazers. Here, we examined how nutrient availability influenced the growth dynamics and biochemical content of the marine diatom Thalassiosira weissflogii and how these biochemical changes impacted the vital rates of a calanoid copepod (Acartia tonsa). Changes in biochemistry (protein, carbohydrate and fatty acids) were compared in diatom cultures that simulated bloom conditions (B-algae) and those maintained in near exponential growth (E-algae) over the course of a 16-day experiment. Egg production rates (EPRs, eggs female−1 day−1) and the developmental success of copepodite stages of A. tonsa fed these different diets were quantified. Copepod EPR was significantly lower (reduced by half) when B-algae entered the senescent phase due to silicate limitation. In a crossover (diet switch) experiment, EPR increased when copepods fed B-algae were switched to E-algae and vice versa. Copepodites of A. tonsa developed normally and reached the adult (C6) stage when fed E-algae, but ceased development (approximately at stage C2) when reared on senescent phase B-algae. Given the importance of copepods as prey for higher trophic levels, our results highlight how nutritional changes that naturally occur during a phytoplankton bloom may influence the productivity of copepods and higher trophic levels.

AB - The biochemical quality of phytoplankton depends in part upon nutrient availability, which has implications for the population dynamics of grazers. Here, we examined how nutrient availability influenced the growth dynamics and biochemical content of the marine diatom Thalassiosira weissflogii and how these biochemical changes impacted the vital rates of a calanoid copepod (Acartia tonsa). Changes in biochemistry (protein, carbohydrate and fatty acids) were compared in diatom cultures that simulated bloom conditions (B-algae) and those maintained in near exponential growth (E-algae) over the course of a 16-day experiment. Egg production rates (EPRs, eggs female−1 day−1) and the developmental success of copepodite stages of A. tonsa fed these different diets were quantified. Copepod EPR was significantly lower (reduced by half) when B-algae entered the senescent phase due to silicate limitation. In a crossover (diet switch) experiment, EPR increased when copepods fed B-algae were switched to E-algae and vice versa. Copepodites of A. tonsa developed normally and reached the adult (C6) stage when fed E-algae, but ceased development (approximately at stage C2) when reared on senescent phase B-algae. Given the importance of copepods as prey for higher trophic levels, our results highlight how nutritional changes that naturally occur during a phytoplankton bloom may influence the productivity of copepods and higher trophic levels.

U2 - 10.1093/plankt/fbp073

DO - 10.1093/plankt/fbp073

JO - Journal of Plankton Research

JF - Journal of Plankton Research

SN - 0142-7873

IS - 11

VL - 31

SP - 1391

EP - 1405

ER -