Plankton based energy transfer rates in four Cuban coastal lagoons

Abstract

Listen

Translate article

Biomass transfer rates between successive trophic levels in plankton based food chains frequently produce inverted pyramids but when productivity data are used instead, such a methodologically caused thermodynamic impossibility is eliminated. A study of plankton based energy transfer rates in 4 Cuban coastal lagoons, including each ecosystem major component biomass, age, productivity, and energy contents values, is presented to illustrate how inverted pyramids are produced, and eliminated.Duplication times and mean ages, variable between lagoons, were 25–77 h for suspended detritus; 48–74 h for phytoplankton, and 60–90 days for zooplankters, 78% of which were copepods. For intertidal sessile filter feeders attached to the red mangrove aerial roots average ages were 0.8–2.5 months for barnacles; 1.1–2.3 months for scorched mussel; 2.9–3.5 months for flat tree-oyster; 4.5–4.8 months for mangrove oyster, and 6.1 months average for soft bodied epibionts such as tunicates and sponges.The average biomass transfer rate for the 4 lagoons from phytoplankton to zooplankton was 141%, and from detritus plus phytoplankton to sessile filter feeders was 423% both reduced to 5% and 8%, respectively, when productivity values were used, demonstrating that biomass transfer rates are intrinsically incorrect, and misleading, and that only productivity values, preferably in energy units, should be considered in trophic ecology studies.