Trophodynamics in a Shallow Lagoon off Northwestern Europe (Culbin Sands Moray Firth): Spatial and Temporal Variability of Epibenthic Communities Their Diets and Consumption Efficiency

Vanda Mariyam Mendonca, David George Raffaelli, Peter R. Boyle, and Chas Emes (2009) Trophodynamics in a shallow lagoon off northwestern Europe (Culbin Sands, Moray Firth): Spatial and temporal variability of epibenthic communities, their diets, and consumption efficiency, Zoological Studies 48(2): 196-214. Epibenthic communities and their diets, at Culbin Sands (a cold-temperate coastal lagoon in the Moray Firth, northeastern Scotland), were sampled every 2-4 wks for 3 yrs (1994-1996). These communities were more abundant and diverse in warmer months, especially in less-exposed areas of the lagoon. The most common species were the brown shrimp Crangon crangon, the shore crab Carcinus maenas, and teleost fish (sandeel Ammodytes tobianus, sticklebacks Gasterosteus aculeatus and Spinachia spinachia, seascorpion Myoxocephalus scorpius, gobies Pomatoschistus microps and Pomatoschistus minutus, flounder Platichthys flesus, and plaice Pleuronectes platessa). Diets of these epibenthic predators included benthic infauna (especially polychaetes Eteone longa, Pygospio elegans, and Fabricia sabella; oligochaetes Tubificoides benedini; isopods Eurydice pulchra; and bivalves Cerastoderma edule and Macoma balthica), small epibenthic organisms (amphipods especially Bathyporeia pilosa and Gammarus sp., and juvenile crabs Carcinus maenas and shrimp Crangon crangon), and zooplankton (harpacticoids, ostracods mostly Cypris sp., calanoid copepods, mysids Praunus flexuosus, and fish eggs and larvae). Insect larvae (Chironomidae) were also common in the stomach contents of the epibenthic predators. In fact, prey items with higher indices of relative importance for the most abundant predators (brown shrimp, common gobies, and plaice) were insect larvae for shrimp, amphipods Bathyporeia pilosa for shrimp and gobies, harpacticoids for plaice and gobies, and bivalves (larvae and siphons of adult individuals) mostly for plaice. Brown shrimp, common goby, and plaice had daily consumption levels of 1%, 3%, and 2.5% of their own body wet weights, respectively. Energy flows of 150, 68, and 65 kJ m(-2) yr(-1) were estimated from benthic invertebrates to brown shrimp, common gobies, and plaice, equivalent to consumption efficiencies of 30%, 15%, and 15%, respectively, of the standing stock of benthic invertebrates and small epibenthic species such as amphipods. http://zoolstud.sinica.edu.tw/Journals/48.2/196.pdf