Contribution of benthic blue‐green algal recruitment to lake populations and phosphorus translocation

Abstract

SUMMARY 1. A two‐season investigation was undertaken to determine the contribution of benthic recruitment to the population development of several species of blue‐green algae. 2. Gloevtrichia echinulata populations were shown to be heavily subsidized by benthic recruitment, deriving on average 40% of their planktonic colonies from the benthos. 3. Benthic recruitment of Aphanizomenon flos‐aquae, Anabaena flos‐aquae and a second Anabaena species contributed less than 2% to planktonic increases, while Microcystis aeruginosa recruitment was negligible. 4. Phosphorus translocation via migrating G. echinulata accounted for most of the phosphorus (P) in the planktonic colonies, and constituted a significant portion of the internal loading of the lake. 5. Estimated P translocation via Aph. flos‐aquae was relatively minor, although there was evidence of luxury uptake in the benthos.