DEVELOPMENT OF A METHOD FOR MEASURING THE PRODUCTIVITY OF THE KELP ECKLONIA-MAXIMA (OSBECK) PAPENF

Ecklonia maxima plants were classified into three growth stages: Type A (small, with a primary blade but no secondaries), Type B (larger, with secondaries on an elongated primary blade) and Type C (very large stipe, shortened primary blade, and large number of secondaries (the sporophylls), (some bearing tertiaries)). Growth of primary and secondary blades was studied by punching holes 10 cm apart, beginning 10 cm from the base. Primary blades appeared to have a meristem at the base of the blade only; secondary blades had a zone of growth extending at least half-way along the length of the blade. New secondaries were continually budded off at the base of the primary blade, and eroding secondaries were cast off at the tip of the primary. Growth production in Type C plants was concentrated chiefly in a few secondary blades near the middle of the primary. It was concluded that during July and August 1975 primaries, secondaries and stipes were each growing at about 1% per day. Productivity of the Ecklonia bed was of the order of 5, 6 gcm−2day−1© 1979 Taylor & Francis Ltd.