Cultivation of Phyllophora nervosa (DC) Grev. on rope collectors in the Black Sea

Abstract

The rate of increase in the biomass of the three formae of Phyllophora nervosa - f. breviarticulata, f. latifolia, f. nervosa — was studied in the Jarylgachsky and Sudak Gulfs of the Black Sea from March 1984 to April 1987. In the Jarylgachsky Gulf from late March until the end of October 1984 the biomass increase of P. nervosa f. breviarticulata was more than 200% and the daily average increase was 1.08–2.40%; in the abnormally cold year of 1985 it was only 65–70% and 0.24–0.85% respectively. In the abnormally cold winter of 1984–1985, a biomass increase was not observed, and during 6.5 months (from October until April) die-off of seawards occurred by 11.6±2.9%. From June to September of 1985 the biomass increase of P. nervosa f. latifolia in this region was 0.30–0.68% daily; higher than that of f. breviarticulata. In the Sudak Gulf from April to September 1986 the daily rate of increase in biomass of P. nervosa f. breviarticulata and f. nervosa was 0.61–0.89% (Capsel Bay) and 0.25–0.66% (Sudak-Liman Bay) and in winter of 1986–1987 was 0.23–0.25%. Phyllophora is overgrown to a great extent by epibionts; in winter hydroids are especially abundant and reduce Phyllophora growth. In other seasons mussels, barnacles, etc. are dominant. The upper volume of biomass production in Phyllophora usually exceeds the average index by 2–3 times or more. Hence direct selection of seaweeds for high productivity may essentially improve the harvest of species under cultivation. The biomass production of the three formae of Phyllophora on rope collectors at 0.5–10 m depth is several times higher than that of similar formae growing under natural conditions.