Seasonal Variations in the Biomass, Quantity and Quality of Agar, from the Reproductive and Vegetative Stages of Gracilaria (verrucosa type)

Abstract

Optimum growth of Gracilaria (verrucosa type) in British Columbia occurred between 5 and 6 meters below mean tide level and correlated with solar radiation throughout the season. Vegetative populations declined with a consequent increase in reproductive forms to a maximum in July. Tetrasporophytes dominated the reproductive population and in July attained the greatest seasonal biomass of all forms of the alga. Maximum population and biomass were attained by carposoporophytes in July and by male gametophytes one month earlier. An inverse relationship between biomass and yield of agar was apparent only for the vegetative and tetrasporic forms of the alga. Variations in yields, gel strengths, and gelation characteristics of the agars isolated, were demonstrated to be dependent on time of season and life stages of the alga. Ranked in the following decreasing order of merit as a source of agar were the cystocarpic, tetrasporic, vegetative and male gametophytic forms of Gracilaria (verrucosa type).

An Assessment of Seaweeds Diversity and Distribution at the Beach of Nathia Gali, Karachi, Pakistan

“…Chock and Mathieson [9] quantified the standing crop and biomass variation of estuarine seaweed at Cedar point, Dover New Hampshire Maine, UK. Similar studies have also been conducted in other areas of the world such as, North Carolina [10], India [11], Dodger channel of Canada [12] and Central Puget Sound Washington, U.S.A. [13]. Josselyn and Mathieson [14] have reported the biomass variation of selected estuarine macrophytes at North temperate estuary, Falmouth Massachusetts, USA.…”

Phycocolloid screening of British Columbia red algae

“…Previous studies demonstrated various verrucosa types (see Yamamoto 1978 for terminology) of Gracilaria contained higher contents of 6-O-methylgalactose and lower contents of sulfate ester than the corresponding chorda type (Whyte & Englar 1980a) . Season and reproductive condition of the verrucosa type markedly affected the quantity, quality and nature of the agar in the algal tissue (Whyte & Englar 1980b ;Whyte et al 1981) .…”

Seaweeds agarophytes and associated epiphytic bacteria along Alexandria coastline, Egypt, with emphasis on the evaluation and extraction of agar and agarose

“…It was reported that agar yield depends on gender and species of agarophytes, which have their specific genetic characteristics (Armisén & Galatas 1987). On the other hand, the variation in agar yield depends on the environmental conditions, the geographical distribution, the season of harvesting the alga (Freile-Pelegrin et al 1996) and different life phases of algae (Whyte et al 1981).…”