Effect of Water Depth on Seasonal Variation in the Chemical Composition of Akamoku, <i>Sargassum horneri</i> (Turner) C. Agardh

Abstract

The brown alga, Akamoku, also known as Sargassum horneri , was harvested at depths of 1 - 2 and 5 m in the oceanic areas of the Chikuzen Sea off the coast of Fukuoka, Japan, and its chemical composition (moisture, protein, lipid, ash, carbohydrate and total dietary fiber content) was investigated. The aim of this study was to elucidate the relationship between the chemical components and the growth of S. horneri as recyclable resource for a sustainable future. S. horneri at an ocean depth of 5 m grew rapidly. The biomass was abundant from January until April. After maturation and gamete release at the middle of April, plant senescence began occurring, and only short plants remained at the sea bottom. On the other hand, S. horneri at an ocean depth of 1 - 2 m grew slowly and could be harvested until early June. The protein, lipid and total dietary fiber content of S. horneri at an ocean depth of 5 m showed apparent gender-based differences.