Potential of Edible Seaweed of the Kenyan Coast as a Micronutrient Source

Abstract

Edible seaweed, a rich source of micronutrients, remains underutilized despite its availability at the Kenyan coast, while micronutrient deficiencies remain a major health concern in Kenya. The study assessed micronutrient content of randomly sampled seaweed and consumption patterns, interviewing 175 seaweed farmers and analysing 58 samples from Mombasa, Kilifi, and Kwale counties. Micronutrients (vitamin A, D, B9, B12, iron, zinc, iodine) and heavy metals (mercury, lead, arsenic, cadmium) were measured. Predominantly female seaweed farmers, aged 30-40, with low income and education levels, focused on commercial farming over personal consumption due to limited nutritional awareness. A diverse array of edible seaweed species was identified; 11 Phaeophyceae (Sargassum, Turninaria, Dictyota, Padina, Eucheuma), 9 Chlorophyta (Ulva, Caulerpa, Eucheuma) and 8 Rhodophyta (Gracilaria, Hypnea, Soliera, Eucheuma). Significant regional and species variations were observed; Kilifi samples had higher vitamin A (p= 0.031), D (p=0.047), B9 (p=0.006), Kwale exhibited elevated iron levels (p= 0.047). Green phyla showed higher vitamin B12, D, zinc, iodine levels, while red phyla were rich in vitamin B9, A, and iron. Eucheuma cotonii had the highest vitamin B12 (696.6 μg/100 g) and vitamin A (298.6 μg/100 g) levels, Ulva intestinalis recorded highest iron (637.85 mg/kg) and Caulerpa taxifolia had highest zinc (277.74 mg/kg). Though some species contained traces of lead and cadmium within permissible limits, mercury was found in only four species, with no arsenic detected. Increasing awareness of seaweed's nutritional value is crucial to combatting micronutrient deficiencies, alongside further research into processing, value addition, market integration, and heavy metal mitigation strategies. Keywords; Edible seaweed, Micronutrients, Micronutrient deficiencies, Kenyan coast