Preliminary investigation into the chemical composition of the invasive brown seaweed Sargassum along the West Coast of Ghana

Abstract

The arrival of the invasive brown seaweed Sargassum in the Western Region of Ghana was first reported in 2009. This impacted negatively on biodiversity, tourism and the livelihoods of the coastal communities. The objectives of the study among others were to identify and determine the nutritional and toxicological contents of the seaweed. Twenty four samples collected from 6 zones along the Western Region were analysed. Nutritional and toxicological analyses were carried out using an Atomic Absorption Spectrophotometer (AAS) 900T. Results of the study indicated that the Sargassum samples analyzed contained low concentrations of nitrogen. However, nitrogen utilized by plants, namely, nitrate and ammonia were very high, together with phosphates. This makes the Sargassum a good source organic fertilizer. However, the high concentrations of toxic heavy metals in the Sargassum defeat this assertion. Heavy metals have implications in both the growth and metabolic activities of plants. Most heavy metals, especially arsenic and lead are carcinogenic and are capable of causing skin, lung, liver and bladder cancers and miscarriages. Indiscriminate domestic and industrial wastes disposal, oil and gas activities, mining and high shipping traffic may have contributed to the heavy metal concentrations in the seaweeds.

Sargassum Inundations in Turks and Caicos: Methane Potential and Proximate, Ultimate, Lipid, Amino Acid, Metal and Metalloid Analyses

“…Oyesiku and Egunyomi [70] found 280 mg kg −1 of potassium in pelagic Sargassum off the coast of Nigeria. Addico and deGraft-Johnson [77] found lower potassium levels for pelagic Sargassum, collected offshore and onshore, from various sites in Ghana of 0.72 to 2.28 mg g −1 on a wet weight basis (~2-15 mg g −1 dw); however, these samples were washed in distilled water which can leach-out minerals [60]. Considerably higher levels have been found in other species of Sargassum from India, 35,000-121,410 mg kg −1 dw [78].…”

Element concentrations in pelagicSargassumalong the Mexican Caribbean coast in 2018-2019

“…Therefore, it is mandatory to evaluate elemental concentrations to ensure that acceptable levels are maintained in terms of health regulations (e.g., Fourest & Volesky, 1997). Previous studies on metal contents in sargasso, were either based on limited number of samples collected mostly from a single locality (e.g., Nigeria Oyesiku & Egunyomi, 2014;Dominican Republic, Fernández et al, 2017) or in a single season (e.g., Addico & De Graft-Johnson, 2016). Hence, it is unclear how much the metal contents can vary in the algal tissues across sites and seasons and between species.…”

Lead, chromium, nickel, copper and zinc levels in Sargassum species reached the coasts of Dominican Republic during 2019: A preliminary evaluation for the use of algal biomass as fertilizer and animal feeding

“…Furthermore, carboxyl, sulfate, hydroxyl, amino groups, and polysaccharides play an important role in the cell wall as acceptor sites for metals (Sinaei, Loghmani, & Bolouki, 2018). However, as shown in Table 5, the levels of these elements found in both Sargassum species and all the studied beaches 2019 are below the acceptability limits (Kabata-Pendias, 2001;Addico, & De-Graft-Johnson, 2016).…”