By: Hafsatu Bangura
Seaweeds which are some brown macroalgae that form a floating bed on the surface of the beaches, in Sierra Leone has got blooming bites on the marine species as well threatening the country’s tourism and the fishing industries especially during the height of the rainy sea. When these putrid beige carpets begin to cover the sands, marine species get entangled and their survivors become less considerate. Even though daily exercise has been underway using dredgers, but the seaweed is being plastered across the beaches in large volumes. In fact, the stench is keeping tourists away to have their usual zoom of the beaches. However, these have caused both economic and social havoc to the country.
Creating of forage and refuge habitat for commercially important fish and diversity of marine life courtesy of seaweeds. Seaweeds also act as a sponge soaking up what’s in the water. These marine plants could potentially be cultivated to reduce heavy metals and other coastal pollutants. In 2017, the Guardian website wrote that the shimmering coastline of Sierra Leone is being destroyed by mysterious brown seaweed which scientists link to a similar invasion affecting beaches thousands of miles away on the other side of the Atlantic. Noting that in some places the strong-smelling algae is piled up to two feet deep, attracting detritus and causing havoc for fishermen.
Jim Franks, a marine scientist who has been studying the phenomenon, believes it is the sargassum seaweed that normally inhabits the Sargasso Sea in the North Atlantic Ocean. “This is not a localized phenomenon”, in Sierra Leone.
“It is not as if there is a plume of pollution coming from a river and then seaweed grows. “This is naturally occurring; it is a transatlantic phenomenon.” Vincent Sweeney, an official with the UN Environment Programme (Unep) in Nairobi said.
Marine biologists are also concerned that it is affecting the marine ecosystem, particularly turtles which use the seaweed for nesting. “Young turtles cannot climb over it to get to sea,” said Sweeney. “It is also affecting fisheries. Propellers get entangled in the seaweed.”
At a conference on the issue in August, the vice chancellor of the University of the West Indies, Sir Hilary Beckles, described the invasion as the single biggest threat to tourism in the region and called for an emergency agency to be established to assist those countries in need. Franks, a scientist with the centre for fisheries research and development at the University of Southern Mississippi, first identified the seaweed in the Lesser Antilles in 2011. It was subsequently reported along the coasts of Sierra Leone, Benin and Ghana and in large mats off the shores of northern Brazil.
The potential to generate damage to the coastal communities in Freetown is one of the limes of seaweed. On that note, seaweed farming is not a well-established industry in Sierra Leone that brings in foreign money otherwise global upscale and it does not even give coastal people, especially women, an opportunity to earn an income for themselves and their families. Food, pharmaceutical, cosmetic, and textile industries, among others, use seaweed extracts such as carrageenan, agar, and alginates as gelling substances, stabilizers and emulsifiers in industrial products like perfumes, shampoos, toothpaste, medicines, ice cream, milk shakes, and yoghurt. Recognizing its potential to uplift the socio-economic status of marginalized coastal populations, international development agencies began promoting seaweed farming in in other countries like Ghana, Gambia, Guinea since the 1980s Seaweed farming is obviously a relatively simple technology and it requires low initial capital investment; in addition, with grow out cycles as short as six weeks and favorable prices, it provides a rapid and high return on investment. However, Sierra Leone has not considered to invest in seaweed but rather being a natural phenomenon that has continuously dwindles the livelihood of coastal communities couple with its stinking smell as an environmental hazard.
Despite its many attributes, seaweed farming is not without its own set of challenges. As a commodity traded in the international market, farm gate prices are subject to volatility. This was particularly evident during the “seaweed price bubble” of 2008, when farm prices reached exorbitant levels and then collapsed in the course of a few months. Although no accurate data are available, world production In contrast, developing countries contributed very little to the total seaweed production in the world. Present estimates show that seaweeds production in developed countries cannot cope with the highly increasing demands for food, pharmaceutical, and industrial purposes. It is estimated that the annual increase in the demand for seaweeds and seaweed products is 8- 10% according to the International Journal of Advances in Science Engineering and Technology in 2017. Hence, the study therefore seeks to assess the socio-economic impact of seaweed production in rural coastal communities in Ghana of which Sierra Leone is not an exception.
Finally, the prevalence of diseases and pests affecting aquaculture production worldwide is a major global concern. This issue is intensified by a reduction in genetic diversity associated with the domestication of wild seaweeds species making crops more susceptible to abiotic stressors, disease and parasites. Unlike terrestrial agriculture, a reduction of genetic diversity of open sea cultivated marine species in favor of a few selected traits cannot be supported by the use of pesticides and fertilizers to support growth. Cultivated stands will likely experience a large reduction in yield where diseases and pests are prevalent, and may also act as a reservoir for diseases which could impact natural populations.
For example, (Kappaphycus) producing countries have seen a dramatic decline in production following rising sea water temperatures which cause bleaching of the thallus making cultivated individuals more susceptible to infection from viruses and bacteria. Protocols that mitigate crop losses are often rudimentary (centered on removal of affected crops) and chemical treatments are known to reduce crop quality.
Knowledge regarding the epidemiology of seaweed pathogens in European species is very poor and in many cases pathogens responsible for diseases are difficult to identify and study using current microbial methods. Further investigation is required to inform appropriate mitigation measures and prevent significant ecological impacts. Mandatory biosecurity planning will ensure actions are taken that mitigate risk where practical and will benefit all stakeholders. Scottish Association for Marine Science study showed in 2019.