The Sargassum saga: Food for thought

Kweku Amoako Atta deGraft-Johnson Opinion Jun - 12 - 2014 , 07:35

Ghana’s coastal environs have been inundated by some “strange” brownish algae in recent times. It has set people wondering what the cause might be. In fact, some have attributed superstitious and supernatural reasons to the phenomena.

Although the Environmental Protection Agency (EPA) had earlier come out with some explanation on the Sargassum invasion of our coastal waters as carried in the national dailies, I am of the view that the Ghanaian public needed some more information on the issue.

Let me state from the onset that there is nothing mystical about the brown alga Sargassum species. It can be found in both temperate and tropical waters of the world and over 300 species are recognised. They are normally found attached (Benthic) on substrates inshore or on offshore reefs and rarely free-floating (Planktonic).

However, two species of Sargassum, namely S. fluitans and S. natans, are holopelagic (i.e. they remain free-floating through the entire life cycle), reproduce vegetatively and never attach to the sea floor during their life cycle. Thus, they do not need a holdfast (an organ at the base of the seaweed that attaches the weed to a surface).

Free-floating Sargassum

The Sargasso Sea, which covers 1.4 million square miles, located in the middle of the Atlantic Ocean, hosts large amounts of free-floating Sargassum. In West Africa, three Sargassum species have been identified. These are S. cymosum occurring mainly in Sierra Leone and Gabon with S. filipendula occurring in Ghana and Gabon while the third S. vulgare, the most common, is found from Senegal to Gabon.

In Ghana, two species, the S. vulgare, are usually found growing attached to inshore rocks and the S. filipendula exists.

Therefore, Sargassum presently invading Ghana’s coastal waters is not any of the three species occurring naturally on the West African Coast.

Why do we say so? It is because the samples of the invading seaweed collected and physically examined indicate that the plants have no holdfasts.

This suggests that the Sargassum is most likely a free-floating one (pelagic species). Again, there are no known places in West African Coastal Waters where large amounts of Sargassum are known to grow either attached and/or are free floating.

The seaweed invasions, as the EPA had indicated in its press release, have also been recorded on the Gulf Coast of North America and Caribbean since 2010/2011 and in the West African sub-region in Senegal, Gambia, Sierra Leone, Togo, among others.

The Sargassum species invading our coastal waters is yet to be fully identified using genetic bar-coding techniques (like DNA Analysis in the UK) because such a facility does not exist at present in Ghana. The question is, can we not also work at getting such a facility in Ghana in the near future to enable us to identify other terrestrial and aquatic plant species when the need arises?

Sargasso sea

I believe some scientists in Ghana, including my dear self, can stick our necks out to point to the “Sargasso Sea” as the most probable source of the Sargassum. This is because the two known free-floating species of Sargassum (S. fluitans and S. natans) occur naturally in the Caribbean and Gulf Coast albeit in small quantities but in huge masses in the 1.4 million square miles of the “Sargasso Sea”.

Some communities were reportedly pointing fingers at the oil rigs or platforms for the menace. This is totally false and unfortunate. The oil platforms (at Cape Three Points , 60km and Saltpond, 14km out at sea, respectively) themselves have had to deal with the seaweed invasion as it is hampering their operations.

Insinuations have been cast at the Nation’s research institutions (the CSIR in the main) and the universities (to a lesser extent) that they have failed to live up to expectation regarding the Sargassum menace.

This can only emanate from either the uninitiated or ignorant and it is most unfortunate to say the least. The reason is that the following questions need answers before anyone points accusing fingers at any of the institutions mentioned above.

The questions are: Do the research institutions and universities have the requisite expertise to determine the specific Sargassum species in question and for that matter any other marine macro-algae species that may bloom in our waters?

Can they determine with certainty the source(s) of such invasions? If they are in a position to undertake any such studies, are they even properly resourced (equipment, materials and funds)? If they are ill-resourced, are there resources readily available elsewhere in the country to access?

Lack of phycologists

I shall attempt to answer the questions I have posed. A quick check on the marine macro-algae expertise in our research institutions and universities will reveal that not more than one phycologist is at post. Phycology is the study of the cells, structure, function, life cycles, ecology and other properties of algae (seaweeds).

It is also called algology. Why? The answer is and I must be very blunt here, while the graduates being produced by disciplines in the Business and Management institutions have seen near exponential growth at least over the last decade or two, the so-called less glamorous and yet very important fields of study such as Botany and Zoology over the last three to four decades have experienced declining growth.

Students do not opt for fields of study such as phycology (algology) which may sooner or later become extinct in our universities. Who then do we expect to undertake the research into these problems and who is to blame for our present predicament?

Another question is, does anybody/institution (research or non-research) have the capacity to stop the influx? The answer is a big No. This is because these ocean currents bringing the algae to our shores cannot be controlled by man and thus by inference the seaweeds influx they carry.

What then can the research institutions/universities possibly do?

They can do the following: Undertake preliminary identification of the species to genus level and or assist in further in-depth identification process by linking up with institutions outside the country; propose ways to manage the menace; analyse the chemical constituents of the plants to enable their possible use to compose/mulch or for other purposes; and advise on proper disposal of the harvested algal mass.

As regards the uses of the plant, we do not have to re-invent the wheel because several well-documented researches on its uses exist in the worldwide research domain.

Furthermore, if we are going to utilise the biomass, we should be careful not to build an industry based on a biomass whose yearly/permanent availability cannot be guaranteed.

I dare say that Ghana is virtually sitting on an “Environmental time bomb” if immediate steps are not taken to train our graduates to acquire the requisite knowledge in the so-called non-glamorous fields of science, technology and environmental studies. In due course, we shall be forced to rely on expatriate expertise anytime an event such as this occurs. This will of course be at great cost not only in financial terms but also national pride and prestige.

Finally, I propose that Ghana, as a matter of urgency, must make sure that the often touted National Invasive Species Co-ordinating Body is formed immediately and get it well resourced to handle such and other invasions (plant, animals and pathogens). This body will also handle the issues of available Ghanaian expertise and equipment, funds, early detection and warning, rapid response, rick analysis and cost recovery mechanisms.

“A stitch in time saves nine”.

The writer is a Retired Public Servant

Email: kaadigi@yahoo.co.uk