By Tonye Princewill
THE prevailing theory among scientists, reports the Mangrove Action Project, is that the plant originated in the Indonesia-Malaysia (Indo-Malaysia) area. Between 66 and 23 million years ago, it apparently migrated, via ocean currents, westward to India and east to South and Central America
From South America, the theory holds, currents carried the mangrove to the Caribbean Islands, from where it colonized the eastern USA and eventually found its way to Africa. This, some investigators believe, explains why Mangrove species in West Africa, the USA and the Caribbean are similar.
“The mangrove swamps of Nigeria and of West Africa generally,” wrote R.W.J. Keay, a British Forestry official in Ibadan, in 1948, “from the River Senegal to Angola, are similar in composition to those of the Atlantic shores of America and its neighbouring islands”.
According to S.A. Abere and B.A. Ekeke, of the Rivers State University of Science and Technology, the mangrove swamps in Nigeria cover a total of 10,000 square km and extend from Badagry in the West to Calabar in the East. They form a 15 km to 45 km “vegetation band” along our coast, consisting of soil that is inundated regularly by salt water.
“The mangrove region is widest,” they write, “on the sides of the Niger Delta 35 km – 45km and narrows towards the centre to a width of 15km except for the channel of the Brass River, which has extensive mangroves far upstream”.
Nigeria’s coastal wetlands are rich in biodiversity. But investigators generally agree that the mangrove population consists mainly of six species which fall into three families. The most important family is Rhizophora—the red mangrove—which makes up about 90 percent of the population.
Rhizophora has contributed immensely to the identity of the Niger Delta, both by its beauty and its distinctive traits. Too often in our struggle to right the wrongs of this society called Nigeria we forget the little things. In the pool of self-pity that many a citizen has waded, the positives are sacrificed for the negatives. With the reader’s forbearance, therefore, I would like to digress a bit and discuss this plant in some detail.
Rhizophora is not only more abundant but it is also the biggest of all mangrove plants in Nigeria. Keay notes that one species, R. racemosa “can reach 150 feet in height and eight feet in girth”. In addition to its size and reddish colour, you can also easily identify Rhizophora by its famous stilted root system.
“The most important feature of the mangrove forest,” Keay avers, “is the stilt roots of Rhizophora”. But these roots, he notes do not penetrate deeply into the ground. Instead, they divide into a gauze-like mat, just beneath the surface, and extend outward from the tree.
Thus the red mango “stands upon a system of arches entirely supported by a thick felt raft of its own making. An ordinary root system,” Keau continues, “would obviously be unable to support a large tree on such a swampy ground”.
Finally, Rhizophora stands out as well, because of its unique reproductive system, which I mentioned earlier. Its seeds actually germinate while still hanging on the tree. The parent tree actually drops the seedling into the mud as a complete plant, with a strong 12-inch root already formed.
A knowledge of Rhizophora’s fascinating biology—and that of other flora and fauna in the Niger Delta–should be taught at every level of our educational system. It should also but be part of the training of boatmen, tour guides pilots, drivers and other individuals who have continuous contact with the public. Any typical lover of nature would marvel at what we have and take for granted.
I am currently on a tour of other civilisations and what I have come to learn is we are simply the best. My prayer is one day leaders we lead us to this realisation. I thank God for the Mangroves.