Mangroves of Kenya and the threats facing them

Mangroves of Kenya

According to Wikipedia, mangroves are ‘salt-tolerant trees and shrubs that usually grow in the intertidal zone throughout the tropics and sub-tropics.’ They are most often located along sheltered shores and can penetrate deep into the estuaries of rivers. Mangroves trees have a very plastic form which means that the same species can grow as a short stunted bush in unfavorable conditions or as a full sized tree reaching heights of 40 meters, forming dense forests several kilometers thick under favorable conditions.

Along the Kenyan coast which is approximately 600 kilometers, mangrove forest form a big to small patches relative to availability of suitable conditions required for their proper development.  The total area of mangrove cover is estimated at 54,000 ha spreads over 18 forest formations along the coast.  The most extensive patch is in Lamu and Tana river counties containing more than 70% of the total mangrove forest area to the North of Mombasa (34,000 ha).  Other smaller and isolated patches of mangroves are found in Kilifi – 1725 ha, Mida and Mtwapa creeks, Gazi bay, Funzi-Shirazi, and around Vanga.

In all these patches there are nine mangrove species which follow a typical zonation pattern.  Sonneratia alba grows closest to the low water line, followed mainly by Rhizophora mucranata, and then comes Bruguiera gymnorrhiza, Ceriops tagal, Avicennia marina, Lumnitzera racemosa and Heritiera litoralis respectively. Other mangrove species include Xylocarpus granatum and Xylocarpus mollucensis.

Why then are mangroves important?

Most of us will find it easy to overlook the seemingly nondescript trees that often line the land found between the sea and the coastline. This is partly because these trees don't grow fruits or nuts, nor are they ideal for shade or breeze, but what they do have to offer far surpasses all of the above qualities.  In fact, Kahindi Charo from Dabaso Creek Conservation Group (DCCG) attests to this fact in saying that, ‘If there were no mangroves, we would be dead, since most of us are fishermen and fish lay their eggs and get their food from mangrove marshes.’

Mangrove forests are among the most productive terrestrial eco systems and are natural and are a renewable resource. Mangroves are not a marvel just for their adaptations but also for the significant role they play in our environment.

• Mangrove ecosystem act as Buffer Zone between the land and sea.
• Mangroves protect the coast against erosion due to wind, waves, water currents and protect coral reefs, sea-grass bed and shipping lanes against siltation. They are also known to absorb pollutants.
• Mangroves host a number of threatened or endangered species, different animal species- mammals, reptiles, amphibians and bird- offer nutrients to the marine food web and provide spawning grounds to a variety of fish and shellfish, including several commercial species among them bats, lobsters, manatees, and birds.
• In mangrove areas water level is shallow, warm water temperatures due to various decaying activities, water current is slow (nearly stagnant) hence ideal place for growing of sea algae and for spawning for fish and marine animals. They are breeding, feeding and nursery grounds for many estuarine and marine organisms.
• Mangroves are known to purify the water by absorbing impurities and harmful heavy metals and also help us to breathe a clean air by absorbing pollutants in the air.
• Mangrove forests are also important in terms of aesthetics and tourism. Many people visit these areas for sports fishing, boating, bird watching, snorkeling, and other recreational pursuits.

In addition to the above ecological importance of mangroves they also possess other attributes that are beneficial to humans in general:

·         They are also a source of a vast range of wood and non-wood forest products including timber, fuel wood, charcoal, fodder, honey, pulp, tannin, medicine and thatch etc.

·         Their ecosystem has a very large unexplored potential for natural products useful for medicinal purposes & also for salt production, apiculture, fisheries products fuel and fodder, etc.

·         Mangroves also provide opportunities for education, scientific research and eco tourism.

Threats to mangroves of Kenya

Despite the significant importance that mangroves have on the environment, they are currently experiencing a major threat: clearance. As the demand for coastal settlements and development continues to increase, so does the elimination of this essential habitat. This is manifested in a study released last year by Landsat, Ocean Coast Management and KMFRI showing that from 2000 to 2010 mangrove depletion in Kenya totaled 1,340 hectares (3,310 acres), compared to 4,950 hectares (12,230 acres) lost in the eight years prior to that.

Kenyan mangroves have not been spared either as shown in the following threats facing them:

ü  Reduction in species diversity due to preferential extraction of certain species and of trees of given specification.

ü  Overexploitation of wood resources for building poles, fencing, fuel wood, fishing stakes, charcoal burning among others.

ü  Pollution effects including oil spills, solid waste and sewage disposal.  Oils are harmful to the mangroves since they clog the breathing roots leading to suffocation.

ü  Opening up beaches have led to chocking of mangroves through beach sand accumulation.

ü  Conversion of mangrove forest areas to other uses including salt mining or even settlement.

ü  Over reliance on mangrove products due to lack of suitable alternatives.

ü  Poverty has been outlined as the main contributing factors towards overexploitation of mangrove forests. 

To curb these threats, Kenya Forest Service (KFS) has embarked on the preparation of the first ever national mangrove forest management plan. By developing this management plan, KFS aims at reducing the loss and degradation of the mangrove ecosystem. This will in turn result in an increased availability of mangrove resources and in the maintenance of biodiversity, and ultimately, would contribute to the wellbeing of the coastal communities. This will greatly contribute to poverty alleviation and to the promotion of sustainable coastal development.

Use of mercury in local mining at Lorgorien area in Kenya

Located in western Kenya, Lorgorien is part of the extensive gold-rich areas and has attracted prospecting and mining companies that want a share of these mineral deposits. Besides the licensed companies operating in this area, small scale miners influx the region and are actively involved in artisanal gold mining (AGM), a subset of great environmental health concern. It’s during this process of mining that mercury is used to hold to hold together the gold particles while washing the crushed stones, a process done using bare hands.

The fact that the workers are in direct contact with the mercury element means that they are exposed to the many health risks associated with mercury. You’ll find women and underage children deeply rooted in these activities, perhaps ignorant of the eminent hazards of health risks. In fact, a study conducted by Aduwo, D.O (2012) found out that mercury is widely used in the processing of gold with majority of the miners (64%) indicating low awareness to mercury toxicity.

Despite its positive contribution to social and economic development, small scale gold mining is often characterized by improper handling, unintentional spillage and dumping into rivers and waterways of the mercury used to purify the gold. The health effects of mercury remain poorly studied in Kenya, and especially in Lorgorien area and thus the need for both scaling up awareness campaigns on what mercury does to human health and on-site training of miners on safe and healthy mining practices. Local miners dump waste with high concentration of mercury on open lands which then vaporized while others absorbed into the soil. This is dangerous as it finds its way into water bodies where human beings drink it or inhale the contaminated air. “Mercury is a heavy metal and its heavy consumption can lead to cancer and Deoxyribo Nucleic Acid (DNA) mutilation resulting to birth deformities”, explains Nyakinye, the regional geologist.

This mercury eventually finds itself either on land or in water, the latter being the most probable outcome as rain water washes the mercury elements on land into rivers and streams. Some of the mercury is ‘pumped’ into the air through the process of burning and thus being availed to humans and other organisms for inhalation. On land, the mercury element is transformed into organic mercury by bacteria and this improves the fertility of the soil. Farmers are therefore ‘lured’ into planting crops on this land not knowing the dangers of this. The crops are able to absorb the mercury which then bioaccumulates naturally in the plant tissue and is eventually biomagnified across the food chain. What this means is that, humans, being at the top of the food chain, have a higher percentage of mercury concentration thus being at a greater risk. The process does not end here! In water certain microorganisms can change it into methyl mercury, a highly toxic form that builds up in fish and in other organisms that eat fish. The methyl mercury is again biomagnified across the food chain, with humans getting the largest concentrations. If used for human consumption, the water in rivers and streams poses a risk to human health as it contains high concentrations of mercury depositions from surface runoff.

The dangers and risks associated with mercury on humans is a major concern as rampant cases of disorders and diseases emerge with every passing day. Since mercury is odorless, invisible and accumulates in the meat of the fish, it is not easy to detect and can't be avoided by trimming off the skin or other parts. Once in the human body, mercury acts as a neurotoxin, interfering with the brain and nervous system.

Exposure to mercury can be particularly hazardous for pregnant women and small children. During the first several years of life, a child's brain is still developing and rapidly absorbing nutrients. Even in low doses, mercury may affect a child's development, delaying walking and talking, shortening attention span and causing learning disabilities. Less frequent, high dose prenatal and infant exposures to mercury can cause mental retardation, cerebral palsy, deafness and blindness.

In adults, mercury poisoning can adversely affect fertility and blood pressure regulation and can cause memory loss, tremors, vision loss and numbness of the fingers and toes. A growing body of evidence suggests that exposure to mercury may also lead to heart disease.

The solution to these problems is not in inciting the locals against the practice of mining that has for long been an important socio-economic pillar. No! The government in collaboration with the county leadership should find a better solution to this problem. This can be achieved through sensitization among the locals on the effects of small-scale mining on the environment and health of the miners. There should be better cooperation between the mining companies and the local miners such that the companies employ the local residents in their mining activities. The government, through agencies such as NEMA should see to it that the miners working in the caves are provided with full protective gear to avert any possibility of direct contact with elemental mercury. Helmets should be a priority and the use of modern technology in mining should be encouraged. The locals can also start up community based organizations (CBOs) so as to pool resources and purchase required equipment for the mining processes. This will improve the effectiveness of the mining process and thus the revenue collected.

Proud Boy

I've been thinking about a special being lately, a person 7 of us share as our mother. So special she is that I'd love to think I was reproduced through cellular fission and not sexual reproduction. Not because we have striking physical characteristics. No! But the bond we share cannot be explained nor described by any adjective. It got me wondering what the cutting of the placenta cord really meant. Whatever it is, it definitely ain't separation, or at least not in my case. We're so enjoined to each other that I tend to think she ain't just my mother.
Could there be another invisible role that she plays that makes me so endowed to her. I could have said 'god' but then that would be tantamount to idolatry. Perhaps a guardian angel unseen in her angelic endeavors.
You'll probably think that am just another guy heralding her mama; like a young boy experiencing teenage love. Yeah! you're free to think so. But one fact will always remain; my mama is more than a mother to me.
Sometimes I feel I could just spend all my life with her. But then I curse nature for the processes of natural succession and reproduction which dictates that we must cede our parents. Many are the times I long to treat her like a love I just met, the love of my life; treat her like a young girl and spoil her with flowers and gifts. That's my mama for you. Lovely as always!