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Environmental Sensitivity Atlas for Coastal Area of Kenya, March 2006

Contents and overview, Environmental Sensitivity Atlas for Coastal Area of Kenya, March 2006
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Environmental Sensitivity Atlas for Coastal Area of Kenya
The Kenya coast is rich in historical and archaeological sites, a testament to
its long and full history depicting centuries of Swahili culture. Various rem-
nants of mosques and other buildings reflect different ensembles of Islamic
architecture using lime, coral stone and timber.
In general the historical and cultural sites are placed in some distance from
the coastline and would not be affected by an oil spill. The Atlas includes
some of the most important historical and cultural sites located close to the
The fishery sector contributes about 4.7 % of the national Gross Domestic
Demand (GDP) and it is an important foreign exchange earner. In the
Government's Policy Document on "Economic Recovery Strategy for
Wealth and Employment Creation (2003 - 2007)", fishing is recognised as
one of the productive sectors and the need to promote capture fisheries and
aquaculture in order to improve food security, nutritional status and inco-
mes is emphasised.
The marine fisheries sector in Kenya land about 10,000 tonnes of fish
which accounts for about 10 % of the total fish landed in Kenya. Marine
fisheries in Kenya are based on a small number of species, the most impor-
tant of which are demersal and caught by artesian fishermen operating bet-
ween the shoreline and the reef. Freshwater fish landings in Kenya have
always been higher than those from coastal waters.
At the coast, ecological studies undertaken by KMFRI have documented
and highlighted the important and crucial roles played by some critical and
sensitive habitats e.g. mangrove forests, seagrass beds and coral reefs in
sustaining the coastal fishery. These habitats serve as important nursery and
breeding sites for an array of fish species of economic importance. From
such findings, measures have been put in place to conserve and rehabilitate
the critical habitats.
Along the Kenya coast, rich inshore marine fishing grounds are found in
and around Lamu Archipelago, Ungwana Bay, North Kenya Bank, and
Malindi Bank. The areas where the two major Kenyan rivers (river Tana
and Sabaki) empty into the sea are also very productive. In these rich ins-
hore fishing grounds within the Malindi-Ungwana Bay area prawn trawling
has been carried out since the 1970's. A comprehensive scientific research
undertaken by KMFRI on the Malindi- Ungwana Bay prawn fishery revea-
led that the prawn fishery is not properly regulated and managed. The fis-
hery is also associated with very high conflicts due to the destruction of tra-
Coastal Resources and Their Use
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ditional fishermen fishing nets; competition for common resources; distrust
between the semi industrial prawn industry and the local fishermen, and
the rampant resources wastage because of the high amount of fish by-catch
associated with prawn trawling.
According tOFish landing records, Mombasa District accounted for 46.6 %
of the mean fish catch between 1988 and 1992, followed by Tana River,
Lamu, Kwale and Kilifi in that order. However, fishermen can land their
catch anywhere, regardless of where the fish are caught, and they are proba-
bly attracted by the bigger market and more affluent potential buyers of
Mombasa and Malindi.
There are only about 5,000 coastal fishermen compared to well over 27,000
fishermen engaged in inland fisheries. Of the 5,000 fishermen, around
4,000 are considered artesian fishermen and the rest are classified as marine
industrial fishermen.
3.2.1 Small Scale and Subsistence Fishing
Marine fisheries in Kenya are mainly, artisanal and undertaken mostly from
small, nonmotorized boats such as outriggers, dhows, cataracts and planked
pirogues. Only about 10% of fishing craft are motorized. This constraint
limits most of the fishing effort to inside the reef and rarely is fishing
undertaken beyond territorial waters (20 km). The exceptions are the
Figure 3-1 Mangrove creeks are highly productive areas providing fish and other produts for subsistence
and for the local market.
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mediumsized trawlers which fish for prawns mainly in the Ungwana Bay
The most commonly used fishing gear is the artesian gill net and the seine,
particularly in the Lamu archipelago and around Malindi. Other gear inclu-
des traps and handlines in Ungwana Bay and the Malindi/Mambrui area,
bottom lines and traps from Mombasa south to the Tanzanian border, and
lobster pots in Lamu, Malindi and Kwale districts.
3.2.2 Marine Farming
Marine farming activity in Kenya is in its infancy. Besides some traditional
brackishwater ponds and artesian shrimp and oyster cultivation, coastal
aquaculture has been restricted to capital intensive shrimp culture on an
experimental scale. Unfortunately, this development at Ngomeni has been
undertaken at the expense of mangrove productivity, with 60ha of mangro-
ve forest being cleared. However, in spite of this inauspicious beginning,
coastal aquaculture in Kenya has considerable potential as a source of eco-
nomic return and, if properly planned and managed, it need not have an
impact on the productive and valuable mangrove ecosystems. There are
three types of marine farming activity which could be utilized on the
Kenyan coastal environment pond culture in cleared mangroves or on land
behind the mangroves, suspension culture (cage and raft) in sheltered water-
ways that are of sufficient depth, and rack culture in the shallow intertidal
Environmental Sensitivity Atlas for Coastal Area of Kenya
Figur 3-2 Fishtraps is often build along the edge of the mangroves.
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Coastal geological formations are predominantly sedimentary in origin,
with marine, shallow water and lacustrine tOFluviodeltaic characteristics.
They form a strip of 50 km wide along the Southern part of Kenya coast.
Mineral deposits that occur in economically meaningful quantities in the
Kenyan coast include salt, coral rocks, limestone, rutile, ilmenite, building
sand, pyrochlore, gypsum, barites, gypsum, silica sands, iron ore and clay.
Other lesser minerals are apatite, galena, and manganese oxide.
Recent discovery of titanium ores (rutile and ilmenite) in the sedimentary
deposits along almost the entire length of the Kenya coast has initiated
national debate on environmental impacts of mining, particularly since the
recent enactment of the Environmental Act. Tiomin Mining Company has
already entered into agreement with the Kenyan Government to undertake
mining at Kwale near Diani beach, which is expected to start in early 2006
and is estimated to continue for 11 years. This and other mining activities
will result in an increasing amount of sea traffic particularly in Mombasa
harbour from where ore will be shipped and mining supplies will arrive.
3.3.1 Salt Works
Salt can be considered as the most widespread mineral in Eastern Africa and
its recovery from the sea is a comparatively simple process given certain en-
vironmental conditions. The location of solar salt works is controlled by the
rainfall regime and the occurrence of suitable impermeable soils. These con-
ditions occur from Ngomeni northwards to the Lamu area. Extensive salt
works have been established at the Gongoni-Karawa. The total area dedica-
ted to salt production is over 5,000 hectares that yield an average of over
170,000 tonnes of salt annually (UNEP 1998).
The method of salt production utilised by the five established companies is
very much the same throughout the area. Seawater is filled into the ponds
which are run in series. Slight variations may occur in the method of filling
the ponds which utilize tidal energy or pumps. In the first pond, undesira-
ble salts of low solubility are precipitated and the water then flow into a
series of ponds where the brine is further concentrated and crystallizes.
Crystallized salt is gathered from the ponds, washed and taken to market.
In addition, in Lamu District, the Mkunumbi area of Mpeketoni Division
has salt deposits which have sOFar not been exploited. It has been observed
that the salt deposits exist in economically viable quantities and therefore a
salt manufacturing industry could potentially be developed in the area
(Republic of Kenya 1997).
3.3.2 Limestone and cement
Limestone deposits are extensive along the coastal zone from the Tanzania
border to the Malindi area. The resource is very abundant, forming a 4-8
km wide band, some 70m thick, running parallel to the coast. North of
Malindi, older limestone units occur further inland but only a few exposu-
res of isolated limestone occur on the coast between Malindi and the Lamu
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area. North of Lamu and the islands, limestone units occur once more
parallel to the coastal zone, however, these are not well mapped.
Exploitation of the limestone is widespread and is governed by local varia-
tion in the limestone texture, composition and demand for the material. In
the Bamburi area north of Mombasa, limestone is used for cement manu-
facturing and in Tiwi for lime manufacturing. However, all along the coast
limestone is being exploited for building stone.
3.3.3 Oil and Gas Exploration
A thick sequence of sedimentary rocks, estimated to reach a maximum of
15,000m in some areas, accumulated along the continental margin in a geo-
synclinal setting that preceded the opening of the Indian Ocean. The ope-
ning of the Indian Ocean was associated with the development of a major
north-south basin, probably with several comparatively smaller basins.
These smaller depositional areas include the Mombasa, Malindi, Lamu and
Anza basins. There is a close relationship between hydrocarbon potential
and the occurrence of such ancient sedimentary basins which have the
potential for good source rocks. In addition to the presence of good mature
Environmental Sensitivity Atlas for Coastal Area of Kenya
Figure 3-3 Solar salt works are sustainable industries regarding power consumption but do often displace
large mangrove areas.
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source rocks, the occurrence of hydrocarbon reserves depends also on the
timely evolution of good reservoir rocks, and traps. Sandstones and carbo-
nates are good reservoir rocks while shale horizons generate good traps
(UNEP 1998).
From the limited data available in Kenya, analysis of hydrocarbon potential
is difficult. However, if there was to be any potential, the most promising
areas along the Kenya coast would be the Lamu Basin, the Malindi High
and the South Anza Graben. The sediment sequences in these areas vary
from Recent to Triassic. However, good source rocks are anticipated at a
depth of 3,000 m to 4,000 m in the Tertiary and Cretaceous sequences.
The Tertiary deposits have been penetrated by many wells, but the
Cretaceous has only been penetrated in a few places. The Cretaceous occurs
at a depth of 3,450 m in Lamu and therefore good mature source rocks are
anticipated (UNEP 1998)
Good source rocks and reservoir rocks for hydrocarbon deposits have been
observed along the Kenyan coast, with conditions becoming more favoura-
ble offshore. Promotion efforts generated new interests in the offshore
Lamu Basin and an Australian firm is at an advanced stage with efforts to
sink initial exploratory wells about 70km off the Lamu coast (NOCK
The potential
Off-shore reservoir
Figure 3-4 Limestone is usually quarried far from the coast, but here it is mined only few meters from the
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The first hotels directed at tourism were built in Malindi during the early
part of the 20
century. In the last thirty years, rapid expansion in the
recreation and tourism industry has occurred. The main attractions for this
new industry include the warm coastal climate slightly mellowed by a cool
sea breeze, the beautiful coastal scenery and foremost, the beautiful and
clean sandy beaches. All the facilities that support the new expansion in the
tourism industry are therefore located next or adjacent to beach environ-
Between 1998 and 2004, the share contribution of coastal tourism has been
ranging between 52 % and 68 % and mainly depending on Marine and
Coastal resources, and Game Parks and Reserves. At the macro level, the
sector generates an average of 18 % of the foreign exchange earning to the
economy and contribute 9.2% to the Gross Domestic Product (GDP). The
sector also provides 270,000 jobs both directly and indirectly.
In some areas, such as the coastal strip around Mombasa, the rapid develop-
Environmental Sensitivity Atlas for Coastal Area of Kenya
figure 3-5 The beach attracts all kinds of activities..This photo is taken during low tide and the waves bra-
king at the outer edge of the reef is seen at the upper right. All kind of boats used to bring tourists for
diving and snorkelling is seen at the beach.
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ment of tourism has put pressure on the sustainable use of coastal resources
such as the coral reef. Demand for seafood, shells and coral souvenirs has
risen sharply as local supplies have become depleted. The pressure on the
coastal ecosystem extends further and further from the resorts, spreading
the impact.
3.5.1 Marine Protected Areas (MPAs)
Parks and Reserves
In order keep up with the increasing pressure on the marine resources, and
to conserve and manage the most important ecosystems along the cost, the
government of Kenya has established a system of protected areas managed
by the Kenya Wildlife Service (KWS). There are two level of protection
with the strictly protected marine parks as the highest level where no extrac-
tion of resources are allowed, and marine reserves where limited exploitation
like traditional fishing is allowed but closely managed.
Kenya has five MPA's, each comprising one or more marine park(s) or re-
Kisite Marine Parks and Mpunguti Marine Reserve are located on the
south coast off Shimoni and south of Wasini Island in Kwale District.
The complex covers a marine area with four small islands surrounded
by coral-reef and is not connected to the mainland.
Kiunga Marine Reserve incorporates about 60 km of the northern
most coast of Kenya south of the Somalian border. The coast consists
of parallel lines of old and living reefs forming a chain of about 50
calcareous islands. Inbetween the islands and the coast, there are
sheltered and calm water habitats with mangroves, mudflats, and
sandy beaches and dunes. The reserve is also designated as a UNE-
SCO Biosphere Reserve.
Malindi and Watamu Marine National Reserves which encloses
Malindi and Watamu Marine National Parks and includes Mida
Creek. Habitats comprise intertidal cliffs, sand-, and mudflats,
seagrass beds, coral reefs, reef flats and islets; sandy beaches, and the
Mida Creek comprises tidal mud flats with fringing mangrove
swamps. The protected areas are also designated as a UNESCO
Biosphere Reserve.
Mombasa Marine Park and Reserve including reefs and reef flats north
of Mombasa are the most highly utilised among the Kenyan MPAs,
because of the proximity to the city centre. The coastline is heavily
developed with tourist facilities and also heavily fished.
Diani and Chale Marine National Park and Reserve are the most
recent established MPA's. They include reefs, fishing grounds, and
mangrove forest, and are heavily used by tourists.
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Environmental Sensitivity Atlas for Coastal Area of Kenya
Another marine reserve, Ras Tenewi, north of Ungwana Bay is planned but
not yet gazetted.
None of Kenya's five designated Ramsar areas (wetlands of international
importance) are coastal wetlands.
Important Bird Areas, IBA's, are bird areas which qualify as Ramsar sites.
Kenya has 5 coastal IBA's including the MPA's of Kisite, Malindi/Watamu/
Mida, and Kiunga and with the addition of the deltas of Sabaki and Tana
3 - KenSea, Environ. Sensitivity Atlas for Coastal Area of Kenya