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Periphyton as Inorganic Pollution Indicators in
Themara River, Kenya
*Mbao O. Evance, NzulaKitaka, Steve O. Oduor and
Julius Kipkemboi
Department of Biological Sciences, Egerton University,
P.O Box 536-20115, Egerton, Kenya.
*E-mail for correspondence:emmbaombao@gmail.com
Abstract
Mara River is located in the Mara River Basin, with
approximately 60% located in Kenya and 40% in
Tanzania, and drains into Lake Victoria. The River is a
tourist attraction site because of its diverse wildlife;
however, it suffers impacts of agricultural pollutants in
its upper course due to anthropogenic activities. The
potential use of attached algae (periphyton), as
indicators of organic pollution, was investigated in one
of its tributaries, namely the Nyangores tributary.
Periphyton were sampled by scrapping 12×75cm 2
wooden substrates after two weeks colonization. This
was done twice a month, for four months, between
February and May 2012. Sampling was carried out at
eight specific stations, according to the levels the
pollutants’ influence. Major concern were nutrient
inputs from agricultural activities upstream, due to their
potential influence on the growth of the periphyton
biomass and effect on community composition.
Identification of periphyton genera and assemblage
descriptors were carried out. Physical and chemical
variables of the water were also measured. Results
showed that nutrient levels in the water had a strong
correlation with periphyton biomass. Periphyton
community composed of mainly diatoms (67%).
Periphyton species diversity was lower upstream
(H=1.773) compared to downstream (H=2.141).
Temporal nutrients concentrations varied significantly
along Nyangores tributary with increased discharge
downstream that was influenced greatly by land use.
This was easily noted during the months of April and
May when discharge was at peak. It is recommended
that the catchment and riparian areas of this river be
well managed through re-forestation programmes to
stabilize the catchment areas and lower excess nutrient
influx into the river caused by increased surface runoffs.
Keywords: Periphyton, inorganic pollution, tributary,
anthropogenic activities, catchment
Biometric parameters and growth of Cyperus papyrus
in seasonally and permanently flooded zones of the
Mara Wetland, Tanzania
Sadiki Lotha Laisser
National Sustainable Wetlands Management- CEPA
Officer, Wetland Unit, Wildlife Division, Ministry of
Natural Resources and Tourism P.O.BOX 9372, Dar es
Salaam, Tanzania
Email for correspondence: laissersadiki@yahoo.com
Abstract
Cyperus papyrus is an emergent and nutrient off take
plant. It is one of the macrophytes in the wetland and
sensitive to ecological zonation. This study is aimed at
determining the capacity of using C. papyrus as buffer to
Mara wetland, Lake Victoria. Data was collected on the
growth patterns, biomass, and nitrogen retention of C.
papyrus. Bi-weekly monitoring was undertaken along
transects in both seasonally and permanently flooded
habitats of the wetland. Linear regression was used to
determine relationships between weight, length and
diameter of individual plants. The seasonally flooded
zone revealed lower average live shoot counts per plant.
Culm density showed slight differences between
habitats and mature stands dominated the wetland
zones. Above and below ground biomass and nitrogen
were greater in permanently flooded zones whilst
similar low levels of aging plants and detritus were
recorded in both habitats. Below ground biomass and
nitrogen recorded high in permanently flooded wetland
zones with nitrogen leisure uptake. Inflow to the
wetland recorded high nitrogen than outflow to the lake
depicting buffering of the Lake from eutrophication. The
study could not establish significant difference in soils
nitrogen retention in different zones. Established was a
strong relationship between ranges of biometric
parameters with nitrogen concentration. A strong
relationship between total dry weight and diameter at
sheathing scale and with nitrogen was established which
could be used to estimate biomass and nitrogen
retention in both habitats in a non destructive method.
The study reveals a need for conservation of the Mara
wetland's at the catchment level and replica studies
before generalization of these findings.
Keywords: Biometric, parameters, flooded, wetland and
Cyperus papyrus
TAAG First African Student’s Conference, Nairobi. 2-4 July, 2013 47