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Detailed Ecological Assessment Report 2008 – Keti Bunder
d) Document the anticipated changes to resident and migratory fish
population in the study area.
e) Document and describe fish species of “special concern” regarding the
economic and ecological perspectives found in the study area
f) Suggest suitable methods of monitoring fish in the core and buffer zones
of the study area.
g) Conduct a local survey of the fishermen to assess the trends of fish
production for the last ten years.
h) Develop simple indicators for assessing the population trends of the fish
that can be applied by the local staff in future.
i) Study the suitability or otherwise of the conventional fish ladders used in
barrages and recommend the suitable measures for safe passage of all
and critical fish fauna including Blind Indus dolphin.
j) Describe and assess potential anthropogenic impacts on fish species
found in the study area
k) Submit a comprehensive baseline reports and monitoring plan to the team
Leader.
1.2.6 Phytoplankton
1.2.6.1 Rationale
Qualitative and quantitative determinations of algae is essential for determining
the aquatic productivity, as algae is the chief source of food for aquatic animals
including the important group of Cryptogamic flora. Some species are excellent
whilst others are good producers of food in the food cycle of aquatic ecosystems.
Algae is widely distributed and is an important component of various ecosystems
like marine, rivers, ponds, streams, dams, lakes etc. Algal flora can also be used
as a good indicator of pollution (Patrick & Reimer, 1966).
Algae are among the most important and prime segment of the aquatic
environment. The quantity and quality of algal flora is affected by many ecological
factors, which influence the diversity of algae directly or indirectly. The main
factors determining algal diversity are temperature, availability of nutrients, light,
CO2 and oxygen. In lake in the subtropical region, water temperature plays an
important role for the production of algae up to a certain limit. Carbon dioxide is
critically important and only those water bodies abundantly supplied by this gas
can support sufficient growth of algae. The excess amount of CO2, however,
causes water-blooms which is a growth of algae at or near the surface of a body
of water; followed by a series of disturbed biological conditions. Oxygen is one of
the primary limiting and determining factors in phytoplankton ecology. Algae
produces abundant oxygen during the daytime, which is, consumed both by the
fish and by the algae itself. The amount of oxygen produced by algae determines
the quantity and kinds of aquatic life which a water body may support at different
levels. Light and nutrients also play a direct role for qualitative and quantitative
growth of algae. Extraordinary high concentration of nutrients is, however,
associated with eutrophication resulting in algal blooms.
It is believed that the first living cell that appeared on planet earth emerged from
the ocean. In all its form, life has developed from the growth of mono-cellular
algae. About 90% of the species of marine autotrophs are algae and about 50%
of the global photosynthesis is algal derived thus every second molecule of
oxygen we inhale come from algae and algae reuse every second molecule of
carbon dioxide we exhale (Melkinian 1995). The importance of algae and their
consumption for human is well known since 300 BC in China and Japan. These
two countries are the major algae/sea weed cultivators, producers and
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