Post on 26-May-2015
Aquatic Environment and
Biodiversity
Banu .S and Nayana .PJr . M.F.Sc College of Fisheries Mangalore
Overviews Ecological concepts Mortality Risk selected species
Habitat concepts Ecological nicheCarrying capacity
Mortality Mortality is the condition of being mortal , or
susceptible to death .Rate at which individuals are lost by death
( death rate)Mortality is a measure of the no. of deaths
( in general , or due to a specific cause ) in a populations .
R- selected species These organisms live in setting, where
population level below the maximum no. that environment can support the carrying capacity.
Their nos are going exponentially high at the maximum rate
Organism tend to be small, short lived and opportunistic .
They grow through irregular boom and bust in a population cycle
R- selected species like insect, bacteria and largest species such as frog, rats
They are capable of rapid growth. They need favorable condition for their
growth.These r- selected species mature later in life
and have fewer offspring with longer gestation times.
Habitat in an ecosystem Ecologist use the term habitat to mean the
role that the organism live and term ecological niche to mean that the role of organism plays in the ecosystem
Habitat is the “address” and Niche is the “profession”
Ecological niche Different species interact in different ways. Interaction can have positive, negative and
neutral impact on the species involved. Each species in an ecosystem occupies a
niche Niche can be defined as interaction of all the
ranges of tolerance, under which an organisms can live.
Niche can be easier to quantify and analyze.It can be described as specific ranges of
variables like temperature, latitude and altitude.
For example: African fisheagle occupies very similar ecological niche to the American bald eagle.
The full range of habitat types in which the species can exist and reproduce without any competition from other species is called fundamental niche.
Carrying capacity Carrying capacity of environment varies from
region to region depending on population pressure.
Their dependences on food, water, energy, raw material requirement, waste production.
Carrying capacity of environment is the threshold limit of use of that ecosystem without damaging the systems.
Every ecosystems has its resources that are used for economic development for survival and for the habitat creation.
Regenerating them over the period of time that are temporary and not exceeding threshold damage limit.
Thank you