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.

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