Environmental Engineering Reference
In-Depth Information
2
Biodiversity of the Blue Zone
…
Come along, come with us
Take a dive into the deep blue mass
Amazing are the creatures
With their unique adaptive features
…
.
The Authors
Several groups of bacteria, including the
purple bacteria, the green bacteria and cyano-
bacteria, are able to photosynthesize. Purple
bacteria and green bacteria are usually strict
anaerobes (organisms that live in environments
that lack oxygen) and are found in areas of the
marine environment such as mud
2.1
Producer Community
The producer community consists of organisms
that are capable of synthesizing their own food
through photo- or chemosynthesis. Most of the
primary production in the marine and estuarine
ecosystems is carried out by phytoplankton.
Apart from phytoplankton that manufacture their
organic food through photosynthesis (in the
photic zone), there are several strains of bacteria
that can prepare their food through the process of
chemosynthesis. Chemosynthetic bacteria (also
known as chemoautotrophs) can produce their
own food from inorganic compounds without
sunlight, a process called chemosynthesis. They
use energy derived from chemical reactions that
involve substances such as ammonia (NH
3
),
sulphides (S
2
−
), nitrates (NO
3
−
) and sulphates
(SO
4
2
−
). This energy is then used to manufacture
organic food molecules. Chemosynthetic bacteria
are found in areas where there is little or no
sunlight and where the inorganic substances that
they require are in abundance. The bacteria that
live around deep-sea hydrothermal vents are
examples of chemosynthetic bacteria. These
bacteria use sulphide ions that spew from the
vents. They oxidize the sulphide to sulphur and
sulphates and use the energy released by this
process to produce food. Like other autotrophs,
they form the base of a productive food chain
that consists of a diverse assembly of organisms,
including worms, clams, and crabs, that consti-
tute the hydrothermal vent community.
ats that pro-
vide light, anaerobic conditions and sulphur-
containing compounds. These organisms cannot
use water in their photosynthetic process, and
therefore, they do not produce any oxygen
(Fig.
2.1
). Instead, they often use hydrogen sul-
phide (H
2
S) and produce elemental sulphur or
sulphate (Fig.
2.2
). Purple bacteria and green
bacteria are an important source of food for some
zooplankton and
fl
lter feeders.
The seaweeds, seagrasses, salt marsh grasses
and mangroves are also among the producer list
of
the marine
and
estuarine
ecosystems
(Figs.
2.3
,
2.4
and
2.5
)
2.1.1 Phytoplankton
Phytoplankton are free-
oral com-
ponents that are widely distributed in the marine
and estuarine environments. Like land plants,
these tiny producers require sunlight, nutrients or
fertilizers, carbon dioxide gas, and water for
growth. The cells of these organisms contain the
pigment chlorophyll that traps the solar energy for
use in photosynthesis. The photosynthetic process
uses the solar radiation to convert carbon dioxide
and water into sugars or high-energy organic
fl
oating tiny
fl
