This document outlines 5 classifications of estuarine ecosystems according to Howard T. Odum: 1. Physically stressed systems that experience high energy waves, currents, temperature/salinity fluctuations or sedimentation. These systems have low diversity but include rocky shores, tidal channels, and man-made canals. 2. Arctic ecosystems with ice stress, including glacial fjords and winter ice zones, which experience light, temperature, and ice limitations. 3. Temperate coastal ecosystems with seasonal programming, like drowned river valleys and embayments, that experience seasonal pulses in productivity and reproduction. 4. Tropical coastal ecosystems of high diversity that experience low physical stresses, allowing greater diversity,

1. 5 CLASSIFICATIONS OF ESTUARINE
ECOSYSTEM
ACCORDING TO HOWARD T. ODUM
by: Noriezhen John Basilio

2. 1. PHYSICALLY STRESSED SYSTEMS OF WIDE
LATITUDINAL RANGE
 Are subjected to high-energy breaking waves, strong tidal currents,
severe temperature or salinity shocks, low nighttime oxygen, or
high rates of sedimentation.
 Rocky sea fronts, intertidal rocks, sand beaches, high velocity tidal
channels, sedimentary deltas, and hyper saline lagoons would be
included in this category.
 Man-made canals connecting waters of greatly different physical
nature are also good examples.
 Such systems are generally characterized by low species diversity at
any one place since few species can meet the physiological demands
required to adapt to the severe oscillatory physical stresses.

3. Sand beach at Zamboanga

4. Canal in Santa Cecilia (Uwak Dagat)

5. Lagoon at Palawan

6. Seafronts in Apo Island

7. 2. NATURAL ARCTIC ECOSYSTEMS WITH ICE
STRESS
 Are exemplified by glacial fjords, winter ice stressed intertidal
zones, and under-ice communities on arctic coasts.
 Arctic and Antarctica coasts and embayment constitute a special
class of physically stresses ecosystems in which light (available
mostly during the very short summer season) and low temperature
are strongly limiting, as is the physical”crunch” of the ice itself. It
may be noted that the impact of certain kinds of man-made
pollution can be quite different on systems already adapted to
physical stress as compared with systems that are not so adapted.

8. Winter ice estuary in Arctic Ocean Hudson River Estuary

9. 3. NATURAL TEMPERATURE COASTAL
ECOSYSTEMS WITH SEASONAL PROGRAMMING
 Include many of the best studied estuaries and shores of temperate
North America, Europe, and Japan.
 Most of the drowned river valley, bar-built,and embayment types
of estuaries that lie in the temperate latitudes would be included in
this category.
 Regular seasonal pulses in primary productivity and in the
reproductive behavioral activities, or both. The more subdued tides,
waves, and currents in the semi-enclosed basins provide energy
subsidies rather than stresses, while the communities in the deeper
sounds and offshore waters often benefit from large imports of
organic matter and nutrients from fertile shallow zones.

10. Marella River valley in Mt. Pinatubo

11. River Valley in Sagada Kiltepan

12. 4.NATURAL TROPICAL COASTAL ECOSYSTEMS OF
HIGH DIVERSITY
 Characteristically, temperature, salinity, and other physical factor
stresses are low so that much energy of special adaptation can go
into diversity and organizational behavior rather than into
“antithermal” maintenance.
 As in other tropical ecosystems, these contain many species and a
great deal of chemical diversity within the species. Bright colors
are often associated with complex life histories, intricate behavior
patterns and a general high degree of interspecific symbiosis.

13. Dauin Beach
in South of Duamaguete
around Apo island

14. 5. EMERGING NEW SYSTEMS ASSOCIATED WITH
MAN
 While it is urgent that pollution in estuaries be reduced and that
secondary and tertiary treatments of wastes become nearly
universal, it is likely that estuaries in urban and industrial areas will
always have to bear some burden of pollution.
 It is important, therefore, that we recognize as a special category
those estuaries which develop adaptations for man-made wastes.
 These need to be very carefully studied in order to determine limits
of tolerance and to delimit those organisms and biological
mechanisms that can be encouraged to assist man in waste
treatment.
 Estuaries have varying capacities to handle “degradable” material,
depending on the size of the system, flow patterns, type of estuary,
and the climatic zone.

15. Past Ilog Pasig

16. Present Ilog Pasig

17. Future Ilog Pasig?