TIDAL POWER DEVELOPMENT AND ECOLOGICAL CONSIDERATIONS
R. Ashok Kumar July 1984/Revised 12 July 2012
Copyright ©2012 Ramaswami Ashok Kumar
ABSTRACT
The
article looks at typical sites where the tides are apparently
favourable for exploitation for tidal power plants to generate
electricity. The ecological context is examined and the present method
of
production and use of energy by preserving energy in natural cycles
where man is harvesting the tidal and other resources by maintaining a
balance between production and continuity is highlighted. It is
shown that this diverse and rich natural ecosystem including man is a
permanent culture in itself sustaining a balanced electricity producing
and using system in which goods and services are used by one another
without losses. The disturbance of such a community by introduction of a
monoculture for the generation only and use elsewhere
of a single economic product - electricity - by tidal power plants with
the tremendous losses such a mechanical energy extraction and use
represents, is wrought with unknown consequences ecological and
otherwise for large size plants. Smaller size plants could be
economically unviable. Further, since the age of a tidal power plant is
an estimated 75 years, it is important to consider the consequences of
compressing 125000 year climatic change into 120 years that are expected
by the build up of greenhouse gases(GHGs) observed to be
accumulating at an unprecedented rate in the atmosphere and the oceans.
Also the direct heating effect of dams on the earth connive with the
GHGs to accelerate climate change including sea level rise, cyclone
intensity increase,landslides,hurricanes, tornadoes,rainfall surges and
increased rainfall,sudden floods and earthquakes, forest fires,
infrastructure fires and damages to infrastructure at a frequency
synchronising with the seasons of rainfall and dry weather. These are
resulting in the designs of modern civilization consistently proving
inadequate to withstand the ravages of climate change so induced by the
contraptions of business as usual artefacts.
It is concluded that for the Kandla and other tidal power plants,
considering the above setting for the next hundred years, a total and
thorough ecological study of the existing site and of consequences after
construction, if at all, is absolutely essential,
concurrent with the other ongoing studies.
1. INTRODUCTION
Dramatic
climatic changes are expected in the coming years with several glaring
lacunae identified in the designs of modern civilization(mc) in meeting
its compartmentalised needs and greeds. The major causes appear to be
the use of fossil fuels engendered by thoughtless 'progress' without
conservation of nature, without energy and financial audit of the plans
for 'growth' of a limitless waste of the earth's constituents,
deforestation for furthering the cause of empires, concentration of
water behind dams without analysis of the cumulative causes of such
growth, blind adoption of nuclear power programmes to supply electricity
requirements seemingly thought to be
met by
nukes and greed. Large consequences of such
progress has left no community unaffected and the world is moving from
crises to crises with the consequences insoluble: changes for the worse
in traditional timeless cultures, separation of workplace from the home
on a large scale,populations disconnected with the consequences of their
ways of life and ways of earning their chappatis, dal and rice. They
became blind to the consequences of their actions. They completely
failed to see the ecological limits to their actions because they became
far removed from nature in their artificial confines: populations saw
the effects of pollution, however, in shrinking the family and losing
bread winners; populations exploded and prosperous populations shrank.
Only when modernism sees the futility of its attitude of ignorance
and ignoring natural limits and abdicates its self proclaimed supremacy
of creation and creator can there be a changeover from modern self
destruction to a normal way of life.
1.1 MARINE CONSERVATION
Seen
against this backdrop any effort at marine conservation and hence the
totality of conservation per se has to take into account this enormously
different setting for design for it to be safe. Taking particularly
tidal changes and their effects on the coastal ecosystems and the
possibility of tidal power plants with a useful life of 75 years being
envisaged, study of the altered ecosystem and its further adverse
changes deserves a top priority together with close monitoring and
implementation of well considered measures.
2.0 HARNESSING OF TIDAL EFFECTS BY NATURE
Nature
has evolved delicate but stable life systems with a rich variety in
areas with big tides without exception. Thus the Bay of Fundy has some
20 species which are being harvested by man year after year(Daborn
1977). The web of life in the Bay of Fundy includes many other species,
like birds for whom the bay is an important feeding place before their
long journey of migration. This fantastic coastal ecosystem is being
maintained by the ebb and flow of tides around the present mean sea
level, the fresh water flow from the rivers draining into the Bay from
the land, the solar radiation and of course the (changing) climate. Each
of these species has its metabolic activity run by electricity and
chemiosmosis(respiration and photosynthesis). At such sites when man
(whose metabolism is also partly run by electricity) came to explore the
possibility
of
harnessing tidal power to produce artificial electricity only,
he confronted a living system on which he himself was thriving on a vast
diversity of species. For example, the richness of variety of life at
the Bay of Fundy, is illustrated by the following list of flora and
fauna found there:
2.1
List of flora and fauna found at the Bay of Fundy
Cod,
Haddock, Redfish, Hake, Pollock, Wolffish, Flounders, Herring,
Mackerel, Tuna, Eels, Salmon, Alewives, Shad, Smelt, Lobsters,Shrimp,
Scallops, Clams, Winkles, Worms, Crabs and Seaweeds, marine algae,
oyster drill, mud snail, slipper limpet, rough whelk, isopods,
amphipods, saltmarshes, Dulse, Irish Moss, Knotted Wrack, green sea
urchin, Blue mussel, Salt marsh cord grass, rushes, slough grass,
bivalve mollusks and others.
These form in the sea water part of the ecosystem, major production pathways as follows:
| Table
1: |
Major
production pathways in the sea water part of the ecosystem of the Bay of Fundy |
|
|
|
|
|
|
|
|
|
|
|
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
| 1 |
Phytoplankton |
|
x |
|
|
x |
|
|
|
|
|
| 2 |
Zooplankton |
|
|
x |
|
|
|
|
|
|
|
| 3 |
Herring |
|
|
|
|
|
|
|
|
|
|
| 4 |
Transported detritus |
|
|
|
|
x |
|
|
|
|
|
| 5 |
Heterotrophic
bacteria |
|
|
|
|
|
x |
|
x |
|
|
| 6 |
Suspension
feeders,e.g. scallops |
|
|
|
|
|
|
|
|
|
|
| 7 |
Macrophytic algae |
|
|
|
|
x |
|
|
|
|
|
| 8 |
Sediment ingestion |
|
|
|
|
|
|
|
|
x |
|
| 9 |
Groundfish |
|
|
|
|
|
|
|
|
|
|
| 10 |
|
|
|
|
|
|
|
|
|
|
|
Thriving on this ecosystem is a huge variety of avifauna in the Bay of Fundy:
2.2
Avifauna thriving on the ecosystem of the Bay of Fundy
Black
Duck and sea ducks(including Common Goldeneye,Buffle Head, Oldsquaw,
Common eider and Scoters), Red breasted Merganser, Scaups, Atlantic
Brant, Pelagic species like Blacklegged Kittiwake, Common Murre,
Dovekie, Razorbill, Puffin, Purple Sandpiper, Arctic Tern, leach's Storm
Petrel, Black Guillemot, Herring Gull, Great Blacknecked Gull, Common
Tern, Double Crested Cormorant, Phalaropes(Red Phalaropes included),
Bonaparte's Gull, Cannets, Shearwaters(Greater Sooty and Manx), The
Canada Goose, Blue-winged Teal, American Greenwinged Teal, Sanderlings
and Red-Knot.
2.3
The Numbers
These
birds number in the hundreds and thousands and sometimes millions as
they use these mudflats during
their migration. How the seas food resources are produced, how the
birds and others use these, and how these resources are affected should
be understood before man made constructions like Tidal Power Plants and
other ocean developments disturb these distribution patterns. Nobody
knows the consequences in brief, namely the effect on the bird
populations and on the tidal food resources, a tidal power plant will
exert. To illustrate the complexity, while studying the Bay of Fundy
ecosystem, it could not be explained how there were high populations of
benthic invertebrates in the sediments of the Minas Basin, given low
values of organic carbon and nitrogen in the sediments(Daborn 1977).
2.4
Some Observations on Tidal Communities and Their Continuity.The particular ecosystem has been studied in some detail
reveals some
interesting facts which appear to be a common characteristic of ecosystems
maintaining a rich diversity of life.First to note is that the number of
species of birds using the tidal mudflats is of the same order as the
major species inhabiting the tidal mudflats enumerated above. That is
the number of species identified in para 2.1 and 2.2 above is
approximately 40. A deeper study of this aspect may prove useful in
tracing the flow of energy through this ecosystem or in a similar tidal
location like that at Kandla.Similarly at Sunderbans.
2.4.1 Harvesting Pattern and Maintenance of Continuity
Drawing upon another ecological attribute we have the following discernible pattern of food resources in the in the area harvested by man(excluding birds):
Table 2 shows that the Herrings are the dominant species that were landed(347 x 10^6 lbs) in a year(1971). ![]()
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| Table
2 |
Landings
in millions of pounds in the Bay o Fundy in 1971 |
|
|
|
|
|
| 1 |
Herring |
347 |
|
|
| 2 |
Seaweeds |
18 |
|
|
| 3 |
Cod |
12 |
|
|
| 4 |
Pollock |
12 |
|
|
| 5 |
Haddock |
12 |
|
|
| 6 |
Lobsters |
7 |
|
|
| 7 |
Alewives |
7 |
|
|
| 8 |
Clams |
5.4 |
|
|
| 9 |
Flounders |
3.4 |
|
|
| 10 |
Mackerel |
2.4 |
|
|
| 11 |
Hake |
2 |
|
|
| 12 |
Redfish |
1.7 |
|
|
| 13 |
Other |
0.9 |
|
|
| 14 |
Wolffish |
0.8 |
|
|
| 15 |
Shrimp |
0.8 |
|
|
| 16 |
Scallops |
0.6 |
|
|
| 17 |
Shad |
0.2 |
|
|
| 18 |
Smelt |
0.2 |
|
|
| 19 |
Eels |
0.1 |
|
|
| 20 |
Salmon |
0.1 |
|
|
| 21 |
Winkles |
0.1 |
|
|
![]()
![]()
The variety of other
harvested species is large but they are comparatively much smaller in
number (varying from 0.1 to 18.1 million pounds. This appears to be a
characteristic property of a rich diverse community: a large variety but
small in numbers in each variety except for one or two dominant
species. See for example an analogous result for a tropical
forest(Howe,1983): The important point is that ' in a community, some
species are common,some are less common and many are rare. The
preservation of a community inevitably requires the preservation of
species present in substantially different abundances.' Apparently this
conservation aspect has to be firmly borne in mind whenever a study is
being made of possible changes in tidal regime owing to man-made causes
like
dams and large tidal power plants, changes in sea level or climate.
3.0
Harnessing Tidal Effects or Harvesting Natural Food Directly?
There
are two ways of making available energy: by machines or by living
things. In the example of tides, the machine is the tidal power plant
and the living things are those discussed above.
3.1
Harvesting the Sea in tidal rich areas.
Discovering
the diversity of life in tidally endowed areas and finding therein a
thoroughly unified community in which there are no losses and
productivities are all utilised 100% and in which the driving force is
the energy of the sun and of the tides, man entered and harvested some
of the natural renewable resources in such a way that production and
continuity were maintained; there were no loss in 'catch' substantialy
from year to
year. Thus in the Bay of Fundy for example, a thriving sea harvesting
community exists employing some 25000 people,and with an annual
financial value of US dollars hundred million(1972).
3.1.1
Nature of living energy in the tidal ecosystem
Looking
closely at the marine ecosystem shows clearly that after all this natural system runs
on electricity produced by photosynthesis and respiration in natural
photovoltaic cells and natural fuel cells, in chloropasts and
mitochondria respectively, utilising the energy of the sun and oxidation
and reduction reactions. Thus, whether it is sea weeds or fish,
electricity is nevertheless generated and used(1.2 volts shockless and
many hundreds of amperes of current). Apart from electricity, however,
chemical potential gradient is also produced and used. Using electricity
ATP is produced which is used as the energy currency of the living
cell. In the Bay of Fundy
ecosystem illustrated above, the total electrical and chemical energy
that that would be produced and used, and this is important,
utilised in such a way that the energy is preserved in cycles of use, in
the marine ecosystem is equivalent to an electric generator of the
order of 600 Megawatts(MW) power capacity. This corresponds to an energy
turnover of 3100 to 3600 million kilowatthours annually to produce the
diverse harvest of marine organisms. When man utilises this harvest, he
must return his excrement corresponding to this use back to the sea. Thus
would these plants, animals and people ' be joined in a sort of energy
community.'(Hinkle and McCarty, 1978).
3.2
Effects of a Tidal Power Plant on the Ecosystem
What
would be the effects on such an ecosystem by the development of a
tidal barrage and a power plant? For example, the
estimated
electricity development in one location(Cobequid Bay in the Bay of
Fundy area), was 4028 MW and 12600 GWH(million kwh) with a tidal range
of 12.4 m using 106 turbines of 7.5 m diameter each. But after 15 years
of the most comprehensive studies on all aspects including the
ecological balance, the net result has been that, only a small
Tidal Power Plant of 20 MW capacity at Annapolis in the Fundy area is being put up. The reason is that ecologically and environmentally, a huge
Tidal Power Plant would
change the whole tidal regime on the Northeast American sea coast with
possibly catastrophic consequences for the bird populations and causing
drainage problems(Daborn 1977). Similarly another
committee found that the 7200 MW, 13000 GWH, mean tidal range 9.3 m
Severn barrage, though technmically and economically feasible, to
require further studies on its environmental acceptability(Birkett et
all 1984). Nearer home, at the Gulf of Kutch, Kandla promises 600 MW at
1600 GWH annually with a mean tidal range of 5.2 m.
3.3
The Gulf of Kutch Tidal Area
Studies
are afoot for a tidal power plant in the Gulf of Kutch. A newspaper
report in the Free Press Journal(1984), envisages completion of the
project by 1987(report submitted in 1988). The report mentions studies in many areas but
ecological studies do not find a place. The project envisages
construction of main dams across Hansthal creek, 3.1 km long, Sara
creek, 0.7 km long and Phang creek, 0.5 km long. The area surveyed
includes 1400 sq. kms of
marshy land.
3.4
Living Energy in the Gulf of Kutch
The
fabulous wealth of rich and diverse life in the Gulf of Kachchh
presents a vivid picture of a thoroughly unified community disposing the
awesome power of solar radiation and tides harmlessly while preserving
energy in cycles of use, analogous to the Bay of Fundy Ecosystem(Chavan
1983). Some 55 coral species, marine worm-like animals, some of them
found only in the Gulf of Kachchh, bottom dwelling forms, crustaceans
like mud crab, Jumbo Lobster, Barnacles, some 200 species of
invertebrates(snails, mussels, oysters and octopus), mammals(dolphins,
whales), some 200 species of fishes, Reptiles(Green sea turtles, Black
banded snakes), a huge number of fantastic birds, luxurient growth of
mangroves, and unique land-building tropical shrubs-species that grow only
in saline waters. Mangroves form one of the pivots of the marine
ecosystem.
3.5
Destruction of the Gulf of Kachchh ecosystem by careless
industrialisation.
This has caused devastation of marine
habitats including mangroves. Misuse of marine flora and fauna,example
living corals for plaster for homes, dredging sand for cement and
destruction consequently of good coral areas, also around a Marine Park,
encroaching by human habitat into the mangrove and mudflat area,
industrial oil leaks, and road building on sand(Chavan 1983).
3.6
Kutch Tidal Power Plant must include comprehensive ecological studies.
Briefly
the problem appears to be lack of knowledge of what would happen to the
ecosystem, after construction of a battery of barrages in the Gulf of
Kachchh as elsewhere- whether it would be catastrophic or not. this
entails perhaps at least a decade long study of the bio geo chemical
cycles such as on:
3.6.1. Physiography and ecological characteristics.
3.6.1.1 Geology and a thoroughly revised tectonic
framework including effects of dams,
3.6.1.2 Tidal influences on the physical oceanography,
3.6.1.3 The climate,
3.6.1.4 The sediment regime,
3.6.1.5 Biological resources including
3.6.1.6 Intertidal resources,
3.6.1.7 Marine and estuarine sublittoral benthos,
3.6.1.8 Aspects of marine ecology relevant to tidal power,
3.6.1.9 Avifauna,
3.6.1.10 Use by shorebirds.
3.6.1.11 Interrelationships of ecosystems and engineering aspects,
3.6.1.12 Effects on physical oceanography by tidal power development including climate change for 100 years
3.6.1.13 Effects of tidal power structures on sediment transport,
3.6.1.14 Earthquakes and climate change caused by dams
3.7
Harvesting of Living Energy Cycles in the Gulf of Kachchh
Simultaneously with the consideration of tidal power harnessing for the
monoculture of electricity generation only, at the site, and its use
elsewhere, must be considered the harvesting of living energy by man,
preserving it in cycles of use. What is the present status of harvesting
marine fish and other life for food? If life is not thriving in such a
way that there exists balance between care and use, what steps have been
taken to restore the original balance? For example, can we cite figures
like we did for the Bay of Fundy? In any case, such a permanent
mariculture striking a balance between plant, animal and human
existence, is urgently to be implemented because it is immediately
possible to do so. A healthy wholeness of creation is possible by
'responsible behaviour in the present' . Whether a tidal power plant
preserves this system or enhances it, a detailed study may reveal. The
chances are, by analogy with other tidally rich areas, a large tidal
power plant would be ruled out. There is a decided complication,
however on account of the global effect of the GHGs and the dams
exacerbated by the nuclear power programmes and general profligacy of
modern civilization's destruction of nature. The modern madness of the
nuclear power programmes is revealed by its energy audit(See my website
by clicking on my name here. We can no longer make long term studies
based on the usual design norms because the reaction of the earth falls
outside these design envelopes and hence the glaring lacunae in design
is leading to catastrophic failures of modern infrastructure because of
climate change effects. What implication this has on the ecosystem can
be gleaned by the catastrophic sea and land creature mass deaths
followed or preceded by earthquakes, high temperatures via surges of
heat waves, flash floods, cloudbursts, cyclones, landslides persistently
caused by dams and other greedy interventions into the biosphere
including reckless consumptive mining sprees. Monitoring and studies on a
global basis together with immediate conservation and life style change
seems a must.
4.0
Ecology tells us and we are experiencing the interlinkages of all that is
The Bhagavadgita is timeless in its teachings that everything is
interconnected and that the soil and the sea are the great connectors of
all life. All diversity is within a universe. In general, man may use
the energy of living systems by preserving energy in cycles of use, by
recycling and via the sun. In this way man does not convert energy in
such a way that he cannot use it again. This negentropic behaviour is
via life presided over by the sun. In this way he need not create wastes
which become pollutants. Or man can mechanically extract energy out of
tides for example, by creating a reservoir behind a barrage, but in the
process subjecting nature's thoroughly unified communities to
degradation and the threat of destruction, by causing a catastrophic
alteration in the tidal resources affecting fish migration and bird
population.The consequences have to be carefully studied. Or in the
process of extracting energy by fossil fuels, creating conditions which
have far reaching adverse effects on tidal power or on other power
development or even on the ecology of the whole planet itself. Or he may
mistake natural living energy itself to be a storehouse of energy and
start extracting mechanical energy and materials out of it- like from
the forest(marine or otherwise) or from the bowels of the earth and
destroy it. And again create ecological unbalances. He may consider man
to be a mechanical slave- a machine in short and replace him by another
seemingly quantitatively more effective monoculture- a 'cheap and fast
machine' - replace the goose that lays the golden egg - and ultimately
destroy the permanence of return - the very reason de etre of a
community and of life itself. This may indeed happen when tidal power
development or a nuclear power programme destroys the livelihood of
fishermen along with the thriving ecosystem.
5.0
Conclusion
Nature typically depends for its strength on a web of resources rigidly
interconnected by evolution happening daily. This is in contrast to
man(part of nature) who typically in ignorance of true knowledge thinks
of monoculture for his short term profits. Exceptions are the thousands
of years old traditional Indian or Chinese farmer or the Amishes in the
USA, to cite some rare species. Again and again when modern man
considers therefore a particular development, he confronts with his
monocultural proposal, a diversity of natural resources whose regime he
would alter, thinking they are separate- a typical fallacy of thought
and action in modern civilization- and hence face a situation new to
nature- like in Fukushima or in Genetic Modification- and create a
crisis. Previously, modern civilization's disparate actions had local
effects and the benign margins of nature were capable of righting these. But now the margins have vanished and
with them the factors of safety. Man's effects are being increasingly
felt globally, witness how the
dams
for example are causing climate change worldwide with terrible
consequences to modern ways of life, including nuclear explosion effects
on infrastructure like nuclear reactors and setting buildings ablaze
and causing mines to explode. In effect these are confirming the ageless
prophecies of the Gita. This is because
he
feels in his ego-led personality, he is supreme and will see the
consequences of interconnections of modern systems with nature at the
conception stage of his creations and hence conquer nature and amass
limitless profits forever. Hence he disregards the need to imitate
nature beyond understanding and instead put his own proposals into
effect without considering the true consequences. Somebody has already
been there at work, in the past, in the present and will be there in the
future- the harmony
of the universe. Look therefore closely at ecology and it may be that we should tune ourselves to Harmony, the Unity behind all that is.
6. References
Chavan Sanat .A. 1983. Marine Park in the Gulf of Khachchh. Centenary Seminar on Conservation. Bombay Natural History Society.Mumbai
Daborn G. R. Ed. 1977. Fundy Tidal Power and the Environment. 28. The Acacia University Institute.
Nova Scotia.
Anon. 1984. Report on first tidal power project by ' 87. Free Press Journal. 29 May 1984. Indore.
Sri Aurobindo. 1920. Essays on the Gita. Sri Aurobindo Ashram Pondicherry.
Berry Wendell. 1977. The Unsettling of America: Culture and Agriculture. Avon. New York.
R. Ashok Kumar. 2005. Earthquakes Caused by Dams. At
http://earthquakescausedbydams.blogspot.com
R. Ashok Kumar.2005. Predicting Earthquakes. At
http://predictingquakes.blogspot.com
Howe Henry .F. 1983. Implications of Mutualistic Seed Dispersal for
Tropical Reserve Management. Centenary Seminar on Conservation. Bombay Natural History Society. Bombay(Mumbai).
King, F.H. 1927. Farmers of Forty Centuries Or Permanent Agriculture in China, Korea and Japan. Jonathan Cape. London.
R. Ashok Kumar. 1983. Concepts for a Civilization Based on Conservation. Centenary Seminar on Conservation. Bombay Natural History Society. Bombay(Mumbai).
Readers Digest. 1972. Secrets of the Seas. The Reader's Digest Association. New York.
Petrides. G. A. 1983. Can we assume that National parks will preserve nature and wildlife? Centenary Seminar on Conservation. Bombay Natural History Society. Bombay(now Mumbai).
Pillai Gopinadha C. S. 1983. The endangered marine and terrestrial habitats of Minicoy Atoll in Lakshadweep.
Centenary Seminar on Conservation. Bombay Natural History Society. Bombay(Mumbai).
Birkett N., Count B.M., and Nichols N.K.1984. Optimal Control Problems in Tidal Power. Water Power and Dam Construction.36. 1.Jan 1984. 37-42.
Armantrout Neil B. 1983. Fish Distribution as influenced by Aquatic Habitat Alteration and Species Introduction.
Centenary Seminar on Conservation. Bombay Natural History Society. Bombay.
Hinkle P.C., McCarty R.E.1978. How Cells make ATP. Sci Am. 238.3.104-123.
R. Ashok Kumar. 1986. Modern Civilization and Normal Civlization: The Need for Small Self-Sufficient Communities. Gandhi Marg. At
http://modernandnormal.blogspot.com
First-ever tidal plant in Sunderbans in West Bengal
Maureen Nandini...
Date: Jun 30, 2006
Sunderbansto have country's first tidal power plant:
http://www.downtoearth.org.in/node/7990
India's tigers at risk from tidal power plant
Saturday 01 July 2006
http://www.independent.co.uk/news/world/asia/indias-tigers-at-risk-from-tidal-power-plant-406224.html
