The oceans are enormous in their size, volume and depth. Animal life in the sea is very varied and more diversified in terms shape, size, form and weight-right from microscopic plankton to the giant whale. Marine pollution is the introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries), resulting in such deleterious effects as; harm to living resources: hazards to human health

1. Impact of human activities on
global marine environment
Presented by
Dr. B. Victor., Ph.D.,
email : bonfiliusvictor@gmail.com
blog : bonvictor.blogspot.com

2. Presentation out line
 Oceans and seas are largest ecological system.
 The oceans of the world - Importance and functions
 Global marine environmental changes
 Marine Biodiversity-components
 Global and Indian coastal lines
 Global marine pollution – Definition and negative impacts
 Direct and indirect effects of human activities
 Natural and cultural Eutrophication
 Marine pollutants and effects
 Conservation of global marine habitats
 Critical marine habitats

3. Oceans and seas are
largest ecological system

4. The oceans of the world
 The oceans are enormous in their size,
volume and depth.
 The oceans are complex and extensive
ecosystems, controlled by a variety of
physical, chemical and biological processes.
 The marine environment dominates that of
land ( 70% of the earth’s surface.)

5. Importance of oceans and seas -1
 Oceans and seas are  Rich reservoir of carbon
extensive and stable dioxide (130 trillion tons :
habitats 50 times more than air ).
 All oceans and seas are
 Richest source of oxygen –
continuous. They form a
largest ecological system. replenish the atmospheric
 The giant reservoir of
oxygen.
water – water wealth 97.3  Large reservoir of
% in oceans and 2.7 % on momentum and energy.
the land.  Mineral wealth – 50
 Complex chemical system million billion tons.
– 96.6% of seawater is
pure water and only 3.4%
contain dissolved solids.

6. Importance of
oceanic habitat -2
Oil and Natural gas – Off-shore waters have
nearly 20% of world’s oil resources.
 Biological wealth – 180 thousand species
from small bacteria to huge mammals –
25000 varieties of fish.
 At present 75-80 % of the total global
transports by world oceans and seas.

7.  The life on earth
first originated
in the seas and
oceans.
 Oceans contain
roughly 97% of
the earth’s water
supply.
 Ocean moderate
earth’s surface
temperature.
 Oceans currents
distribute heat
energy around
the globe.
Significance of oceans

8. Life support functions of oceans

9. Ocean as the great carbon sink
 The ocean is a natural sink of co2.
 The net annual uptake of co2 by oceans is
estimated to be approx. 2 thousand million tonnes.
 The Co2 dissolves in sea water and forms carbonic
acid.
 It hydrolyses into carbonates and bicarbonates.
 About 90 % of co2 exists as carbonates and
bicarbonates.
 Co2 is taken up by phytoplankton in photosynthesis
and converted into plant material.

10. Global marine
environmental changes
 About 390 million tonnes of run-off water enters
our marine environment each year.
 Approx. 7 billion tons of litter enters the world's
oceans each year.
 Approx. 35% of mangrove area has been lost or
converted.
 Approx. 20% of coral reefs have been destroyed
globally in the last few decades.
 Coastal wetland loss in some places has reached
20% annually.
 Indiscriminate fishing practices kill and waste
between 18 - 40 million metric tons of "unwanted"
fish, seabirds, sea turtles, marine mammals, and
other ocean life annually ( FAO - U.N).

11. Oil spills in the ocean
Oil spills may occur when an ocean oil rig
springs a leak or when an oil tanker wrecks.
E.g., The Santa Barbara spill in 1969, and
the Exxon Valdez spill in Alaska in 1989.
In 1991, millions of gallons of oil was released
into the Persian Gulf during the Gulf War .

12. The Indian coastal lines
 Indian coastal line measures
about 7500 km and 2000 km
wide Exclusive Economic
Zone.
 The Indian coastline
supports almost 30% of its
human population.
 India is the 7th largest
marine fishing nation in the
world.
 The Bay of Bengal and the
Arabian Sea are rich fishing
grounds.

13. Global coastal lines
 Two-thirds of the
world population
lives in coastal lines.
 Over 90% of the
world’s living
biomass is contained
in oceans.
 Coastal areas
produce 80% of the
marine resources.

14. Marine Biodiversity

15. Marine
biodiversity
Animal life in the sea is very
varied and more diversified
in terms shape, size, form
and weight-right from
microscopic plankton to the
giant whale.
 The total number of marine
species is ranging from
178,000 species to more than
10 million species.

16. Biggest biodiversity repositories of
marine species

17. Regions of the sea

18. Oceanic provinces and zones

19. Ecosystem services of
Continental shelf
 Continental shelves account for at least 25%
of global primary productivity.
 90–95% of the world’s marine fish catch.
 80% of global carbonate production.
 50% of global de-nitrification.
 90% of global sedimentary mineralization
(UNEP 1992).

20. Composition of Marine Biodiversity
 321 species of marine
fungi
 40000 species of
foraminifera
 Of the 28000 fish
species , ¾ colonizes
marine habitats
 More than 2500
macro fauna species
 More than 600 species
of Benthic algae

21. Marine species diversity gradients

22. Marine Biodiversity

23. Plankton
Features of
plankton
Mostly of minute or
microscopic size
Have no means of
locomotion or self-
propulsion
Surface large in
relation to bulk
Often with elongate
body parts

24. Nekton

25. Benthos
 Bottom dewelling
organisms
 Epifauna - those living on
the sea floor
 Infauna - those living in
the sea floor
 Sessile – sea weeds,
sponges, anemones, corals,
barnacles, oysters
 Creeping – crabs, lobsters,
snails, echinoderms
 Burrowing – clams and
worms

26. Diversity of coastal habitats
 Mangrove swamp ecosystem – water logged
saline soil
 Sea grass ecosystem – highly productive macro
algae
 Coastal lagoon ecosystem – Most fertile littoral
ecosystems
 Coral ecosystem – richest in species
 Estuarine ecosystem - meeting place of river
and sea
 Delta ecosystem –
 Sandy beach ecosystem – intertidal zone
 Rocky shore ecosystem – intertidal zone
 Coastal upwelling ecosystem

27. Hydrologic parameters of sea water

28. Overview –Global marine pollution
Human negative
impacts
Harvesting sea foods
The impacts of human
activities on land
The introduction of marine
pests.
Global changes
a.Climate change,
b.Rising atmospheric
carbon dioxide,
c.Excess nutrient inputs,
d.Pollution

29. Human impacts on
marine environment

30. Direct human impacts

31. Direct human impacts

32. Direct human impacts
 Coastal aquaculture can contribute to
degradation of coastal habitat.
 Land based discharge (sewage, industrial effluent
and urban/river run off etc.) and atmospheric
inputs from industry sources account for some
77% of marine pollution.
 Maritime transport is responsible for some 12%
of the total.

33. Marine Environmental Problems
Coastal erosion – sand erosion by strong
winds, high waves, heavy rains, flooding,
and storm waves.
Pollution with toxic substances
Eutrophication – over-enrichment with
nutrients
Sedimentation- Land based discharge and
deposition of sediments
Over exploitation of living resources-
selective commercial exploitation
Over exploitation of non-living resources

34. Definition of marine pollution
Marine pollution is the introduction by man,
directly or indirectly, of substances or energy
into the marine environment (including
estuaries), resulting in such deleterious
effects as; harm to living resources: hazards
to human health; hindrance to marine
activities including fishing; impairing the
quality for use of sea water and reduction of
amenities (The Inter-Governmental
Oceanographic Commission, -UNESCO).

35. Causes of coastal marine pollution

36. Pollutants in the marine environment

37. Marine eutrophication

38. Natural eutrophication
upwelling nutrient
inputs, river-borne
nutrients (not
polluted)
slow process (time
scale 10³-10
years)
induce ecosystem
adaptations

39. Coastal marine cultural
eutrophication
cultural or man-
•(
made)
•sewage,
•solid wastes,
•industrial
•effluents,
•agricultural
fertilizers,
Anthropogenic nutrients

40. Features of Eutrophication
 high nutrient concentrations
 high phytoplankton densities
 high densities of herbivores and predators
 depletion oxygen level in bottom waters by
decomposition of organic matter.
 presence of red tides
 Near -bottom anoxia-loss of benthos
 mass mortalities-ecosystem crisis

41. Eutrophying substances

42. Sources of Eutrophying substances

43. Eutrophication – induced changes
 Increased input of nutrients – deterioration of
water quality
 Increased plankton blooms or coastal macro
algal vegetation
 Decreased water transparency due to mineral
turbidity , cloudy detritus – reduced euphotic
layers -occlusion of gills
 Acute/sub-lethal toxicity by industrial or
domestic effluents- toxic metals, detergents,
pesticides,phenols,ammonia,H2S etc.
 Reduced species and tropic diversity
 Loss of fisheries resources

44. Eutrophication – induced changes
 Hindrance of aquaculture and/or
impairing quality of its products
 Reduction of tourist – recreational value
– loss water clarity, dead animals on
shore, foul smells, toxic shell fish etc.
 Hazards to human health.

45. Negative impact of sewage disposal
Ecosystem effects
 Turbidity – depresses phytoplankton production
 Sedimentation – changes benthic environment –
anoxic benthos
 Reduces species diversity leads to species – poor
communities
Habitat unsuitable for benthic organisms of
commercial importance
Human health effects
 Offensive odor
 Cause bacterial and viral enteric infections
 Contaminated shell fish – affect human consumers

46. Negative impact of pesticide
contamination
Ecosystem effects
 mortality
 reduction of growth
 impairment of reproduction fish and invertebrates
 egg-shell thinning in marine birds
Human health effects
 Potential toxic effects
 Neurological disorders

47. Negative impact of petroleum
hydrocarbons
Ecosystem effects
 mortality
 smothering and clogging of organs
 Interfere with feeding , reproduction, growth and
behaviour
 Tainting leads to unmarketability
Human health effects
 Cancer risks

48. Negative impact of heavy metals
Ecosystem Effects
 mortality of juvenile stages of marine organisms
 affect morphology, physically and behaviour of
marine organisms.
 Toxic to phytoplankton, invertebrates, fish.
Human health effects
 potential mammalian toxicity.
 Skeletal, muscular and neurological problems

49. Negative impact of radionuclides
Somatic effects – acute lethality. skin
allergies
 Genetic effects – cause mutations, cancers

50. Conservation of global
oceanic environment
The ocean is international property-global
commons. No nation has any right , moral
or legal to pollute any part of it, including
territorial waters.
Habitat protection is the most serious
need for coastal and marine biodiversity
The presence of toxic wastes in offshore
waters must be curtailed by stricter laws.
There should be an optimum exploitation
of living and non-living resources.

51. Conservation of global
oceanic environment
 Co-ordinated , centralized and highly sophisticated
research programmes are needed
i) to identify various pathways by which
pollutants enter the ocean.
ii)to analyse the behavior of individual
pollutants
 Restoration of habitat by re-vegetation of mash
grasses, mangroves and sea-grasses.
 International and national bodies should be
initiated to monitor the growth of marine
pollution.

52. Impact of Global Climate Change on
coastal and marine environment
 Climate change will affect plant and animal
physiology, abundances, and distributions.
 Climate change will alter bio-productivity and
species interactions.
 Climate change may decrease or increase
precipitation, thereby altering coastal and
estuarine ecosystems.
 Species that are unable to migrate or compete
with other species for resources may face
extinction.

53. Impact of Global Climate Change on
coastal and marine environment
 Changes in precipitation and sea-level rise
affect the water balance of coastal
ecosystems.
 The increases in precipitation and runoff
may cause the risk of coastal flooding .
 Climate change affect the structure (e.g.,
plant and animal composition) and function
(e.g., plant and animal production, nutrient
cycling) of estuarine and marine systems .

54. Critical coastal ecosystems
 Wetlands, estuaries, and coral reefs are
particularly vulnerable to climate change.
 Such ecosystems are among the most
biologically productive environments in the
world.
 Climate change may degrade these valuable
ecosystems, threatening their ecological
sustainability and the flow of goods and
services they provide to human populations.

55.  Dr.B.Victor is a highly experienced professor,
recently retired from the reputed educational
institution- St. Xavier’ s College, Palayamkottai,
India-627001.
 He was the dean of sciences, IQAC coordinator
and assistant controller of examinations.
 He has more than 32 years of teaching and
research experience
 He has taught a diversity of college courses and
guided 12 Ph.D scholars.
 He has published 5 articles in international and 35
articles in national research journals.
 send your comments to :
bonfiliusvictor@gmail.com