Pacific Islands Environment Outlook - UNEP

MARINE AND COASTAL ENVIRONMENT 13
Atolls suffer from minimal surface water storage and
limited exploitable groundwater resources. Freshwater
lenses are governed by the interaction of rainfall volume
and periodicity, tidal fluctuations, seepage, hydraulic
conductivity, and abstraction rates. Once the lens,
which is in a dynamic state of equilibrium, is
contaminated (by saltwater intrusion, for example), the
delicate balance between fresh and salt water may take
years to re-establish in certain situations. If the
contamination is from a land-based source (pesticides or
leachate, for example), the problem may persist much
longer. There is a growing consensus that global
warming may lead to increased energy in the
hydrological cycle and consequent greater intensity and
frequency of extreme events (drought and flood). This,
together with sea-level rise and, on limited land masses,
increasing population pressure on the carrying capacity,
is likely to further exacerbate the problem.
In urban areas, fast-growing settlements without
appropriate water supply and sanitation are not simply
the inevitable result of rapid and uncontrolled population
growth; they also suggest inadequate government
investment in urban services as well as in the rural
sectors. Urban centres have an increasingly high demand
for water usage. In Tonga, demand for water has risen
because of the higher standard of living and on Tongatapu
it is estimated that potable water consumption increased
almost tenfold over the 1970s–1980s, with the average
daily consumption in Nuku’alofa now about 80 litres per
person (Thistlethwaite, Sheppard and Prescott 1993).
Tonga has highlighted the need for public education on
conservation of water and promotes a roof water
catchment and rainwater storage programme. Tonga has
also embarked on a programme to reduce water loss in
the reticulation system. In Guam, residential waste
disposal by septic tank systems adds to nitrates in
groundwater. Nitrates can reach unhealthy levels if
urbanization is not served by central sewage treatment
and disposal (Loerzel 1998b). In Fiji, though no data
exist, there is a potential problem of diminishing
groundwater and river water quality caused by the longterm
use of fertilizers and pesticides in the many sugar
cane farms. The impact on groundwater recharge and
storage caused by the introduction of non-indigenous
agriculture (pine forests, for example) is another activity
whose impact has not been fully assessed.
Industrial use of water, though limited in the Pacific,
may provide a bigger concern through the waste it
generates rather than the quantity consumed. Beer
making, soft drink manufacture, fish processing and
sugar refining are some of the larger users of water, as
are activities associated with the tourism industry. Water
is also used for hydroelectric power in some countries,
such as Fiji, Samoa, PNG and Vanuatu, but this is not, in
general, a competing or consumptive use. In some PICs
there is a growing number of light industries and
commercial agricultural practices, placing further
demands on water supplies. In Fiji water bottling and
hydroponics are two new users.
Conclusion
Water and sanitation as foundations of economic
growth, social development and, in some cases, basic
survival are vital. The protection and conservation of
the supply and quality of water is expected to become
an increasingly important issue in the Pacific of the
future, especially if global climate change results in
increasing rainfall variability in the region. Population
growth, urbanization and damage to water catchments
as a result of rampant deforestation, inappropriate
agricultural activities and inadequate waste disposal are
all likely to have an increasing impact on water supplies
throughout the region. Improvement in water resource
management is fundamental and will require a coordinated
effort across many sectors, including:
improvements in watershed management; reductions in
deforestation rates; raising public awareness of wise
water use and management; controls over agricultural
activities, and improvements in waste disposal,
especially sewage disposal facilities.
In many of the PICs management of the resources
that exist is a greater challenge than identifying new
sources. A management structure or regime is often
difficult to put in place when there is a policy vacuum,
outdated legislation, insufficient budgetary provisions, an
absence of technical capacity and the perennial problem
of land ownership.
Marine and coastal environment
Developments over the past 100 years
There are very few data on the historical pressures on
the marine and coastal environment in the Pacific.
However, it should be noted that an extensive database
for offshore fisheries in the Pacific has been developed
over the past few decades. There is evidence that, since
the vast majority of Pacific islanders (excluding PNG)
live in the coastal zone, there was considerable
pressure on coastal and marine resources, which
occasionally led to resource shortages. Local shortages