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Land-based
pollution
Sea pollution
originating from land sources can be classified into two types:
point sources and diffuse sources. The first type contains
forms of pollution delivered to the sea by rivers, coastal
lagoons, sewage, storm water out-falls, leakages, solid waste
and sludge disposal, dumping sites. The second type (non-point
pollution) relates to all those forms of sea pollution which
emerge from the diffusion of pollutants along the coast: run-off,
leaching of nitrate and other fertilisers, untreated sanitary
out-falls, airborne pollution (such as trace metals, petroleum
hydrocarbons, DDT, PCBs).
Statistics
from Coastal Clean-up Campaigns
Data obtained by coastal clean-up programmes in 1999 shows
that plastic and metal account for 80% of coastal litter,
paper (9.9%), glass (7.4%), rubber (1.2%), cloth (0.9%) and
wood (0.6%).Of these, as much as 71.9% is attributed to land
sources, 13.4% to ocean and waterways, and 14.4% is of unknown
origin.Items collected during the clean-up were cigarette
butts and beverage cans (20% of the total each), plastic bottles
(9%) and milk/water gallon jugs (7.5%).
Pollution
by ships
Data on
oil spills are difficult to obtain. The number of oil spills
and the volume of oil released into the sea cannot always
be well correlated. Yet pollution from oil spills appears
to be decreasing worldwide, according to the International
Maritime Organisation's estimates. Indirect estimates
of sea pollution can be made by the fines imposed on companies
and ship-owners, whose ships were found to pollute. Going
by data published by the Ministry of Mercantile Marine for
the period 1981-1997, ships were responsible for 56% of all
oil pollution.
Fighting
Sea Pollution
Usual
methods to combat sea pollution in Greece are the use of:
- absorbents
(substances like chalk and straw which absorb oil)
- skimmers
(used in open seas and ports)
- chemical
dispersants (when the previous methods have failed).
Several protection
projects have been implemented through EU funds for Greece (1994-1999),
including:
- The
establishment of marine parks in Lagana Bay, Zakynthos and
in the Sporades, where the sea turtle and the monk
seal breed respectively
- The
management of Amvrakikos Bay.
- The
protection of coastal
wetlands.
Trailblazing
Greeks Use Magnetic Pull to Clean Seas
A
new method, based on the principle of magnetic susceptibility,
was recently presented by the Technological
Educational Institute of Piraeus. The project, to be funded
by the EU's DG-XI (Environment), proposes the use of magnetic
materials to collect heavy pollutants from the sea. Reduced
cost for clean-up (down to 10% of present rates) and potential
for recycling are among the anticipated benefits.
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