145
Nearshore oil pollutions are the most dangerous because in shallow water oil damages directly
both the benthos (sea floor life) and coastal habitats. The thin oil layer developed on the water
surface blocks gas exchange between the water
and the air hindering the breathing of marine living beings.
Other contaminants are mostly transported by
major rivers into the World Ocean since the rivers
themselves are also polluted. A vast amount of
soil particles rich in nutrients (mostly nitrogen
and phosphorous) is washed into rivers from
agricultural areas due to intensified soil erosion
and rivers transport these into the sea. Pollutions
affect coastal areas most. Excessive nutrients
result in the boom of algae while the degradation
of the vast amount of dead algae withdraws oxygen from the water. The lack of oxygen is further
increased by the degradation of other pollutants
(e.g. oil pollution) and organic matter. Also the
increasing temperature of the water contributes to
the lack of oxygen as warmer water contains less
dissolved oxygen.
Increasing areas show the lack of oxygen
according to scientists (Breitburg et al. 2015;
Miller et al. 2016; Kolesar et al. 2017; Limburg
et al. 2017) both in nearshore waters and in the
open ocean. Scientists also pointed out that climate change together with water pollution significantly increase the number and extension of
such dead areas. The Intergovernmental
Oceanographic Commission of the UN declared
the situation so severe that it founded the Global
Ocean Oxygen Network (GO2NE).
This chapter was started with the fact that a
significant amount of pollutant material gets
from the continents into the sea via the atmosphere (33% of the total pollution). Solid particles with various sizes enter the water in a
significant mass due to the enormous water surface. Pollutants sticking to their surfaces could be
strongly toxic. Since deposition from the atmosphere takes place along an enormous surface
and mixed into a huge mass of water it causes no
acute problem for life in the sea. Atmospheric
gases (CO 2 , NO x , SO 2 , etc.) are dissolved moreor- less in seawater and change the chemical
properties of the water, mostly reducing its
pH. Dust, soot and hydrocarbons from burning
fossil fuel also get into the sea in large
quantities.
In 2017 The Ocean Conference was organised
by UN with the participation of 193 countries
discussing the general state of the World Ocean.
It was declared, among others, that the size of the
anoxic areas and those severely lacking oxygen
in the sea multiplied by fourfold over the last
50 years. Nearshore anoxic areas increased more
than tenfold. On the conference the pollution of
the sea, acidification of the water were declared
serious while overfishing and illegal fishing were
declared dangerous to marine life. The closing
document of the conference, however, contains
warnings and recommendations for governments
and civil organisations that are not compulsory;
therefore, no significant changes could be
expected in hindering harmful processes.
As could be expected regarding population
density and industrial development, European
seas are most polluted. This can be explained by
not only great emission but water geographical
conditions as well (enclosed sea). Most of the
deep sea waste disposal sites are located near the
European shores of the Atlantic Ocean. These
alone are no sources of pollution but—depending
on the safety of disposal—can be regarded potential pollution sources. Continuous monitoring of
seawater in the vicinity of such sites is required.
Conditions of the water of the Gulf of Mexico
can be regarded severe as well due to increased
ship traffic, marine oil mining, agricultural pollution and the load transported by the Mississippi
and other rivers. News in 2018 revealed that continuous oil seeping was going on since 2004 at
several oil rigs 16 km off the shores of Louisiana
(IFL Science 2018). In 2004 Hurricane Ivan triggered sea bottom landslides causing the start of
seeping from 25 oil rigs that was successfully
stopped only in the case of 9 of them; therefore,
the rest of the oil rigs have been continuously
polluting the water of the gulf.
The state of the World Ocean could be summarised as critical in several regions and deteriorating overall. Impeding further deterioration is
only possible with strict complying with the
already existing international conventions,
4.3 Changes in the Hydrosphere
Nearshore oil pollutions are the most dangerous because in shallow water oil damages directly
both the benthos (sea floor life) and coastal habitats. The thin oil layer developed on the water
surface blocks gas exchange between the water
and the air hindering the breathing of marine living beings.
Other contaminants are mostly transported by
major rivers into the World Ocean since the rivers
themselves are also polluted. A vast amount of
soil particles rich in nutrients (mostly nitrogen
and phosphorous) is washed into rivers from
agricultural areas due to intensified soil erosion
and rivers transport these into the sea. Pollutions
affect coastal areas most. Excessive nutrients
result in the boom of algae while the degradation
of the vast amount of dead algae withdraws oxygen from the water. The lack of oxygen is further
increased by the degradation of other pollutants
(e.g. oil pollution) and organic matter. Also the
increasing temperature of the water contributes to
the lack of oxygen as warmer water contains less
dissolved oxygen.
Increasing areas show the lack of oxygen
according to scientists (Breitburg et al. 2015;
Miller et al. 2016; Kolesar et al. 2017; Limburg
et al. 2017) both in nearshore waters and in the
open ocean. Scientists also pointed out that climate change together with water pollution significantly increase the number and extension of
such dead areas. The Intergovernmental
Oceanographic Commission of the UN declared
the situation so severe that it founded the Global
Ocean Oxygen Network (GO2NE).
This chapter was started with the fact that a
significant amount of pollutant material gets
from the continents into the sea via the atmosphere (33% of the total pollution). Solid particles with various sizes enter the water in a
significant mass due to the enormous water surface. Pollutants sticking to their surfaces could be
strongly toxic. Since deposition from the atmosphere takes place along an enormous surface
and mixed into a huge mass of water it causes no
acute problem for life in the sea. Atmospheric
gases (CO 2 , NO x , SO 2 , etc.) are dissolved moreor- less in seawater and change the chemical
properties of the water, mostly reducing its
pH. Dust, soot and hydrocarbons from burning
fossil fuel also get into the sea in large
quantities.
In 2017 The Ocean Conference was organised
by UN with the participation of 193 countries
discussing the general state of the World Ocean.
It was declared, among others, that the size of the
anoxic areas and those severely lacking oxygen
in the sea multiplied by fourfold over the last
50 years. Nearshore anoxic areas increased more
than tenfold. On the conference the pollution of
the sea, acidification of the water were declared
serious while overfishing and illegal fishing were
declared dangerous to marine life. The closing
document of the conference, however, contains
warnings and recommendations for governments
and civil organisations that are not compulsory;
therefore, no significant changes could be
expected in hindering harmful processes.
As could be expected regarding population
density and industrial development, European
seas are most polluted. This can be explained by
not only great emission but water geographical
conditions as well (enclosed sea). Most of the
deep sea waste disposal sites are located near the
European shores of the Atlantic Ocean. These
alone are no sources of pollution but—depending
on the safety of disposal—can be regarded potential pollution sources. Continuous monitoring of
seawater in the vicinity of such sites is required.
Conditions of the water of the Gulf of Mexico
can be regarded severe as well due to increased
ship traffic, marine oil mining, agricultural pollution and the load transported by the Mississippi
and other rivers. News in 2018 revealed that continuous oil seeping was going on since 2004 at
several oil rigs 16 km off the shores of Louisiana
(IFL Science 2018). In 2004 Hurricane Ivan triggered sea bottom landslides causing the start of
seeping from 25 oil rigs that was successfully
stopped only in the case of 9 of them; therefore,
the rest of the oil rigs have been continuously
polluting the water of the gulf.
The state of the World Ocean could be summarised as critical in several regions and deteriorating overall. Impeding further deterioration is
only possible with strict complying with the
already existing international conventions,
4.3 Changes in the Hydrosphere