Conservation, ecological justice and harm to nature - Environmental Harm: An Eco-justice Perspective - page 80

ingestion and entanglement in plastic and other debris, and through
chemical contamination by ingestion. The importation of alien species
can also alter endemic community structures of animals. In general,
'potential chemical effects are likely to increase with a reduction in the
size of plastic particles while physical effects, such as the entanglement
of seals and other animals in drift plastic, increase with the size and
complexity of the debris' (UNEP, 2011: 25). Fish, seabirds, sea turtles
and marine mammals have all been affected by ingestion of plastics.
A key concern is the biochemical and physiological response of
organisms to ingested plastics contaminated with PBTs. Not only are
there issues associated with the potential impacts of the releases of
chemical additives that were part of the plastic's original formulation,
but as plastic breaks down into fragments (plastic particles of small
size) it accumulates PBTs that are already present in seawater and
sediments. Many of these specific pollutants cause chronic effects such as
endocrine disruption affecting reproduction, increases in the frequency
of genetic mutations (mutagenicity) and a tendency to cause cancer
(carciogeniticy). According to UNEP (2011: 28):
We know that microplastics are ubiquitous in the ocean,
contain a wide range of chemical contaminants, and can be
ingested by marine organisms. However, the lack of certainly
about the possible role of microplastics, as an additional
vector for contaminants taken up by organisms, calls for
caution and further research.
Compounding these continuous processes of contamination by plastics
are other types of contamination, some of which are systemic, others
the outcome of extraordinary events.
For example, there is evidence that the nitrogen-based fertiliser used
in (the increasing) corn production is causing environmental harm in
its own right. Millions of kilogrammes/pounds of those nitrates end
up in the Gulf of Mexico each year, where it is causing a massive algae
bloom. This bloom has a negative impact on the ecology of the Gulf:
'When the algae dies it sinks to the bottom, where it absorbs oxygen as
it decays. In recent years that oxygen depletion has created an aquatic
'dead zone' covering about 8,000 square miles in which shrimp, fish,
oysters and crabs cannot survive' (Reliable Plant, 2007).
Meanwhile, on 20 April 2010, the oil rig 'Deepwater Horizon'
exploded in the Gulf of Mexico, resulting in the largest 'accidental'
marine oil spill in the petroleum industry's history and causing damage
to wildlife and marine habitats, and to the fishing and tourism industries.