Marine Ecosystem Notes

Sources:
- Urban run-off: Stormwater can carry various contaminants, including oil, from roads and industrial areas into marine environments, leading to significant degradation of water quality.
- Oil tanker washing: The cleaning of oil tankers often leads to the discharge of residual oil into the ocean, contributing to pollution.
- Accidents involving oil tankers: Accidents can lead to catastrophic oil spills, which have immediate and long-term impacts on marine ecosystems.

1967 – Torrey Canyon: Wrecked off the coast of England.
- Estimated 15,000 sea birds were killed, showcasing the disastrous impact of oil spills on avian populations and the broader marine ecosystem.
1978 – Amoco Cadiz: Ran aground off the coast of France.
- Estimated 20,000 sea birds and 9,000 tonnes of oysters were killed. This incident highlighted the dangers of tanker accidents and their broad ecological impact.
1989 – Exxon Valdez: Ran aground near Alaska.
- Unknown number of sea birds killed, but over 2,800 sea otters lost their lives. The cleanup methods employed, such as hot pressured water, further damaged the already fragile ecosystems.
2010 - Deepwater Horizon: An oil drilling rig explosion in the Gulf of Mexico caused one of the largest marine oil spills in history.
- Estimated that up to 698 million liters of oil leaked into the Gulf, leading to extensive damage to marine life, habitats, and local economies.

Oil Toxicity: Animals slowly ingest oil, leading to long-term health issues such as liver damage, reproductive failure, and increased mortality rates.
Physical damage: Birds covered in oil suffer from loss of insulation and buoyancy, leading to hypothermia and drowning.
Effects on food webs: Disruption of food chains affects not just individual species, but entire marine ecosystems can collapse if keystone species are affected.
Damage to coastal ecosystems: Oil accumulation on beaches leads to loss of habitat for many sea creatures, including nesting sites for marine turtles.
Damage caused by the cleanup: Clean-up methods can be harmful, such as crude oil burning, which emits sulfur dioxide and other pollutants that can lead to air quality issues.

Renewable Energy:
- Wind Turbines: Harness wind energy with minimal environmental impact, providing a cleaner alternative to fossil fuels.
- Tidal Power Electricity Generator: Utilizes the energy of tidal movements to generate power, contributing to a more sustainable energy grid.

Wave-driven pumps harness the energy of ocean waves to create renewable energy while also providing fresh water through desalination.
The technology includes pipelines that deliver high-pressure water ashore, ensuring efficient energy conversion.
Offers the potential for directly driving standard desalination equipment, reducing reliance on oil for freshwater supply.

Run-off can carry fertilizers and pesticides into oceans, leading to serious environmental issues.
Fertilizers: Their excess can create eutrophication, leading to harmful algal blooms that deplete oxygen in water and cause dead zones.
Pesticides: Many pesticides, especially organophosphates, can cause biomagnification. Chemicals stable in the environment accumulate in the food chain, posing risks not only to marine life but to human health as well.

Poorer countries often send untreated sewage directly into the ocean, exacerbating pollution issues.
Domestic Sewage: Comprises faeces, urine, and wastewater, which can introduce pathogens into marine environments.
Surface Run-Off: Carries microplastics and other contaminants, further degrading marine ecosystems.
Effects include reduced light penetration due to sedimentation, lower oxygen levels from decomposition processes, altered mineral ion concentrations, and significant loss of biodiversity in affected areas.

Refuse: Material discarded improperly can include household waste, industrial by-products, and plastics.
Waste made of plastic can take hundreds of years to degrade, leading to microplastics entering marine food webs.
Dumping at sea can involve everything from sewage sludge to old ships and industrial waste. Many plastic products degrade slowly, posing long-term dangers to wildlife, especially animals like turtles that may ingest plastic mistaken for food.

The process of removing salts from ocean water to use for drinking or irrigation raises two significant environmental concerns.
- Effects on marine organisms: Withdrawal of large quantities of water may affect local ecosystems, and returning concentrated brine can create imbalances in salinity and temperature.

Brine from distillation plants is very hot and denser than ocean water, causing it to sink and potentially harm bottom-dwelling organisms.
Changes in water temperatures and salinity can severely disrupt local marine ecosystems and food chains.

Microplastics are plastic particles with a diameter less than 5mm and they can originate from various sources.
- Primary Microplastics: Directly manufactured (e.g., microbeads in cosmetics).
- Secondary Microplastics: Result from the breakdown of larger plastic items.
Microplastics are not biodegradable, and despite breaking into smaller pieces, they persist in the environment, posing severe risks to organisms at all levels of the food chain.

Uptake by plankton can introduce microplastics into the food web where they can accumulate and affect various marine species.
Transfer through food chains can lead to absorption and release of harmful toxins, risking human health through seafood consumption.
Chemicals like Bisphenol A (BPA) can disrupt endocrine systems, contribute to fertility issues, and impact overall fish populations.

Intergovernmental Agreements: Collaborations among nations can help implement comprehensive waste management practices.
National Government Policies: Regulations targeting plastic production, use, and disposal are crucial for reducing microplastic pollution.
Individual Consumers: Adoption of sustainable practices by individuals can significantly impact the levels of microplastics in marine environments.
Local Groups: Grassroots movements advocating for conservation can raise awareness and influence policy changes.