Journal of Learning – Week 8.

Journal of learning – Week 8.

 

  1. After watching the video, explain in your blog the conditions required for the formation of oil and gas deposits.
  • Organic wastes – Carbon, Hydrogen, Nitrogen & Oxygen all resulting from the death of living creatures (Animals and vegetation) are deposited onto the floor of aquatic locations (sea, river, lagoon etc). (Somewhere poor in Oxygen to prevent bacterial interaction.)
  • Build up layers with sediment (sand, mud)
  • Faults push and move the sediment deeper into the Earths crust. The deeper it is pushed down, the higher the temperature and pressure.
  • Chemical reactions remove Oxygen & Nitrogen atoms. Leaving only the Carbon and Hydrogen behind (Hydrocarbons)
  • Hydrocarbons are found in the “source” rock. They move around and tend to make their way to the earths surface. This is because they (as gases) are lighter than water. They are able to leak out.
  • It is possible however that they are unable to leak out by being caught by a barrier rock or “cap rock” They become trapped in the “reservoir” rock.
  • In the reservoir rock the gassier atoms float above the oil pushing the water below.
  • Many years later an oil or gas field will be discovered. These are fossil fuels.

 

  1. Explain the factors that have lead to the present-day distribution of oil and gas deposits.
  • Plate tectonics – Have moved the surface of the earth.
  • This has enabled portions of land previously covered by oceans to form deserts above sea level.
  • As it was previously underwater it was a perfect place for oil and gas deposits to form.
  • Since its now accessible to people its extracted and used.
  • It is distributed worldwide.
  • This is the case in many Middle Eastern countries.

 

  1. After reading the paper briefly summarize in your blog the various mechanisms by which ecological impacts of oil spills can arise.
  • Oils spills can have many ecological impacts.
  • Acute Phase Mortality.

This involves floating oil on the oceans surface. It causes direct impacts such as death to all marine wildlife such as birds and fish. The oils can smother these animals causing them to drown, and can also poison them if the oil in ingested.

  • The long term pollution impacts can include the oil seeping into the bottom sediments of the ocean, which again can cause death or filter feeding/benthic communities such as mussels and oysters. In this form the oil has direct impacts towards the food web. This can cause a continuous cycle of poisoning to many creatures for years to come.
  1. In your blog, explain the risks and benefits of the rigs-to-reefs program.
  • Risks
  • The program is only relatively new (was only started in the 1980’s) and because of this the best locations of where to place these rigs/reefs is still yet to be determined.
  • At this time there is also minimal information to support that these artificial reefs are actually attracting and increasing the biomass of species in these locations.
  • Potential to over fish. Provide an easily accessible location for fishers, who could potentially wipe out any new populations.

 

  • It recycles old oil rigs and makes them into artificial reef systems to help improve fish populations.
  • Cost efficient – saves coil companies’ money in that they are not paying to tear down and remove the old rigs.
  • Provides an artificial reef system to species of fish – helping to promote growth and abundance of new species.

 

Week 7. Journal of Learning

 

  1. Take a photo (or video) of yourself engaging in an activity (or making a behavioral choice) that will minimize pollution of NSW waterways. Add this to your blog and, in the accompanying text, explain what it is you are doing and why it will make a difference, in terms of marine pollution.

 

Im using an environmentally friendly washing powder to wash my clothes. The powder has been proven to have no negative effects on animals and doe not contain any harmful chemicals that could contaminate waterways. The packaging is also make of cardboard and can be recycled.  This will make a difference as there will be no harmful chemicals being introduced into teh waterway and the packaging is biodegradable and will either break down or be recycled into something else. This means it won't end up floating around the ocean for years to come.
I’m using an environmentally friendly washing powder to wash my clothes. The powder has been proven to have no negative effects on animals and doe not contain any harmful chemicals that could contaminate waterways.
The packaging is also make of cardboard and can be recycled.
This will make a difference as there will be no harmful chemicals being introduced into the waterway and the packaging is biodegradable and will either break down or be recycled into something else. This means it won’t end up floating around the ocean for years to come.
  1. List some of the key contaminants found in the sediments of Sydney Harbour, and their sources.
    Some of the key contaminants found within the sediments of Sydney Harbour include:
    (Anoxic – No oxygen found in the sediment).
  • Concentrated metals.
  • Organic chlorine pesticides (DDT)
  • Heavy metals (lead)
  • Toxic hydrocarbons (PAH – car & truck exhaust

Their sources can come from:

  • Storm water.
  • Industries (However for 30 years no dumping of toxic waste has been allowed).
  • Factories at Home bush bay. (Moves sediments to other sections via currents)
  • (Inlets filled in to make parks & golf courses)
  • Everyday run off from households and the city.
  1. Summarize the sources of plastics in our oceans, and the mechanisms by which they are impacting marine organisms.
  • Plastic bags
  • Plastic bottle
  • Party balloons
  • Micro plastics – small beads found in shower gels.
  • Cosmetics contain micro plastics. – However being phased out.
  • Fishing nets.
  • Food packaging

They are impacting marine organisms in the way that:

  • Being eaten by marine life, causing them to die. Many birds eat plastic – they mistake the floating rubbish for fish.
  • Killing wildlife – Massive decrease in Shear water birds at Lord Howe Island Aust.
  • Seals/turtles being trapped in fishing nets & marine debris.
  • Plastic attract other contamination. When an animal eats it the contamination (mercury) seeps into the animals’ blood stream causing poisoning.
  1. Summarize how coastal eutrophication arises.
  • Run off of phosphates such as fertilizers, detergents and sewerage.

When it rains phosphates such as fertilizers used to maintain grass at gold courses or gardens runs off into the waterways.

  • Phosphate increases in our waterways can cause certain species of algae to grow more rapidly, limiting the resources other organisms or fauna need to grow such as sea grasses.
  • Rate of production will exceed rate of grazing, meaning there will be more of the algae being grown than organisms consuming it causing it to eventually over run & start to “kill off” other primary producers.
  • Sediment become low in oxygen causing it to become a dark black colour, making the sediment and surrounding environment unsuitable for other organisms to inhabit.