Does Our Environment Affect Our Welfare and Health?

There's no question that we are having a grave impact on our environment whether that is through climate change or habitat destruction. Many of us believe that in order to improve our happiness and welfare we need to have a high income and economic growth in our country but there have been many reports to suggest that there is a strong link between growing the economy and environmental degradation. So what does this mean for our health? Can we really be at our happiest and healthiest with the current trend of over exploitation?

According to the World Bank, in 2014 globally we emitted 36.2 million Ktonnes of CO2 in contrast to the 9 million Ktonnes emitted in 1960 which has made us more vulnerable to respiratory illness. The WHO has linked 3 million deaths each year to outdoor air pollution with reference to illness ranging from asthma and bronchitis to lung cancer. These reports also state these illnesses are higher in industrial areas and larger cities due to excess transport fumes and burning of fossil fuels. There has also been a link between high concentrations of air pollution and cardiovascular illness which puts us at greater risk of heart attack, stroke and angina. One way this occurs is through particulate matter entering the blood stream, restricting the movement of blood vessels, increasing blood pressure and therefore increasing our risk of suffering a heart attack.

Sunlight provides us with vitamin D which is needed to regulate calcium and phosphate within the body, helping to maintain healthy bones and muscles. We as humans require 10 micrograms of vitamin D a day, most of which we are supposed to get naturally through sunlight meaning we do have to step out of the house occasionally. A lack of vitamin D in extreme cases can cause rickets in children that leads to weak bones and deformities. This causes a high number of bone fractures and can eventually cause a curvature of the spine, leading to a permanent disability. Low vitamin D can also cause osteomalacia, which is similar to rickets, in adults causing bones to soften. With 1 in 5 people in the UK having low vitamin D levels, it is important we spend more time outdoors (and maybe consider a supplement in winter).

There have also been studies suggesting a link between time outside and an improvement in mental health with studies showing time outdoors reduces stress and reduces the symptoms of depression and anxiety. Scientists have suggested that urban and man made environments has 'constant simulation' that leads to mental fatigue, making those living in cities at greater risk of mental illness. Those living in rural areas also have better sleep with less noises keeping them awake. This will help to improve concentration, lower stress and improve moods which will allow people to be more productive.

There is also the obvious benefit that walking in a natural environment keeps us active, aids weight loss and maintains a healthy heart. Sitting down for too long can cause a decline in bone density and increase blood pressure after deposits in the blood vessels are not removed. All of these factors have been linked to a lower life expectancy by increasing our risk of stroke, heart disease and diabetes just to name a few.

So we all need to get outside in nature to help improve our health and wellbeing. However, I'm not saying that if you live in a city you're going to get ill and live a shorter life because that's not the case. Most large cities have parks and open spaces you can visit and city councils should be turning old sites into open spaces to encourage the urban population the get out and appreciate nature and we should all be doing our bit to protect it to protect the health of the future generations.


References
https://ourworldindata.org/air-pollution#death-rates-from-air-pollution
https://www.bhf.org.uk/informationsupport/support/practical-support/air-pollution
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
https://patient.info/health/osteoporosis-leaflet/vitamin-d-deficiency

Mangroves: The Natural Defence for Coastlines

Figure 1 - A map highlighting the distribution of mangrove forests (in black) throughout the globe (Romañach, 2017)

Across the intertidal zone are a collection of mangrove forests located along the coastlines of equatorial countries (figure 1), the largest being The Sundarbans in Bangladesh covering a total of 140,000 ha. These forests are often referred to as 'the roots of the sea' due to the complex aerial root system that spend the majority of the time above sea level enabling the plant to survive in the anaerobic soil, making these ecosystems tolerant to a hypersaline environment. With 40% of mangrove species labelled threatened by the IUCN, these coastal areas could be at greater risk of coastal erosion, storm surges and sea level rise. It is important these issues are understood to aid conservation of global coastlines as well as these beautiful unique habitats.

Figure 2 - A photograph showing the dense root systems of mangrove forests that reduce erosion 

Erosion is defined as “the process of eroding or being eroded by wind, water, or other natural agents”  and the complex, uneven aerial root system (figure 2) of mangroves reduces erosion of the shore. Mangroves have reportedly reduced the height waves up to 66% and slow the flow of seawater as the vegetation acts as a buffer between the land and sea. This enables 70-80% of incoming sediment to settle resulting, increasing biomass. This helps to increase the fertility in these harsh environments, increasing biodiversity, as mangrove soils have a high nutrient content. This gradual accumulation of biomass, over a long-time period, allows peat to form which is a long-term carbon sink helping to reduce carbon in the atmosphere. The dense roots bind soil particles together meaning an increase in mangrove trees means that less soil particles will become dislodged by incoming waves. This reduces the risk of flooding and damage to infrastructure in coastal communities. This risk increased in Guyana as after the removal of mangroves, coastal erosion increased 3 m annually.

The dense vegetation helps to reduce the impact of hurricanes and tsunamis inland by reducing the force of the storm surge. Figure 3 shows a storm surge is a large increase in sea water due to extreme weather, that often carries debris, that causes damage to infrastructure and flooding. The complex structure of mangrove forests increases the frictional resistance resulting in a drop in the force of the storm surge and slowing the flow rate of the wave. Storm surges are the biggest cause of damage during storms affecting causing large scale damage to properties, roads, biodiversity and coastal erosion. Studies have reported that mangroves can reduce the amplitude of a storm surge by 6 to 10 cm/km resulting in a decline in inland flooding and may fewer individuals at risk. However, the force from the waves can damage the mangroves often resulting in uprooting and damaging trunks so the health of mangrove forests should be monitored to ensure future storm surges have a reduced impact.

Figure 3 - A graphic showing the large increase in wave size during a storm surge 

Not only do mangroves provide a habitat to endangered species, including the Bengal tiger, but there are also major benefits to the human population as they reduce the risk to coastal settlements. Despite these major benefits, deforestation of these unique habitats is still on the rise due to the growth in aquaculture and the high value of mangrove wood potentially putting coastlines at risk.

Bibliography

• Gracia, A., Rangel-Buitrago, N., Oakley, J., & Williams, A. (2017). Use of ecosystems in coastal erosion management. Ocean & Coastal Management, 156, 277-289. Retrieved October 12th, 2018, from https://www.sciencedirect.com/science/article/pii/S0964569117301588#bib42
• ICUN. (2010, April 8th). Mangrove forests in worldwide decline. Retrieved from ICUN Threatened List: http://www.iucnredlist.org/news/mangrove-forests-in-worldwide-decline
• Leggett, M. (2011, April 5th). Carbon grasped by Mangrove roots vastly underestimated. Retrieved October 12th, 2018, from Earth Times: http://www.earthtimes.org/conservation/carbon-grasped-mangrove-roots-vastly-underestimated/662/
• NOAA. (2018, June 25th). What is storm surge? Retrieved October 12th, 2018, from National Ocean Service: https://oceanservice.noaa.gov/facts/stormsurge-stormtide.html
• Oxford University. (2010). Oxford Dictionary of English (Third ed.). Oxford: Oxford University Press. Retrieved October 10th, 2018
• Romañach, S. (2017). Conservation and restoration of mangroves: Global status, perspectives, and prognosis. Ocean & Coastal Management, 154, 72-82. Retrieved October 11th, 2018, from https://www.sciencedirect.com/science/article/pii/S0964569117301710#fig
• Sivasothi, N. (2001). How plants cope in the mangroves. Retrieved October 11th, 2018, from Guide to the Mangroves of Singapore: http://mangrove.nus.edu.sg/guidebooks/text/1043.htm
• Spalding, M., Mclvor, A., & Tonneijck, F. (2014). Mangroves for coastal defence. Cambridge: The Nature Conservancy. Retrieved October 11th, 2018, from https://www.nature.org/media/oceansandcoasts/mangroves-for-coastal-defence.pdf
• United Nations. (2017). The Sundarbans. Retrieved October 11th, 2018, from UNESCO: http://whc.unesco.org/en/list/798

The Danger of the Fishing Industry

Overfishing is defined as “the taking of fish species which exceeds its reproductive capacity” and as a result, we could have fishless oceans by 2048. Overfishing is a result of the mismanagement of fish stocks which leads to fishing above the maximum sustainable yield which is what lead to the collapse of the Newfoundland cod stocks in 1992. Reports show that between 90-100 million tons of fish are caught annually but with a growing population and consequently a higher demand for fish, overfishing is on the rise which could lead to grave environmental impacts.

One of these impacts is bycatch, or the removal or non-target species, due to unsustainable fishing methods such as demersal trawling.At least 40% of global catch is estimated to be bycatch and has been linked to a decline in population of large marine species, including the hammerhead shark. Leatherback turtles are likely to become extinct in the next 5 – 30 years with the main cause being pacific long line fisheries, designed to catch tuna. However, a large proportion of bycatch is believed to be unreported as it is discarded overboard to avoid fines once the vessel reaches shore which can stop effective conservation and designations in the areas in greatest need of protection. Bycatch has a major impact on marine ecosystems and will increase as the fishing industry grows.

Unsustainable fishing methods are also a major cause of habitat destruction, the most damaging being deep-sea trawling (figure 1) that tears up the sea bed which kills a range for species including coral and sea grass. This can also have an indirect effect as the disturbance of the sea bed causes a decline in photosynthesis by the removal or green sea plants and suspended particles, created by trawling, cause oxygen levels to fall making areas of the ocean uninhabitable to certain marine species. Trawling has been linked to the destruction of 30-50% of the coral along the Norwegian continental shelf and was the main reason for the Røst reef becoming a no take zone in 2002 with other nations protecting habitats on the sea bed.

Abandoned fishing nets has created the issue of ghost fishing which is when marine organisms become trapped in unused fishing gear. Not only does this account for 10% of marine debris, but each net can catch anywhere between 30-40 individuals included the Leatherback turtle. A positive feedback mechanism is also created as trapped organisms can act as bait for the apex predators, including rare shark species that can put them at greater risk.

Figure 2 - A list of the most and least sustainable fish to buy (activation.com)

Consumers have the ability to reduce these impacts by buying sustainable fish or cutting fish from their diet altogether. If consumers wish to buy fish they should purchase from the MCS sustainable fish list (some of which can be seen in figure 2) and look for the MSC logo on the packaging. Overall the fishing industry is unsustainable and this needs to change to protect the oceans. Personally, I feel the only 'sustainable method' is to stop fishing as there are many scientific studies showing we don't actually need to eat fish. If fish populations are going to recover, we need to stop eating them.

Bibliography

Activation. (2016). Fish: The Farmed v. Wild Debate, from activation.com. Retrieved October 1 2018. https://www.activationproducts.com/blog/farmed-fish-wild-fish-debate/

Australian Government. (2018). Trawling. Retrieved October 1, 2018, from Australian Fisheries Management Authority: https://www.afma.gov.au/fisheries-management/methods-and-gear/trawling

Buhl-Mortensen, P., & Buhl-Mortensen. (2018, Febuary 27). Impacts of Bottom Trawling and Litter on the Seabed in Norwegian Waters. Frontiers in Marine Science. Retrieved October 1, 2018, from https://www.frontiersin.org/articles/10.3389/fmars.2018.00042/full

FAO. (2012). WORLD REVIEW OF FISHERIES. New York: United Nations. Retrieved October 1, 2018, from http://www.fao.org/docrep/016/i2727e/i2727e01.pdf

Kemp, D. (1998). The Environment Dictionary. London: Routledge. Retrieved October 1, 2018

Mason, F. (2002). The Newfoundland Cod Stock Collapse: A Review and Analysis of Social Factors. Electronic Green Journal, 1(17).

NOAA. (2009, October 19). Deep Water Corals. Retrieved October 1, 2018, from National Oceanic and Atmospheric Administration: https://web.archive.org/web/20100221152237/http://coris.noaa.gov/about/deep/#fossa

Roach, J. (2002, November 2). Seafood May Be Gone by 2048, Study Says. Retrieved from National Geographic: https://www.nationalgeographic.com/animals/2006/11/seafood-biodiversity/

United Nations. (2009, May 6). Ghost nets hurting marine environment. Retrieved from FAO: http://www.fao.org/news/story/en/item/19353/icode/

WWF. (2010). Factsheet: Bycatch. Retrieved October 1, 2018, from panda.org: http://awsassets.panda.org/downloads/bycatch_factsheet.pdf

Are Fireworks Damaging Our Environment?

Happy new year! Our beautiful planet has taken another journey around our sun meaning that we celebrate with over the top and elaborate firework displays and excessive drinking. Whilst watching the London fireworks on TV, I couldn't help but notice the large amount of smoke being emitted which got me thinking could these beautiful sparks of light actually be having a big impact on the environment?

A picture of fireworks. From pixabay.com

Before looking at the impact I was curious what these were actually made of. In the simplest form, fireworks are tubes filled with gunpowder, wrapped in flash paper and attached to a fuse, hence the explosion. However, to create the sparkle and the colour aluminium, iron, steel, zinc, or magnesium are added as these ensure that fireworks will burn for longer and brighter. Compounds of strontium, lithium, sodium, barium or copper are added to change the colour as these react with heat differently to produce different coloured flames, thus creating the beautiful displays we see twice a year. These additions are the biggest concern as in high concentrations, they can be toxic for both humans and wildlife. The fireworks create particulate matter containing the toxic elements that will eventually settle on land and, if landed on soil, can be taken into the plant system via the roots and enter the food chain via bio-magnification. Aluminium alone can affect the functions of gills in fish as it acts as an inhibitor for the enzyme responsible for the uptake of ions and will therefore reduce fish populations and any predators feeding on the poisoned fish.

Another issue is the smoke caused as it increases particulate matter levels and increases carbon dioxide concentrations within our atmosphere. Particulate matter is a collection of particles (under 100 micrometers) that are either produced naturally or, in the case of fireworks, are produced from chemical reactions. Minerals (including aluminium, silicon, iron and calcium) are producers of particulate matter and, as previously stated, some of these are included in the makeup of fireworks but this composition varies depending on colour. The monitoring of particulate matter has shown that pollution episodes (above average concentrations) occur around January and November implying there may be a link between New Year and Bonfire night. During these winter months, high PM concentration have been linked to temperature inversion that are responsible for trapping pollution at ground levels, in turn increasing our exposure time. There are a range of health impacts ranging from respiratory illness to affecting the cardiovascular system with these risks being greatest during inversions which is shown by the increase of breathing problems of over 30% during Diwali. However, there is also a large environmental impact the first one being the impact of photosynthesis as PM deposits on the leaves of green plants reducing the contact to sunlight. This can reduce the rate of plant growth and therefore lessening the amount of food available to primary consumers. This can affect of the rest of the food web as it reduces energy available for higher tropic levels (basically reducing food for top predators) especially if the primary consumer populations are affected.

The chemical process of lighting the gun powder has been linked to the pollution of sulphur dioxide and nitrogen dioxide, both of which are major polluting gases. Sulphur dioxide is directly linked to the production of acid rain that can corrode metal and limestone structures as well as the exoskeletons of invertebrates. As many small invertebrates are the basis of any food web, this can again affect higher tropic levels and affect the food availability within the ecosystem. This can also affect the pH of water bodies and has the potential to cause ocean acidification which is a cause for coral bleaching. As our coral reefs are currently in decline shouldn't we be doing everything in our power to reduce acid rain, especially for things that are not strictly necessary?  Nitrogen dioxide has been linked to increased eutrophication, decreasing the sunlight available to a water supply by the growth of algal blooms. This causes a decline in oxygen from a lack of photosynthesis affecting the populations of marine organisms thus reducing biodiversity. This, again, can affect human health and can cause nitrogen dioxide poisoning as it can irritate the mucous membrane in the lungs.

So with these major environmental impacts shouldn't we be focusing on reducing our use of fireworks rather than spending millions on elaborate firework displays every year? With so much advancement in scientific knowledge, it does seem strange to me that we have not found a more sustainable alternative, despite the fact that firework displays are unnecessary to our well being but I can see that it is a tradition and culturally we associate these with celebrations. With the development of renewable energy sources, light and laswer shows could be an alternative if done safely. With climate change being on the tip of everyone tongue, I think we should be looking at smaller issues, like fireworks, in order to help the bigger picture.


References

• B Rosseland, T Eldhuset, M Staurnes. Environmental effects of aluminium. 1990. https://www.ncbi.nlm.nih.gov/pubmed/24202562
• Wonderopolis. How are fireworks made? 2014. https://www.wonderopolis.org/wonder/how-are-fireworks-made
• McLendon, R. Are Fireoworks Bad for the Environment? Earth Matters. 2018. https://www.mnn.com/earth-matters/translating-uncle-sam/stories/are-fireworks-bad-for-the-environment
• Fuller, G. Our prettiest pollutant: just how bad are fireworks for the environment? The Conservation. 2015. http://theconversation.com/our-prettiest-pollutant-just-how-bad-are-fireworks-for-the-environment-52451
• Compound Interest. The Dark Side of Fireworks. January 2017. https://www.compoundchem.com/2017/01/05/fireworks-environment/

The Impacts of Sailing

http://www.wikiwand.com/en/Sailing_(sport)

The boating and sailing industry has been growing over recent years with many of us participating as a way to connect with oceans and nature. This growth has aloud us to go scuba diving and snorkelling in areas that otherwise wouldn't be accessible as well as take part in a seemingly fun team sport with boat races even being included in the Olympics. However, with out oceans and the creature that call them home being in great danger, this got me thinking if this recreational activity could have a grave environmental impact.

In recent years there has been evidence to suggest that boats have caused a decline in dissolved oxygen, stunting the growth of sea plants that in turn affect the entire food chain. The propellers  and rudders bring up sediment from the sea bed which reduces the turbidity (i.e. it stops sunlight from reaching the seabed). This reduces the amount of photosynthesis that can occur and reduces the amount of oxygen available meaning that habitat cannot sustain larger fish populations, especially in shallow waters. With nutrients also being brought to the surface, large amounts of boats have also been linked to algal blooms which also reduce the turbidity but, in some cases, produce products that are toxic to both marine and terrestrial organisms. Safe to say that the reduced turbidity caused by high speed boats has a major impact on marine life and is something that can be easily avoided if we anchor these boats further out, away from shallow waters with less chance of the motors touching the sediment.

Another major impact is the potential for fuels to spill and leak into the surrounding environment. We have all seen those photos of sea birds drenched in oil and boats have the potential do do this on a much smaller scale, particularly if the boat is driven and managed poorly. When the boat is stationary, there is significant potential for small amount of partially burnt fuel to leak into the surrounding area. Smaller fuel particles are more likely to be ingested by marine life therefore there is great risk for bio accumulation up the food chain. Needless to say these chemicals are toxic to marine life. These chemical can also affect both the biotic and abiotic conditions of the habitat, making them less habitable for the species that live there. One potential change is pH and if it were to increase in acidity (or decline in pH) could mean damage to crustaceans with the acidic water dissolving shells and other carbonaceous structures including corals.

Although sailing can increase tourism and GDP, there is also the physical damage done to habitats. Sailing and other marine activities produce large amount of litter that end up in the ocean which included nets, ropes and plastic bags. With 43% of all boat activity being recreational sailing in Australia alone, it it fair to say that the majority of the waste from boats come from the sailing industry. Marine debris poses a huge threat to wildlife with organisms becoming trapped in discarded nets as well as smothering coral and other sea plants. Not to mention the fact that some organisms mistake plastic for food with sea turtles in particular mistaking plastic bags for jelly fish. The boats themselves have also done physical damage to marine environments with boat anchors being the biggest offender. Anchors can damage the sea bed but uprooting plants, disturbing bottom feeders and destroying coral.

The main solution to this would be to designate protection areas with no or limited access to areas with high biodiversity. However evidence suggests that this requires greater regulation with 43% of sailing boats in Australia ignoring the Marine Protection Areas. I'm not saying we should stop ailing as it is a way for us to grown closer to our marine environment and fall in love with the beautiful marine wildlife. I am however suggesting we act responsibly by staying within designated zones, ensure the boat is maintained to a high standard and stop treating the ocean as our personal landfill.

Resources -

• Environmental Protection, The Environmental Impacts of Boating, May 2017, https://eponline.com/articles/2017/03/27/the-environmental-impacts-of-boating.aspx 
• Brynes. T, Science Direct, 2016, https://www.sciencedirect.com/science/article/pii/S0959652615002413#kwrds001

Animal Agriculture and Climate Change

https://climatevulture.com/category/blog-topics/agriculture/

Climate change is a major global issue with it being a key talking point amongst governments and IGO's (*ahem America*). Everyone is aware of the obvious contributors including exhaust emissions and fossil fuels but recently it has been suggested that animal agriculture may be a bigger contributor to the greenhouse effect than originally thought. There has been evidence to suggest that as our meat consumption has grown so have our carbon emissions but this could also be due to the growth of industry, population and a greater dependence on fossil fuels. So does this mean documentaries like Cowspiracy are wrong?

It is suggested that livestock is responsible for 18% of greenhouse gas emissions globally. With the addition of the byproducts, it could be as high as 51% with a projected increase of 80% by 2050. These byproducts include transportation, food and heating. Most of these emissions are methane that are produced by the growing cattle industry and bad land management and with methane having a global warming potential 86 times greater than carbon dioxide, it is no wonder livestock are essentially destroying out planet. Methane is produces in the stomach of cows and sheep as the ingested plants undergo fermentation that produces methane as a by-product essentially meaning cow farts are destroying the environment. It doesn't take a genius to realise that as the "need" for beef grows so will these toxic methane emissions. In fact methane emissions from livestock are similar to those produced by natural gas, questioning if we should be shifting from promoting electric cars to a more plant based diet.

With animal agriculture covering an estimated 45% of land, livestock is a primary contributor to habitat loss and deforestation on a global scale. Globally, all agriculture is responsible for 80% of deforestation, with the biggest causes for habitat destruction in the Amazon basin being cattle ranches and soya plantations. Although crops are a cause for deforestation, we will see a very small percentage of these yields as most will be used for animal feed. In order to achieve maximum yield and profit, cattle require a large amount of food. If we think about this in terms of tropic levels, as we move up a level (or a stage in the food chain) 90% of energy is lost so we need more cows to produce the amount of beef we need to meet our energy needs. This means more cattle ranches and more animal feed. As most of us are aware, forests are an important carbon sink and help to reduce the enhanced greenhouse effect and if agriculture continues to grow, so will the amount of greenhouse gases in the atmosphere.

Did you know a farm with 2,500 cattle produces the same amount of waste as over 410,000 people? If it is disposed of incorrectly it can result in anaerobic digestion, again resulting in the release of methane. Another side effect is eutrophication reducing nutrient availability, creating algal blooms and a decline in biodiversity. Not to mention the fact it is a direct cause of water pollution and poses a huge health risk to animals and humans alike.

So overall do I believe a plant based diet will help reduce carbon emissions. Yes, all the facts support this. However it is important that we also understand that we have a meat eating culture spanning thousands of years and we have been taught our whole lives nutrition must contain animal products. Therefore this change cannot be expected to happen overnight but even if you only eat meant 3 or 4 times a week, you will still have significantly cut your carbon footprint.



Resources -

• https://www.onegreenplanet.org/animalsandnature/this-is-how-animal-agriculture-causes-deforestation/ 
• http://stockfreeorganic.net/deforestation-livestock-destroying-the-living-earth/
• https://news.mongabay.com/2012/09/agriculture-causes-80-of-tropical-deforestation/
• http://www.cowspiracy.com/facts/
• https://www.edf.org/climate/methane-other-important-greenhouse-gas
• https://nepis.epa.gov/Exe/ZyNET.exe/901V0100.txt?ZyActionD=ZyDocument&Client=EP
• https://www.gao.gov/archive/1999/rc99205.pdf

How Does Plastic Travel in the Ocean

Map of ocean currents - (Pidwirny, 2006)

In 2017, scientists estimated that there was roughly 100 million tons of plastic in our oceans, with this figure constantly on the rise. The plastics are constantly circulating the globe via ocean currents which is the movement of sea water between locations, in a similar way to a conveyor belt, that are generated by a range of forces that change regionally including wind speed and force as well temperature difference. This has led to large accumulations, particularly of microplastic, specific areas of the ocean with the most well-known being the Great Pacific Garbage Patch. All the mentioned factors (plus many more) mean that rubbish from my university in Plymouth could end up polluting the Great Barrier Reef.

Ocean currents are defined as “a horizontal flow of water through the ocean” (according to the freedictionary.com) that redistributes heat from the sun through the globe. The movements that generate the currents are often seasonal and affected by a range of factors including:
• Differences in temperature
• Wind direction and speed
• Gravitational pull from moon and sun
• Rise and fall of the tides
• Salinity
• Atmospheric pressure

The global system of ocean currents has an important role within a range of ecosystems as well as the global climate. Ocean currents carry heat from tropical regions and transports and redistributes this heat away from the equator to warm coastal areas, making land more habitable and increasing soil fertility. They also have an impact on the weather as warmer water has a higher rate of evaporation, resulting in heavier rainfall in tropical regions which allows the tropical rainforests to have the heavy rainfall and humidity it is known for. This is what gives these rainforests the fertile soil that allows the beautiful tropical plants to grow. Currents also increase the biodiversity in the photic zone (or the top layer of the ocean) as upwelling occurs that bring nutrients to the surface. This allows phytoplankton to grow and increase in population that increase oxygen levels and provide more food for the primary consumers in the food chain. Needless to say this has a knock on effect and affects higher trophic levels within the ecosystem.

The global transport of plastics via ocean currents has created ‘rubbish hotspots’ such as the Great Pacific Garbage Patch. Despite public belief, the Great Pacific Garbage Patch is not a large mound of debris in the middle of the pacific like the name suggests and it is not even visible by satellite. The other name the Pacific Trash Vortex describes the area much better as it is a gyre containing high concentrations of marine litter and chemicals that circulate the North Pacific Ocean. With 1.9 million pieces of microplastic per square mile, the risk to the ecosystem in this area is huge and as 70% of all litter in the ocean sink to the floor the unseen impacts may be even greater than expected. The North Pacific Gyre keeps the debris circulating the North Pacific Ocean and creates convergence zones that are the natural gathering points within the ocean current system. In the case of the North Pacific, the two largest convergence zones are the western Garbage Patch and the eastern Garbage Patch (shown below). The constant movement of the gyre means that the microplastic and other marine debris remains trapped within the North Pacific ecosystem, amplifying the damage even more.

A map showing the North Pacific Garbage patch, (NOAA - Response and Restoration, 2013)

As the amount of plastic within our oceans continues to rise, we could be seeing more gatherings of plastics like the pacific garbage patch as it is transported globally and deposited by ocean currents. This has a huge impact on biodiversity in these areas and have been ingested by species, particularly seas turtles, as well as entangling others. With 17% or all threatened marine species being affected by plastic in our oceans, we need to be more aware that plastic does travel within our oceans and dropping a plastic bottle on your local beach could impact the Great Barrier Reef or be ingested by the endangered Leatherback turtle. 

References -

• Krieger, A. (2016, Febuary 7). What will it take to get plastics out of the ocean? Vox: https://www.vox.com/2016/2/7/10928788/ocean-plastic-pollution-solutions
• National Geographic. (2014, September 19). Great Pacific Garbage Patch.  https://www.nationalgeographic.org/encyclopedia/great-pacific-garbage-patch/
• NOAA - Response and Restoration. (2013, Febuary 7th). How Big Is the "Great Pacific Garbage Patch"? Science vs. Myth. Office of Response and Restoration: https://response.restoration.noaa.gov/about/media/how-big-great-pacific-garbage-patch-science-vs-myth.html
• Pidwirny, M. (2006). Surface and Subsurface Ocean Currents: Ocean Current Map. Retrieved from Fundamentals of Physical Geography: http://www.physicalgeography.net/fundamentals/8q_1.html
• Sea Turtle Conservancy. (2017). Information About Sea Turtles: Threats from Marine Debris. Sea Turtle Conservancy: https://conserveturtles.org/information-sea-turtles-threats-marine-debris/