So long, farewell!

This is the end of my blog for now. Thanks for reading, and I hope you have found it as educational as I have.

The plastic wave. Source.

Is there a way out of this mess? Potential solutions to cleaning up our oceans

Potential solutions to cleaning up the plastic in the oceans are still in their infancy, however I've selected four ideas which could go someway towards reducing marine plastic pollution. However, given the huge amounts of plastic we're still producing I think this quote is rather relevant:

"Imagine using a thimble to empty a bathtub, with the faucet still running."                             Algalita marine research and education

For now, let's just imagine that we have managed to shut off that 'faucet' and prevented more plastic polluting our oceans. How can we remove the plastic that is already there? The ideas I'll discuss are by no means the only ones out there, and they range in the scale of their ambition.

1) Ocean Cleanup

The Ocean Cleanup is an ambitious project led by 20 year old founder and CEO Boyan Slat. Slat's idea is to place massive V-shaped floating structures in the ocean. The structure has a non-permeable screen going down into the water. Most of the current will still run under the screen, taking with it things of 'neutral buoyancy' i.e. sea-life, so there will be no by-catch. The 'positively buoyant' plastic will be caught, relying on ocean currents to bring it there. The project is well underway, having received crowd-funding. A lot of testing has already been done. In 2016, a 2000 meter long barriers will be deployed off the coast of Japan, with a smaller 100m to be tested later in the Netherlands, with the overall aim of deployment in the Pacific.

The V-shaped boom. Source.

2) Plastic Republic, UCL iGem

This idea has arisen out of a student synthetic biology competition. Deciding to tackle the issue of marine plastic pollution, the student team from UCL came up with the idea of releasing an engineered bacteria into the North Pacific Garbage Patch to first degrade the plastic, and then release a biofilm to adhere to the plastic particles, with the overall aim of creating huge floating plastic islands. These large plastic aggregates would then be easily visible from air and collected, thus cleaning the oceans and reclaiming the plastic for potential second use. Watch their trailer below and check out their website here for more information on this very cool idea!

3) Seabin Project: in-water automated marina rubbish collector 

On a smaller scale, two Australian guys have come up with the idea of automated rubbish bins placed in marinas, ports etc. which will catch rubbish (including plastic), fuel, oil and laundry detergent. The bins are then simply lifted out, emptied (for sorting and recycling) and put back to start all over again.  Seabins are only really for use at coastal infrastructure, such as marinas, but these sheltered environments protect the seabins from ocean storms and use the tides to bring the rubbish to them. The location also means people can see first hand what is in the oceans, in the places where they swim or sail. Again please check out their website and watch their video below!

4) International Coastal Cleanup

Finally, I have to mention the Ocean Conservancy's International Coastal Cleanup. Whilst this isn't removing plastic from the ocean it is 'stemming the tide' of plastic going into the ocean, and collecting items washed ashore by waves. It's a voluntary movement, and anyone can get involved. In 2014, 560,000 volunteers in 91 countries picked up more than 7,000 metric tonnes of rubbish, an awful lot of it being plastic. It's great work, and I will definitely be looking into helping out!

Top 10 items collected by the Ocean Conservancy's International Coastal Cleanup in 2014. Source.

Microplastic update: Obama bans microbeads!

A few blogs ago I mentioned that laws were being drawn up to phase out microplastics in the USA. Well it's good news. Last week (28/12/15) President Obama signed a bill banning microbeads in facewash, toothpaste, and shampoo from 2017. Go Obama!

President Obama has banned microbeads. Source.

Now, it's time for the UK to step up as well. Sign this petition to call for our government to ban microbeads and halt microplastic pollution.

It's time for Dave to step up and face the microplastics. Source.

So that's what happens to our rubbish! Rising global plastic production and mismanaged waste

Judging from the amount of plastic being produced globally, we clearly do think that life in plastic is fantastic. We absolutely love the stuff. It's convenient, relatively cheap, light weight, and amazingly adaptable - all in all the perfect consumer product! Except for once we've finished using it... then it mounts up in our landfills, and pollutes our oceans. Oh dear.

PlasticEurope produces an annual report on the plastic market. Globally, plastic production is steadily increasing. Insatiable demand has driven global production up almost 50% from 204 million tons in 2002, to 299 million tons in 2013; and almost 750% since 1975 (0.4 million tons).

Global plastic production, and European plastic production. Source: PlasticEurope.

Unsurprisingly, most of the demand and production is in more economically developed countries, such as USA and western European countries, with China, India and other southeast Asian countries catching up quick. In western Europe and northern America plastic consumption per capita has reached 100kg annually. In Asia, it is at 20kg per capita per year, but rising rapidly. Asia is taking the lead in production too, producing 45.6% of global plastic in 2013, predominantly in China and India. Demand for plastics is largely driven by packaging, with plastic replacing metal, glass and paper packaging. Packaging is the most common use for plastic, followed by consumer and household products, then building and construction. Personally, I found this surprising - the majority of plastic is made to thrown away?!

Different types of plastics and their uses. Source: PlasticEurope.

With the increasing global production of plastic, the proportion of municipal solid waste that is plastic has risen accordingly. In 1960 plastics equalled less than 1% of such waste in the USA, in 2000 plastics were making up over 10% of such waste in 58% of the countries with available data. What happens to the plastic next is of crucial importance for the oceans. Taking the example of Europe in 2012, most of the plastic is 'recovered' - meaning that it is incinerated for energy recovery (36%) or recycled (26%). However, a great volume of it is still headed for landfill - 38% on average in Europe, and that average is being pinned down by countries with effective landfill bans such as Germany and Switzerland. The UK sends almost 70% of its plastic to landfill, ranking as the 5th worst country in Europe! Furthermore, 87% of Europe's plastic sent to 'recycling' is exported out to China, where it is not fully transparent how it is processed.    

The destination of plastic waste in Europe. Source: PlasticEurope.

Proportion of plastic sent to landfill by country in Europe. Source: PlasticEurope.

Where there is ineffective and insufficient management of plastic waste, there is also the potential for that plastic to end up in the oceans. UNEP reports that somewhere between 10 and 20 million tons of plastic ends up in the oceans each year. Jambeck et al. (2015) estimate the amount to be between 4.8 and 12.7 million tons. They estimated that in 2010, in 192 coastal countries, 275 million tons of plastic was generated. The map below shows the amount of plastic waste available to enter the oceans from populations with 50km of the coast. Jambeck et al. define plastic waste available to enter the oceans as that which has been 'mismanaged', including all plastic that goes to dumps and open landfills. China had the largest amount of potential marine plastic, producing 8.82 million tons a year of mismanaged plastic waste. The next highest produced less than half that of China. In 2nd place was Indonesia, producing 3.22 million tons a year of mismanaged plastic waste. 16 out of the top 20 producers of mismanaged plastic waste are middle-income countries. In these countries, rapid population growth follows rapid economic growth, whilst waste management infrastructure lags behind.  

Mismanaged plastic waste with the potential to enter the oceans, by country. Source: Jambeck et al.

To conclude, we are producing enormous amounts of plastic to satisfy the growing global demand. Everyone loves using plastic, but there is a global ambivalence at best towards responsibly and effectively managing plastic waste. Poor plastic waste management enables plastic to end up in the oceans. It's estimated there are currently 5.25 trillion floating plastic particles, costing $13 billion a year in damage to marine ecosystems. The solutions appear to me to be two-fold: improve waste management, and reduce the amount of waste plastic in the first place.    

Toxic chemicals make for poisonous plastic

Toxic chemicals are yet another weapon in plastics arsenal, in its apparent bid to destroy marine life (don't get me wrong, this is people's fault, not the plastics). Plastic debris has the potential to act as both a sink and a source for toxic chemicals, transferring them to marine organisms. If that doesn't concern you, the toxic chemicals accumulate up the food chain until they reach our plates. So just remember: what goes in the ocean goes in you.

Toxic chemicals can make their way up the food chain from plastic-ingesting marine species into human diets. Source.

Plastic as a sink for toxic chemicals

Plastic can act as a sink when it adsorbs toxic chemicals in the ambient seawater. These chemicals include persistent, bioaccumulative and toxic substances (PBTs), dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), and persistent organic pollutants (POPs). PBTs, DDT, PCBs and POPs present a health concern to humans and the environment. The chemicals can be released into the oceans through pesticides, industrial processes, leaching, or being released from objects into the environment. The interactions between plastic and chemicals in the ocean is complex, but it is more likely than not that PBTs will preferentially sorb to plastic debris, as they have a low water solubility. 

Resin pellets (or nurdles) are the raw material used to make plastics in industry. Mato et al. (2001) studied 4 sites on the Japanese coast, examining PCBs, and DDE (a DDT derivative) in polypropylene resin pellets. The concentrations found in the resin pellets were equivalent to that of the seawater and sediments where they were found. A control experiment measured the absorption of virgin resin pellets, finding a regular and significant increase in PCBs and DDE concentration with exposure to the seawater. Mato et al. (2001) showed that the source of PCBs and DDE in the resin pellets was the ambient seawater, as the pellets absorb the chemicals through a process of enrichment.

Plastic resin pellets act as a sink for toxic chemicals in the ocean. Source.

   

Plastic as a source for toxic chemicals

Plastic act as a source for toxic chemicals due to the compounds added during manufacture to give the plastic certain desirable properties, such as pliability. When the plastic is ingested, the chemicals can leach from the plastic directly into the organism. Here are some examples of the chemicals:

• Phthalates. Added to PVC for softness and pliability. 
• Bisphenol A (BPA). A monomer used to make polycarbonate plastics. Can have toxic and biological effects on humans. 
• Brominated flame retardants. Added to reduce flammability. 

With all the added chemicals, plastic debris has the potential to be a source of toxic chemicals for months or decades.  

In a study of 12 short-tailed shearwaters collected from a research trawler in the North Pacific Ocean, Tanaka et al. (2013) demonstrated that chemicals are not only transferred to the birds from prey but also from ingested plastics. The abdominal fat tissue of the birds was analysed for polybrominated diphenyl ethers (PBDEs), a POP which is added as a flame retardant. 6 lanternfish and 1 squid were also collected and analysed, being common prey for the birds. In 9 of the 12 birds lower-brominated congeners were the dominant form of PBDEs found. The lower-brominated congeners were also dominant in the prey, indicating accumulation through the food chain. However, in the other 3 birds higher-brominated congeners were dominant - this doesn't match the profile of the prey. Plastics can provide the answer here. Higher-brominate congeners are present in plastics, including those found in the stomachs of the 3 birds. The results indicate that ingestion of plastic is the likely source of the higher-brominated congeners.   

Plastic debris acts as both a sink and a source for toxic chemicals. Source.

Interactions between plastic, toxic chemicals and the food chain

There are 3 key terms to know about the interaction between toxic chemicals and the food web:

1. Bioconcentration. Species living in chemical polluted waters concentrate the chemicals in their tissues
2. Bioaccumulation. Species face exposure to toxic chemicals from bioconcentration and ingestion. If the exposure is occurring faster than the chemicals can be eliminated, this is bioaccumulation. 
3. Biomagnification. Chemicals are found in progressively higher concentrations in progressively higher trophic levels in the food chain.

These 3 processes mean that even a small addition of chemicals can lead to large concentrations in species higher up the food chain. That includes humans too. Toxic chemicals and their interactions with plastic debris are a real concern for all people who eat seafood. Plastic is a sink and a source for toxic chemicals, but it is really a vector for transferring toxic chemicals from water, into marine organisms, and into us. Have a think about that next time you eat seafood. 

Biomagnification of toxic chemicals up the food chain. Source. 

A second life: ocean plastics re-imagined

Perhaps we can re-imagine the plastic in our oceans. It is still a pollutant, of course, but it could have greater potential. Adidas and Parley for the Oceans have been working on a project which would use 3D printing to turn ocean plastic into trainers. That's right. The plastic in our oceans could even be a resource! Projects like this could transform the lifecycle of plastic, reforming it into something useful again.

Trainers made from ocean plastic. Source: Adidas group. 

Little plastics, big problem: microplastics

Great for washing your face, terrible for marine environments: it's microplastics. They may be little, but they are a massive problem.

Microplastics: admittedly quite pretty, but definitely deadly. Source.

Microplastics (<5mm) have become an increasingly common ingredient in toiletries such as facial cleansers and toothpaste. They are often called 'micro-beads' by the toiletries industry and praised for "exfoliating skin and clearing out pores". The average consumer ends up using microplastics on a daily basis. There's a few reasons why these tiny pieces of plastic are seriously bad news:

• Microplastics are too small to be caught by wastewater screens, so they go directly into our oceans ...
• ... but they're plenty small enough to be easily consumed by small marine animals, such as filter feeders, which can starve from satiation, reduced food consumption or intestinal blockages 
• They then have the potential to pass up the food chain and accumulate
• Smaller pieces means a bigger surface area, which means more potential for binding and up-taking of toxic contaminants 

They're in our oceans and they're in our rivers too. In a study from earlier this week it was found that the Rhine has the highest levels of microplastic pollution in any recorded river, transporting an unbelievable 191 million plastic particles every single day! Microplastics are bad for you as well our waterways. Microplastics in toothpastes can end up embedding plastic in your gums.... Definitely count me out!

Plastic in my toothpaste? No thanks! Source.

However, not all hope is lost! As consumers, we can all make an effort to avoid products containing microplastics. What's more, major toiletry brands such as L'Oreal and Johnson have made commitments to phase out microplastics and replace them with natural alternatives. Even more encouragingly, laws are beginning to be drawn up which will ban microplastics. Addressing the issue of microplastics rapidly and effectively is a win for ocean conservation!