|One of the bags from Cramond clean up - Image from s1cramond.com|
- Plastic parts
- Consumer rubbish (i.e. crisp packets, lolly sticks)
- Caps and lids
- String, cord, cloth, and string.
- Fishing line
- Cigarette butts
|No butts on the beach!|
As human population and waste levels explode, the oceans which cover 71% of the Earth's surface are in grave danger of becoming what can only be described as 'plastic soup' . Plastics have been part of our everyday lives for over 50 years now. Compared to glass or metals they are much cheaper to produced in the masses and tend to be more durable. As such, plastics have replaced much of these materials and, unfortunately, constitute a large proportion of the marine litter problem. Scientists have revealed that up to 80% of the waste found on the coast, ocean surface or seabed is plastic. That's a shocking amount, however considering that the annual plastic production (globally) has been estimated to be in excess of 250 million tonnes (!!) this figure does not seem so shocking - especially when Greenpeace suggested than up to 10% of these end up on our oceans. Whilst it is near impossible for plastics to be eliminated entirely, there are a series of methods that can help mitigate this problem.
|Image by Lindsey Hoshaw |
Compared to their larger older brothers, the macroplastics, microplastics are a bit like the evil unknown at the moment because no one really understands what direct effect they can have on the marine environment, particularly at ecosystem level. Baseline data is often difficult to collect as you can imagine - most of these little plastics are less than 1mm in length and, as such, cannot be tallied in a survey from a boat. There persistence in the marine environment has therefore been assessed by other means, such as via CPRs. Continuous Plankton Recorders (not cardiopulmonary resuscitation...) can be deployed from merchant vessels and towed during a normal day-to-day sail. Via this method, collaborative work between SAHFOS (Sir Alistair Hardy Foundation for Ocean Science) and the University of Plymouth (where I did my undergraduate - hurrah) has shown that there has been a significant increase in the amount of microplastics present over the last 40 years.
Marine litter has the potential to cause a myriad of problems for marine ecosystems. Plastics are likely to cause problems associated with:
- Facilitating the movement of alien species, or
- Entanglement of marine species, or
- Ingestion of the plastics.
In July 2009, Murray Gregory from the University of Auckland published a study in the Philosophical Transactions of The Royal Society B assessing the environmental implications and dangers posed from marine litter in our oceans. One of the main concerns that he highlighted was the potential for individuals to ‘hitch-hike’ on floating marine debris therefore moving them elsewhere into areas previously inaccessible. This movement of ‘alien species’ can have serious detrimental effects of resident populations and may drive species’ extinctions. In remote areas such as the tropical islands of Oceania or the sub-Antarctic islands, resident species may be unique to that area and as such warrant serious consideration for their protection.
|Image source: Greenpeace|
|Image source: NOAA|
hard truth; Albatross chicks are fed plastic particles|
mistaken for food and as a result die from starvation, suffocation
or toxicity. (Image source: Chris Jordan).
- Sub-lethal: Decline in feeding resulting in starvation and stunted growth rate due to malnutrition.
- Lethal: intestinal or oesophageal obstruction.
The relative abundance of plastic and plankton in the North Pacific Ocean reveals shocking results. In a study in 2001, on average 330,000 pieces were found per square kilometre with a max count of nearly one million. This is likely to affect a number of organisms based on their feeding habits. Seabirds, filter-feeders, and other species that feed within the ocean’s surface layers are likely to be affected. Laysan albatross chicks of the Midway Atoll (Northern Hawaiian Islands) are severely affected; of the 500,000 individuals born annually 200,000 die as a result of the debris accumulation from the Great Pacific Garbage Patch.
As well as the ingestion of macroplastics, the ingestion of microplastics is a growing concern given their tendency to absorb Persistent Organic Pollutants or POPs. The most common POPs include PCBs (Polychlorinated biphenyls), DDT (Dichlorodiphenyltrichlorethane), and BPA (Bisphenol A). Various adverse health effects have been documented with regards to these, ranging from effects on the immune system, reproductive system, nervous system, and the endocrine (hormone) system. DDT, for example, can induce what is referred to as imposex (development of male sex characteristics) in dogwhelks, whilst BPA mimics oestrogen causing problems to both fish and humans. POPs accumulate in the animal's fatty tissue and, with this in mind, apex predators of the ocean food chain tend to show the highest levels.
You are what you eat.
In the UK alone we are estimated to consume over 380,000 tonnes of seafood per year. Given what I have just told you about POP accummulation and such, seafood consumption includes toxic and plastics remains too. The Nephrops (Scampi) fishery, a commerically important fishery within UK waters (bringing in about £95.8 million per year), was studied in 2011 for plastic remains. Over 83% of Nephrops caught contained little indigestible plastic fibres.
The image on the right (source: http://www.care2.com/causes/you-are-what-you-eat-and-youre-eating-trash.html) is a fantastic pictorial of the marine debris problem, relating it back to human consumption. Just to highlight some key points from it:
- Humans consume, on average, 36lbs of seafood per person per year.
- The Great Pacific Garbage Patch contains an estimated 3.5 million tonnes of rubbish.
- 51 billion bottles are used (yearly) in the U.S. alone, only 1 in 5 are recycled.
- 260 known species eat non-biodegradable plastic materials (of course not out of choice, it is mistaken for food!)
- Some of these fish are eaten by other fish, the contamination is therefore biomagnified up the food web.
I understand that telling the ever-increasing population that they all have to ditch their synthetic clothes and reduce their weekly washing amounts is an unlikely scenario (and would most likely result in me being a very unpopular person). Being a little more careful about what we buy - cosmetics especially - will help substantially with the microplastic issue. Reducing macroplastic prevalence is much easier (easier said than done mind you), but make a few simple changes and you're on your way to helping the environment.
Reduce, Reuse, and Recycle.
It is imperative that there is a continuation in these 'three Rs'. This should reduce the amount of waste discarded within the environment, a lot of which ends up in our oceans. The UK effort for the recycling programme has improved substantially over the years, so let’s continue our efforts. Reducing the amount of waste discarded is easy, opt for a re-usable cloth bag for groceries and only drink beverages in glass bottles or buy items with very limited packaging. If you DO use a shopping bag for whatever reason, do reuse it. We actually have a drawer in the kitchen stuffed full of shopping bags. They will always be used for for rubbish and never thrown away AS rubbish.
For marine debris that has washed up on our coasts, the solution is simple and requires very little physical effort. Beachwatch, MCS' coastal environmental initiative, aims to involve local people and communities that want to help clean up the shore. They organise various big beach clean ups (as aforementioned) so check out when the next one is and get involved. Even if you are not part of a formal clean-up programme, next time you’re at the beach take a bag and pick up some of the rubbish yourself.