Eutrophication... Meatrophication! A pun on so many levels!

Eutrophication; another problem (partly) caused by meat consumption.

Now I said I wanted to look into pollution caused by livestock farming in a bit more depth… so I am going out to the open ocean…lol not a very good joke is it?

There is a lot of material on the topic of eutrophication and I have already touched upon it before in some of my previous blogs and referenced some really useful sources. Here are three more!

The World Resource Institute commissioned three reports on eutrophication or as they call them ‘Policy Notes’:

• Eutrophication and Hypoxia in Coastal Areas: A globalAssessment of the State of Knowledge. (Selman et al. 2008) 
• Eutrophication: Sources and Drivers of Nutrient Pollution.(Selman and Greenhalgh, 2009a)
• Eutrophication: Policies, Actions and Strategies to AddressNutrient Pollution. (Selman and Greenhalgh, 2009b)

The reports define eutrophication as ‘over enrichment of water by nutrients such as nitrogen – and most topically for us – phosphorous’.

Selman et al. (2008) shows the extent of the problem. In the United states and Europe’s Atlantic coastal waters, 78 and 65 % of the respective areas were exhibiting some symptoms of eutrophication. In this case symptoms of eutrophication include the most common hypoxia and algal blooms.

The severity of the problem is not widely known due to the poor monitoring of global ocean water quality. Like with many research projects funding is required; most countries especially those who face challenges of greater importance (like epidemics/droughts/famines/natural disasters/wars) simply cannot spread resources to measure a trivial data set when there are more important things to hand.

However what is known is the responses of the ecosystem. Initial growth of phytoplankton, micro-algae and macro-algae; these can cause:

• Reduction of light penetration into waters (planets below the surface of the water cannot photosynthesise as the light is being absorbed and blocked out the excessive algal growth).
• Benthic (bottom-dwelling) aquatic community species change, less biodiversity.
• Algae can outcompete coral larvae for nutrients, so there is reduced coral growth.
• A shift in the phytoplankton species composition, allowing toxic algal blooms to develop.
• Collapse of oxygen reserves in the water resulting in ‘dead-zones’.

These symptoms damage the ecosystem and more importantly inhibit its economic potential, either directly through ecosystem servicing (what you can ‘harvest’ from the ecosystem, i.e. fishing; biodiversity; carbon sequestration) or indirectly through loss of income from reduced tourism; reduced income from fishing; recreational facilities.

Hypoxic zones exist around the world. Some of the best examples are the Gulf of Mexico (Mississippi outflow) and the Black Sea (Volga and others outflow). Particularly in the case of the Black Sea, there is a strong correlation between agricultural intensification in the 1980s and the size and rate of the hypoxic zone formation. Since the collapse of the USSR, the Black Sea has in part been in recovery.

Agriculture is not the only source of excess nutrients: human and animal sewage (…yep POO and PEE!!!), urban runoff, industrial effluent and fossil fuel combustion (not just more nutrients but more CO₂ allows more photosynthesis/productivity as CO₂ is generally seen as the limiting factor in plant growth).

The relative importance of the sources of nutrients is spatial. In Europe and USA, the biggest source is fertiliser application and runoff into the sea via rivers; whereas in Africa, Latin America and Asia as industrial regulations are laxer effluent is the largest contributor. Dry nitrogen deposition (from volatilisation of fertilisers) adds to eutrophication; Chesapeake Bay, in the US (as seen in an earlier post referencing Megan Smith’sblog) and the Baltic Sea in Northern Europe are good examples of this.

There is a necessity to collect information on nutrient sources and their quantities and a time series of all factors involved; from nutrient influx to chlorophyll, oxygen concentrations; quantifying the impacts on income (cost of loss of fish production, etc.). Selman et al. (2008) conclude with the importance of eutrophication to governments and the requirement to never leave it unchecked.

Selman and Greenhalgh (2009a) goes on to further highlight the significance of increased population (demographic pressures; 9.2 billion by 2050) coupled with greater demand for food and fertiliser to increase production; intensification driven by changing dietary patterns, for instance increased meant consumption up 54% from 2002 to 2030, during the same time frame energy is expected to grow 50 %. Most of the growth will occur in the developing world where there is greater vulnerability to resource pollution due to lack of funds to cope with environmental degradation and the health implications stemming from it (untreated water, spread of disease).

The tables from Selman and Greenhalgh (2009a) show nutrient sources (table 1) and percent of treated sewage (table 2).

Focusing on agricultures role in eutrophication, fertiliser leaching, runoff from agricultural fields, manure from concentrated livestock operations and aquaculture are the largest sources. Focusing on manure (a direct impact of more livestock) and fertiliser leaching and runoff (proportional to livestock feed) the relationship between eutrophication and these processes is strong. As shown from Cordell et al.’s (2009) paper with the phosphorous source graph over time, inorganic P use has tripled since the onset of the 1960s green revolution; eutrophication has also shot up. Nitrous oxides (from farts!) also add to the N used by algae. An important note is they mention that manure application to fields is timed not by necessity but by storage; when too much is in stock, they ‘fertilise’ the land, this exacerbates the run-off and leaching issue resulting in greater amounts of eutrophication. Selman and Greenhalgh cite Ellis, 2007 and Mee 2006 as studies which show poor pollution controls in China and also the production of an equivalent 5 million inhabitant city quantity of excreta from a 1 million pig farming operation in the Black Sea (respectively).

The Figures below show Meat consumption per capita against time (figure 2) and projected fertiliser consumption (figure 3) (Selman and Greenhalgh, 2009a). The link between meat consumption, fertiliser use, land use change, manure production, population growth and eutrophication is clear; ‘a by-product of unsustainable agricultural production and energy use’ (page 6).

The final report (Selman and Greenhalgh, 2009b) looks at the potential to tackle this problem. Other than the issue of monitoring which has already been looked at, they shed some light on other elements; increasing environmental awareness and greater public knowledge of the problems faced due to our consumption patterns.

Regulation and the imposing of standards in: environmental quality; pollution (effluent/emissions) capping; technology (up-to-date and efficient as well as sound).

Financial incentives like eco-taxes on environmentally degrading products (like meat); subsidies like payment for ecosystem services (PES) where a government subsidises farmers who employ an eco-friendly agricultural practice at the expense of profit – that profit is then compensated as the cost of the ecosystem service provided by the farmer (i.e. less intensive use of fertilisers, ditch management, receive £50 a month rather than production subsidies); eco-labelling and consumer awareness in the market place (successful with free range).  

Creation of protected areas via either nature preserves, sites of scientific interest, national parks which all limit the types of activity that can be performed in the area; land purchases and habitat restoration and conservation (like in Chesapeake Bay).

The requirement for institutional support is emphasised as well. Greater transparency, accountability and participation are all listed as vital to the success of schemes from the outset, to implementation, to completion. This is also the same set of criteria for what is referred to as ‘Good Governance’ in development literature.

Summing up; it is integral to sustainability that eutrophication is reversed. The issues around water quality are large. Where agriculture and livestock come into it is simple, more meat requires more fertiliser which produces more poo and other wastes! It is through the large wastes in agriculture that we get side-shows of eutrophication which further degrades our environment. What is needed as hinted to by the literature is a holistic approach, a multi-disciplinary approach involving all parts of the puzzle. There are successes highlighted in tables but that would be too much copying and pasting!!!

Please feel free to read them, especially if interested on the topic of eutrophication!

For an alternative summary please look at this site! It explains it in a much more eloquent way than I! 

Save the water! Eat less meat! (I will try!!!) :D