Food Chain UPDATES

A Book About The Poultry Industry —

I was brought up in Farming. When I was a teenager the poultry trade was free range hens or at the most confining wire surrounded runs for the hens. The lucky poultry roamed the fields. Then came deep litter and then the intensive farming of poultry. If you go to a super market the ready made meals are primarily chicken in any food style you like. Indicating the size of the industry. The birds are bred and reared to mature at a remarkable rate.

Any one who has seen or looked in the sheds where there is intensive farming of hens or who has seen the chicken processing factories might feel less keen on these delicacies.

A book devoted to this topic is

Planet Chickens; The shameful story of the bird on your plate. By Hattie Ellis published by Sceptre Publications

Arsenic And Rice —

Rice is very efficient in assimilating arsenic polluting paddy fields. The plant uses the same transport system as for silicon to achieve this , with two transporter proteins belonging to the aquasporin family.

As if polluted wells was not enough of a tragedy.

Proc.NatlAcad Sci . USA dol 10.1073/pnas. 0802361105 ( 2008)

Dioxins —

Dioxins are polychlorinated dibenzodioxins, formed from two benzene rings joined by 2 oxygen bridges, forming an aromatic ether. These are environmental pollutants and are teratogens, mutagens and possibly carcinogens. They are fat soluble and accumulate in mammalian tissues , giving them a prolonged biological life.

Chlorine atoms are attached at 8 different sites at positions 1-4 and 6-9. There are more than 75 cogeners of dioxin, where dioxin have chlorine at 2,3,7 and 8 positions there is enhanced toxicity.

Dioxins originate from the incineration of chlorine containing substances such as polyvinyl chloride, in the bleaching of paper and from natural events e.g. volcanoes and forest fires. Open burning of wood, waste, and diesel emissions are important sources of dioxin. Dioxins are to be found in cigarette smoke.

Dioxins enter the human body by eating food especially fish, meat and dairy products. The fat solubility of dioxin holds dioxin in the food chain. Dioxins are an occupational risk during herbicide use. Dioxin may be transposed to children through breast milk. This persists for 6-8 years. The lipid accumulation of dioxins is a major factor in the accumulative toxicity of these substances with a half life of 8 years.

Toxicity includes:

  • Increase tumour incidence
  • Developmental abnormalities
  • Thyroid disorders
  • Immune problems
  • Diabetes
  • Altering the male to female ratio in babies in an at risk population.
  • Skin lesions
  • Food Chain

Doomsday Seed Bank —

Seeds and the preservation of seed lines is an important silent part of nutrition. We assume as constancy in our vegetables and fruit. Changes in this forms part of our unease over GM crops. Are they as good as we have preciously experienced and enjoyed.

There are some 1.5 million different crop strains. These are always at risk from war, climate change and economic and cultural change.

The Norwegian Government has developed the Svalbard International Seed Vault where examples of most seeds in the world will be stored deep in an Arctic mountain. The first seeds will be stored in 2008. A global insurance policy. Or shuffling the deckchairs on the Titanic. .

The caveat to this wonderful and imaginative idea is that seeds loose their ability to germinate in about 20 years. This will mean a massive programme in addition to the $125,000 costs for maintaining the bank.

Michael Hopkin Nature vol 445—February 2007 p 693

El Nino Up to Date —

The Times of July 13th 2009 describes how El Nino, the warming of the Pacific Ocean that creates chaos in global weather patterns, is on its way back, threatening droughts, floods, crop failure and social unrest. Scientists at America’s National Oceanic and Atmospheric Administration (NOAA), warn that a new bout of El Nino is under way as the surface of tropical waters across the eastern Pacific has warmed roughly IC (l.8F) above normal and is still rising. Further down, some 150 meters (500ft) below the surface, the waters are heating up – by around 4C (7.2F). The persistently warm sea tempera¬tures are important indicators of an El Nino. There is also a link between the ocean and the atmosphere, with In¬donesia tending to dry out as tropical rainfall shifts towards the inter¬national dateline in mid-Pacific.” The implications are severe, not just for climate but for the effects on food, water supplies and other commodities. Australia, still recovering from its worst drought in a century will be affected again if the rains fail with consequences for the wheat belt. Indonesia is one of the world’s biggest producers of palm oil – a basic source of income for many of its poor – and a drought would hit this commodity hard. Farming in India is already suffering from an abnormal monsoon, which scientists think could be related to the emerging El Nino. The rains arrived early but stalled. Shortages and food prices caused riots all over the world in 2008, from western Africa to Mexico, Uzbekistan, Haiti and Egypt, as well as consumer protests in Europe and panic in food ¬importing countries. Rice-producing nations were urged to stop hoarding supplies as stocks fell to their lowest levels for 30 years. The emerging El Nino is expected to continue strengthening over the next few months and reach a peak during the northern hemisphere’s winter. The regions affected 1 Pacific coast of South America prone to floods 2 Australia. Indonesia. Philippines suffer droughts 3 United States tends to have fewer hurricanes. California stormy. and milder winters 4 Southern Africa can suffer drought 5 Parts of East Africa flooded 6 Indian monsoon can be disrupted El Ninos recur every few years and vary hugely in strength . A severe one badly influences wea¬ther patterns across the Pacific and be¬yond, leading to drought in some areas and heavy rains in others, such as the western coast of South America, In the last severe episode in 1997-98 torrential rains pulverised California, heat waves swept across Australia and Brazil, forest fires swept Indone¬sia, Eastern Africa was flooded while southern Africa withered under drought, and floods and storms caused billions of dollars’ damage to crops and buildings. There is even a positive aspect for Australians: a recent study has linked El Nino to increased chance of an Aus¬tralia-in-Australia Cricket Ashes victory. Records from 1882 to 2007 show that the tendency for dry wickets in El Nino years favours their fast bowlers. This was written by Paul Simons, the Times Weather Correspondent and author of Weird Weather, The Strangest Weather in the World

Effect On Fishing Population —

I have long felt that our population is one that has survived massive upheavals over the last few hundred years, the black death, emigration, starvation, war and tuberculosis .There is little to support this , but there is an interesting paper written on fish which is heavily fished in Nature vol 452 pp 835-839..

Christian N. K. Anderson et al have written a paper in Nature “Why fishing magnifies fluctuations in fish abundance ” showing that fished populations can fluctuate more than unharvested stocks. However, it is not clear why. They distinguish among three major competing mechanisms for this phenomenon, by using the 50-year California Cooperative Oceanic Fisheries Investigations larval fish record. First, variable fishing pressure directly increases variability in exploited populations. Second, commercial fishing can decrease the average body size and age of a stock, causing the truncated population to track environmental fluctuations directly. Third, age-truncated or juvenescent populations have increasingly unstable population dynamics because of changing demographic parameters such as intrinsic growth rates. They find no evidence for the first hypothesis, limited evidence for the second and strong evidence for the third. Therefore, in California Current fisheries, increased temporal variability in the population does notarise from variable exploitation, nor does it reflect direct environmental tracking. More fundamentally, it arises from increased instability in dynamics.

This is an empirical example of how selective harvesting can alter the basic dynamics of exploited populations, and lead to unstable booms and busts that can precede systematic declines in stock levels.

Maybe the culling of human populations has the same effect.

Anderson et al 2008, Why fishing magnifies fluctuations in fish abundance Nature vol 452 pages 835-839.

Food Chain —

Modern farming industry and other industries are causing a large amount of nitrogen to enter the soil at double the natural rate.

The nitrogen is in the form of nitrates and much elutes into streams, rivers and lakes. There is increased plant and bacterial growth in the water, a process known as eutrophication.

However some nitrate is retained by biological processes by plants and bacteria. Most importantly there are bacteria which convert the nitrate to molecular nitrogen and nitrous oxide. These bacteria persist in the sediment of streams and banks. However at higher concentrations of nitrate the efficiency of this process declines.

Seitzinger Out of reach Nature vol 452, pp162-3

Food Chain 2 —

Marine life and nitrogen cycle fix
I live by an estuary and this stretch of water is inhabited by lots of fish who have seals as predators. The local fishermen dislike the seals and would rather they left.

In the last month their wishes have come true and a pod of killer whales has appeared on the scene and they are feasting on the baby seals. The baby seals are very vulnerable as they begin to swim out of their mothers care.

The natural balance of he shore life will no doubt change as a result of these new visitors. Killer whales are the third most common mammal on the planet after man and the rat.

The cycle of life is ultimately dependent upon the massive food cycles. One such is the nitrogen fixation that takes place in the oceans.

The flow of nitrogen compounds between the oceans and the atmosphere is central to life, as nitrogen is a fundamental component of bio-mass and is essential for many biological processes. Much is known about the nitrogen cycle of the oceans, but there unanswered question.

Evidence is developing which shows that the primary process which puts nitrogen compounds into the sea i.e. biological nitrogen fixation is intimately associated, with marine nitrogen removal. The ratio of nitrogen to phosphorus in sea water may be the central factor that regulates nitrogen fixation.

Biological nitrogen fixation, the enzyme-catalysed reduction of nitrogen gas (N:) continually adds nitrogen to the sea in the form of compounds that can be used as nutrients. Nitrogen fixation is commonly associated with certain cyanobacteria that live in the warm, sunlit surface waters of low-latitude oceans’. These photosynthetic bacteria tap the immense reservoir of dissolved N: gas in sea water, but their growth is often limited by the scarcity of other nutrients such as phosphorus and iron . A ratio of iron to phosphorous of 16:1 is the norm.

Fixed nitrogen is eventually converted to nitrate by nitrifying bacteria. Ultimately, the loss of nitrogen from the ocean occurs by denitrification, a process that converts nitrogen compounds such as nitrate back to N-. Denitrification occurs mostly at depths of 200-700 metres in the ‘oxygen minimum zones’ (OMZs) of the ocean — that is, in the eastern tropical north Pacific, the eastern tropical south Pacific Ocean , the Arabian Sea and in marine sediments.
The unusually high growth rates of nitrogen fixers in the north Atlantic result from the high rate of growth of nitrogen fixers stimulated by the high flux of iron containing dust blown in the wind from North Africa

Capone and Knapp Nature 2007, January 11, vol 445, pp 159-160
Deutsch et al Nature, 2007, , vol 445, 163-167.

Iron And Carbon Sequestration —

The Southern Ocean plays a major role in the climate system, and is recognized as the ocean most sensitive to climate change . The control of biological productivity e.g. the phytoplankton community by iron in the Southern Ocean has been shown by iron adding experiments.

The availability of iron limits biological productivity and the associated uptake of carbon over large areas of the ocean. Iron plays an important role in the carbon cycle, and changes in iron supply to the ocean surface may have had a significant effect on atmospheric carbon dioxide concentrations.

Blain and his colleagues in Nature 2007, 26th April , vol 446, pp 1070-74, have shown that a large phytoplankton bloom over the Kerguelen plateau in the Southern Ocean is maintained by the supply of iron and major nutrients to surface waters from iron-rich deep water below. The efficiency of fertilization, defined as the ratio of the carbon export to the amount of iron supplied, was at least ten times higher than previous estimates from short-term blooms induced by iron-addition experiments’. This result sheds new light on the effect of long-term fertilization by iron and macronutrients on carbon sequestration, suggesting that changes in iron supply from below may have a more significant effect on atmospheric carbon dioxide concentrations. .

Blain and his colleagues in Nature 2007, 26th April , vol 446, pp 1070-74

Nitrates And Farming —

Modern farming industry and other industries are causing a large amount of nitrogen to enter the soil at double the natural rate.

The nitrogen is in the form of nitrates and much elutes into streams, rivers and lakes. There is increased plant and bacterial growth in the water, a process known as eutrophication.

However some nitrate is retained by biological processes by plants and bacteria. Most importantly there are bacteria which convert the nitrate to molecular nitrogen and nitrous oxide. These bacteria persist in the sediment of streams and banks. However at higher concentrations of nitrate the efficiency of this process declines.

Seitzinger Out of reach Nature vol 452, pp162-3

Nitrogen And Carbon Cycles And Global Warming —

The acceleration of the nitrogen cycle as a result of the production and industrial use of artificial nitrogen fertilizers worldwide has enabled humankind to increase food production. However there are unforeseen environmental problems.
Studies on these alterations in the nitrogen cycle have led to a much improved understanding of the scope of the problem and possible strategies for managing it. These alterations in the nitrogen cycle affect other major biogeochemical cycles, particularly that of carbon.

The release of carbon dioxide (CO:) from the burning of fossil fuels has major consequences for the functioning of the global carbon cycle, and as nitrogen has a crucial role in controlling key aspects of this cycle, the nitrogen-carbon-climate interactions are becoming increasingly pressing.

Does the availability of nitrogen affect the capacity of Earth’s biosphere to continue absorbing carbon from the atmosphere, and hence continue to help in mitigating climate change. The dynamics of the nitrogen cycle are important in the context of a changing carbon cycle, a changing climate and changes in human actions.

Nitrogen is a fundamental component of living organisms; but is in short supply in forms that can be assimilated by plants in both marine and land ecosystems. Nitrogen has a critical role in controlling primary production in the biosphere. Nitrogen is also a limiting factor for the plants grown by humans for food. Without the availability of nitrogenous fertilizer produced by the Haber-Bosch process, the enormous increase in food production over the past century, which in turn has sustained the increase in global population, would not have been possible. All the nitrogen used in food production is added to the environment, as is the nitrogen emitted to the atmosphere during fossil-fuel combustion.

In the 1990s, these two sources of anthropogenic nitrogen to the environment amounted to more than 160 teragrams (Tg) N per year On a global basis, this is more than that supplied by natural biological nitrogen fixation on land (HOTg N per year) or in the ocean (UOTgN per year}.

Given expected trends in population, demand for food, agricultural practices and energy use, anthropogenic nitrogen fluxes will increase; that is, humans are likely to be responsible for doubling the turnover rates not only of the terrestrial nitrogen cycle but also of the nitrogen cycle of the entire Earth.

The negative consequences of these nitrogen additions include excessive growth of plant and microorganisms in terrestrial and aquatic systems to global acidification and stratospheric ozone loss

Also chemical transformations of nitrogen along its transport pathway in the environment is important. Nitrogen oxide can first cause photochemical smog and then, after it has been oxidized in the atmosphere to nitric acid and deposited on the ground, can lead to soil and water acidification and excessive growth of plant and microorganisms

The human acceleration of the nitrogen cycle did not occur, alone as the phosphorus, sulphur and carbon cycles ere are affected. The burning of fossil fuels and carbon emissions from land-use change, atmospheric CO, has increased to levels that are more than 30% above those of pre-in Industrial times and the observed warming over the past century, particularly that of the past 30 years”.

The perturbations of the global nitrogen and carbon cycles caused by human activity are in part linked to each other. This is mostly a result of the atmosphere’s being very efficient in spreading the nitrogen oxides and ammonia emitted as a result of energy and food production, and also because this nitrogen is deposited on the ground in a form that is readily available to plants, thereby stimulating productivity and enhancing the uptake of CO, from the atmosphere

The deposition of both nitrogen product s and carbon in the oceans has unknown effects.

Gruber and Galloway 2008 An earth-system perspective of the global nitrogen cycle . Nature vol 451, 293-296

Nutrients In Synergy —

One of the great discoveries in Nutrition was that of Justus von Liebig in the 19th century. He showed that crop production is limited by the nutrient in shortest supply. His law of the minimum.

Plants require carbon, hydrogen and oxygen from atmospheric gases and water. And of course trace elements.

The work of Liebig has transformed agriculture and taken some of the worry of Malthus and his theory of population from us, at least for a while.

The ready provision of food has enabled the human population to grow in an unfettered manner. However the excess of nitrates and phosphorous added to the land and the seepage into the overall system especially water has had dire consequences. Including a proliferation of algal bloom. This has had consequences for fish stock and available oxygen in the water.

Elser and colleagues in Ecology Letters have made a meta analysis of the effects of these two elements on the biomass. The effect of adding nitrogen and phosphorous to growing plants is profound. At the same time there is a synergistic effect and both are required. The effect is to alter complex metabolic relationships within the plant which have yet to be fully understood

Nevertheless we have here an important nutritional point of relevance to human nutrition. There are limiting elements in our diet.

The concept of a balanced diet is not a platitude but central to good nutrition.

Davidson and Howarth 2007 Nutrients in synergy Nature vol 449, 1000-1001

Ocean CO2 —

The ocean is very important in modulating atmospheric carbon dioxide through a variety of physical, chemical and biological processes.. A key process responsible for about three-quarters of the surface to deep-ocean gradient in dissolved inorganic carbon is the biological carbon pump. This transports carbon bound by photosynthesis from the sunlit surface layer to the deep ocean.. Small changes in this pool, for example, caused by biological responses to ocean change, would have a strong effect on atmospheric CO2.
At present, one of the must far-reaching global perturbations of the marine environment is caused by the massive invasion of fossil fuel CO2 into the ocean, making it the second largest sink for man made carbon dioxide after the atmosphere itself. CO2 entering the ocean alters the seawater carbonate equilibrium, decreasing pH and shifting dissolved inorganic carbon away from carbonate towards more bicarbonate and CO2-

The oceans have absorbed nearly half of the fossil-fuel carbon dioxide emitted into the atmosphere since pre-industrial times, causing a measurable reduction in seawater pH and carbonate saturation. If CO2 emissions continue to rise at current rates, upper-ocean pH will decrease to levels lower than have existed for tens of millions of years and, critically, at a rate of change 100 times greater than at any time over this period. Recent studies have shown effects of ocean acidification on a variety of marine life forms, in particular calcifying organisms.
In a paper in Nature Riebesell et al show that the dissolved inorganic carbon consumption of a natural plankton community increases with rising CO2. The community consumed up to 39% more dissolved inorganic carbon at increased CO2 partial pressures compared to present levels, whereas nutrient uptake remained the same.

This excess carbon consumption was associated with higher loss of organic carbon from the upper layer of the stratified mesocosms. If applicable to the natural environment, the observed responses have implications for a variety of marine biological and biogeo-chemical processes, and underscore the importance of biologically driven feedbacks in the ocean to global change.

Riebesell et al 2007 Enhanced biological carbon consumption in a high CO2 ocean Nature vol 450 pp 546-8

Plastic Containers For Food —

Plastics are an omnipresent part of our food bought in shops or supermarkets. These are varied in Chemistry. Hopefully now most are recycled . Most of the plastic for recycling is carried to Hong Kong or China and the remainder is processed in the UK.

Vilified as they are, plastic containers are important in the carriage of foods. Whereas 50% of food in India is wasted by the time it comes to be sold the figure for plastic covered food is 3%

This topic is well aired in an article by Sam Knight in Financial Times Weekend Magazine April 26-27 , 2008 pages 15 to 22

The Global Food Chain —

Nutrition on a macro scale is a compelling subject. The Television News frequently carries pictures of awful deprivation. A recent radio programme spoke of the horrors of the famine around Calcutta in India during the second World War when millions died.

Raj Patel’ has written a timely book

Stuffed and Staved: Markets , power and the hidden battle for the World’s food system. Portobello Books

He discusses the food chain . He emphasises the importance of our relationship with the land and the natural world. Global warming, in part, is the consequence of ignoring this.

Coupled to the excess number of humans alive today. Yet who can deny each individual their life

This very important book is reviewed in the Lancet 2007 vol 370 pp2089-90 by . Jonathan Porrit. Even if you don’t get the book at least try to read this captivating review.

Vernalisation —

In Melvyn Bragg’s BBC programme In Our Time and News letter ( 5/6/2008 ) he describes how Lysenko, the controversial Russian Agronomist promoted an agricultural technique known as “vernalisation”, which can be defined as the subjection of seeds or seedlings to low temperatures in order to hasten plant development and flowering. The word vernalisation comes from the Latin word “vernus”, meaning “of the spring”. Lysenko was not the first person to discover
this technique, but he was the first to champion it as the sure fire way to improve crop yields in record time. Peasant farmers had been carrying out their own version of vernalisation for generations when they left grain out in a cold barn which served to toughen the seeds.
A young plant given a cold blast will toughen but Lysenko’s claim was that
through vernalisation one species of wheat – winter wheat could be
transformed into another – spring wheat. He germinated the winter
wheat and then subjected it to very low temperatures to halt its
growth until it was sown in spring. Lysenko believed that the shock of
the cold would cause the transformation from one species to another,
and produce greater yields. Lysenko believed that the
crucial factor in determining the length of the vegetation period in a
plant was not its genetic constitution, but its interaction with its
environment. This claims meant that wheat could potentially be grown in the barren north where previously the temperature had proved detrimental to agricultural development .

This was all before Molecular Biology transformed our thinking.

This theory came when the Ukraine and other areas were staving due to collectivisation. Lysenko was taken up at a time when millions were dying in the Ukraine from starvation. It was a desperate, desperate situation and he seemed to be offering solutions.


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