Principles of marine degradation 3

cycles and trends in marine degradation

by Dr J Floor Anthoni (2004) 

How do cycles and trends work? Are they natural or unnatural? What can we learn from cycles and trends?
Could the increase in rainfall have been produced by the plankton? Are we entering a disastrous vicious cycle? How could DMS (dimethyl sulfide) influence global climate and weather? Where does DMS come from?
Some organisms are sensitive whereas others are more robust. Why? What does resilience mean? What is resilience in ecosystems?
go to part1 (contents) <=> go to part2  go to part4

For comments, corrections or suggestions, please e-mail the author Dr Floor Anthoni.
Note! for best printed results, set your page up with a left margin of 1.5cm (0.3") and right margin of 1.0cm (0.2"). Read printing instructions.
-- Seafriends home -- conservation index -- issues index -- sitemap --
Rev:20040310,20050523,20051123,20060325,20060629,20070507, 20070728


Cycles and trends

The natural world experiences many natural cycles like the daily day/night cycle, the monthly tide cycle, the yearly seasonal cycle and much slower cycles like the IPO Interdecadal Pacific Oscillation 'El Niño' (9-11) years, which is perhaps triggered by the sunspot cycle of similar frequency. Much slower cycles exist, such as the ice ages and others slower still. 
Human-made cycles have now been identified, like the traffic peak hour cycle, the weekday/weekend cycle and the pronounced summer holiday cycle. Believe it or not, they have shown to affect the weather but not likely the marine environment. (but they do affect the creatures found in the rock pools at Leigh. Why?)

Trends are slow progressions, and global warming or the present climate change can be called one. The gradual increase in the human population is a very important one, with its associated influence from pollution, habitat change, introduced species and many more. Although climate change to a possible new ice age is another trend, all others are recognisably caused by humans. So the perception that trends are unnatural whereas cycles are natural, has taken hold in the minds of many. However, this may not be entirely true or not true at all when one looks at their effects on nature.

Suppose a warm/cold water cycle exists of about 10 years, superimposed on the yearly warm/cold cycle. It could bring summers that are warmer than normal and winters colder than normal, and these extremes could affect the environment, although such extremes are entirely natural. Now add to this the trend of plankton blooms increasing in density, and suddenly the temperature extremes are amplified as they work through the plankton ecosystem, causing cyclical mass mortalities. In other words, the effects of the natural cycles have become unnatural although the cycles themselves are natural. This has become the norm rather than the exception. Is the change in climate natural or unnatural? Are the suddenly increasing torrential rains natural or unnatural?
cycles and trends and degradationBut there is an important aspect of cycles superimposed on trends, as the diagram shows. Although natural cycles are often undulating slowly like a clock's pendulum, their effects on the environment are usually not. It has to do with the difference between life and death, which is a profound long-term change. Because of this, disasters strike rapidly whereas their recovery times proceed more slowly, as shown in the diagram. As disasters become more frequent, or when these are superimposed on a gradual degradation, nature appears to become tired, and recovery proceeds more slowly and less complete. This is how degradation proceeds, something to keep in mind when reading every point made in this document. 
Think of the ups as good and the downs as bad. A bad year allows one to look far into the future whereas good years look a little backward. Likewise the leftover species allow one to look backward in time. Eventually today's bad year will be tomorrow's good year. Today's bad summer will be tomorrow's good summer. Think about it.

There are people who claim that we cannot make a value judgement about the environment. Is a fine day better than a stormy day? Is summer better than winter? Is a desert better than a tropical rainforest? Is gravity good? and so on. If one reasons in a human-centric way, and looks back at how Homo sapiens evolved, one can say that it did well somewhere in between starving in the desert and dying from disease in the rain forest, not unlike the plankton balance hypothesis suggests for all creatures in the sea. From that perspective we can say what is good for us and what is bad. But can we say that degradation is bad? Is losing both the quantity and quality of life (which is not our life) bad? What do you think?

DMS cycle

From the above it is clear that increased rain intensity leads to a massive increase in runoff and consequent stress to marine organisms, but could the increased rainfall and increased occurrence of torrential downpours have been caused by the plankton? 

how DMS makes water dropletsIn search of the cycles of essential minerals for life, Dr James Lovelock discovered the sulphur cycle from sea to land already some 30 years ago. As a by-product of photosynthesis, marine plankton produces an invisible gas called di-methyl sulphide (DMS). Its molecule CH3.S.CH3 resembles that of water H.O.H with similar polarity and shape and this attracts water molecules to it. Dr Lovelock discovered that DMS plays a major role in the formation of clouds (tiny water droplets) from water vapour which is invisible and transparent. He posited that the marine plankton played a major role in controlling the Earth's temperature by producing more white, sun-reflecting cloud, when the Earth needed cooling. Global circulation scientists now acknowledge that the DMS cycle should become part of their computer models if these are to predict global temperatures reliably. But the DMS cycle may have other consequences.

Increased runof from the land fertilises the sea, which causes more intense plankton blooms. These produce more DMS which produces more rain and more torrential rains. These in turn produce more runoff, and more plankton blooms, and so on, a self-intensifying cycle. But there is more to it.

We have recently discovered wit the DDA method that when plankton density increases, the planktonic decomposers can very suddenly increase their numbers, to such extent that they command most of the solar energy. This means that the phytoplankton is decomposed before it can be grazed by the zooplankton. During decomposition, the DMS gas is formed as is now known from other studies. (DMS with its molecular structure CH3.S.CH3 resembles the decomposition gas hydrogen sulphide H.S.H. Also an intermediate form CH3.S.H can be formed during decomposition) The conclusion is unavoidable: in recent times suddenly much more DMS has been formed and this is accelerating still.

Could we have entered an accelerating vicious cycle which leads to more and more dense plankton blooms and loss of land? It could help explain why the sea's problems are accelerating so fast, world-wide. Is this vicious cycle going to exceed all other known threats? The speed with which the degradation of the sea accelerates, confirms it. Think about it.

In case of increased DMS levels in the atmosphere, the following can be predicted:

The reason I think that the threat from the vicious DMS cycle should be taken seriously, is that it is the only mechanism that explains why we are getting more intensive rains despite the fact that temperature has not changed. Indeed, even during periods of cooling, torrential rains keep pouring. We have mentioned the importance of the change in the water cycle which may well be the very cause of the world's climate change, but this alone cannot explain why rains are becoming more torrential.

Reader please note that the threat from the DMS cycle has not been published elsewhere.


In the chapter on resource management we discussed the ingredients that make up resilience, the capacity to rebound to original, from bad times in between. We noted that its main components are: overcapacity, replication, diversity, connectivity and adaptability. We also noted that the memory functions within such ecosystems may well be the only functions that matter. Note that ecosystems and habitats do not resist change because they are made up of many species and individuals. As environmental threats arrive, they change or yield gradually in response. When threats retreat, they recover to the original state. Sometines a gradual change introduces a flip to an apparently different form of environment and sometimes the return to the original state does not occur or not immediately. The idea of resilience describes the ability of an ecosystem to return to its original state. Please notice that ecology (= knowledge of the environment) is still very vague about this with few if any hard examples. 
But individuals do exhibit forms of resilience because they tolerate a range of conditions and because life repairs and because the transition from life to death is a flip. Here are some of the reasons why some species are hardy whereas others are not. Reader please note that what follows below is speculation in order to think more clearly about resilience.

The Plankton Balance Hypothesis posits (= proposes, assumes) that decomposing organisms like bacteria, viruses and fungi are bound to pose the main threats when an environment degrades. We will now posit that an organism has two major defences: its immune system which fights infections within, and its microcosmos of friendly microbes which protects it from the outside. In the world of microbes a new microbe won't make it when all space is occupied by others. Likewise evidence exists that the main protection of the human skin is the microcosmos of microbes living on it. Thus we conclude that organisms who are covered in a rich cocktail of friendly microbes, are correspondingly more hardy:

Conversely we can imagine what makes organisms sensitive: 
  • thin skins: thin skins can be pierced easily by offending microbes: fish larvae, some corals, anemones, 
  • dry skins: lacking protective slime: leatherjacket, sick seaweed, slow growth,

Finally we must realise that the type of food organisms feed on, may determine many resilience characteristics: 
  • producers: these are the seaweeds (and phytoplankton). Seaweeds have no roots to take up water and nutrients like land plants do. Their leaves are designed to take up nutrients and to exchange gasses. As a result, most seaweeds are sensitive to pollution and infection. Seaweeds depend on light which makes them sensitive to deposition by mud. Many seaweeds excrete slime for their protection and to remove dust. Where the water sways, seaweeds clean one another by overlapping fronds. Seaweeds are bound to be sensitive.

  • [Our slush hypothesis (see DDA chapter) suggests that many seaweeds live in harmony with 'friendly' decomposers that enable them to be more productive. It may help explain why many seaweeds are so sensitive to degradation.]

resilience or slide?
Reader please note that although resilience is real in individuals, resilience of ecosystems may not exist in nature, living solely in our minds. My own observations have confirmed that ecosystems just adapt gradually according to the changes applied, even if those changes are very small. When following ecosystems along a gradient that extends over a considerable distance (like water clarity), the (underwater) ecosystems do not make step-wise changes but rather, change gradually and imperceptably. Thus ecosystems have no thresholds, as is important in resilience theory. Much has been written about resilience theory but with no evidence to back it up experimentally or with robust data. It may just be a scientific fantasy.

Holling, C. S. 1973. Resilience and stability of ecological systems. Annual Review of Ecology and Systematics 4:1-23.

go to part1 (contents) <=> go to part2 <=> go to part4