Precaution: A case-study

In the southern North Sea algal blooms are common. The water is shallow, currents carry nutrient-rich water over great distances, and in the coastal margins the hydrographical conditions for phytoplanktonic proliferation are very favourable. Along the eastern coastal regions of the Netherlands, Germany, and Denmark nutrient enrichment is particularly noticeable, caused primarily by insufficient removal of phosphorus from municipal sewagetreatment plants, and run-off from agricultural lands, where nitrates are the culprit.

There is controversy over how much of this is anthropogenic. Obviously this is important in the sense that if algal productivity is caused primarily by humans, regulations or investments aimed at reducing the nutrient burden would be nominally worth while. The economic argument would then be essentially one of identifying the point where the pay-off of nutrient removal matches the marginal gains in reduction of algal productivity.

It is not as simple as this, unfortunately. At the heart of this issue is the relationship between authoritative science and political action in an international commons.

From a purely scientific viewpoint, there is reasonable evidence that exceptional algal blooms predate the growth in municipal wastewater treatment and may be linked to nutrient-rich current inflows from the north-east Atlantic (see ISQR, 1990). This interpretation, however, is not conclusive because the necessary time-series data are simply not available. There is also good scientific monitoring to suggest that nutrient build-up is concentrated in the north-eastern parts of the southern North Sea, and is confined largely to the coast.

For example, in the German Bight of Heligoland, plankton biomass has increased fourfold between 1962 and 1985, and an occurrence of a bloom of Ceratiumfurca in September 1981 depleted oxygen to the point of disrupting a vast area of benthiccommunities. Exceptional blooms apply to occurrences of algal productivity that are sufficiently intense to be noticeable and to have adverse effects on tourism, fishfarming, and inshore fishing. These may now be more dramatic owing to more extensive data-collection, greater media coverage, wider distribution of vulnerable economic activity, and heightened public sensitivity to environmental change. In addition, unrelated events, such as the 60 per cent mortality of seals in the southern North Sea in July 1989, attracted speculation on a link between chemicals generally and environmental catastrophe.

In the public mind, the seal became a symbol like the canary in the coal mine, the national "barometer of ecological stress" that could eventually cause environmental catastrophe. To the scientific mind, the algal bloom is primarily an object for study, not for instant reaction as to cause and effect.

A particularly prominent bloom of Chrysochromulina polylepis occurred in the Skagerrak in May-June 1988. Subsequent investigation suggested that meteorological factors coupled to current movement had advected Atlantic water into the area. This column of water contained high concentrations of nitrogen, phosphorus, and silicates, but was stabilized by higher than average rainfall and the outflow of fresh water from the rivers. This stability led to a high nutrient density in subsurface levels, which was aggravated by further columnar stability due to the presence of a higher than normal outflow of cold fresh water from the Baltic. A spring diatom bloom removed much of the silicate and phosphorus, leaving a high nitrogen to phosphorus ratio in the column.

The rapid bloom of Chrysochromulina was probably limited by a lack of phosphorus, a condition which turned the species toxic and affected the shellfish industry across a wide area. A bloom of Prymnesium parva, another species of alga with toxic properties, caused $5 million worth of damage to Norwegian fish farms (IQSR, 1990).

At issue here are three interconnected themes. First, the scientific evidence of primarily natural causes is persuasive but not complete. The actual conditions that lead to bloom build-up and to associated toxicity are either unknown or cannot readily be modelled. Second, the damage to commercial interests is serious but not crippling. It is the greater extent of vulnerable economic activity in areas with algal bloom histories that contributes to the demand for action. Third, there is genuine anxiety about the possibility of a catastrophic spread of algal activity across a wide area that may not correlate with meteorological and marine conditions, hence a perceived need to stop the increase of nutrients from waste-water treatment plants and agricultural run-off.

The cost of nutrient removal, of course, will be high. In Germany and the Netherlands, the aim is to remove phosphorus and nitrogen from over three-quarters of municipal treatment plants by 1995 (ICPNS, 1990). This will reduce inputs between 25 and 50 per cent for these nutrients. In addition, Germany intends to tax industry on its nitrogen and phosphorus emissions, and the Netherlands has embarked on a strict ammonia control programme over unprocessed animal manure (Dietz et al., 1992). (Ammonia translates into nitrogen-rich aerosols that are deposited in the open North Sea.)

The British position is that the current level of scientific knowledge does not require the United Kingdom to take such drastic measures. It is said that there is no evidence of significant variation in algal bloom off the UK coast, riverine inputs are estimated as being less than a tenth of total N and P inputs, and though air emissions are considerable they are spread over 525,000 km² of ocean surface. Yet the British do concede that the "scientific picture is incomplete and important areas of research are now being addressed, particularly the relationship between gross inputs of nutrients via rivers and the estuarial processes which determine net inputs to the seas" (ICPNS, 1990).

In its declaration on nutrient removal of inputs into the North Sea, the International Conference on the Protection of the North Sea (ICPNS), composed of the Environment Ministers of the eight basin states, agreed in 1990 that each would commit funds for a substantial reduction of nutrients, up to 50 per cent, by 1995. In addition, the European Community, which covers all the eight states except Norway and Sweden, has proposed new directives on both municipal waste water and nitrogen removal in fresh waters that may add further to the costs of environmental protection. The United Kingdom government is, however, resisting the linkage of precaution to these policies.

Nevertheless, as a signatory to the Paris Commission, which deals with pollution from land-based sources, and as a participant in the 1990 ministerial conference, the United Kingdom has committed itself to a $2.5 billion sewage-treatment programme to bring its coastal outfalls up to at least primary levels of treatment. This is in line with the declaration that waste-water treatments plants must be evaluated on a case-by-case basis, and that primary levels of treatment should only be provided where "comprehensive scientific studies demonstrate to the satisfaction of the competent international authorities that this discharge will not adversely affect the North Sea environment at the local or regional level."

The point of this case-study is to show that the kind of argument proffered by the United Kingdom is no longer tolerable where a "commons" resource is perceived to be degraded. A "commons" resource in this case is the assimilative capability of the North Sea to absorb nutrients yet still remain ecologically viable and diverse. Where a group of nations believes that they collectively are responsible for that assimilative capacity, they will tend to support the principle of "equivalence of burden." This is also a part of the precautionary principle. Put simply, it means that each responsible party to a commons regime must share its commitment to the collective wellbeing of the resource and of its other partners. This means that, to a point, and irrespective of the scientific evidence, the United Kingdom must simply play its part.

In fact this was the outcome of the 1990 North Sea Conference, and the United Kingdom is committed to reducing nitrogen and phosphorus from its waste discharges into the North Sea, even though the government still protests that the benefits of nutrient removal are not justified, on grounds of scientific evidence, given the costs involved.

It is true that the ICPNS has limited the precaution principle to the narrow area of avoiding potentially damaging impacts of substances "that are persistent, toxic and liable to big-accumulate." In its guidance note, the UK government comments as follows:

The UK government . . . will take action to minimise inputs of such substances wherever there is reasonable evidence to suggest a causal link between emissions and effects even though such a link cannot be proven. The UK government...also considers that account should be taken of the costs of a measure in relation to its benefits. (Department of the Environment, 1990)

What is interesting in the nutrient case is a relaxation of the non-precautionary approach in a case where it would normally be justified, in favour of a shift towards a precautionary investment to meet international obligations and to be seen to be "pulling weight" on the costs of reducing coastal eutrophication. In short, the United Kingdom was forced to modify its purist stance in favour of recognizing that at least an element of precaution can be justified on political and moral grounds.

This shift may not look like much, but it shows that the politics of precaution are powerful, enduring, and progressive. In the 1990 International North Sea Conference, the United Kingdom agreed not to allow the dumping of sewage sludge in the southern North Sea, even though the government and its advisers claimed there was no scientific case to warrant such a move. The argument was that the sludge contains less than 2 per cent of any of the heavy metals that constitute the European Community "Black List." As regards eutrophication, the British view is that the sludge is disposed of in a region that is actually nutrient-poor. Yet the United Kingdom will now embark on a $600 million programme of sludge repatriation in order to play its part in the protection of the North Sea.

To gain leverage on other issues, notably the nutrient issue, the British government, as it saw the matter, "gave way" on the sludge-dumping controversy. This shows that precaution cannot and should not be divorced from politics and the tortuous tactics of international environmental diplomacy; the politics of precaution are in the ascendant in managing a common property environmental resource such as the North Sea.