TOLERANCE LEVELS UNDER STANDARD CONDITIONS

REACTIONS IN STATIC TESTS

With the widespread use of DDT and allied chlorinated hydrocarbon insecticides for pest control in the 1950s and 1960s it became increasingly clear that stream invertebrates were highly vulnerable to these chemicals. This destructive effect was particularly evident when stream and river habitats were unavoidably contaminated by repeated aerial applications of insecticides against forest pests such as the American spruce budworm. Experiences with mass destruction of river fauna in one of these campaigns in the Yellowstone National Park in the US, stimulated the need for more precise information about the susceptibility of stream invertebrates to the different insecticides then in use. This resulted in perhaps the first serious development of a laboratory evaluation programme for stream invertebrates in general as distinct from such target fauna as Simulium larvae (Gaufin, Jensen & Nelson, 1961; Jensen & Gaufin, 1964, 1966; Gaufin et al., 1965). That and the other contemporary work has already been reviewed in depth (Muirhead-Thomson, 1971), but there are still aspects of those studies which are of particular significance in the light of developments in the 20–25 years since that period. First of all, two aquatic invertebrates which played a prominent part in those laboratory tests, namely the stonefly (Plecoptera) nymphs of Pteronarcys californica and Acroneuria pacifica, were typical of clean unpolluted running water and were also important food organisms of trout. Second, both species were robust creatures, easy to obtain and to maintain in a healthy condition in the laboratory.

INTRODUCTION

In Chapter 1 it was pointed out that many of the striking advances in knowledge over the last 10–15 years regarding pesticide impact have been the outcome of field studies in practical pest control programmes. In all these projects, the environmental studies relate to the known chemical and formulation which is either applied directly to the stream at a predetermined application rate calculated to produce the desired concentration of the chemical in the water, or which contaminates the stream indirectly as a result of aerial application of pesticide to control terrestrial pests in the environs of the stream or river, and where the dosage rate in terms of kilograms per hectare has again been predetermined. In both instances the actual time of application is also known precisely.

The object of these environmental studies is to find out the extent to which the pesticide treatment produces significant changes in the composition of stream fauna produced by mortality or downstream movement, with particular reference to the macroinvertebrates which are the subject of this review. In order to measure these effects and to ascertain significant population changes among the different organisms of running water community – both in the short term and the long term – pesticide ecologists have to rely on a variety of sampling methods. It is these various capture or trapping techniques which provide the essential data for measuring changes in population density or in population composition attributable to pesticide impact.

ARTIFICIAL STREAM COMMUNITIES

The laboratory streams described so far have been designed mainly for single species at a time, or for limited select groups of macroinvertebrates. The logical progress from this point is to design simulated streams in which impact of toxic chemical on a whole community can be studied under conditions akin to those in the natural habitat, but allowing certain factors to be controlled and studied separately in a way that is not feasible in the stream complex. Noteworthy developments along these lines have indeed been made, though not necessarily with the same objective. For example, in studies on the community effect of the lamprey larvicide TFM (see page 214) in Michigan, six fish hatchery channels 8 m long and 0.6 m wide were used, allowing three complete systems, each comprising one control and one adjacent experimental channel (Maki & Johnson, 1977). Each channel was divided into a 4 m upper pool section and a 4 m lower riffle section. The upper pool section was allowed to become colonised by introduction of organic matter and by drift of fauna in the gravity-fed water supply from an adjacent creek. The riffle section was also colonised from natural stream substrates, with associated fauna and flora introduced from a natural source. These communities were allowed to grow and become stabilised for a period of 2 months before experiments started, by which time a very good representation of stream organisms was established, including five species of stonefly (Plecoptera), three of mayflies (Ephemeroptera) and no fewer than nine species of caddis (Trichoptera), as well as the crustaceans Gammarus and Asellus.

The preparation of this review, and the final writing up, was only made possible by generous support from two organisations, namely the Water Research Centre, Medmenham, Marlow, Buckinghamshire, UK, and Jealotts Hill Research Station (ICI Plant Protection), Bracknell, Berkshire. I am greatly indebted to the sponsors concerned, Mr J. F. Solbe of the WRC and Dr B. G. Johnen of ICI for authorising donations without which this project would not have seen the light of day. Their assistance was particularly vital, coming as it did at a period when research funding in general, and in this field in particular, was being severely restricted in this country.

I am also grateful for the cooperation of many colleagues through correspondence from overseas, who have not only been kind enough to send reports and material not easily available here, but who have also – by correspondence – provided up-to-date progress information and comments. I am particularly indebted to the following: Dr Peter Kingsbury of the Canadian Forest Service; Dr D. C. Eidt of the Maritime Forest Research Centre, New Brunswick; Dr P. E. K. Symons of the Fisheries Research Board, Canada; Dr W. 0. Haufe of the Animal Parasitology Research Station, Lethbridge, Alberta; Dr Joan Trial of the Department of Zoology, University of Maine, US; Prof. John Giesy of the Pesticide Research Centre, Michigan State University, US; Dr. Aarne Lamsa, of the Great Lakes Fishery Commission, Ann Arbor, Michigan; Dr L. A. Norris of the USDA Forest Service, Oregon State University, US;

Introduction

Pollution, in its many forms, is widely regarded as our major environmental problem. Pigou (1932) was perhaps the first academic economist to take it seriously, but recorded expressions of concern go back much further. The use of coal was prohibited in London in 1273, and at least one person was put to death for this offense some time around 1300. Why did it take economists so long to recognize and analyze the problem? Apart from the concern of Pigou, little was done until the 1960s, although elements of the theory of externalities and public goods that would later be useful were developed largely in the 1950s.

One plausible explanation for this lack of interest is that the problem has only recently become competitive, in its severity, with others we face. True, there have been local and temporary episodes, as the unfortunate Londoner would attest, but it is only recently that we have come to fear that “environmental reservoirs” may be filling up over large areas and in ways that may be difficult to reverse.

This view of the world has, in fact, been advanced in some conceptual contributions from economists. Boulding's ”spaceship earth” (1966) suggested that pollution, or at least material residuals from production and consumption activities, must always and increasingly be with us, because the earth is, like a spaceship, a closed system with respect to materials. A related concept developed by Ayres and Kneese (1969) is that of materials balance.

Scope of the study

In recent years there has been a revival of interest in the concerns expressed by the early conservationist movement, primarily concern as to the adequacy of the natural-resource base in our advanced industrial economy. The early conservationists stressed the importance of extractive resources, in the words of Pinchot (1910, p. 123), “the five indispensably essential materials in our civilization … wood, water, coal, iron, and agricultural products.” Today, of course, we are worrying a great deal about energy resources: oil, gas, uranium, renewables of all kinds, in addition to coal. In this sense our focus seems to have narrowed, but in another sense it has broadened to include what might be called in situ natural resources, such things as clean air, natural beauty, and other aspects of the environment that yield satisfaction directly rather than through some productive transformation.

However we interpret its focus, there is no question that there is renewed concern. It is no exaggeration to say that one can hardly pick up a newspaper without coming across several items dealing directly with one or another energy or environmental issue. For example, in looking through the San Francisco Chronicle for March 27,1980 (not an unusual day, not an unusual paper), we find the following: “Angry San Francisco Hearing on Lake Tahoe Plan” (p. 4), which deals with public reaction to a plan to try to control pollution in Lake Tahoe;

This book is intended as a response to the recent explosion of interest, both popular and scientific, in resource (especially energy) and environmental issues. I sought to deal with some of these issues in two recent survey articles, one in the Journal of Economic Literature (“The Environment in Economics”) and one in the Economic Journal (“The Exploitation of Extractive Resources”). This book was originally conceived as an extension, but I soon came to realize that the survey format would not be adequate for the needs of students and others wishing to examine the detailed empirical findings and learn something of the structures and solutions of economic models used to address the issues. The book in its present form seeks to provide a self-contained development of selected portions of this material. However, the purpose originally conceived for the book has not been totally sacrificed. Footnotes and an extensive list of references at the end of the book serve as guides to the literature for those interested in further study of the questions treated here, as well as related questions not considered here. For the most part, references are cited in the text only when they are relevant to discussion of various positions on a controversial issue.

Why this particular book? Other books dealing with resources and the environment have appeared in recent years, but I believe this one offers some distinctive, even unique, features. First, it is almost evenly divided between the topics of resources and the environment.

We began this volume by noting, as evidence of widespread interest in the subject, several items dealing with natural resources and the environment in an average edition of a local (San Francisco) daily newspaper. The items dealt with technical and policy options for controlling pollution, energy conservation, and prospects for oil production and gold mining in California. In each case the story was developed with little or no reference to the findings and insights of economic analysis. This is not surprising. It may not be an exaggeration to say that the “conventional wisdom,” as we have heard it expressed by those concerned with issues of resource depletion and environmental protection, holds that economics can contribute little to their resolution (or, worse, that the problems we face are due to the depredations of an economic system explained, justified, and occasionally guided by economists). To the extent that economics is seen as relevant, it follows that what is needed is a radical shift, away from the system characterized by advanced industrial technology, growth, and a largely market-determined allocation of resources, such as is found in the United States and other developed Western countries. According to this view, the discipline of economics is itself in need of a radical restructuring.

Introduction

Are our exhaustible energy resources being depleted too rapidly? Or are they perhaps being depleted too slowly as a consequence of efforts by producing nations and large corporations to restrict output and thus raise prices? Questions like these, which have been given new urgency by the energy crisis of recent years, lead quite naturally to an inquiry into what constitutes optimal use of exhaustible resources. A fairly standard approach in such an inquiry, and the one taken here, is first to derive the conditions that characterize socially efficient resource use and then determine to what extent these are also realized in a competitive equilibrium. In other words, does the fundamental theorem of welfare economics continue to hold in the context of exhaustible resources?

As the question about the large energy producers implies, all sorts of imperfections are known to interfere with the tendency of a system of competitive markets to allocate resources efficiently. Thus, even if it turns out that a competitive equilibrium is efficient, one still must consider the effects of relevant imperfections, or market failures. For example: What about monopoly? What about the environmental disruption that often accompanies the extraction, conversion, and use of exhaustible resources? Further, as will be argued later in this chapter, there may be other kinds of market failures peculiar to these resources, involving such things as the uncertainty that surrounds their discovery and the long-lasting effects of current decisions about their use.

Introduction

It is probably fair to say that the question in the title has triggered much of the recent interest in natural resources by economists and others. In Chapters 2 and 3 we derived conditions that must be satisfied by optimal programs of resource use under different market or institutional arrangements. We were specially interested in the relationship between market-determined use and socially efficient use. This chapter concerns the evidence on actual rates of use, to date, as well as future prospects. In short: Are we running out of resources? And does it matter?

A conventional view (or, at least, one we often hear expressed) is that the questions are meaningless, because they have no policy implications. The U.S. economy might, according to this view, be facing greatly depleted stocks of some resources, much higher resource costs and prices, and a consequent slowing of growth; yet no intervention by government would be warranted in the absence of clearly demonstrated market failure.

My own view is somewhat different. If, as discussed in Chapter 2, the welfare of future generations is a public good, members of the present generation might be made better off by government intervention to promote conservation and reduce the anticipated drag on growth. For that matter, the government might intervene to promote intergenerational equity even if the market were allocating resources efficiently from the standpoint of the present generation. We certainly do not need to resolve these issues here.

Introduction: the transition from extractive to in situ resources

In the discussion of the theory of optimal depletion in Chapter 2 we noted (and formalized) two ideas from Mill (1848) that have a contemporary ring: (1) Extraction costs will increase as mineral deposits are depleted, owing to the need to sink shafts deeper, and so on. (2) The increase will be mitigated by discovery and technical change. Mill had another modern idea: that a stock of land was valuable not only for what could be extracted from it but also for the opportunities it provided for experiencing natural beauty and solitude.

Whether this had any influence on resource policy is not clear, but Mill's treatise had been through several editions by the time the national park system was established in the United States (1872), and preservation of natural beauty in wilderness environments was a minor goal of the early conservation movement (1890–1920). But the theme was not, to my knowledge, picked up by the economics profession until very much later. Instead, environmental disruption was first analyzed as a static externality, following the work of Pigou (1932) and his examples of sparks from railway engines, factory smoke, and the like. By the 1950s, several economists were developing elements of the modern theory of externalities, but in the process they were losing sight of Pigou's environmental examples.

Introduction

The line between exhaustible resources and renewable resources is not always clearly drawn. Exploration and technical change can, for a time at least, “renew” exhaustible resources by making possible production from new deposits and low-grade materials. Models that describe the effects of these activities on resource price and production paths were developed in Chapter 2.

Just as exhaustible resources can be renewed, renewable resources can be exhausted. In fact, as we noted in the concluding remarks to Chapter 2, much of the concern about resource exhaustion appears to involve renewable resources, endangered species ranging from the snail darter to the whale. As one prominent biological scientist put it:

A major purpose of this chapter is to try to shed some light on the reasons that even commercially valuable stocks of plants and animals can be threatened with extinction. It is clear enough how this can happen to a species that is not commercial.