Role of natural history museums

AlfG. Johnels

Outside scientific circles the discoveries of natural science tend to be regarded as important only if they lead to results that can be used in practical life. But scientific methodologyis the one wayto an understanding of the physical, chem- ical and biological processes which take place on this planet. The only reliable knowledge of the reality around us comes from the natural sciences: perhaps we do not sufficiently bear in mind that much of this ‘reality’ is still unknown.

Sciences such as physiology and ecology require a comprehensive and de- tailed understanding of the structure of living matter as manifested in the biological units called species and subspecies. In this area museums have long made a considerable contribution as centres for systematic research. But a great deal still remains to be done, particularly regarding the lower animals and plants, which often play a dominant part in the ecosystems. The study of fos- sils is an important element, not only in the comprehension of structures and functions in presently living organisms, but also as regards distribution of animals and plants at the present time. Animal and plant geography have long been valued subjects of study at natural history museums.

Geological conditions have a decisive effect on life forms and their develop- ment in the various parts of the world. Here too natural history museums have made an important contribution, as they have to the locating, understanding and utilization of the many resources concealed within the earth‘s crust which are used by man. Teclhical developments-perhaps in the communications sector above all-have been such that modern men and women have ceased to regard the earth as boundless. We can no longer consider the natural stock of, for instance, valuable ores, oil and water to be unlimited. Nor is the capacity of earth, air and water as recipients for refuse so immense as to be unaffected by man’s activities. On the contrary, scientific and technical developments have increased, on a revolutionary scale, our ability to exhaust resources rapidly and to pollute earth, air and water with various kinds of refuse. Man has always influenced his environment. However, that influence has never been anywhere near as great as it is today, and it is increasing at an accelerating rate.

One need not be a professional historian to perceive that we live in a changing world. The technical, economical and social achievements of human society have brought about an improvement in our living conditions: this has been so obvious that sufficient attention was not directed to the attendant drawbacks until a fairly late stage. Some of these unexpected side-effects are so serious that action evidently must be taken. The &d of man may well continue to reach out and conquer new challenges in space, but it cannot exist outside its bio- logical shell, Man’s destiny is ultimately bound with that of the earth and if the vital biological needs of human beings can no longer be fully satisfied the course of development on this planet must be changed and tolerable living conditions restored where impaired.

Role of natural historv museums

In many instances destruction threatens resources which cannot be created afresh, in any event not at the rate at which they are exhausted. This is the case as regards oil, mineral and ore supplies. On the other hand, as regards renew- able (living) natural resources, recuperation may be possible and attempts are being made in various~parts of the world to remedy a destroyed or damaged natural environment. In many cases, however, the transformation has been so rapid and so far-reaching that nothing much of the original fauna and flora now remains. In such situations it has been found that information on previous conditions can be obtained from the collections of natural history museums: but material relating to the field in question must of course have been collected, and unfortunately this has rarely happened to the necessary extent. In certain cases the knowledge available about a particular organism’s environmental needs provides a surprising amount of information on what the background conditions must have been at the time when the material was collected. A breeding bird, for instance, may have very specific environmental needs; a piece of moss can give accurate information on the pH at the place where it was found, etc. Such data may serve as guidance should restoration be attempted. It now seems most important that natural history museums are given increased opportunities to provide records for the future by collecting material in areas which-one way or another-will be affected by human exploitation. It is of extreme importance that such evidence be available in the future; but the re- sources of natural history museums are totally out of proportion to the value of such information.

Soil and water pollution, particularly in the industrialized countries, has re- ceived a great deal of attention recently. There are many different kinds of pol- lution, however, and at the moment it is particularly appropriate to observe with care the, effect of persistent poisons emitted either deliberately as pesticides or unintentionally as the result of industrial processes. DDT and related chlo- rinated hydrocarbons are of course notorious pesticides; the polychlorinated biphenyls (PCB) are examples of industrial substances. Mercury is introduced into the environment in both ways.

A method of disinfecting seed with an alkyl-mercury substance was devel- oped in Sweden around 1940 (inorganic mercury substances had been used in the 1920s and phenyl mercury came into use in the 1930s). By 19jo alkyl- mercury disinfection was predominant in Sweden. By studying the feathers of birds preserved in museums (Johnels and Westermark, 1969) it proved pos- sible to throw light on the mercury level from the early years of the nineteenth century until the present. It was found in the course of this research that the introduction of alkyl-mercury had been followed by a general rise in the mer- cury level in the feathers of certain kinds of birds. These and other findings (Borg, Wanntorp, Erne and Hanko, 1969) resulted in the authorities taking a number of measures, including the prohibition of alkyl-mercury as a disin- fectant in early 1966. Following this prohibition and the replacement of alkyl- mercury by other mercury substances (alkoxy-alkyl-mercury) the content fell rapidly, almost reaching the original level of the ISOOS (Fig. 48).

However, the effect of disinfectants containing mercury is restricted almost entirely to field fauna which themselves feed on mercury-contaminated material and wild animals living off this fauna, e.g. the goshawk. Analysis of the feathers of ospreys (Johnels, Olsson and Westermark, 1968) which live on a diet that is 99 per cent fish, showed that water is contaminated by mercury in other ways (Fig. 49). Instead of a sharp rise at the beginning of the 1940s (as in the goshawk, for instance), it was found in the case of the osprey and the great crested grebe (which also take their food from water) that the mercury content has risen gradually from the turn of the century onwards: the curve is parallel to that of industrial development in Sweden. Mercury has many different industrial uses and experience has shown that it is primarily the water environment that is eventuallv affected bv industrial discharpe. whether into the atmomhere or via v -

Mercury content in mglkg

1815 1840 1865 1890 1915 1940 1965 O

48 Mercury content in feathers of female goshawks shot near their nests during the months April-June from the early nineteenth century up to the present day. Material collected for twenty-five-year , periods. The results for 1966 (when alkyl-mercury disinfectants were forbidden) onwards are indicated by dotted line (n = 12). (Content given in mg/kg; n = number of specimens studied.)

56 AlfG. Johnels

15

10

49 5 Mercury content in osprey and grebe feathers from the nineteenth century up to 1966. Material collected for twenty-five-year periods. The osprey lives gg per cent on fish and the great crested grebe at least

water. (n = number of specimens studied.) 75 per cent on organisms growing in O

Mercury content in n g / k g

Osprey

I m n = l n = 4 n = 2 n=.8 1=1:

1840 1865 1890 1915 1940 1966

Mercury content in mglkg

15

10

5

O

Great Crested Grebe

1865 1890 1915 1'

-

waste water. These discoveries have broadened the problem of mercury in the environment as it was first understood-in connexion with its utilia- ation in agriculture-to the considerably more complex area of industrial development.

Mercury (in common with several other substances relevant to discussions on nature conservation, e.g. arsenic, lead and other heavy metals) is very wide- spread and, with refined methods of analysis, can be found in practically any- thing. It is disseminated in the atmosphere by natural circulation, for instance, after a volcanic eruption. Consequently in discussing the significance of human activity in connexion with the broad problem of mercury it is necessary to have an idea of the natural mercury level. To ascertain this, and so enable human influence to be measured, museum material has been useful, as shown above. However, in such contexts, findings must be treated with considerable caution so that all suspicion of contamination can be eliminated. In the case of mercury, the impact of industry on the natural environment has of course been considerable in many cases since the turn of the century. , Birds of many species, e.g. the osprey, already mentioned, and other water

birds, make long flights in the spring and autumn. Mgratory birds therefore visit a number of often very different environments in the course of their We- time. Their plumage is gradually worn out and has to be replaced. Birds of prey have to be able to fly continuously so as to get their food; the feathers wkich they employ for flying are moulted successively throughout their whole lives and therefore some feathers will have been formed in the nesting area while others will have grown elsewhere. If the pattern followed in this process of feather replacement is acertained, then of course analysis of the feathers will throw light on the mercury situation in various parts of the world. The mercury content of the feathers is related to the mercury content of the blood at the time of growth. In addition we must have an accurate knowledge of the bird's normal migration routes. Information is obtained primarily by ringing birds. This work too is often in connexion with museums. A special study of osprey moulting has been carried out at the Swedish Museum of Natural History precisely in order to explore these possibilities (Edelstam, 1969). A comparison of the mercury content in the feather shafts of a young bird taken from its nest with that of an old bird, some of whose feathers have been replaced during a visit to his winter quarters in Africa, will indicate the ratio between exposure to mercury in Sweden on the one hand and in the bird's winter quarters on the other (Fig. JO).

a

Role” of natural history museums 57

When Jensen pointed out that some of the peaks shown by the chromato- gram in connexion with DDT analysis were really due to polychlorbiphenyls (PCB), he used museum material to prove that these peaks had existed in the biological material before the use of DDT as an insecticide (Jensen 1972). They could therefore not be metabolites of DDT, as had previously been assumed.

In I 9 67 Ratcliffe showed that at the end of the 1940s there had been a sudden decline in the thickness of the egg shells of birds of prey in England compared with previous decades. This change occurred during the period when chlori- nated pesticides were coming into wide use in England; it can be related to an effect on the hormone system which regulates reproduction. Here again museum collections of eggs were used to authenticate fundamentally important effects of a pesticide on bird life.

By analysing the lead content of mosses taken from herbarium collections which grew at various times, Riihling and Tyler were able to show in 1968 that the lead content of the environment had increased from the nineteenth century until the present time. The lead must have entered the mosses through the atmosphere; its increase is attributed partly to the fact that fossil fuels contain small but perceptible quantities of lead, which are released and are then

Mercury content in mglkg

25

10 ::( 5 O 1

Wing quill No.

Mercury content in mglkg

Old bird J O 5 Jdly 1964

Göksholm, St. Mellösa Närke

Mercury content in individual osprey wing-quills. Above: older birds; below: nestlings. The level for young birds is approximately 20 mglkg or slightly lower, which gives some indication of the general mercury content of the water. As regards the old bird, a couple of wing-quills (4 and 8) were grown in Sweden. Quills Nos. I and 5 , z and G are two pairs which were replaced in Africa, south of the Mediterranean, where the average mercury content in foodstuffs is much lower. Pair 3 and 7 were grown roughly two months after the bird left Sweden and give some indication of the speed with which mercury is eliminated from the bird’s body.

Young bird (1 Z months) 7 July 1965 Stava, Õsteråker Uppland

25i

Wing quill No.

transported by smoke; and partly to the presence of substances cdFtaining

few examples. Many more uses for museum collections will undoubtedly be discovered in the future.

Reference has already been made to the need for rational collection pro- cedures so that valuable material may be available in our museums. In view of

‘ the work and cost involved (collection, storage and conservation), only material of sufficiently high quality should be retained. A procedure must be sought which satisfies both qualitative and quantitative requirements, and new methods of conservation must be tested and put into effect. Scientific progress makes it likely that the research worker of tomorrow will have far greater possibilities of extracting information from old and dead material than we have. He will also make demands, the nature of which we cannot conceive at this time. Today’s museum curator, in his capacity as collector, ought indeed to possess super- human powers of foresight so as to be able to fulfil appropriately the require- ments which science will impose in the future.

The poisonous substances which are inteationally or unintentionally released into our environment and thus endanger fauna and flora do not merely involve the problem of protecting nature, or of deciding whether one or another species shall be allowed to disappear. The symptoms which nature’s organisms show after exposure to poisons are also an indication of what may well be a threat to mankind itself. Museum research has therefore a stronger and closer connexion with public well-being than is perhaps generally realized.

Other aspects of the value of natural history museums and their collections could of course be quoted. But the above pages will suffice to show that a skilled and far-sighted scientific attitude must underlie the actual work of col- lection. Without scientific direction at a high level and witho& adequate re- sources natural science museums cannot perform their function as bases for future research activity.

[Translated from Swedish]

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References

BORG, I<.; WANNTORP, H.; ERNE, IC.; HANKO, E. 1969. A¿&¿-merczLv poisoning in terrestrial Swedish wi¿dh$e.

EDELSTAM, C. I 969. Ruggologi eller Fåglarnas fjäderbyte. Forsktjing och framsteg, no. 3 , 1969.

JENSEN, S. 1972. How PCB was discovered. Ambio, vol. I, no. 4. (See also New scientist, no. 3 2, I 9 6 6 .)

JOHNELS, A. G.; OLSON, M.; WESTERMARK, T. 1968. Esox lucius and some other organisms as indicators of mercury contamination in Swedish lakes and rivers. Bu¿¿. Off. int. Epiroot., 69.

JOHNELS, A. G.; WESTERMARK, T. 1969. Mercury contamination of the environment in Sweden. In: M. W. Miller and G. G. Berg (eds.), Chemical fa¿¿out. Current research on persisteitt pesticides. Springfield, Ill., Thomas.

RATCLIFFE, D. A. 1967. Decrease in eggshell weight in certain birds of prey. N a t w e , no. 21j.

R~HLING, A.; TYLER, G. 1968. An ecological approach to the lead problem. Bot. Notiser, no. I 2 I.