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Translation Series No. 3076
Some new terms in seston research
by Einar. Naumann.
Original title: Ueber einige neue Begriffe der Sestonkunde. Lunds Universitets Arsskrift
From: Acta Universitatis Lundensis 20(3) . 3-]5, 1924
Translated by the Translation Bureau(HC'C:) Multilingual Services Division Departmènt of the Secretary of.State of Canada
Department of the Environment Fisheriès and Marine Service Canada Centre for Inland Waters Burlington, Ont. 1974
20 pages typescript D.EPARTMENT OF THE SECRETARY OF STATE eM11 SECRÉTARIAT D'ÉTAT TRANSLATION BUREAU BUREAU DES TRADUCTIONS „ DIVISION CANADA MULTILINGUES Fe-A4 30 7 • CLIENT'S NO. ' DEPARTMENT DIVISION/BRANCH CITY N 0 DU CLIEnr MINISTRE DIVISION/DIRECTION VILLE 534609 Ezwironment Inland Waters Branch Burlington BUREAU NO. LANGUAGE TRANSLATOR (INITIALS) NO DU BUREAU LANGUE • • TRADUCTEUR (INITIALES) . 4 - ' • • .German . • 1. - (. ./ ' 1 . . HGC . .1!Yi ... SOME NEW TERMS IN SESTON RESEARCH •• By Einar Naumann (Ueber einige neue Begriffe der Sestonkunde. Lunds Universitets Arsskrift. N.F. Avd. 2 Bd 20. Nr. 3. Acta Universitatis Lundensis. 1924.) . • e?* The term** esSestonn was introduced into limnology by R. • Kolkwit z (1912). Under- s est on - we- understand-. the- t otality- of bodies contained in water, whether in suSpension or floating in its surface • fi2m. • . • • Thus seston embraces several formation classes of animals and plants. In addition, it includes every kind of inanimate matter contained in free water -- detritus or tripton 1916). . • The following . formation classes comprise seston: plankton (Hensen,.1887)„ nekton (Haeckel, 1891), pleuston (Schrdter and Kirchner, 1896), and neuston (Naumann, 1917). • * Figures in the margin give page nuMbers in the original. —1. TRANSL. ** IlBegriffil may mean both nterm” and ?concept." Both words are used in .. this translation, according to apparent context. • -- TRANSL. . • UNEDITM TRANSLAT;ON For Informeion only • • TRADUC..TION NON REVISEE Aon—zoo. 0-31 • Informan soulemon• , As regards a more deta iled definition of these terms, we shall .confine ourselves to the following remarks. 1. In accordance with Kolkwitz (1912), plankton is defined as the organism formation of free mater. The initial term, as defined by Hensen, was extremely broad and could even be compared to the current term seston. Modern researchers e however, view plankton as a component part] of seston... 2. Nekton s according to Haeckel (1891) embracesienerally the larger water fauna that is relatively unaffected by external influences, divide nekton into planktonekton and neustonekton. . The latter includes above all the insects of the mater surface studied by Brocher. 3. In accordance with SchrUter and Kirchner (1896), pleuston means the higher floating flora of the water. 4. Neuston. Organisms belonging thereto, in accordance with E. Naumann (1917), are defined as micro—organic formations found in the surface film of the water. Neuston, of course, also embraces all in- animate bodies found 'suspended in the surface film. The introduction of these definitions of the main term seston and its component terms has been very useful for the further treatment of limnological problems. This is especially true of certain branches of applied limnology. A further study of these matters, however, will probably lead to the need for a more detailed definition of the above noted mainl •• terms. This paper May be seen as a contribution in that direction. . H • . . . . . 'I. . . . ! . . i . . . . . . I. SIZE CLASSES OF SESTON Initially, seston may simply be divided into the Size classes of . .megâ10—, macro—, meso—, micro— and nannotypes. These are terms which have found wide application in plankton research for some time, through the witingn SchUtt (1892) and Lehmann (1911). The lable that follows Provides. information as to the current size relationships and technical characteristics denoted by these terms. 1 %.. To these terms 1 should now like toadd \the new term ultra- seston„ which is also included in the Table. By it 1 understand that part of the seston ranging in size from a fee microns to microscopie it is characterized by the fact that with invisibility. Technically the present state of technology it cannot be quantified completely. The term ultraseston is..based pr. imarilyi on technical considerations. Its purpose is, first of all, to indicate that this size class is outside . the research possibilities of modern investigational techniques, whose Units are defined by the bacteria and the finer detritus. Partly, however, ultraseston is also composed of bodies that are genuinely ultramicroscopic, i.e.: that are situated on or beyond the borderline of direct microscopic Observation. 1 This is easily demonstrated with dark—field illumination of water samples from waters with abundant seston. however, knowle%e on the ultramicroscopic conditions of natural bodies of water is still incomplete. .1 Ultraseston is composed of a highly heterogeneous material. The following elements predominate: • .(Text cont. on page 5) gze class Characteristics Technical Data Megaloseston Minimum size several centimeters Maybe caught with coarse nets and , Eacroseston and other filters • • Mesoseston Minimum size apprOx. 500-1,000 May be caught with coarse nets and nierons. (Tissue-building animDls et.) other filters Microseston Minimum size apprôx. 60 microns • May be caught r1..th finer nets and (The larger Protista; detritus flakes, other filters etc.) Nannoseston Minimum size approx, 5 microns Cannot be,calight with nets. Complete (Smaller Protista; finer detritus, etc.) quantitative determination possible 'only with centrifuge methods or with. chadber. • Ultraseston Size ranging from 5 microns at most to At besé, qualitatively determinable :microscopic invisibility. (Bacteria; with centrifuge or. chamheï-=---quantitatively the finest detritus, .etc.) . . not fully determinable. .,,.,..v..^ • Aquatic bacteria • Peritripton resulting from the call.aborAtion of limnic organisms Colloidal f7.occula,tes of assimilates that Autochthonous I have entered the water elements Other colloidal flocculates Colloidal solutions a Allochthonous ^ Bacteria, peritripton and colloidal flocculates elements introduced from the outside None of these elements can be deter-mined quantitative77 i-r3,th present limnological methodology. We have as yet very few details con- cerning their h ature. This is especially true of bacteria. Although bacteriology of water has become tremendously important in' practical tezms, in theoretical terms it carries little weight. This is a disadvan- tage,'tahich results from the fact that bacteriolog -to the method of obtaining its material by concentration. . ' Given Ithe present state of li.mnologg, we are.almost cer"in7y justified in characterizing ultraseston as one of.the most important factors in the total metabolism of freshwater bodies. 1 This element lof the total seston is the Unk in the total budget that represents the transition between dissolved nutrients and I the higher production of the water. It is here that the bacterial processing of expired vorganisms takes place, and it is also here that we find the source of colloidal flocculates. From this point, two paths diverge; one leads-vialthe further separation of organic substances ,1 into the realm of solutions; the other leads directly to a reincarnation in the 13.fe of the xoop:Lankton. In pure:y schematic terms, the position of ultraseston in the total spectrum of aquatic life may be represented appro^dm.ate],y as fol.l.o^rs. Y.^^►ldnuki^^s► (4,1641%. \i{Ihrnlnf(p Dïssolved ..nutrients 6 In advancing this scheme,.1 base myself primarily on the . resurks of ;vLy- investigations of the nutritive biology of ara_.?ma1 limno- plankton, on which I have reported in greater detail in several special publipations (1910, 1421,' y92.31). As described thereiln,, the productive biol4gy of the entire zooplankton of the filtrating and sedimentatinR .type. is dependent primarily on the nanno- and ûltraseston.in the water. This is true above all for the non-predatory Cladocera, where ultrasest^on is of the greatest importance, as wexl as for Diaptomidsa and, thirdly,- for the Rotifera. The important ro1,e thus being played by ultraseston in the total metabolism of freshwater makes more detailed investigationsof this subject highly desirable. Thus far, study of ultraseston has been confined to hygieniç bacteriology. Theoretical ^ interest must now focus I on biological bacteriology and tr3.pton research in the area of ultraseston. • • . . II DETAILED GROUPING OF NEUSTON The . term neuston was introduced by me for the firet time in 1917. I used it to refer to the organism formation of the surface fila of water, in distinction to plankton, which defines the organisms of free water. The term has found wide acceptance. The further differentiation of the old plankton concept resulting therefrom should contribute to a continued development of various concepts and terms in the field of theoretical and applied limnology. A grouping of this formation class within the systematics of plant sociology,which I believe is not quite. correct, has been undertaken • y Gams (1918). He compares neuston with pleuston e and even classifies thu former as a subseries of the actual pleuston e which he terms micropleuston. This, hogever, is misleading. Pleuston is e after all, a Tr/holly different - formation ) since e according to the original definition of SchrUter and 7 Kirchner, it embraces that part of the higher, freely floating aquatic • vegetation which _must simu1taneously be adapted to atmospheric life. Neuston, on the contrary, consists of those microphytes that have their habitat in the surface film of the water. • They are thus true aquatic organisms. Pleuston and neuston are therefore entirely different.plant formations, and their sociological systematics must not be mixed up. * * * . A more detailed understanding of life :processes in the . surface film, however, is bound to show that we shall not be able to make do mereazr with the basic'terms neuston and plankton. This applies both in the field of bioseston and in the field of abioseston. We can therefore subdivide neuston as follows. . Neustonic Bioseston 1. EUneuston This is ihat formation of microorganisms whose members live in the surface film, and thus make up the neuston proper, or euneuston. Thus far no other collectivities of this basic type have been studied. In addition to these associations, however, there are also others that occur in neuston only quite accidentà.13y. A brief review of these circumstances will also demonstrate the need for a further develop- ment of the original neuston concept. • • • , Aironeuston In distinction to the proper neuston or euneuston, I am using . the tenu aironeuston to include, first of all, those associations that occur only accidentally in the surface film. We are dealing here exclusively with forms originally belonging to the deeper water or even soil layers. ' As our first example we may refer to those microphytes that are found only occasionally floating at the surface, e.g., the large algae carpets consisting of Spirogyra, Oedogonia, Conferve, etc. Do these re- - . present a genuine neuston? This question cannot be answered.without difficulty. It is certainly ' true that these algae may act as typical members of the euneuston, i.e., they may grow in the surface film and reproduce there. The carpets drifting on the surface may indeed originate in this manner. Generally, however , 8 they conte about in a different way; for example, when algal vegeta- . . tation, because of intensive assimilation, rises from the bottom., reaches the surface, and floats there. Obviously, thià cannot be considered true euneuston in the original sense. net name, hanever, shall me give to this formation? ; it is - true that neuston covers everything having to do mith the surface and not clearly definabie as 'either plankton or pleuston. The abovenamed algae must therefore be included in neuston s. lat. • Another example is furnished by the accidental accumulation of specifically light plankton algae in the surface film during periods of calm weather. In larger mater bodies this may occur only periodically. In smaller water bodies, hawever, such accumulations may characterize . neuston for longer periods of time. They cannot, howevere be defined as neuston s. str. Abundant secondary colonization of the surface film with a saprogenic tendency, made up of euneustonic fonns e may occur as a •result of the extinction of primary colonies. • Suc h accidental inhabitants of the neustone as described here, am'defining as aironeuston.*. . • • B. Neustonic AlDioseston is partly purely auto • • . The. inanimate seston of the neuston . . Chthonous, as it originates from the decomposition (necrotization) of ' neuston or pleuston, It'may also be defined collectively'aS necroseston. . * From Greek baecu -- to rise. I. This process, however, i s also affected by aU.ochthonic influences. Among these, the"most peculiar phenomenon,is duo to neustonic anesno- .S. eston. ' L Neustonic Anemoseston Under zieustonic anemoseston* I understand all those components that are tntrodiZced into neuston by the *vri.nd. Pi^obab:l,g the beat known of .thosQ is the apparent water bloom produced by the introduction of Scotch. pine po]..1.en. ( k':i.nus silvestr:s ). In small -water bodies, it may play an important role during the further development, of neuston from euneustonic for ms . This pseudo-bloom, however, is not confined to neuston but extends into plankton. 2.Neustonic Necroseston The limno-authochto7li.c -abios eston from the neustonic zone is of a highly heterogeneoûs origin. Part of it derives from the dying euneuston, • another part from the dqd.ng ai.ro.- and/or ane,m.oneuston, yet another part is supplied by drifting matex°ia1, originating at the -Uttoral. Co].lectivel,p-, this matter may l= defined as neustonic necrosqston 'oz, briefly, necro-- .nouston (Swedish: flytUvja = neustoni.c Uvja). It is'of trenendous ecological importance, especially in regards to further colonization conditions of the water. r # From Greek dW" 0 S ^-- wind. C. Summary In summing up the above considerations, we get the following • classification of that seston pertaining to the surface film of the mater: 1. .Euneuston • Bioneuston Actual inhabitants of neuston • 2. Aironeuston • • Accidental inhabitants of neuston . • derived from soil or plankton . . I. Limno-autochthonous objects .. , • . .. Neusto-, pleusto-, necto- and planktogenic . . . - tripton . Abioneuston . . • • . 2. .Limno-allochthonous objects. • . • - ' A substantial role is being played only ' • • •_ . by neustonic anemoseston • • • Thus far, we possess detailed information only of a very few of• these several elements, mostly in relation to intensive production of 'the euneustôn. Neuston is therefore a fruitful.field for future studies. :III.. THE CONCEPT OF SESTON TITER. Aquatic bacteriology- is part of seston research. It concerns ' itself chiefly with bioseston of the ultra type. The methods used by this branch of seston research are mostly quite different from those s..cm. which (research into plankton, neuston, pleuston and tripton is based.. Whereas the latter is concerned mainly with the direct determinatic of seston bodies, the bacteriologist is for the most_part forCed to study his . _ material by growing cultures. • Further development of the various. special disciplines of . 10 seston research in recent years has created certain formal mutual rela- tionships in methodology. One of the most important events in that respect is pi•obably the choice of the cubic centimeter -- initiated by Kolkwitz -- as the common unit of population statistics of seston of the nanno and ultra type. This unit was first introduced by bacteriologists. Another approach also deriving from bacteriology- but which can . also be widely useful in seston research is the concept of bacteria titer. We shall therefore provide a brief ingairy into the general applicability of this concept in seston research as a whole. ...Definition of the Term BacteriaYiter The titer concept in bacteriology is derived from the practice of sewage and mater—supply technology. As we know, a large role is piayed . there by the oCcurrence of the coli complex. It is determined with the fermentation test, withyarious amounts of water being used as the starting' material. 1 It is then found that the complex can be shown to be present in greatly varyireaamounts of mater, depending on the degree of - purity of the mater. In some cases, it is'determinable in fraCtions of one cubic centimeter, in others only in amounts of several hundred cubic • centimeters. Sinco it is not possible to test an infinite range of water quantities, the results of conform tests have to be related to volumes . within a certain range. If.we assume that the complex cannot be deternined • in a water sample of 10 cu. au, but that it can be determined in 100 eu. ca, • it is then clear that the coli titer will in any case be more than 10. The relatinnship will be as follows:. 10< C41 It is obvious that this results in A considerably greater brevity and clarity of formulation. However, the results can also be represented in the form of a. table, as follo^:s: e-F 100' 1 tc► The table will then be read in the same manner as the precedin; formula., which seems preferable. from the point of view of brevity. General Definition of the Term Titer lI. It is evident9 at the present stage of nethodology in seston research, that this tertn can easily and advantageously be géneralized. In very general terms 9we may provide the following definition: ^:pxitude--det ernined equanion,, The seston titer /^o f^ nÛV^+a by mear.s of an a.. provUes the lowest productive quantity in respect of a certain specificlelemont. We shall give.below some examples of this approach, along with some explanations. C. F.irther Developrnent of the Titer Concept The original application of the titer concepts as we have seen, relates to the occurrence of individuals. It is clear, hoaiever, that it can also be developed substantially in other directions. The foll.oi.-ing special titer terms can ; be considered: (a)' Individual titers.. Thesô relate to the occurrence of individuals, generally the occurrence-of a single individual. I t• (b) Volumetric titers. These relate to the occurrence of a production from a certain standard volume. It is natura11that thus far bacteriology has made use only of individual titers. In the rest of seston research, however, both individual and volumetric titers may play important roles. . Plankton Titers 1. Individual Plankton Titer In very general tex, I au defining the individual plankton titer as Pe and the various size classes may easily be indicated by hie, Pua, Pcni„ Pn and Pu. If we use this approach to compare, for example, the summer plankton of eutrophie and oligotrophic water bodies, we got the following relationships. 0 type • E type 1 < Pnii 25_10 1/1000 < rzizi 1 . • 1;1000 < 1. 1/10 000 < Pu 111000 These equations mean that; microplankton can be shown to be present in . oligotrophic water bodies often only in 10, in any case not in 1 cu.cm of water. In the case of eutrophic water these figures are rand 2/1000.cu an. nannoplankton can be shown to be present in oligotrophicmater bodies often onl• in 1, in any case not in 1/1000 cu.cm of water. For eutrophic water the figur es are 1/1000 and 1/10000 eu. an, We thus find that the introduction of the titer concept into comparative plankton studies results in considerable clarity and ease of interpretation. • Another area where this is particularly true is e4perimenta1 plankton research. ;Let us, for erample, compare the'Trachelomonas titer of an oligotrephic-mater body under natural conditions and after eutrophi- cation. We obtain the following equations. Natural production Cultured production 1/100 < P(rr) 1 1/50 0-00 < 1/1000 These formulas show that: original production ranges frau 1 to 100 individuals per cu. an; . cultured production ranges frau 1,000 to 50,000 individuals • .per cu. an. The above examples should be sufficient to demonstrate the advantages that may be obtained frem a more widespread application of the titer concept in plankton studies. Basically, this is a logical ' consequence of the methodology first introduced by-R. Kolkwitz through the use of the cubic—centimeter method. 2. Volumetric Plankton Titers • Volumetric plankton titers are particularly important in the general production biology of water bodies. This is best represented by giving the titers for a certain .standard volume. - If me .compare„ for example, the. production of nannoplankton in oligo— and eutrophie water bàdies, we obtain the following data, assuming a.standard volume of 1 ou... cm: 0 type E type - (1)111 . These formulas show that: the volumetric production, related to à standard unit of 1 eu. cm j in oligotrophic conditions,.can be shown to be present onlyin'amounts of water ranging from 2 to 20 Cu. m; • the corresponding amounts of water in eutrophic conditions equal 1/250 eu. m to 1/25 au. • When.dealing with the volumetric. titer concept, voluMes must always be given in cubic meters and volumetric data in cubic centimeters. . Neuston Tit ers . It is obvious that neuston titers, in view of the peculiar circumstances surrounding that formation, cannot easnly be related tà cubic centimeters. Rather, WG must first calculate the titer per cubic • millimeter. In order to solve the special problems of comparing 'biological production between neuston and plankton it will still be necessary to convert the values to a common titer type. As far as this * cbm cubic meter. TRANSL. subject is concerned I shall confine myself to a reference to one of • my previous publications (1915), which describes in detail the principles to be applied to such calculations. F. Total Seston Titer With the present state of seston—research methodology, me are unable to provide data concerning the total seston titer of various types of mater bodies, either in individual or in volumetric terms. This is due mainly to the still very rudimentary methodology in research dealing mith ultraseston. Even thoughwe are still unable to deal theoretically with the total seston titer; this subject is of great importance in a •practical sense. This applies particularly to the field of water. supply and sewage. • This is because in the interpretation of a number of problems related to this field, scientists operate with the volumetric relationships of a practically defined "total seston. 0 The utotal sestonu as applied in Practice is represented by the filtration residue fran 1 cubic meter of the mater to be tested. - .As filtration is being carried out with phosphorus—bronze fabric, the applied "total sestonu will consist only.of those size classes of the total seston that exceed the largest nannoplankton. Thus, in testing • drinking water the following rule applies: . Om cbut dun • This means that a volumetric seston titer of Pvl must not occur in any less than 1 cubic meter of pure water. As to the testing of purified waste water, the following - rule applies: thui This means that a volumetric seston of le must not occur in any less than 1 cubic meter of purified waste water. The application of the titer concepts meuld most likely be in daily operational checks. i An operational table compiled in this manner mould indicate immediately tO what extent the acceptable titer had been exceeded or not attained: - re. LOOKING BACÈ I The groat development experienced by plankton research since the introduction of inquiries relating to biological production and of new methodological possibilities during the last decade has naturally •led to a certain reformulation and expansion of general limnological • terminology. This is only natural. New tasks require ever new tools. Anyone who is satisfied with the old and well—icaown methods 'will. faii.to • make progress. The development of science demands a continuous develop- mont of new terms and concepts. .Ny first criterion in 'assessing newly created terms.is that •they should as much as possible be brief and apt ratheethan consist of lengthy definitions. • If we review the preceding explanations in this light WO 1 see that I have always striven to adhere to this criterion. The; further analysis of seston research, the introduction of the term ultraseston, . the di£ferent:iation of the term neuston, and the generalization of the titer concept have been undertaken primarily from this viewpoint. The new terms of seston research which I have briefly explained in the preceding paragraphs have therefore all been created in order to provide modern limnol.ogy, which is now engaged in a rapid advance in tho area of productive biologyr w6.th ncv means of e.Vression that are appropriate to its present state. Fti.nal:ty, I hope that my efforts may in some rncasure contribute to the future development of limnology. Bi^ ra hv 15 7. Gatns, H. Principienfragen der Vegetationsforschung. Viert;eljahrsschrift der TJaturforsch. *Ges. '3az ZUrich. Band 63- . 1918. (Basic problaris of v'égetdtion research. Quarterly of the Socp of Naturalists of Zurich. Vol. 63. 1918.) 2. Hensen, V. Ueber die Bestimin.ung des Planktons. Komm. z, vrlss, Unters. der. deutschen Meere. (Determination of plankton. Comment: on the scient. 3.nvest. of Gel-man seas.) Kiel., 1887. 3, Haeckel, E. Planktonstudium. Jenaer Zeitschrift fUr Naturrrissenschaft. Vol. 25s 1591. Plankton und Seston. Berichte der Ueutschen. 4. Ko1kv;-^, R. -Botanischen Gesellschaft.. 1912. 5. Lohmann, H. Ueber das Nannopïankton . (Concerning Nanno 1911. -plankton.) Internationale Revue der Hydrobiologie, 6. Naumann, E. Beitr1l;e zur Kenntnis der VegetationsfIlrbungen in Sitss-wasser, VI. (^ontributions to the understanding of vegetation coloring in freshwater; VI. Sweclish with Gennan summary.) Bot. Notiser, 1915• 7. Naumann, E. i3eitrdgo zur Kenntnis don 'rt; c:hr:dar^ric=,x ,›. tons; I7. (Contributions to the uriderstandiiig of pond II.) Diol. Ceritra7blatt. 1917. g. Uebor die natiixli.che Nahrung des ;;- tons „ (Natural nutriment of animal :lzsnn.oplànln,on. ) Liuicla i;n^ ^c z^i^c,h,s Arsskrift. N.F. Avde 11, vol. )J^., 1918s ^1. ^aumsnn, E. Speziel.l.e Untersuchungen über- do ^_.z•;^tihzt^rj^r,s-^ biologie des tierischen Eumnoplanlcbons. (Special investigations of Lho nutrition biology of animal limnoplankton.) Ibid., I, vol. 1.7, 192.1g ' 1.0. Schi°13ter,, C., and Kirchner, 0. Die Vegatai:J.on des I Bodenseos. (Vegetation of Lake Constance.). Hodensee-For. schungen, Lind-au in B. ..1896. 11. SchUtt,- F. Ana1ytische ï'lanktonstudien. (Anu]ytica:L plankton studies.) .1892. 32. Steuer, A. plankLonlcunde. (Plankton research.) 1910. J3. Wili-ie1rn, J. Plankton und Tripton. Archiv flAr Hydroq biologie, XI, 1916.