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“Fish middens”: Anthropogenic accumulations of fish remains and their bearing on archaeoichthyological analysis
Journal of Archaeological
Science 1992,19,683-695
“Fish Middens”: Anthropogenic Accumulations of Fish Remains and Their Bearing on Archaeoichthyological Analysis Wim Van Neeraand Arturo Morales Muf& (Received 9 October 1991, revised manuscript accepted 7 February 1992) Extensive accumulations of animal remains, in the absence of anthropogenic contextual evidence, tend to be interpreted in strictly palaeobiological terms. The fact that anthropogenic thanatocoenoses may, to a great extent mimic natural ones has so far not been documented in detail. This paper gives an example of a recent man-made accumulation of fish remains, some characteristics of which might lead researchersto incorrect thinking. Should the assemblagebe covered by sediment and later excavated, it would probably be misinterpreted as a product of mass mortality of isolated populations in seasonalpools. In particular, the large number of specimensretrieved, the undisturbed articulation of most skeletal elements and the small sizeof the fishes, together with an almost complete absenceof signs of human activity could lead to such a misinterpretation. A palaeontological example of accumulated fish remains, which has very similar characteristics to the present-day one, is also discussed. Keywords: FISH, TAPHONOMY,
AFRICA, ARCHAEOZOOLOGY.
1. Introduction
The importance of man as a major taphonomic agent has long been recognized. While occasionally misunderstood and overrated, this importance runs, to a large extent, parallel to the existence of activity signs (artefacts, chopmarks, burned bones etc.) which provide clues to the interpretation of a particular assemblage’s formation (Noe-Nygaard, 1967: Brain, 1981). When no signs of human activity appear, however, there might be a tendency to disregard anthropogenic influences as causative agents and to concentrate instead on “natural causes”. One should always be careful when attempting to dismiss human activity, for abundant data indicate that humans can work in most subtle ways, as the present paper intends to illustrate.
Studies describing distinguishing features between naturally deposited and man-made bone assemblages are increasing in the literature, especially those concerned with terrestrial faunas (Koch, 1989). For fishes, however, few data are available (Schafer, 1972; Butler, 1987; Colley, 1987,199O; Richter, 1987; Yerkes, 1987; Wheeler&Jones, 1989) and, particularly in Africa almost no work has been done. Robbins (1980: 130-l 35) conducted an ethnoarchaeological study of a fisherman’s camp at Lake Turkana (Kenya), which “Royal Museum of Central Africa, B-3080 Tervuren, Belgium. Wniversidad Autonoma de Madrid, E-28049 Madrid, Spain.
683 03054lO3/92/060683
+ 13 $08.00/O
0 1992 Academic
Press Limited
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Figure croses
NEER
AND
A. M. MUfiIZ
1. Location of Dakar-Bango. The dam is indicated the river Djeuss east of the village.
by the black
line that
involved the excavation of the refuse areas of a camp occupied for about 2 years but abandoned I7 months before investigation. In an attempt to find criteria to distinguish naturally derived lacustrine bone scatters from anthropogenic ones, Stewart (1989: 78-98) analysed a natural fish bone assemblage from a beach at the western shore of Lake Turkana and then compared it with the bones found at a site used by Turkana fishermen for the roasting and consumption of fish. In a later paper, Stewart (1991) also includes channel-associated contexts in the comparison of natural and anthropogenic deposits. The assemblages described here represent a somewhat different type of approach to the problem. 2. The Fish Middens 2.1. Location and history offormation
The middens were discovered in June 1990 at Dakar-Bango, Senegal, during fieldwork in the region east of Saint-Louis (Figure I). The village of Dakar-Bango lies on the left bank of the Djeuss river, close to its outlet to the Senegal river. At the eastern extremity of the village a dam crosses the Djeuss, allowing regulation of the drainage and preventing incursion of saltwater. Just outside Dakar-Bango, at the west side of the dam five heaps of decaying fish were found (Figure 2). Inquiries among the inhabitants of the village, including fishermen, made it clear that all heaps had been “recently” deposited. Our informants could not give a precise chronological reconstruction of the events that resulted in the formation of the heaps. One single fisherman was said to be responsible for the accumulation of fish, which occurred over a time period of “several months”. This person had left the village “a few months ago”. The man used to empty his nets at the landing place and selected marketable from unmarketable fish in function of their size. The discarded fishes were those which were difficult to sell because of their small size. According to one of our informants the small fish could originally have been left at the surface to sun-dry. This idea was finally abandoned after speaking with other people and
“FISH
685
MIDDENS”
Figure 2. View of the fish middens midden in the front is heap 5.
at Dakar-Bango,
taken
from
the north.
The fish
also due to the fact that some of the heaps were rather thick with many layers of fish on top of each other. The fish had been caught with drifting monofilament gill nets with a mesh size of 20 mm (knot to knot), the same type used by the remaining fishermen at Dakar-Bango. 2.2. Analysis of thejsh middens 2.2.1. Size and overall features. Before studying the content of the heaps, measurements
were taken and a sketch of the area was made (Figure 3). The greatest length of the middens ranged from 2.2 to 3.25 m and the greatest width ranged from 1.6 to 2.0 m. The height of the heaps varied from about 10 cm (for heap 1) to 50 cm (for heap 5). All heaps were lying on firm ground but middens 3 and 4 were partially in contact with the water. Some other occasional material was mixed with the fishes. This was especially true for heap 1 which could be considered as a more general waste heap; it included lots of broken branches of trees, some stones, some Arca shells and even a sandal. This waste was lying below a layer of fishes. Part of this material, especially the branches, may also have come from the nets. The other heaps also contained such plant remains. Each heap contained numerous dermestid beetles and their larvae. They were identified as Dermestes maculatus. The degree to which these beetles had attacked the fish bodies varied from one area to another for any given heap. The most striking differences were observed in heap 2. At the eastern edge of that pile, the skin and the flesh of the fishes was almost completely eaten away by the dermestids, leaving perfectly cleaned skeletons (Figure 4). It was noted that this was the best-aerated part of the midden. During the course of the investigation of the heaps there was a strong and constant wind blowing from the east. It is known from the behavior of the dermestids that they only start feeding on carcasses which have lost a great part of their humidity (Waterman, 1976: 26). This explains why the fishes lying in or close to the water had not yet been attacked and also why the more humid parts inside the heap contained largely undefleshed individuals
686
W. VAN NEER AND A. M. MUSIZ
5 hl Irn l-l
Figure
3. Sketch
DAM
of the landing
place and the fish mounds.
Figure 4. Eastern edge of heap Chrysichthys (scale bar is 5 cm).
2 with
well-defleshed
specimens
of
mainly
(Figure 5). The defleshed skeletons were still articulated and had no tendency to fall apart, except for an occasional disconnection of the head, or breakage of the vertebral column. It was also noted that in certain fishes, such as Elops and Liza, isolated heads and bodies were more frequent than in other species. Strong winds, such as the prevailing easterly
“FISH
Figure
MIDDENS”
5. Heap
3 with Erhmalosa
687
not well-defleshed
(scale bar is 5 cm).
one, are believed not to be responsible for dispersal of corpses or isolated portions from them. Further analysis of the fish middens involved the establishment of a species list, an estimation of the relative abundance of the taxa in each heap and an overall description of the size distribution of the main species. 2.2.2. Species diversity. A total of 23 different fish taxa, both marine and freshwater have been identified from the heaps (Table 1). All marine species represented are known to enter rivers and small specimens from these taxa constitute a substantial portion of the annual catch in estuaries (Daget & Iltis, 1965). Among the freshwater species several taxa (e.g. Chrysichthys and Tilapiini) are reputed for their high salinity tolerance. Others, however, are less tolerant of brackish water (e.g. Mormyridae). This indicates that the heaps accumulated not only during the dry season, when the incursion of saltwater into the Djeuss was high, but also during the wet season when the freshwater influx was important. Our visit to the area took place at the very end of the dry season (June) when salinity levels were high downstream from the Dakar-Bango dam. Fishing with handthrown cast nets in the downstream section of the river, close to the midden site, yielded Mugilidae, Sarotherodon melanotheron, Sarotherodon galileus and Citharichthys stamp& which are all euryhaline species (persona1 data). However, due to the aforementioned strong winds blowing during our stay at the site, no gill-net fishing was practicable and hence the regular catches could not be verified. 2.2.3. Relative importance of the taxa. The fish middens included accumulations ranging from several hundreds (for heap 1) to several thousands of individuals (all remaining heaps). In order to get an impression of the importance of each taxon, counts of samples were made (Table 2; Figure 6). Specimens were counted in a 10 cm wide strip along the greatest length and at the surface of each heap. In each case approximately 100 individuals were identified to species. The species composition within each heap seemed to be more or
688
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Table 1. List offishes
identiJiedfrom
theJive
heaps ai Dakar-Bango
Marine fishes
Freshwater fishes
Elopidae
Mormyridae Small species (cf. Marcusenius) Cyprinidae Labeo sp.
Elops
sp.
Clupeidae Ethmalosafimbriata Ilisha africana
Citharinidae
Carangidae
Characidae
Haemulidae Brachydeuterus
AlesteslBrycinus
auritus
Bagridae
Monodactylidae Psettias
Bagrus bajad Chrysichthys maurus
sebae
Schilbeidae
Mugihdae Liza sp. Polynemidae Galeoides
Schilbe
mystus
Clariidae Clarias
decadactylus
anguillaris
Mochokidae
Bothidae Citharichthys
sp.
Citharinus
Selene dorsalis Lichia amia
Synodonris
stampflii
schall
Centropomidae
Cynoglossidae Cynoglossus sp.
Lates niloticus
Cichlidae Oreochromis
niloticus
Tilapiini indet.
Table 2. Species composition of the heaps at Dakar-Bango, of individuals found in samples of about 10afishes. Minor as “others”
expressed as the number fish taxa have been lumped
Hla
Hlb
H2
H3
H4
H5
Total
Tilapiini Others
22 14 29 15 13 6 7
6 20 12 63 50 22 19
1 25 52 3 4 19
I 76 1 12 5 4 4
73 17 25 4
1 53 4 18 15 3 2
31 261 63 160 86 64 55
Total
106
192
104
103
119
96
720
Elops Ethmalosa Liza Chrysichthys Synodonris
less homogeneous in each area without apparent concentrations of single species at any place. An exception to this was a concentration of Chrysichthys occurring in a small spot at the eastern edge of heap 2 (see also Figure 4). It was also noticed that heap 1, which contained the lowest number of specimens, would give a different spectrum depending upon the area chosen for a subsample. Therefore, two different counts were made on this heap, one along the greatest length (heap la in Figure 6) and one including all specimens lying in the northwestern “subheap” (heap 1b).
“FISH
689
MIDDENS” Others
Synodonlis
60 1 L:
z 40
1 --I
Ethmalosa
a Hops
20
0
I Chrysichthys
heap la (N= 106)
heap lb (N=192)
heap 2 (N= 104)
heap 3 (N= 103)
Figure 6. Relative importance been calculated from number
-L-
heap 4 (Nzll9)
d heap 5 (N=96)
of the main fish taxa in each heap. Percentages of individuals.
have
2.2.4. Size distribution of the d&@rent species. In order to evaluate the sizes of the discarded fishes, standard lengths (SL) were measured for the most common species. For statistical relevance, we tried to measure about 25 specimens for each species. This was straightforward for Ethmalosa, Synodontis, Chrysichthys and Tilapiini since they were common and well preserved. Analysis of the graph (Figure 7) indicates that animals with a standard length between 9 and 11 cm are most common in the samples. Data for other taxa are incomplete, mainly because they were not so well represented, but also because whole specimens were rare. Only seven complete specimens from Clarias gariepinus were measured (between 14 and 20 cm SL). The Bagrus bajad specimens are in the same size range (15.5-20 cm SL). In Psettiassebae the range is from 6.5 to 8.5 cm SL (four specimens only). Z The observed minimum length varies from species to species. This phenomenon has long been known from fishery studies where the effectiveness of nets of a given mesh size has been investigated as a function of the length and height of the captured fishes (Fryer & Iles, 1972: 417-421; Jensen, 1990). In our samples it is obvious that deep-bodied species (Psettias and tilapia) are represented by smaller individuals than more fusiform fishes such as Elops. According to our informants the fishes were unmarketable specimens because of their small size. Despite this, however, occasional larger individuals have been found: Ethmalosa of more than 20 cm, as well as Clarias and Bagrus of approximately 20 cm. In the case of Ethmalosa, those larger individuals may have fallen among the refuse fishes during sorting of the catch or they may have been considered unmarketable for another reason (damaged or spoiled). Initially it might seem surprising that Clarias and Bagrus between 14 and 20 cm are found among the unmarketable fish, but they do represent the smallest individuals of the catch and may therefore have been considered not worth taking. 3. Discussion
Wheeler & Jones (1989: 77) give an overview of the processes involved in the formation of archaeological fish assemblages. In their scheme they assume that undesired fishes are
690
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AND A. M. MUr;;rIZ
‘thmoloso
SLkm) 6 Chrysichlhys
4 z 2
0
SL(cm)
6
4 z
2
0 8
9
10
II
12
SL(cm)
4
0 Figure
5
6 7 6 9 7. Length distribution
IO I2 I3 of the most common
SL(cm) fishes.
“FISH
MIDDENS”
691
discarded at the place of capture and hence all such animals are rarely landed (Wheeler & Jones, 1989: 64). During our stay in Senegal we have noticed that this is true when the fish are captured far offshore. However, when fishing is practised close to the shore-in coastal, riverine as well as lacustrine environments-fish selection usually occurs at the landing place. This was the case at Dakar-Bango. Hence, in this study we are dealing with an accumulation of fish which underwent only very limited handling by man. Excluding the catch, the selection by size and the accumulation in heaps, man did not manipulate the fishes. One is tempted to speculate how these mounds would be interpreted if they were to be covered by soil and later excavated. Naturally, we cannot predict possible future disturbances, nor can we gauge the taphonomic loss that might occur during further exposure at the surface, or during and after burial. Neither can we predict how accurate the methods would be during future excavation. For discussion’s sake we will assume that most of the observable features described thus far would also be apparent, to some extent, during future excavation. Certainly, the contents of the mounds give almost no indication of their anthropogenic origin. Only heap 1 contains abundant waste that is easily attributable to man and which would give sufficient grounds for interpreting the heap as a culturally-derived assemblage. Conversely, in the other mounds the only objects included in the deposits are broken branches, and these are likely to have come from the nets. It is highly improbable that these wood pieces, if preserved, would be considered as an indication of an anthropogenic origin for the heaps, except perhaps if all mounds were totally excavated. If this were done then, based on the premiss that heap 1 is of anthropogenic origin (see above), the others could possibly be considered to have had a similar taphonomic history. Nevertheless, the fishes do not show any sign of manipulation (butchery marks, traces of fire, etc.). Moreover, the majority of the skeletons are still articulated. When these facts, combined with the small size of the individuals, are considered on their own, then they imply, albeit by convergent means, that the deposit resembles a natural death assemblage. Circumstances under which such natural deposits can originate are numerous in Africa along waters with a seasonally fluctuating level. 3.1. Distinguishing natural and anthropogenic thanatocoenosis The level of rivers and lakes in many regions in Africa fluctuates seasonally as a result of flood waters. During such periods when lake margins and floodplains are inundated, most fishes migrate to the flooded areas to spawn. Their fry grow fast in this nutrient-rich environment. When the water level drops, the larger fish migrate back towards the main water body but the smaller individuals delay their return and may eventually become trapped in residual pools at the lake margin or on the floodplain (Welcomme, 1975). The species composition of such water bodies is not well studied but the work of Holden (1963) indicates there is much variation even between pools lying close to each other. The seasonal pools studied by Holden (1963) were relatively large and the number of genera was high. When the pools dry up further, they become smaller and less oxygenated, making it difficult for most species to survive. The genera with the highest tolerance to low oxygen levels are Clarias (with its accessory breathing organs) and tilapia (Fish, 1956). This also explains why these two genera are present in many Saharan waterbodies isolated since the end of the last humid period of the Holocene (Le Berre, 1989). A well-documented fossil assemblage of African freshwater fishes that died as a result of seasonal drying-up of a pool comes from Bir Tarfawi (Eastern Sahara, Egypt). The fauna is dated to the Last Interglacial and corresponds to the contents of a small pool which was seasonally connected with a lake. Geomorphological observations and the lack of artefacts indicate that the assemblage is a naturally derived one. It is also believed that most of the fish remains represent individuals that died as the pool dried up, but
692
W. VAN NEER AND
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Table 3. List qfJi.sh identified,from expressed as percentages of number individuals ( MNI)
Mormyridae Alestes/Brycinus Bagrus Clarias Synodontis Lales Tilapiini indet. 1 indet. 2 indet. 3
the natural-death assemblages at Bir Tarfan?. qf,fragments (NF) and of minimum number of
(N,N:47)
MN1 (N=355)
0.3% 0.3% 0.1% 38.7% 8.1% 3.5% 49.0% + + +
0.3% 0.3% 0.6% 32.7% 39.1% 4.2% 22.8% + + +
the abundant remnants of reed cormorant Phalacrocorax africanus (including many juveniles) indicate that this species has probably also contributed to the deposit (Kowalski et al., 1989). The ichthyofauna of Bir Tarfawi contains 10 different taxa, but comprises mainly Clarias, tilapia and Synodontis (Table 3). Size reconstructions of the different species indicate a preponderance of small individuals. Most specimens are between 10 and 20 cm SL for Clarias, between 5 and 15 cm SL for tilapia and less than 7 cm SL for Synodontis (Van Neer, in press). Differences between the assemblages of Dakar-Bango and Bir Tarfawi lie not in the size distribution of the species, but rather in the species diversity itself. At Dakar-Bango a much wider spectrum of the ichthyofauna is present. This probably relates to the fact that this assemblage comes from a much larger catchment area which includes different habitats exploited over different seasons, whereas in the natural assemblage of Bir Tarfawi only species that are tolerant of the adverse conditions in the pool occur. A particular feature of this natural assemblage, besides its low specific diversity, is the abundance of Clarias and tilapia. These taxa have the highest chances of survival in poorly oxygenated biotopes. This last criterion, however, will not always allow discrimination between naturally derived and anthropogenic accumulations. Should people discard small fish after exploitation of seasonal pools dominated by Clarias and tilapia, then it will be difficult to discriminate such an assemblage from a naturally derived one. In such cases, one can only hope to find circumstantial evidence to distinguish between the two. 3.2. Contextually derived evidence: the Wadi Howar case study A specific case, recently studied by one of us (Van Neer, 1988), illustrates how geomorphological and archaeological observations can occasionally help to distinguish between natural and anthropogenic assemblages. The Holocene site BOS 84/ 13 in the Middle Wadi Howar, Sudan, incorporates eight pits which have been excavated on a dune of the southern bank of the wadi. All pits are refuse dumps containing pottery, lithic material and bones, mainly from cattle. However, one pit is different in that it yielded a large number of small fish. So far only a small part of the 3 mm sieve fraction has been investigated, the 1 mm fraction not being available for analysis at the time of this study. A preliminary analysis of the sample indicates that at least 17 different taxa are present and that Clarias and tilapia are the most abundant fishes. While size reconstructions are unavoidably biased, since the 1 mm fraction is not included, they nevertheless indicate an
“FISH MIDDENS”
693
abundance of small individuals. It seems clear from the relative frequencies of the taxa (mostly Clurius and tilapia) and from the small sizes of the specimens, that the fishes must have come from a residual pool along the wadi. During identification of the material, and reconstruction of the sizes of the corresponding fishes, the overwhelming similarities with the natural death assemblage of Bir Tarfawi, inclined us towards a similar explanation for the history of deposition at the Middle Wadi Howar. Despite recognizing that people readily eat small fishes, we still initially tried to explain the coexistence of artefacts and fish bones as a result of natural causes. The scenario we first devised involved high floods covering that part of the dune. The anthropogenic pit structure of the abandoned site was believed to have acted as a trap in which small fish were retained after the water level dropped. However, a geomorphological survey of the site and its surroundings made it clear that floods could have never reached such a high level on the dune (Kropelin, pers. comm.). Furthermore, the archaeological analysis showed the pit to be probably a multifunctional unit, viz, a storage place during the initial phase of filling and a refuse dump later on (Keding, 1986, in press). Thus, the initial archaeozoological interpretation of the fish assemblage as a natural thanatocoenosis was actually a misguided automatic response, resulting from the presence of large numbers of small fish combined with the absence of manipulative marks on the bones. The results from the work at Dakar-Bango clearly indicate that anthropogenic accumulations of this kind are indeed perfectly possible. 4. Conclusions
The processes whereby fishes become deposited in heaps similar to the middens described above may be governed by several factors. Inefficiencies associated with food processing are responsible for many such factors. For example, rapid decomposition of these fishes caused by weather changes, insect pests, etc. will render them unacceptable for human consumption and hence they will be discarded. Other, related processes of product rejection include the disposal of caught fishes which are too small for profitable marketing. There are, of course, alternative solutions to overcome such waste of resources (e.g. fishes may be used for soup, or dried and used as fodder for domestic stock). Nevertheless, rejective decisions of the type described above will remain as important factors in the formation of fish middens and they are always complicated phenomena to evaluate a posteriori. There can be other factors, including epiphenomena such as ritualistic offerings, foods, status symbols etc. which may be regarded as potential causative agents of non-consumable and consumable fish accumulations. However, any detailed discussion of these lies beyond the scope of this paper. The most significant point is the degree of convergence occasionally produced between some man-made accumulations and natural ones (Rose110 & Morales, 1990; Morales & Rosello, in press). Consequently, in order to describe accurately the history of any particular accumulation, the researcher is required to make comparative analyses of all complementary information relevant to the assemblage. We hope that future investigations along such lines will eventually provide a database against which other hypotheses may be tested. Acknowledgements
The field work in Senegal would not have been possible without the help of Marie-Amy Mbow (I.F.A.N.-Ch.A.Diop; Dakar) and Marie-Isaac Diop who acted as interpreters and arranged several practical matters. The drawings for this article were made by Alain Reygel (Tervuren). J. Decelle (Tervuren) identified the dermestid beetles. Earlier drafts of
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this paper were read and commented upon by Dick Brinkhuizen (Groningen), Inge BDdker-Enghoff (Copenhague), Leif Jonsson (Gijteborg) and Ian Harrison (Tervuren). To all these colleagues and friends we express our sincere thanks. References Brain, C. K. (1981). Hunters or the Hunted? An Introduction to African Cave Taphonomy. Chicago: Chicago University Press. Butler, V. L. (1987). Distinguishing natural from cultural salmonid deposits in the Pacific northwest of North America. BAR International Series 352, 131-149. Colley, S. (1987). Fishing or facts. Can we reconstruct fishing methods from archaeological evidence?Australian Archaeology 24, 1626. Colley, S. (1990). The analysis and interpretation of archaeological fish remains. In (M. Schiffer, Ed) Archaeological Method and Theory. Tucson: University of Arizona Press. Daget, J. & Iltis, A. (1965). Poissonsde Cote d’Ivoire. Memoires de f’lnstitut Francais de 1’Afrique Noire 74, l-385. Fish, G. R. (1956). Some aspectsof the respiration of six speciesof fish from Uganda. Journal of Experimental
Biology
33,186195.
Fryer, G. & Iles, T. D. (1972). The Cichlid Fishes ofthe Great Lakes of Africa: Their Biology and Evolution. Edinburgh: Oliver and Boyd. Holden, M. J. (1963). The populations of fish in dry seasonpools of the River Sokoto. Fishing Publications Colonial Ofice 19, l-58. Jensen, W. (1990). Comparing fish catches taken with gill nets of different combinations of mesh sizes.Journal of Fish Biology 37,99-104. Keding, B. (1986). Gabarona 84113. Siedlungsfunde des 2. und 3. vorchristlichen Jahrtausends im Wadi Howar (Ostsahara). Magisterarbeit, Universitat Koln, Germany. Keding, B. (in press). Leiterbandsites in the Wadi Howar. In (L. Krzyzaniak & M. Kobusiewicz, Eds) Environmental Change and Human Culture in the Nile Basin and Northern Africa Until 2nd Millenium BC. Poznan: Poznan Archaeological Museum. Koch, C. P. (1989). Taphonomy: A Bibliographic Guide to the Literature. Peopling of the Americas Publications. Bibliographic Series.Orono, Maine: Center for the Study of the First Americans, . University of Maine. Kowalski, K., Van Neer, W., Bochenski, Z., Mlynarski, M., Rzebik-Kowalska. B., Szyndlar, Z., Gautier, A., Schild, R., Close A. E. & Wendorf, F. (1989). A Last Interglacial fauna from the Eastern Sahara. Quarternary Research 32,335-341. Le Berre, M. (1989). Faune du Sahara. 1. Poissons-amphibiens-reptiles. Paris: ChabaudLechevalier. Morales, A. & Rosello, E. (in press).Casual or intentional? Comments on fish taxa skeletal representation from Iberian archaeological settlements. Proceedings Fourth Meeting of the ZCAZ Fish Working Group, September 1987, University of York. In (A. K. G. Jones & R. A. Nicholson, Eds) Fishes and Man. Noe-Nygaard, N. (1967). Present-day “kitchen middens” in Ghana. Geogrufisk Tidsskrift 66, 179-197. Richter, J. (1987). Evidence for a natural deposition of fish in the middle neolithic site, Kainsbakke, East Jutland. Danish Journal Archaeology 5,11&l 24. Robbins, L. H. (1980). Lopoy: a Late Stone-Age fishing and pastoralist settlement in the Lake Turkana Basin, Kenya. Publications of the Museum, Michigan State University, Anthropological Series 3, l-140. Rosello, E. & Morales, A. (1990). Global patterns of skeletal abundance in Spanish archaeoichthic assemblages.In (S. Fernandez-Lopez, Ed) Communicaciones Reunion de Tafonomia y Fosilizacion. Madrid: Universidad Complutense de Madrid pp. 319-325. Schafer, W. (1972). Ecology and Paleoecology ofMarine Environments. Edinburgh: Oliver and Boyd. Stewart, K. M. (1989). Fishing sitesof North and East Africa in the Late Pleistoceneand Holocene. Environmental change and human adaptation. BAR International Series 521, l-273.
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Stewart, K. M. (1991). Modern fishbone assemblages at Lake Turkana, Kenya: a methodology to aid in recognition of hominid fish utilisation. Journal qf Archaeological Science l&579-603. Van Neer. W. (1988). Fish remains from a holocene site (84/13-9) in Wadi Howar, Sudan Archaeozoologia 2,339-348. Van Neer, W. (in press). Fish remains from the Last Interglacial at Bir Tarfawi (Eastern Sahara, Egypt). Waterman, J. J. (1976). The production of dried fish. FAO Fisheries Technical Paper 16, l-52. Welcomme, R. L. (1975). The fisheries ecology of African floodplains. FAO CIFA Technical Paper 3, l-51. Wheeler, A. & Jones, A. K. G. (1989). Fishes. Cambridge Manuals in Archaeology. Cambridge: Cambridge University Press. Yerkes, R. W. (1987). Seasonal patterns in late prehistoric fishing practices in the North American Midwest. Archaeozoologia 1, 137-148.
Science 1992,19,683-695
“Fish Middens”: Anthropogenic Accumulations of Fish Remains and Their Bearing on Archaeoichthyological Analysis Wim Van Neeraand Arturo Morales Muf& (Received 9 October 1991, revised manuscript accepted 7 February 1992) Extensive accumulations of animal remains, in the absence of anthropogenic contextual evidence, tend to be interpreted in strictly palaeobiological terms. The fact that anthropogenic thanatocoenoses may, to a great extent mimic natural ones has so far not been documented in detail. This paper gives an example of a recent man-made accumulation of fish remains, some characteristics of which might lead researchersto incorrect thinking. Should the assemblagebe covered by sediment and later excavated, it would probably be misinterpreted as a product of mass mortality of isolated populations in seasonalpools. In particular, the large number of specimensretrieved, the undisturbed articulation of most skeletal elements and the small sizeof the fishes, together with an almost complete absenceof signs of human activity could lead to such a misinterpretation. A palaeontological example of accumulated fish remains, which has very similar characteristics to the present-day one, is also discussed. Keywords: FISH, TAPHONOMY,
AFRICA, ARCHAEOZOOLOGY.
1. Introduction
The importance of man as a major taphonomic agent has long been recognized. While occasionally misunderstood and overrated, this importance runs, to a large extent, parallel to the existence of activity signs (artefacts, chopmarks, burned bones etc.) which provide clues to the interpretation of a particular assemblage’s formation (Noe-Nygaard, 1967: Brain, 1981). When no signs of human activity appear, however, there might be a tendency to disregard anthropogenic influences as causative agents and to concentrate instead on “natural causes”. One should always be careful when attempting to dismiss human activity, for abundant data indicate that humans can work in most subtle ways, as the present paper intends to illustrate.
Studies describing distinguishing features between naturally deposited and man-made bone assemblages are increasing in the literature, especially those concerned with terrestrial faunas (Koch, 1989). For fishes, however, few data are available (Schafer, 1972; Butler, 1987; Colley, 1987,199O; Richter, 1987; Yerkes, 1987; Wheeler&Jones, 1989) and, particularly in Africa almost no work has been done. Robbins (1980: 130-l 35) conducted an ethnoarchaeological study of a fisherman’s camp at Lake Turkana (Kenya), which “Royal Museum of Central Africa, B-3080 Tervuren, Belgium. Wniversidad Autonoma de Madrid, E-28049 Madrid, Spain.
683 03054lO3/92/060683
+ 13 $08.00/O
0 1992 Academic
Press Limited
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Figure croses
NEER
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A. M. MUfiIZ
1. Location of Dakar-Bango. The dam is indicated the river Djeuss east of the village.
by the black
line that
involved the excavation of the refuse areas of a camp occupied for about 2 years but abandoned I7 months before investigation. In an attempt to find criteria to distinguish naturally derived lacustrine bone scatters from anthropogenic ones, Stewart (1989: 78-98) analysed a natural fish bone assemblage from a beach at the western shore of Lake Turkana and then compared it with the bones found at a site used by Turkana fishermen for the roasting and consumption of fish. In a later paper, Stewart (1991) also includes channel-associated contexts in the comparison of natural and anthropogenic deposits. The assemblages described here represent a somewhat different type of approach to the problem. 2. The Fish Middens 2.1. Location and history offormation
The middens were discovered in June 1990 at Dakar-Bango, Senegal, during fieldwork in the region east of Saint-Louis (Figure I). The village of Dakar-Bango lies on the left bank of the Djeuss river, close to its outlet to the Senegal river. At the eastern extremity of the village a dam crosses the Djeuss, allowing regulation of the drainage and preventing incursion of saltwater. Just outside Dakar-Bango, at the west side of the dam five heaps of decaying fish were found (Figure 2). Inquiries among the inhabitants of the village, including fishermen, made it clear that all heaps had been “recently” deposited. Our informants could not give a precise chronological reconstruction of the events that resulted in the formation of the heaps. One single fisherman was said to be responsible for the accumulation of fish, which occurred over a time period of “several months”. This person had left the village “a few months ago”. The man used to empty his nets at the landing place and selected marketable from unmarketable fish in function of their size. The discarded fishes were those which were difficult to sell because of their small size. According to one of our informants the small fish could originally have been left at the surface to sun-dry. This idea was finally abandoned after speaking with other people and
“FISH
685
MIDDENS”
Figure 2. View of the fish middens midden in the front is heap 5.
at Dakar-Bango,
taken
from
the north.
The fish
also due to the fact that some of the heaps were rather thick with many layers of fish on top of each other. The fish had been caught with drifting monofilament gill nets with a mesh size of 20 mm (knot to knot), the same type used by the remaining fishermen at Dakar-Bango. 2.2. Analysis of thejsh middens 2.2.1. Size and overall features. Before studying the content of the heaps, measurements
were taken and a sketch of the area was made (Figure 3). The greatest length of the middens ranged from 2.2 to 3.25 m and the greatest width ranged from 1.6 to 2.0 m. The height of the heaps varied from about 10 cm (for heap 1) to 50 cm (for heap 5). All heaps were lying on firm ground but middens 3 and 4 were partially in contact with the water. Some other occasional material was mixed with the fishes. This was especially true for heap 1 which could be considered as a more general waste heap; it included lots of broken branches of trees, some stones, some Arca shells and even a sandal. This waste was lying below a layer of fishes. Part of this material, especially the branches, may also have come from the nets. The other heaps also contained such plant remains. Each heap contained numerous dermestid beetles and their larvae. They were identified as Dermestes maculatus. The degree to which these beetles had attacked the fish bodies varied from one area to another for any given heap. The most striking differences were observed in heap 2. At the eastern edge of that pile, the skin and the flesh of the fishes was almost completely eaten away by the dermestids, leaving perfectly cleaned skeletons (Figure 4). It was noted that this was the best-aerated part of the midden. During the course of the investigation of the heaps there was a strong and constant wind blowing from the east. It is known from the behavior of the dermestids that they only start feeding on carcasses which have lost a great part of their humidity (Waterman, 1976: 26). This explains why the fishes lying in or close to the water had not yet been attacked and also why the more humid parts inside the heap contained largely undefleshed individuals
686
W. VAN NEER AND A. M. MUSIZ
5 hl Irn l-l
Figure
3. Sketch
DAM
of the landing
place and the fish mounds.
Figure 4. Eastern edge of heap Chrysichthys (scale bar is 5 cm).
2 with
well-defleshed
specimens
of
mainly
(Figure 5). The defleshed skeletons were still articulated and had no tendency to fall apart, except for an occasional disconnection of the head, or breakage of the vertebral column. It was also noted that in certain fishes, such as Elops and Liza, isolated heads and bodies were more frequent than in other species. Strong winds, such as the prevailing easterly
“FISH
Figure
MIDDENS”
5. Heap
3 with Erhmalosa
687
not well-defleshed
(scale bar is 5 cm).
one, are believed not to be responsible for dispersal of corpses or isolated portions from them. Further analysis of the fish middens involved the establishment of a species list, an estimation of the relative abundance of the taxa in each heap and an overall description of the size distribution of the main species. 2.2.2. Species diversity. A total of 23 different fish taxa, both marine and freshwater have been identified from the heaps (Table 1). All marine species represented are known to enter rivers and small specimens from these taxa constitute a substantial portion of the annual catch in estuaries (Daget & Iltis, 1965). Among the freshwater species several taxa (e.g. Chrysichthys and Tilapiini) are reputed for their high salinity tolerance. Others, however, are less tolerant of brackish water (e.g. Mormyridae). This indicates that the heaps accumulated not only during the dry season, when the incursion of saltwater into the Djeuss was high, but also during the wet season when the freshwater influx was important. Our visit to the area took place at the very end of the dry season (June) when salinity levels were high downstream from the Dakar-Bango dam. Fishing with handthrown cast nets in the downstream section of the river, close to the midden site, yielded Mugilidae, Sarotherodon melanotheron, Sarotherodon galileus and Citharichthys stamp& which are all euryhaline species (persona1 data). However, due to the aforementioned strong winds blowing during our stay at the site, no gill-net fishing was practicable and hence the regular catches could not be verified. 2.2.3. Relative importance of the taxa. The fish middens included accumulations ranging from several hundreds (for heap 1) to several thousands of individuals (all remaining heaps). In order to get an impression of the importance of each taxon, counts of samples were made (Table 2; Figure 6). Specimens were counted in a 10 cm wide strip along the greatest length and at the surface of each heap. In each case approximately 100 individuals were identified to species. The species composition within each heap seemed to be more or
688
W. VAN NEER
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Table 1. List offishes
identiJiedfrom
theJive
heaps ai Dakar-Bango
Marine fishes
Freshwater fishes
Elopidae
Mormyridae Small species (cf. Marcusenius) Cyprinidae Labeo sp.
Elops
sp.
Clupeidae Ethmalosafimbriata Ilisha africana
Citharinidae
Carangidae
Characidae
Haemulidae Brachydeuterus
AlesteslBrycinus
auritus
Bagridae
Monodactylidae Psettias
Bagrus bajad Chrysichthys maurus
sebae
Schilbeidae
Mugihdae Liza sp. Polynemidae Galeoides
Schilbe
mystus
Clariidae Clarias
decadactylus
anguillaris
Mochokidae
Bothidae Citharichthys
sp.
Citharinus
Selene dorsalis Lichia amia
Synodonris
stampflii
schall
Centropomidae
Cynoglossidae Cynoglossus sp.
Lates niloticus
Cichlidae Oreochromis
niloticus
Tilapiini indet.
Table 2. Species composition of the heaps at Dakar-Bango, of individuals found in samples of about 10afishes. Minor as “others”
expressed as the number fish taxa have been lumped
Hla
Hlb
H2
H3
H4
H5
Total
Tilapiini Others
22 14 29 15 13 6 7
6 20 12 63 50 22 19
1 25 52 3 4 19
I 76 1 12 5 4 4
73 17 25 4
1 53 4 18 15 3 2
31 261 63 160 86 64 55
Total
106
192
104
103
119
96
720
Elops Ethmalosa Liza Chrysichthys Synodonris
less homogeneous in each area without apparent concentrations of single species at any place. An exception to this was a concentration of Chrysichthys occurring in a small spot at the eastern edge of heap 2 (see also Figure 4). It was also noticed that heap 1, which contained the lowest number of specimens, would give a different spectrum depending upon the area chosen for a subsample. Therefore, two different counts were made on this heap, one along the greatest length (heap la in Figure 6) and one including all specimens lying in the northwestern “subheap” (heap 1b).
“FISH
689
MIDDENS” Others
Synodonlis
60 1 L:
z 40
1 --I
Ethmalosa
a Hops
20
0
I Chrysichthys
heap la (N= 106)
heap lb (N=192)
heap 2 (N= 104)
heap 3 (N= 103)
Figure 6. Relative importance been calculated from number
-L-
heap 4 (Nzll9)
d heap 5 (N=96)
of the main fish taxa in each heap. Percentages of individuals.
have
2.2.4. Size distribution of the d&@rent species. In order to evaluate the sizes of the discarded fishes, standard lengths (SL) were measured for the most common species. For statistical relevance, we tried to measure about 25 specimens for each species. This was straightforward for Ethmalosa, Synodontis, Chrysichthys and Tilapiini since they were common and well preserved. Analysis of the graph (Figure 7) indicates that animals with a standard length between 9 and 11 cm are most common in the samples. Data for other taxa are incomplete, mainly because they were not so well represented, but also because whole specimens were rare. Only seven complete specimens from Clarias gariepinus were measured (between 14 and 20 cm SL). The Bagrus bajad specimens are in the same size range (15.5-20 cm SL). In Psettiassebae the range is from 6.5 to 8.5 cm SL (four specimens only). Z The observed minimum length varies from species to species. This phenomenon has long been known from fishery studies where the effectiveness of nets of a given mesh size has been investigated as a function of the length and height of the captured fishes (Fryer & Iles, 1972: 417-421; Jensen, 1990). In our samples it is obvious that deep-bodied species (Psettias and tilapia) are represented by smaller individuals than more fusiform fishes such as Elops. According to our informants the fishes were unmarketable specimens because of their small size. Despite this, however, occasional larger individuals have been found: Ethmalosa of more than 20 cm, as well as Clarias and Bagrus of approximately 20 cm. In the case of Ethmalosa, those larger individuals may have fallen among the refuse fishes during sorting of the catch or they may have been considered unmarketable for another reason (damaged or spoiled). Initially it might seem surprising that Clarias and Bagrus between 14 and 20 cm are found among the unmarketable fish, but they do represent the smallest individuals of the catch and may therefore have been considered not worth taking. 3. Discussion
Wheeler & Jones (1989: 77) give an overview of the processes involved in the formation of archaeological fish assemblages. In their scheme they assume that undesired fishes are
690
W. VAN NEER
AND A. M. MUr;;rIZ
‘thmoloso
SLkm) 6 Chrysichlhys
4 z 2
0
SL(cm)
6
4 z
2
0 8
9
10
II
12
SL(cm)
4
0 Figure
5
6 7 6 9 7. Length distribution
IO I2 I3 of the most common
SL(cm) fishes.
“FISH
MIDDENS”
691
discarded at the place of capture and hence all such animals are rarely landed (Wheeler & Jones, 1989: 64). During our stay in Senegal we have noticed that this is true when the fish are captured far offshore. However, when fishing is practised close to the shore-in coastal, riverine as well as lacustrine environments-fish selection usually occurs at the landing place. This was the case at Dakar-Bango. Hence, in this study we are dealing with an accumulation of fish which underwent only very limited handling by man. Excluding the catch, the selection by size and the accumulation in heaps, man did not manipulate the fishes. One is tempted to speculate how these mounds would be interpreted if they were to be covered by soil and later excavated. Naturally, we cannot predict possible future disturbances, nor can we gauge the taphonomic loss that might occur during further exposure at the surface, or during and after burial. Neither can we predict how accurate the methods would be during future excavation. For discussion’s sake we will assume that most of the observable features described thus far would also be apparent, to some extent, during future excavation. Certainly, the contents of the mounds give almost no indication of their anthropogenic origin. Only heap 1 contains abundant waste that is easily attributable to man and which would give sufficient grounds for interpreting the heap as a culturally-derived assemblage. Conversely, in the other mounds the only objects included in the deposits are broken branches, and these are likely to have come from the nets. It is highly improbable that these wood pieces, if preserved, would be considered as an indication of an anthropogenic origin for the heaps, except perhaps if all mounds were totally excavated. If this were done then, based on the premiss that heap 1 is of anthropogenic origin (see above), the others could possibly be considered to have had a similar taphonomic history. Nevertheless, the fishes do not show any sign of manipulation (butchery marks, traces of fire, etc.). Moreover, the majority of the skeletons are still articulated. When these facts, combined with the small size of the individuals, are considered on their own, then they imply, albeit by convergent means, that the deposit resembles a natural death assemblage. Circumstances under which such natural deposits can originate are numerous in Africa along waters with a seasonally fluctuating level. 3.1. Distinguishing natural and anthropogenic thanatocoenosis The level of rivers and lakes in many regions in Africa fluctuates seasonally as a result of flood waters. During such periods when lake margins and floodplains are inundated, most fishes migrate to the flooded areas to spawn. Their fry grow fast in this nutrient-rich environment. When the water level drops, the larger fish migrate back towards the main water body but the smaller individuals delay their return and may eventually become trapped in residual pools at the lake margin or on the floodplain (Welcomme, 1975). The species composition of such water bodies is not well studied but the work of Holden (1963) indicates there is much variation even between pools lying close to each other. The seasonal pools studied by Holden (1963) were relatively large and the number of genera was high. When the pools dry up further, they become smaller and less oxygenated, making it difficult for most species to survive. The genera with the highest tolerance to low oxygen levels are Clarias (with its accessory breathing organs) and tilapia (Fish, 1956). This also explains why these two genera are present in many Saharan waterbodies isolated since the end of the last humid period of the Holocene (Le Berre, 1989). A well-documented fossil assemblage of African freshwater fishes that died as a result of seasonal drying-up of a pool comes from Bir Tarfawi (Eastern Sahara, Egypt). The fauna is dated to the Last Interglacial and corresponds to the contents of a small pool which was seasonally connected with a lake. Geomorphological observations and the lack of artefacts indicate that the assemblage is a naturally derived one. It is also believed that most of the fish remains represent individuals that died as the pool dried up, but
692
W. VAN NEER AND
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Table 3. List qfJi.sh identified,from expressed as percentages of number individuals ( MNI)
Mormyridae Alestes/Brycinus Bagrus Clarias Synodontis Lales Tilapiini indet. 1 indet. 2 indet. 3
the natural-death assemblages at Bir Tarfan?. qf,fragments (NF) and of minimum number of
(N,N:47)
MN1 (N=355)
0.3% 0.3% 0.1% 38.7% 8.1% 3.5% 49.0% + + +
0.3% 0.3% 0.6% 32.7% 39.1% 4.2% 22.8% + + +
the abundant remnants of reed cormorant Phalacrocorax africanus (including many juveniles) indicate that this species has probably also contributed to the deposit (Kowalski et al., 1989). The ichthyofauna of Bir Tarfawi contains 10 different taxa, but comprises mainly Clarias, tilapia and Synodontis (Table 3). Size reconstructions of the different species indicate a preponderance of small individuals. Most specimens are between 10 and 20 cm SL for Clarias, between 5 and 15 cm SL for tilapia and less than 7 cm SL for Synodontis (Van Neer, in press). Differences between the assemblages of Dakar-Bango and Bir Tarfawi lie not in the size distribution of the species, but rather in the species diversity itself. At Dakar-Bango a much wider spectrum of the ichthyofauna is present. This probably relates to the fact that this assemblage comes from a much larger catchment area which includes different habitats exploited over different seasons, whereas in the natural assemblage of Bir Tarfawi only species that are tolerant of the adverse conditions in the pool occur. A particular feature of this natural assemblage, besides its low specific diversity, is the abundance of Clarias and tilapia. These taxa have the highest chances of survival in poorly oxygenated biotopes. This last criterion, however, will not always allow discrimination between naturally derived and anthropogenic accumulations. Should people discard small fish after exploitation of seasonal pools dominated by Clarias and tilapia, then it will be difficult to discriminate such an assemblage from a naturally derived one. In such cases, one can only hope to find circumstantial evidence to distinguish between the two. 3.2. Contextually derived evidence: the Wadi Howar case study A specific case, recently studied by one of us (Van Neer, 1988), illustrates how geomorphological and archaeological observations can occasionally help to distinguish between natural and anthropogenic assemblages. The Holocene site BOS 84/ 13 in the Middle Wadi Howar, Sudan, incorporates eight pits which have been excavated on a dune of the southern bank of the wadi. All pits are refuse dumps containing pottery, lithic material and bones, mainly from cattle. However, one pit is different in that it yielded a large number of small fish. So far only a small part of the 3 mm sieve fraction has been investigated, the 1 mm fraction not being available for analysis at the time of this study. A preliminary analysis of the sample indicates that at least 17 different taxa are present and that Clarias and tilapia are the most abundant fishes. While size reconstructions are unavoidably biased, since the 1 mm fraction is not included, they nevertheless indicate an
“FISH MIDDENS”
693
abundance of small individuals. It seems clear from the relative frequencies of the taxa (mostly Clurius and tilapia) and from the small sizes of the specimens, that the fishes must have come from a residual pool along the wadi. During identification of the material, and reconstruction of the sizes of the corresponding fishes, the overwhelming similarities with the natural death assemblage of Bir Tarfawi, inclined us towards a similar explanation for the history of deposition at the Middle Wadi Howar. Despite recognizing that people readily eat small fishes, we still initially tried to explain the coexistence of artefacts and fish bones as a result of natural causes. The scenario we first devised involved high floods covering that part of the dune. The anthropogenic pit structure of the abandoned site was believed to have acted as a trap in which small fish were retained after the water level dropped. However, a geomorphological survey of the site and its surroundings made it clear that floods could have never reached such a high level on the dune (Kropelin, pers. comm.). Furthermore, the archaeological analysis showed the pit to be probably a multifunctional unit, viz, a storage place during the initial phase of filling and a refuse dump later on (Keding, 1986, in press). Thus, the initial archaeozoological interpretation of the fish assemblage as a natural thanatocoenosis was actually a misguided automatic response, resulting from the presence of large numbers of small fish combined with the absence of manipulative marks on the bones. The results from the work at Dakar-Bango clearly indicate that anthropogenic accumulations of this kind are indeed perfectly possible. 4. Conclusions
The processes whereby fishes become deposited in heaps similar to the middens described above may be governed by several factors. Inefficiencies associated with food processing are responsible for many such factors. For example, rapid decomposition of these fishes caused by weather changes, insect pests, etc. will render them unacceptable for human consumption and hence they will be discarded. Other, related processes of product rejection include the disposal of caught fishes which are too small for profitable marketing. There are, of course, alternative solutions to overcome such waste of resources (e.g. fishes may be used for soup, or dried and used as fodder for domestic stock). Nevertheless, rejective decisions of the type described above will remain as important factors in the formation of fish middens and they are always complicated phenomena to evaluate a posteriori. There can be other factors, including epiphenomena such as ritualistic offerings, foods, status symbols etc. which may be regarded as potential causative agents of non-consumable and consumable fish accumulations. However, any detailed discussion of these lies beyond the scope of this paper. The most significant point is the degree of convergence occasionally produced between some man-made accumulations and natural ones (Rose110 & Morales, 1990; Morales & Rosello, in press). Consequently, in order to describe accurately the history of any particular accumulation, the researcher is required to make comparative analyses of all complementary information relevant to the assemblage. We hope that future investigations along such lines will eventually provide a database against which other hypotheses may be tested. Acknowledgements
The field work in Senegal would not have been possible without the help of Marie-Amy Mbow (I.F.A.N.-Ch.A.Diop; Dakar) and Marie-Isaac Diop who acted as interpreters and arranged several practical matters. The drawings for this article were made by Alain Reygel (Tervuren). J. Decelle (Tervuren) identified the dermestid beetles. Earlier drafts of
W. VAN NEER AND A. M. MUNIZ
694
this paper were read and commented upon by Dick Brinkhuizen (Groningen), Inge BDdker-Enghoff (Copenhague), Leif Jonsson (Gijteborg) and Ian Harrison (Tervuren). To all these colleagues and friends we express our sincere thanks. References Brain, C. K. (1981). Hunters or the Hunted? An Introduction to African Cave Taphonomy. Chicago: Chicago University Press. Butler, V. L. (1987). Distinguishing natural from cultural salmonid deposits in the Pacific northwest of North America. BAR International Series 352, 131-149. Colley, S. (1987). Fishing or facts. Can we reconstruct fishing methods from archaeological evidence?Australian Archaeology 24, 1626. Colley, S. (1990). The analysis and interpretation of archaeological fish remains. In (M. Schiffer, Ed) Archaeological Method and Theory. Tucson: University of Arizona Press. Daget, J. & Iltis, A. (1965). Poissonsde Cote d’Ivoire. Memoires de f’lnstitut Francais de 1’Afrique Noire 74, l-385. Fish, G. R. (1956). Some aspectsof the respiration of six speciesof fish from Uganda. Journal of Experimental
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Stewart, K. M. (1991). Modern fishbone assemblages at Lake Turkana, Kenya: a methodology to aid in recognition of hominid fish utilisation. Journal qf Archaeological Science l&579-603. Van Neer. W. (1988). Fish remains from a holocene site (84/13-9) in Wadi Howar, Sudan Archaeozoologia 2,339-348. Van Neer, W. (in press). Fish remains from the Last Interglacial at Bir Tarfawi (Eastern Sahara, Egypt). Waterman, J. J. (1976). The production of dried fish. FAO Fisheries Technical Paper 16, l-52. Welcomme, R. L. (1975). The fisheries ecology of African floodplains. FAO CIFA Technical Paper 3, l-51. Wheeler, A. & Jones, A. K. G. (1989). Fishes. Cambridge Manuals in Archaeology. Cambridge: Cambridge University Press. Yerkes, R. W. (1987). Seasonal patterns in late prehistoric fishing practices in the North American Midwest. Archaeozoologia 1, 137-148.