Brazilian publications in International Limnological Journals:
The Potential Role of the International Review of Hydrobiology
Norbert Walz
Leibniz-Institute of Freshwater Ecology and Inland Fisheries Berlin (IGB),
Mueggelseedamm 301, D-12587 Berlin, Germany, E-mail: walz@igb-berlin.de
1
Abstract
Brazilian publications in International Limnological Journals:
The Potential Role of the International Review of Hydrobiology
Norbert Walz
In the time period 1999 – 2006 Brazil was able to push its appearance in international
limnological journals to nearly 3%, prolonging the trend already presented by Melo et. al.,
(2006). Nevertheless, the mean impact factor of the publications decreased from 1.8 to 1.4
during this period. The publication profile was compared with that of other Latin American
countries as well as that of the People’s Republic of China which showed the same trend but
could increase its share to about 3.5 by the end of this period. In comparison to China, Brazil
showed a low standing in journals of applied limnology, but produced more articles in
ichthyology. It appears that Brazil is not well adapted to the current limnological paradigms
which are based on temperate water bodies. An analysis of keywords disclosed Brazil’s main
strength lies in tropical research. For this reason Brazil should promote paradigms adapted to
the tropical or subtropical environment.
Key words: impact factor, paradigms, tropics, Latin America, China, biodiversity
2
Introduction
Many countries, like those in South America and Asia, have well recognized the pace making
value of science for the development of their economy and invest more and more money in
this field. Scientists in these countries have learned over the past years to produce publications
which find respectable international resonance (Hill, 2004). As part of the co-operation
between Brazil and Germany in the field of limnology, one should aim to increase the public
awareness of Brazilian publications. For this reason it should be determined which fields of
Brazilian limnological research are strong and which are weak. A similar approach was
undertaken by Sarvala (1992) to analyse the trends in Finnish limnology. Research in a
tropical country has to struggle against the current paradigms in limnology which are based
on examples in temperate water bodies. On the other hand, scientific work in such climate
zones opens a huge field for new scientific discoveries, for example the highly unexplored
biodiversity in tropical rainforests and its water bodies (Agostinho et al., 2005).
The International Review of Hydrobiology (IRH), established in 1908, is a journal with a
long tradition and a high reputation. It has already published many articles from South
American authors as well as South American objects in recent years. However, although
numbers are increasing, there is still a high potential for further development both measured
absolutely and in comparison with other countries, such as China which may be the most
capable competitor to Brazil among the so-called outreach states (Peoples Republic of China,
India, South Africa, Brazil, Mexico). For this reason all data will also be collected for the
People’s Republic of China. As already many authors from Latin America have been
published in the IRH, it should be studied if publications of this origin can be increased in the
future.
3
Methods
Using the ISI Web of Science (http://portal.isiknowledge.com/portal.cgi) of the Thomson
Corporation, the number of publications (N) in 28 limnological journals between 1999-2006
was analysed and compared between Brazil and the above mentioned outreach states (Table
1). Five or more publications during this period from Brazil or the People’s Republic of China
were the minimum requirement for each international journal to be considered for this
analysis. The following journals did not meet this criterion and therefore were not considered:
Journal of the North American Benthic Society, River Research and Applications, Marine and
Freshwater Research, Lake and Reservoir Management, Aquatic Ecology, Limnology. No
differentiation was made between authors and co-authors as long as one address was from
Brazil. The same applied to the comparison of other countries. Also, no restriction was made
if the papers were of true limnological content. The impact factors (IF) were taken from all
journals for the year 2006, published by ISI Journal Citation Report in July 2007.
Mean weighted IF were determined according to the number of papers in the respective
journals divided by the number of all papers found: IF = Sum (Ni * IFi)/tot N.
Secondarily, specific key words were recorded by the ISI Web of Science for a number of
countries, but these were not restricted to specific journals.
Results
Mean number of articles and impact factors within the time period of 1999 to 2006
Between 1999 to 2006 Brazil produced 765 limnological papers (Table 2). The USA
dominated the publications and published more than 16 times as much. The domination was
4
so distinct that it published 5.6 times more than Germany and produced 35% of all published
papers (36350) in the analysed journals for that time period. China was a successful
competitor against Brazil with a little higher number of publications; however, other South
American countries published considerably less.
The bottom row of Table 2 shows the mean Impact Factor for each journal in which the
papers were published between 1999 and 2006. As shown, the USA not only produced more
articles but they also appeared in higher ranking journals. The other Latin American countries
which published less than Brazil did so in comparable or better journals.
Development of the number of publications and impact factors for the period 1999-2006
During the past 8 years the number of Brazilian publications increased from about 60 to 160
papers per year with an increment of about 11 papers per year, however, the most ambitious
country was the People’s Republic of China which raised its publications by about 19 papers
per year (Fig. 1). China’s increase was steadier than Brazil's where retardation took place
between 2002-2003. Comparing both these countries to the other contributing countries they
were also able to increase the share of their publications from about 1% to 3% within the
analysed journals. In contrast to the increasing number of publications the weighted impact
factors decreased slowly, however significantly (P < 0.05) both for Brazil (r = - 0.72, as well
as the People’s Republic of China (r = -0.78) (Fig. 2).
Analysis of particular journals and of Brazil's research strength
Fig. 3 gives an impression of the journals in which Brazil and China mostly published and
how the journals were ranked. Most Brazilian papers between 1999 and 2006 were published
in "Hydrobiologia" with an IF of now 1.0, whereas the People’s Republic of China
5
dominantly published in "Water Research" (IF = 2.5). Also, a large number of Brazilian
publications were in "Journal of Fish Biology", "Biodiversity and Conservation" and
"Biological Conservation", whereas China had many publications in "Journal of Freshwater
Ecology" and "Biodiversity and Conservation".
"Hydrobiologia" is a journal of general limnology and marine biology in which most
Brazilian papers appeared (Fig. 4). However, Brazilian publications in journals with a higher
impact factor were less, such as in the "Freshwater Biology" (IF = 2.5) and "Limnology and
Oceanography" (IF = 3.2), in which the People’s Republic of China dominated over Brazil,
except for the highest ranking journal "Ecology" (IF = 4.8) where it was vice-versa. While
this journal publishes limnological articles, most articles are designated to other ecological
areas.
But the scientific strength of the countries could only be shown by the analysis of the
development in more specialised journals. As shown by the example of "Water Research"
with an IF of 2.6, but also of "Water Resources Research" (IF = 1.9), China’s capacity for
applied limnology (Fig. 5) is higher than that of Brazil. The same is shown for "Ecological
Engineering" (IF = 1.3) in which China produced 31 papers, whereas Brazil published only
15, with however an increasing tendency since 2003. Even publications in "Water
Environmental Research" (IF = 0.15) were completely dominated by articles from China. The
low appearance in applied limnology by Brazil is remarkable as it is well known that many
reservoirs are located in Brazil with many employed engineers and limnologists (see Tundisi,
1980).
Phycology and microbiology are two areas where Brazilian science was visible but only with
a moderate strength. In "Aquatic Botany" (IF = 1.4) Brazilian papers first increased but later
China won the case (Fig. 6). On the other hand, in the higher ranked "Journal of Phycology"
(IF = 2.6) Brazil could hold its standing.
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Even lower is Brazil’s appearance in microbiology ("Aquatic Microbial Ecology", IF = 2.2,
and "Microbial Ecology", IF = 2.3), where China was able to push the number of publications
in the last years.
In contrast, Brazil stands its ground against China in "Biodiversity and Conservation" (IF =
1.4) and was superior in the high ranked "Biological Conservation" (IF = 2.9) (Fig. 7). In both
journals the number of publications was higher than those in former fields. This shows
Brazil’s capacity in analysing biodiversity in subtropical and tropical zones, a special need of
today.
The actual scientific centre of Brazil’s limnological science, however, is fish biology, fish
ecology and fisheries (Fig. 8), although this field is also is in sharp competition with China,
which is especially strong with publications in "Journal of Applied Ichthyology" (IF = 0.8).
Brazil dominated in "Fish Biology" (IF = 1.2) and "Fisheries Research" (IF = 1.2), although
some articles were marine, as well as "Ecology of Freshwater Fish" (IF = 1.5). The journal
"Neotropical Ichthyology" (IF = 0.5), published by the Sociedade Brasileira de Ictiologia
managed to get cited by the ISI Web of Science® in 2006 with 46 Brazilian articles in English
language and, therefore, appears to have achieved the status of an international journal,
although all articles were published by Brazilians.
Present and future paradigms
Brazil is struggling with present paradigms in limnology which are based on classical issues
of temperate zones. The following list is not exhausted and may be biased by personal
experience:

Ecology of temperate lakes, esp. deep, dimictic lakes

Ecology of temperate rivers, „River continuum“ in temperate rivers

Eutrophication, input of nutrients in temperate zones, re-oligotrophication
7

Climate change in freshwater bodies of temperate zones

Ecology and aquaculture of freshwater fish in temperate zones

Lake food webs based on primary production
This situation was adversarial to Brazil for publications in the past, as it could not serve with
articles in the main fields of interest. However, the situation appears to be changing.
Paradigms are starting to shift and more and more attention is directed to the tropics. The
reason being is that the neotropics are a centre of biodiversity, which is becoming more and
more endangered as it is receiving more attention. At first terrestrial ecology was concerned
with problems of conservation but now such problems seem to be taken up by freshwater
ecology. In fact, also many terrestrial studies in the tropics depend on limnology, e.g., on the
flooding of rivers, so that even in the past there was an indirect overlap.
Table 3 shows the proportion of papers in which there is a relationship of tropical or
subtropical subjects. Although the numerical evidence is still weak when compared, e.g., with
“freshwater” as a baseline, the relative proportion for some of the keywords is high for Brazil,
partly higher than for the USA. As could be shown, the share is high for tropical lakes and
tropical rivers and regarding tropical reservoirs, Brazil is on second place. Due to the
importance and frequency of its reservoirs this could and should be an area where Brazil
could dominate. The same argument could apply for rain forests, where Brazil is competent
but mostly in the terrestrial sector. The south of the USA is belonging to the subtropics, so the
proportion of wetlands in the USA is high. However, this is not the case for flood plains,
where Brazil is as competent as the USA. The above mentioned optimistic numbers of papers
in biodiversity seem to apply mostly for the terrestrial sector, as the combination with
freshwater gave only weak correlation.
In tropical fish and fisheries Brazil sits on second place behind the USA. Humic acids are an
important object in the tropics and this field is dominated by Brazil. Unfortunately most
papers of this topic are not limnological, but it shows the Brazilian potential. There are now a
8
number of papers (e.g., Pace et al., 2004) which underscore the importance of allochthonous
organic compounds as a subsidy of materials and energy for food webs in shallow lakes, a
very exciting paradigm shaking the orthodox view that life in a lake depends only on primary
productivity, a fact which has been known for rivers for a long time (e.g., Vannote et al.,
1980). It is to be expected that life in nutrient poor Amazonas basin lentic waters as well as in
lakes and running waters of the nutrient poor Cerrado savannah depends on allochthonous
subsidies even more than in temperate zones.
Potential role of the International Review of Hydrobiology
Since 2001 the "International Review of Hydrobiology" (IRH) has had a nearly constant
impact factor of about 0.8. Between 1994 and 2006 the IRH published an average of 5.8 %
Latin American and 8.4 % Asian origin. While the numbers of Latin American or Asian
articles were high in 1998 (Fig. 9), they suddenly decreased in 1999. However, from then on
they increased again and in 2006 both origins combined reached a proportion of 40% of the
publications of the IRH. During this period the yearly number of articles was constant with
about 41 papers printed. The decrease in 1999 could be explained by the fact that the year
before the journal changed from its former title “Internationale Revue der gesamten
Hydrobiology” to its current name, but the ISI-institute did not count the references together.
In the past the IRH produced also Special Issues in co-operation with guest editors. Since the
year 2000 the following issues appeared, hitherto only with European guest editors:

Plant Litter Processing in Freshwater (2004, 2007)

Advances in River Bottom Ecology (2001, 2003, 2007)

Bioindication and Functional Response in Flood Plain Systems (2006)

The Ecology of Large Rivers (2002)

Sturgeon: Caviar, Reproduction and Conservation (2002)
9

Ecological Role of Woody Debris (2000)

Alien Species in the Baltic Sea (2000)
Special Issues are published under the same scientific strength as the normal issues. All
submitted manuscripts are selected by a peer review of at least two international referees.
Discussion
This study documented in principle similar results as those presented by Melo et. al. (2006).
The number of Brazilian papers increased in both studies. However, Melo et al. (2006)
analysed a much longer time period, from 1970 to 2004, however, they only reviewed 13
journals. They found for the years of 2003-2004 that Brazilian articles had increased to a
proportion of about 2% in relationship to the total numbers of articles published by the
reviewed journals. This is the same proportion that was found in this study for the year 2004.
From 2004 – 2006 a further gain to 3% could be found. The linear rise of articles shown in
Fig. 1 seems to apply only for shorter time periods. For longer periods of time the increase is
rather exponential if Melo’s Fig. 1 is extended by the data of this study.
From their Fig. 2, which was similar to Fig. 3 of this study, Melo et al. (2006) first supposed
that there was a negative relationship between the number of publications and the impact
factor of the journals where they were published, but they could not confirm this relationship
by statistical analysis. The results of the present study do not contradict this view, but the
decrease of the impact factor within the time period of 1999 to 2006 (Fig. 2) was significant
for Brazil as well as for China. However, the absolute difference between both countries was
not significant.
In general, the results of Melo et al. (2006) correspond well with the findings of this study,
although in the present study more journals were analysed. But I did not prove in detail
whether the articles were truly limnic, marine or terrestrial. As most journals are restricted to
10
specific domains, the exact titles of the papers did not matter. However, there is evidence that
this was not true for the two biodiversity journals. The above mentioned high proportion of
publications in these journals is deceiving for the Brazilian limnology as the combination of
keywords "biodiversity" and "freshwater" resulted in only few hits (Table 3). This backlog of
freshwater behind terrestrial research which is becoming evident here is in agreement with the
results of Agostinho et al. (2005). Their paper can serve as a stimulating example for studies
on freshwater biodiversity. As aquatic environments are becoming exceedingly endangered,
studies on freshwater biodiversity and its special and temporal dynamics will be very
important for the protection of aquatic environments as well as for the progress of science.
With the results in Table 3 we can come to the conclusion that the tropics are a natural
domain of Brazil. It makes sense to conclude that Brazil’s competence and scientific strength
in this field should be expanded. For this reason Brazil should not so much orientate on the
present paradigms of limnology. Instead it should prefer an alternative list. From my analysis
I would suggest the following objects:

Biodiversity in tropical water bodies

Ecology of wetlands

Ecological role of flood plains

Ecology of tropical and subtropical fish

Ecological role of allochthonous, organic subsidies for food webs

Ecological role of humic acids

Food web analysis in tropical water bodies with stable isotopes
This article is not intended to restrict the objects where the research of Brazilian limnology
should take place. As many of the Brazilian ecosystems (e.g. the tropical savannah, the
Cerrado, Marris, 2006) are highly endangered, applied studies to theses areas would be highly
welcome. The analysis is surely not exhausted and others will create new proposals. It rather
shows a method of how to find such objects in which Brazil is already strong and where it
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could potentially get a precursor role for nature offers unique research possibilities in Brazil.
A simple look on a globe makes it clear that there is no other large and developed country
with such a possibility for research in the tropics (and partly also the subtropics). Brazil
should get aware of its “unique selling proposition” in this area. Talling and Lemoalle (1998)
show in their book that Africa is another focus of tropical freshwater research. But in contrast
to Brazil, which performs its research mainly without assistance by other countries, African
research is heavily supported and sometimes even carried out by scientists from France, the
United Kingdom, the USA or other northern countries.
On the other hand, sooner or later many of the successful paradigms characterizing
limnological research in the northern hemisphere today seem to become exhausted anyway.
Since the publication of T.S. Kuhn’s The Structure of Scientific Revolutions (1962) it is
known that the advancement of science is not a linear process but rather is characterized by
shifts in paradigms. As scientific knowledge advances, new findings will contradict the
“current paradigm”. Many paradigms are based on water bodies of the northern temperate
zones and will not necessarily fit those in other climate zones. Therefore, sub-tropical and
tropical countries should develop and research their own paradigms which also will benefit
the global scientific community as the results will throw light from different angles on
limnological research.
The IRH is aware of such developments. For the occasion of its 100th anniversary a special
issue “Paradigm Shifts in Limnology and Marine Biology” with invited contributions of wellknown scientists is in preparation and should be published in 2008. The steady increase of
publications from Latin America as well as Asia in the IRH seems to be unbroken. The IRH is
further encouraging Latin-American authors to publish in its journal. Scientists from this area
are also invited to act as guest-editors of special issues.
Acknowledgements
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I am thankful to the president of the Brazilian Society of Limnology, Prof. Dr. Ricardo Motta
Pinto Coelho, for his invitation to the DAAD-workshop for Brazil-German co-operation in
limnology and to the XI Congress of Brazilian Limnology from 24.08.2007 to 28.08.2007 in
Macaé/Brazil. I found the discussion on this workshop very stimulating. I thank the German
Academic Exchange Service (DAAD) for financial support. I further thank Björn Gücker,
Belo Horizonte, for his comments to this manuscript.
References
Agostinho, A.A., Thomaz, S.M. & Gomes, L.C. 2005. Conservation of the biodiversity of
Brazil's inland waters. Conservation Biology, 19: 646-652.
Hill, D.L. 2004. Latin America shows rapid rise in S&E articles. InfoBrief -NSF, 04-336, p.
1- 9.
Kuhn, T.S. 1962. The structure of scientific revolutions. University of Chicago Press,
Chicago.
Marris, E. 2005. The forgotten ecosystem. Nature, 437: 944-945
Melo, A.S., Bini, L.M. & Carvalho, P. (2006): Brazilian articles in international journals on
limnology. Scientometrics, 67 (2): 187-199.
Pace, M., Cole, J., Carpenter, S., Kitchell, J., Hodgson, J., Van de Bogert, M., Bade, D.,
Kritzberg, E. & Bastviken, D. (2004): Whole-lake carbon-13 additions reveal terrestrial
support of aquatic food webs. Nature, 427: 240-243.
Sarvala, J. 1992. Trends In Finnish limnology during 1940-1989. Hydrobiologia, 243: 1-19.
Talling, J. F. & Lemoalle, J. 1998. Ecological dynamics of tropical inland waters. Cambridge
University Press, Cambridge, 441 pp.
13
Tundisi, J.G. 1980. Aquatic ecology in Brazil - Problems and prospects. Interciencia, 5 (6):
373-379.
Vannote, R.L., Minshall, G.W., Cummins, K.W., Sedell, J. & Cushing, C.E. 1980. The river
continuum concept. Can. J. Fish. Aquat. Sci., 37: 130 - 137.
14
Figure legends
Figure 1. Development of the proportion of Brazilian and Chinese papers in limnological
journals from 1999 – 2006.
Figure 2. Development of the mean impact factor from 1999 – 2006.
Figure 3. Number of publications in journals according to their Impact factors.
Figure 4. Number of publications in General Limnology from 1999 - 2006
Figure 5. Number of publications in Applied Limnology from 1999 - 2006
Figure 6. Number of publications in Phycology and Microbiology from 1999 - 2006
Figure 7. Number of publications in Biodiversity and Conservation from 1999 - 2006
Figure 8. Number of publications in Fish Biology, Fish Ecology and Fisheries from 1999 2006
Figure 9. Proportion of Latin American and China’s articles in the "International Review of
Hydrobiology" from 1994 - 2006.
15
Table 1. Analysed journals and impact factors for 2006.
Impact Factor
Journal
0.148
Amazoniana
0.149
Water Environment Journal
0.374
Journal of Freshwater Ecology
0.512
Neotropical Ichthyology
0.775
International Journal of Hydrobiology
=.812
Journal of applied Ichthyology
0.885
Water Environment Research
1.049
Hydrobiologia
1.216
Fisheries Research
1.320
Acta Oecologia
1.331
Ecological Engineering
1.338
Aquatic Botany
1.369
Archiv für Hydrobiologie
1.393
Journal of Fish Biology
1.423
Biodiversity and Conservation
1.479
Ecology of Freshwater Fish
1.563
Aquatic Sciences
1.617
Journal of Plankton Research
1.645
River Research and Application
1.882
Canadian Journal of Fisheries and Aquatic Sciences
1.895
Water Resources Research
2.332
Aquatic Microbial Ecology
2.459
Water Research
2.502
Freshwater Biology
2.580
Journal of Phycology
2.854
Biological Conservation
2.955
Ecosystems
3.249
Limnology and Oceanography
4.785
Ecology
16
Table 2. N = Number of papers (N) published by the different countries in the journals of
Table 1 from 1999 to 2006. N(%) = Number per total number of publications in these
journals, IF = Mean weighed impact factor.
Brazil
China
Argentina
Chile
Germany
USA
N
761
942
359
202
2250
12504
N (%)
2.1
2.6
1.0
0.6
6.2
34.5
IF
1.6
1.7
1.7
1.9
1.9
2.3
17
Table 3. Percentage proportion of papers with specific keywords during 1999 - 2006. Sum N = sum of all papers from all countries.
Brazil
Freshwater
China Argentina
Chile
Venzuela
USA
Germany
Sum N
6.7
7.5
3.0
1.1
0.7
64.3
16.8
7555
Tropical lakes
26.7
1.3
2.7
4.0
9.3
49.3
6.7
75
Tropical rivers
30.7
0.0
0.0
1.3
9.3
46.7
12.0
75
Tropical reservoirs
18.8
2.1
1.3
0.5
3.7
29.9
5.8
378
26.8
3.7
0.0
1.2
2.4
50.0
15.9
82
8.7
8.7
2.8
1.0
3.5
68.6
6.6
287
31.8
4.5
9.1
0.0
9.1
31.8
13.6
22
5.2
14.3
2.8
2.4
1.6
61.8
12.0
251
35.2
1.9
0.0
3.7
6.5
42.6
10.2
108
37.2
7.0
0.0
0.0
4.7
30.2
20.9
43
Rain forests/aquatic or
freshwater
Wetlands, tropical or
subtropical
Flood plains, tropical or
subtropical
Biodiversity freshwater
Tropical fish or tropical
fisheries
Humic acids tropical or
subtropical
18