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Invasiveness Assessment of Pumpkinseed Fish, Lepomis Gibbosus, in Albanian Freshwater Ecosystems by Using the Aquatic Species Invasiveness Screening Kit (AS-ISK)


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Pumpkinseed fish is considered to be highly invasive; it has demonstrated great variability in its environmental biology in response to environmental conditions, since its first appearance in the European waters this species has established populations in at least 28 European countries. In Albania, pumpkinseed, was introduced in 1994, even though the pathways of its introduction are not very clear. Aquatic Species Invasiveness Screening Kit (AS-ISK) risk identification screening tools was used to assess the invasiveness potential of pumpkinseed fish, Lepomis gibbosus, in Ohrid and Prespa lakes, in order to evaluate the current or future impacts of this non-native fish species. The basic AS-ISK score of 38.3 suggests the species poses a high risk of being invasive, and this risk is expected to even higher in the future, taking in consideration the potential effects of climate change (AS-ISK Climate Change Assessment = 49.7). This study was the first application of AS-ISK in Albania, and the results suggest that it can be a useful decision-supporttool for informing legislation, policy and management of potential, existing and future, undesired translocations of non-native freshwater fish species in the country.
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Albanian j. agric. sci. 2022; 21 (1): 37-44 Agricultural University of Tirana
*Corresponding author: Rigers Bakiu; E-mail:
(Accepted for publication )
ISSN: 2218-2020, © Agricultural University of Tirana
Invasiveness Assessment of Pumpkinseed Fish,
Lepomis Gibbosus
, in
Albanian Freshwater Ecosystems by Using the Aquatic Species
Invasiveness Screening Kit (AS-ISK)
1Department of Aquaculture and Fisheries, Faculty of Agriculture and Environment, Agricultural University of Tirana, Koder-Kamez,
Tirane, Albania
2Albanian Center for Environmental Protection and Sustainable Development, Tirane, Albania
Pumpkinseed fish is considered to be highly invasive; it has demonstrated great variability in its environmental
biology in response to environmental conditions, since its first appearance in the European waters this species has
established populations in at least 28 European countries. In Albania, pumpkinseed, was introduced in 1994, even
though the pathways of its introduction are not very clear. Aquatic Species Invasiveness Screening Kit (AS-ISK) risk
identification screening tools was used to assess the invasiveness potential of pumpkinseed fish, Lepomis gibbosus,
in Ohrid and Prespa lakes, in order to evaluate the current or future impacts of this non-native fish species. The basic
AS-ISK score of 38.3 suggests the species poses a high risk of being invasive, and this risk is expected to even higher
in the future, taking in consideration the potential effects of climate change (AS-ISK Climate Change Assessment =
49.7). This study was the first application of AS-ISK in Albania, and the results suggest that it can be a useful decision-
supporttool for informing legislation, policy and management of potential, existing and future, undesired
translocations of non-native freshwater fish species in the country.
Keywords: Biological Invasion; Risk Analyses, Non-native Species, Ohrid lake, Prespa lakes
1. Introduction
In Europe, several decision support tools have been
developed for screening aquatic organisms as a
required step in the analysis of risks posed by non-
native species (NNS) [6, 8, 9]. Risk screening is
especially required for risk assessment areas
characterized by high endemism or great biodiversity,
such as the Balkan peninsulas [35, 19], especially for
species like pumpkinseed fish (Lepomis gibbosus),
which is known to be highly invasive [41, 1] in several
countries. Invasiveness risk is particularly interesting
to conduct for inland waters of the Balkans
(Mediterranean region), where a high level of
endemism has considerably contributed to increases
the likelihood of native fish extinctions, due to their
restricted natural ranges [31].
In the Balkans, pumkinseed fish, as a popular aquarium
species, was accidentally (with a high level of
uncertainty) introduced into some trans-boundary river
systems in central North Macedonia and northern
Greece [22, 13, 18], as well as into Lake Kastoria,
Prespa (north-west Greece), River Alfios
(Peloponnesus) [14] and Lake Tavropos (central
Greece) [3].
According to [11], probably it was an accident even in
the case of Albania, while according to [34], it was
introduced in Albania in 1994. It is encountered in the
Bakiu et al., 2022
Lake of Oher and the Lakes of Big Prespa and Small
Prespa, respectively [12, 14]
The aim of the presently reported study was to assess
the current and future invasiveness potential of L.
gibbosus by using the Aquatic Species Invasiveness
Screening Kit (AS-ISK) of [42] for the first time with
aquatic species living in Albanian aquatic ecosystems.
The outputs of the presently reported study will serve
to demonstrate to environmental managers and
stakeholders in Albania the potential use of AS-ISK as
a decision-support tool for informing legislation, policy
and management (i.e. prevention, control, containment,
eradication) of potential, existing and future undesired
translocations of non-native freshwater fishes in the
2. Material and Methods
The risk assessment (RA) area includes Ohrid and
Prespa lakes parts, as parts of the Albanian territory.
The Prespa and Ohrid climate is Continental/sub-
Mediterranean [29], at the transition zone between
Mediterranean and Continental climates, characterised
by warm dry summers and rather cold humid winters.
For instance Prespa average annual precipitation at lake
level reaches 763 mm and lake evaporation 833 mm
over the period 1951–2004, while open-pan
evaporation amounts to 1041 mm [40]. Popovska and
Bonacci [30] have found a statistically significant
increase in temperature variability over the period
1961–1990, with an average annual precipitation
decreased statistically significantly in Ohrid, but non-
significantly in Prespa. This freshwater ecosystem is
threatened by the dramatic fall in water level (~8 m) of
Lake Big Prespa over the past three decades, which has
been inconclusively related to climate change, water
abstraction or earthquake-induced changes to
underground karst drainage channels [27, 30]. Since
1995 water levels have remained the lowest on record,
since observations started around 1917 [5]. The Lake
of Big Prespa currently contributes about 25% of the
total inflow into Lake Ohrid through underground karst
drainage channels.
In order to identify the potential invasiveness of
L.gibbosus, the AS-ISK decision-support toolkit was
used by us. All the assessments were conducted
independently by the three authors. A direct derivative
of FISK v2 (the Freshwater Fish Invasiveness
Screening Kit [26], AS-ISK consists of 55 questions
(Qs) on the assessed species’ LHTs, invasion and
environmental biology, biogeography and history of
introduction [42]. Responses to these Qs provide a
Basic Risk Assessment (BRA) score, which is
complemented by six additional ‘climate change’
questions that ask the assessor to foretell the likely
effects of predicted future climate on the risk screening
(risks and magnitude of introduction, establishment
and dispersal). Response scores to these Climate
Change Assessment (CCA) Qs are added to the BRA
score (BRA + CCA score). To each question, the
assessor must provide a response and a justification for
their response (including bibliographic references) and
then rank their confidence in that response. The
confidence ranking categories are: 1 = low, 2 =
medium, 3 = high, 4 = very high [19]. In all cases, an
overall score < 1 assigns a status of ‘low risk’ (hence,
not likely to be invasive), whereas values ≥ 1 identify
alien species as potentially invasive and posing either a
‘medium risk’ or a ‘high risk’. Consequently the
certainty factor (CF) ranges from a minimum of 0.18
(i.e. all questions with certainty score equal to 1) to a
maximum of 1 (i.e. all questions with certainty score
equal to 4). Furthermore, it is important to identify a
‘threshold’ value for the RA area concerned by way of
a ‘calibration’ process to distinguish between species
of medium and high risk of invasiveness [6, 21].
Because there has been no calibration of AS-ISK for
(freshwater fish in) Albania, the choice of BRA and
BRA + CCA thresholds to distinguish between medium
vs high risk was based on the identified threshold
values by [19] for 24 freshwater fish species in
Balkans, the BRA threshold of 10 and BRA + CCA
threshold of 12.62, for the same set of species.
3. Results and Discussion
Based on the reference threshold score of 10, the
identified average BRA score (by the three assessors
for L. gibbosus) in Albania (38.3) falls within the ‘high
risk’ category (Fig. 1A). When the potential effects of
climate change on the risk screening responses are
taken into consideration, L. gibbosus BRA + CCA
score increases to 49.7 (hence well above the 12.62
threshold) reflecting an even higher risk of the species
being invasive in Albania in the future (Fig. 1A).
Albanian j. agric. sci. 2022; 21 (1): 37-44 Agricultural University of Tirana
*Corresponding author: Rigers Bakiu; E-mail:
(Accepted for publication )
ISSN: 2218-2020, © Agricultural University of Tirana
Figure 1. Graphical presentation of the identified score values from the invasiveness assessment of pumpkinseed fish
by the three authors, expressed as (A) average score values of BRA and BRA+CCA and (B) confidence level of BRA,
The mean confidence levels for responses to Qs
contributing to the BRA, CCA, and BRA + CCA scores
for L. gibbosus in Albania were 0.81 (± 0.05 SE), 0.75
(± 0.08 SE) and 0.80 (± 0.06 SE), respectively, which
suggests high level of confidence and furthermore a
comparability among AS-ISK groups of Qs (Fig. 1B).
Factors and traits that increased L. gibbosus’ AS-ISK
score (Fig. 2A) included a history of being invasive
elsewhere (12.7 ± 2.31 SE) and to lower level regarding
the other historical and biogeography characteristic,
represented by the high climatic match and elevated
likelihood of being illegally stocked. Regarding the
characteristics corresponding to the biology and
ecology, the undesirable (or persistence) traits (8.3) (in
case of pumpkinseed fish mainly represented by the
opportunistic foraging behaviour) represented one of
the most important traits together with likelihood high
risks posed to native threatened or protected taxa
(resource exploitation, 7.0).
Traits that reduced the overall score included
reproduction and dispersal mechanisms, though it is
known the existence of parental care and relatively
small size at maturity of this species. The average score
of tolerance attributes (3.7 ± 3.51 SE) indicate no
likelihood of hybridisation with native species, though
with a high uncertainty by the assessors. Generally, the
high score registered for the climate change factor
(11.3 ± 1.15 SE) indicate that it is likely that L.gibbosus
will continue to disperse and establish in the RA area
under current climate conditions, and more likely under
predicted future climatic conditions. In the latter case,
the risks of establishment and dispersal would increase
the species’ risk of invasiveness (Qs 50–52), and also
the magnitude of future potential impacts (Qs 53–55).
Bakiu et al., 2022
Figure 2. Graphical presentation of Score Partition of (A) Biogeography/History related factors, (B) Biology/Ecology
contributors and (C) Climate change on the invasiveness level of pumpkinseed fish in the Albanian ecosystems.
In Fig. 3 are shown the sectors affected by the
pumpkinseed fish invasiveness in the Prespa and Ohrid
ecosystems. The species (24 ± 4 SE) populating the
ecosystem due to the population nuisance traits will be
mostly affected by the presence of L. gibbosus, while
the commercial sectors (like the fisheries or tourism)
will be less affected by the potential invasiveness of
pumpkinseed fish (18 ± 2.31 SE). Generally, the
environment will suffer less than the previously
mentioned sectors by the presence of this species (12 ±
1.53 SE).
Figure 3. Graphical presentation of the impact toward different sectors close to the Prespa and Ohrid Lakes by the
presence of pumpkinseed fish.
Albanian j. agric. sci. 2022; 21 (1): 37-44 Agricultural University of Tirana
*Corresponding author: Rigers Bakiu; E-mail:
(Accepted for publication )
ISSN: 2218-2020, © Agricultural University of Tirana
In the RA freshwater ecosystems, a strong climate
related impact on the limnology and physical
parameters including the Lake Prespa [2], is predicted
to be followed by a significant decrease in productivity,
enhanced mixing, strong decomposition and soil
erosion. For instance, future climate changes could lead
to an accelerated water-level fall and a reduction in lake
volume, then there will be substantial negative
consequences for regional water resources and global
biodiversity. The lake Prespa currently contributes
~25% of the total inflow into Lake Ohrid through
underground karst drainage channels, while it has been
observed that falling lake levels will decrease this
underground discharge [27] and the Lake Ohrid
outflow to the Drini River will decrease consequently.
Furthermore, a reduction in lake volume will
consequently bring out to an increase in pollutant
concentrations and accelerate the on-going
eutrophication of the Prespa Lakes [27]. Another
deteriorating factor is represented by the introduced
species, like L. gibbosus, which has been shown to be
highly invasive in other European countries. For the
first time in Albania, this species invasiveness potential
was assessed by identifying L. gibbosus BRA and
BRA+CCA (Fig. 1). Relative to L. gibbosus BRA and
BRA+CCA scores published for other RA areas,
except the case of Thrace and Anatolia (Turkey, [39]),
those for Albania were consistently higher than for
Poland [20], Lake Marmara (Turkey, [38]), River
Neretva catchment (Bosnia and Herzegovina, and
Croatia [19]).
Differently to Albanian freshwater ecosystems (Fig. 2),
the analysed factors and traits that increased L.
gibbosusAS-ISK score in the study of [20] (Poland)
included a historyof being invasive elsewhere, high
climatic match, parental care, relatively small size at
maturity, opportunistic foraging behaviour, and
elevated likelihood of being illegally stocked. Traits
thatreduced the overall score included no likelihood of
hybridisation with native species and low risksposed to
native threatened or protected taxa.
Twenty-eight taxa of fish have been identified from
Prespa and Ohrid lakes [37], mostly represented by
members of Cyprinidae and Salmonidae members,
where there are endemic species like Squalius
prespensis in Prespa and Salmo letnica together with
Salmo ohridanus in Ohrid Lake. Most of the fish
catches in Prespa lakes are represented by carp, while
in Ohrid Lake the main interest is toward the two
endemic species (authors observatons). As shown in
the graphic of Fig. 3, the presence of L. gibbosus could
deteriorate the abundance of the endemic fish species
subject of fishing activities, with a considerable impact
not only to this commercial activity, but also to tourism
related activities – strictly linked to the presence of the
endemic species. Other vertebrate and invertebrate
species population could also suffer by the presence of
the pumpkinseed fish populations, because
pumpkinseed fish is omnivorous [10, 7] and
demonstrates trophic and/or resource polymorphism.
For example, individuals in the pelagic zone appear to
be specialized for foraging on zooplankton, while those
that live in shallow littoral habitat feed primarily on
macro-invertebrates [32, 28]. With age, pumpkinseed
fish becomes increasingly predatory, and its diet may
consist of small fishes and amphibians [33, 23].
Pumpkinseed fish has also been known to consume fish
eggs and aquatic plant debris [17, 10].
However, despite the BRA and BRA + CCA scores,
which classify L. gibbosus as likely to pose a high risk
of invasiveness, the species’ known adverse impacts
are not yet fully understood for the RA area, here
represented mainly by south-eastern Albania. For
instance, studies in southern England of the species’
microhabitat and trophic interactions with native fishes
found limited or no evidence for adverse impacts [36,
24], whereas impacts have been recorded in managed
ponds in the Netherlands [41] and in natural streams of
the Iberian Peninsula [1].
4. Conclusions
Each county provides particular evidences regarding
relative impacts of pumpkinseed fish to the aquatic
ecosystem. As such, further research is needed in
Albania to assess the potential impact of L. gibbosus on
this country’s native species and ecosystems. This
could be considered as the first step followed later by
surveys and similar initiatives. Several similar studies
would be needed not only for creating an invasive alien
species strategy (including a plan of action), but also
with interest at international level (as part of
comparisons with other neighbour countries outputs).
5. Acknowledgements
This study was supported by the Albanian Center for
Environmental Protection and Sustainable
6. References
Bakiu et al., 2022
1. Almeida D, Merino-Aguirre R, Vilizzi L,
Copp G.H: Interspecific aggressive
behaviour of invasive pumpkinseed
Lepomis gibbosus in Iberian fresh
waters. PLoS One, 9 (2) 2014, e88038.
2. Aufgebauer A, Panagiotopoulos K,
Wagner B, Schaebitz F, Viehberg FA,
Vogel H, Zanchetta G, Sulpizio G, Leng
M, Damaschke M: Climate and
environmental change in the Balkans
over the last 17 ka recorded in sediments
from Lake Prespa (Albania/F.Y.R. of
Macedonia/Greece). Quaternary
International 2012, 274, 122-135.
3. Bobori DC, Tsikliras AC, Economidis NI:
Some morphological and biological
characteristics of fishes from Tavropos
reservoir (western Greece). Folia
Zoologica 2006, 55 (2), 199–210.
4. Britton JR, Cucherousset J, Davies GD,
Godard MJ, Copp GH: Non-native fishes
and climate change: Predicting species
responses to warming temperatures in a
temperate region. Freshwater Biology
2010, 55 (5), 1130–1141.
5. Chavkovski I: Hydrology of Lake
Prespa. In: PPNEA (society for Protection
and Preservation of Natural Environment
in Albania), ed. International symposium
towards integrated conservation and
sustainable development of transboundary
macro and micro Prespa Lakes. Tirana
(Albania): ILAR Typography 1997, 9–14.
6. Copp GH: The Fish Invasiveness
Screening Kit (FISK) for non-native
freshwater fishes—A summary of
current applications. Risk Analysis 2013,
33 (8), 1394– 1396.
7. Copp GH, Bianco PG, Bogutskaya NG,
Erős T, Falka I, Ferreira MT, Fox MG,
Freyhof J, Gozlan RE, Grabowska J,
Kováč V, Moreno-Amich R, Naseka AM,
Peňáz M, Povž M, Przybylski M, Robillard
M, Russell IC, Stakėnas S, Šumer S, Vila-
Gispert A, Wiesner C: To be, or not to be,
a non-native freshwater fish? Journal of
Applied Ichthyology 2005, 21 (4), 242–
8. Copp GH, Vilizzi L, Tidbury H, Stebbing
PD, Tarkan AS, Moissec L, Goulletquer P:
A generic decision-support tool for
identifying potentially invasive aquatic
taxa: AS-ISK. Management of Biological
Invasions 2016, 7, 343–350.
9. Copp G, Vilizzi L, Wei H, Li Sh, Piria M
et al.: Speaking their language
Development of a multilingual decision-
support tool for communicating invasive
species risks to decision makers and
stakeholders. Environmental Modelling
& Software 2020, 135, 104900, ISSN
10. Copp GH, Fox MG, Przybylski M,
Godinho FN: Life-time growth patterns
of pumpkinseed Lepomis gibbosus
introduced to Europe, relative to native
North American populations. Folia
Zoologica 2004, 53, 237-254.
11. Dhora Dh, Dhora A: Të dhëna më të plota
mbi peshqit alienë Shqipërisë.
Universiteti i Shkodrës “Luigj Gurakuqi”
Bul. Shk., Ser. Shk. Nat. 2015, 65, 94-102.
12. Dhora Dh, Smajlaj RR, Dhora A:
Katalogu i peshqve ujërave ëmbla
Shqipërisë. Buletin Shkencor i
Universitetit Shkodrës “Luigj
Gurakuqi”, Nr. 58, Seria e Shkencave
Natyrës 2008, 100 -131.
13. Economidis PS, Dimitriou E, Pagoni R,
Michaloudi E, Natsis L: Introduced and
translocated fish species in the inland
waters of Greece. Fisheries Management
and Ecology 2000, 7, 239–250.
14. Economou AN, Giokoumi S, Vardakas L,
Barbieri R, Stoumboudi M, Zogaris S: The
freshwater ichthyofauna of Greece – an
update based on a hydrographic basin
survey. Mediterranean Marine Science
2007, 8 (1), 91–166.
15. Ferreira MT, Caiola N, de Sostoa A, Casals
F, Cortes R, Economou A, Zogaris S,
Garcia-Jalon D, Ilhéu M, Martinez-Capel
Invasiveness assessment of pumpkinseed fish in Albanian freshwater ecosystems
F, Pont D, Rogers C, Prenda J: Ecological
traits of fish assemblages from
Mediterranean Europe and their
responses to human disturbance.
Fisheries Management and Ecology 2007,
14 (6), 473–481.
16. Fobert E, Zięba G, Vilizzi L, Godard MJ,
Fox MG, Stakėnas S, Copp GH:
Predicting non-native fish dispersal
under conditions of climate change:
Case study in England of dispersal and
establishment of pumpkinseed Lepomis
gibbosus in a floodplain pond. Ecology of
Freshwater Fish. 2013, 22 (1), 106–116.
17. Garcia-Berthou E, Moreno-Amich R:
Food of introduced pumpkinseed
sunfish; ontogenetic diet shift and
seasonal variation. Journal of Fish
Biology. 2000, 57, 29-40.
18. Giapis A.J: Ecology of the Lepomis
gibbosus (L.), in Kerkini lake (PhD
Thesis). School of Forestry and Natural
Environment, Aristotle University of
Thessaloniki (in Greek), 2003.
19. Glamuzina B, Tutman P, Nikolić V,
Vidović Z, Pavličević J, Vilizzi L, Copp
GH, Simonović P: Comparison of taxon‐
specific and taxon‐generic risk
screening tools to identify potentially
invasive non-native fishes in the River
Neretva Catchment (Bosnia and
Herzegovinaand Croatia). River
Research and Applications. 2017, 33 (5),
20. Grzegorz Zieba G, Vilizzi L, Copp G: How
likely Lepomis gibbosus to become
invasive in Poland under conditions of
climate warming? ACTA
2020, 50 (1), 37–51
21. Hill JE, Tuckett QM, Hardin S, Lawson
LL, Lawson KM, Ritch JL, Partridge L:
Risk screen of freshwater tropical
ornamental fishes for the conterminous
United States. Transactions of the
American Fisheries Society. 2017, 146 (5),
22. Holcik J: Fish introductions in Europe
with particular reference to its Central
and Eastern part. Canadian Journal of
Fisheries and Aquatic Science 1991, 48
(1), 13–23.
23. Holtan, P: Pumpkinseed (Lepomis
gibbosus). Wisconsin Department of
Natural Resources, Bureau of Fisheries
Management 1998, 1-6.
24. Jackson MC, Britton JR, Cucherousset J,
Guo Z, Stakėnas S, Gozlan RE, Godard
MJ, Roussel J-M, Copp GH: Do non-
native pumpkinseed Lepomis gibbosus
affect the growth, diet and trophic niche
breadth of native brown trout Salmo
trutta? Hydrobiologia 2016, 772 (1), 63–
25. Kowarik I, Rabitsch W: Biologische
Invasionen: Neophyten und Neozoen in
Mitteleuropa. 2nd edn.Verlag Eugen
Ulmer , Stuttgart (Hohenheim), Germany,
26. Lawson LL jr, Hill JE, Vilizzi L, Hardin S,
Copp GH: Revisions of the Fish
Invasiveness Screening Kit (FISK) for
its application in warmer climatic zones,
with particular reference to peninsular
Florida. Risk Analysis 2013, 33 (8), 1414–
27. Matzinger A, et al.: Is Lake Prespa
jeopardizing the ecosystem of ancient
Lake Ohrid? Hydrobiologia 2006, 553,
28. Mc Cairns RJ, Fox MG: Habitat and
home range fidelity in the trophically
dimorphic pumpkinseed sunfish
(Lepomis gibbosus) population.
Oecologia 2004, 140, 271-279.
29. Papadakis J; Climates of the world. Their
classification similarities, differences
and geographic distribution. Buenos
Aires: Libro Edicion Argentina 1970.
30. Popovska C, Bonacci C: Basic data on the
hydrology of Lakes Ohrid and Prespa.
Hydrological Processes 2007, 21, 658–
Bakiu et al., 2022
31. Ribeiro F, Leunda PM, 2012. Non-native
fish impacts on Mediterranean
freshwater ecosystems: current
knowledge and research needs. Fisheries
Management and Ecology 2012, 19, 142-
32. Robinson BW, Wilson DS, Margosian AS,
Litito PT: Ecological and morphological
differentiation of pumpkinseed sunfish
in lakes without bluegill sunfish.
Evolution and Ecology 1993, 7, 451-464.
33. Scott WB, Crossman EJ: Freshwater
Fishes of Canada. Fish. Res. Board Can.
Bull. 1973, 184, 713-718.
34. Shumka S, Paparisto A, Grazhdani S:
Identification of non-native freshwater
fishes in Albania and assessment of their
potential threats to the national
biological freshwater diversity.
Proceedings Balwois Conference, 2008,
vol. 40, pp. 1-6.
35. Simonović P, Tošić A, Vassilev M,
Apostolou A, Mrdak D, Ristovska M,
Kostov V, Nikolić V, Škraba D, Vilizzi L,
Copp GH: Risk assessment of non-native
fishes in the Balkans region using FISK,
the invasiveness screening tool for non-
native freshwater fishes. Mediterranean
Marine Science 2013, 34 (2), 369–376.
36. Stakėnas S, Vilizzi L, Copp GH: Habitat
use, home range, movements and
interactions of introduced Lepomis
gibbosus and native Salmo trutta in a
small stream of southern England.
Ecology of Freshwater Fish 2013, 22 (2),
37. Talevski T, Milosevic D, Maric D,
Petrovic D, Talevska M, Talevska A:
Biodiversity of Ichthyofauna from Lake
Prespa, Lake Ohrid and Lake Skadar.
Biotechnology and Biotechnological
Equipment 2009, 23 (1), 400-404,
38. Tarkan AS, Vilizzi L, Top N, Ekmekçi FG,
Stebbing PD, Copp GH: Identification of
potentially invasive freshwater fishes,
including translocated species, in
Turkey using the Aquatic Species
Invasiveness Screening Kit (ASISK).
International Review of Hydrobiology
2017, 102(1–2): 47–56.
39. Tarkan AS, Sarı HM, İlhan A, Kurtul I,
Vilizzi L: Risk screening of non-native
and translocated freshwater fish species
in a Mediterranean-type shallow lake:
Lake Marmara (West Anatolia).
Zoology in the Middle East 2017, 63 (1),
40. van der Schriek T, Giannakopoulos C:
Determining the causes for the dramatic
recent fall of Lake Prespa (southwest
Balkans). Hydrological Sciences Journal
2017 62 (7), 1131-1148
41. van Kleef H H, van der Velde G, Leuven R
S E W, Esselink H: Pumpkinseed sunfish
(Lepomis gibbosus) invasions facilitated
by introductions and nature
management strongly reduce
macroinvertebrate abundance in
isolated water bodies. Biological
Invasions 2008, 10 (8), 1481–1490.
42. Vilizzi L, Copp G, Hill J et al.: A global-
scale screening of non-native aquatic
organisms to identify potentially
invasive species under current and
future climate conditions. Science of The
Total Environment 2021, 788, 147868,
ISSN 0048-9697.
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Mediterranean lake–wetland systems are threatened by climate change and intensive human impacts. Individual lake responses to these threats are poorly known but urgently required to steer preservation strategies. The dramatic water-level fall (~8 m since 1987) of Lake Megali Prespa endangers this global biodiversity hotspot and the wider catchment’s water resources. Annual lake fluctuations are found to be strongly related to wet-season (Oct.–Apr.) precipitation variability, which is linked to the North Atlantic Oscillation. The lake primarily adjusts to sustained inflow changes through amending surface evaporation. Cumulative water abstraction since 1951 (~19 × 10⁶ m³/year: ~0.006% of lake volume) explains ~70% of the long-term decrease in surface evaporation; climate variability explains the remainder. Persistent low lake levels after 1995 are caused by water abstraction. Compared to 1952/53–1977/78, the period 1978/79–2003/04 experienced significant decreases in wet-season precipitation, snowfall and discharge; the number of very dry years increased. EDITOR A. Castellarin; ASSOCIATE EDITOR D. Gerten
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Screening tools are being increasingly used to identify more effectively non-native species that pose an elevated risk of being invasive. Of the available decision-support tools, the Fish Invasiveness Screening Kit (FISK) has been widely used, but has recently been replaced by a generic screening tool, the Aquatic Species Invasiveness Screening Kit (AS-ISK), which is applicable to any aquatic species and complies with the minimum requirements for risk tools under the new EC alien invasive species Regulation. With its unique zoogeography and rich native fauna, Turkey is highly susceptible to non-native species’ introductions and translocations. In order to inform non-native species policy and management regarding fishes in Turkey, AS-ISK was used to re-assess species previously screened using FISK and to assess additional non-native and translocated fish species. In this first calibration study of AS-ISK for Turkey, a basic score threshold of 28 was achieved, which reliably distinguished between potentially invasive (high risk) and potentially non-invasive (medium to low risk) fishes. Of the 64 species assessed, only one was ranked as ‘low risk’, 40 were categorised as ‘medium risk’, and the remaining 23 as ‘high risk’ of which five were translocated. Non-native species currently not present in Turkey, but that pose a high risk of being invasive, were Ameiurus melas, Ameiurus nebulosus, Hemiculter leucisculus, Hypophthalmichthys molitrix, Micropterus salmoides, Perccottus glenii, Pimephales promelas; whereas, the highest scoring translocated species were Cyprinus carpio, Esox lucius and Silurus glanis. When the potential effects of climate change on the assessments were considered, risk scores increased for some (sub)tropical fishes of which two are translocated species.
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Risk screening tools to identify species with a high or low risk of invasiveness are being increasingly used for effective management purposes. Amongst the available tools, the Fish Invasiveness Screening Kit (FISK) has been used extensively and successfully in large risk assessment (RA) areas, and was recently upgraded to the new generic tool Aquatic Species Invasiveness Screening Kit (AS-ISK). The aim of the present study was to assess with AS-ISK the invasive potential of introduced non-native and translocated fishes in a Mediterranean-type shallow lake (Lake Marmara) located in north-west Anatolia (Turkey). Based on independent evaluations of 35 species by two assessors, calibration of AS-ISK resulted in a threshold score of −3.65, which reliably distinguished between potentially invasive (high risk) and potentially non-invasive (medium to low risk) fishes. Of the 35 species assessed, 17 were categorised as ‘low risk’ and included native/endemic and translocated natives, and the remaining 18 as ‘high risk’ and comprised non-natives and translocated natives. Carassius gibelio had the highest score in the Climate Change Assessment section, suggesting that it might potentially impact on the native fish fauna under likely climate change scenarios for the RA area. Some cool water non-native (Oncorhynchus mykiss, Salvelinus fontinalis), translocated (Luciobarbus lydianus) and endemic species (Ladigesocypris mermere) in the catchment will likely be affected negatively by predicted climate change conditions.
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Electronic decision-support tools are now an essential component of government strategies to battle non-native species, with taxon-specific, paper-based risk analysis schemes often being replaced by taxon-generic tools. This study reports on the development of a decision-support tool for aquatic species, the Aquatic Species Invasiveness Screening Kit (AS-ISK), which replaces five taxon-specific toolkits for amphibians, freshwater and marine fish and invertebrates (FISK, MFISK, FI-ISK, MI-ISK, Amph-ISK). Adapted from Pheloung et al.’s Weed Risk Assessment (WRA), the “-ISK” toolkits were also ‘self-automated workbooks’ in Excel® VisualBasic® architecture of the ’WRA. In creating AS-ISK, we incorporated the conceptual approach (questions and guidance) of the generic risk screening module of the European Non-native Species in Aquaculture Risk Analysis Scheme (ENSARS) into a single ‘turnkey application that was based on the Excel® VisualBasic® architecture used by the WRA and its “-ISK” derivatives. Applicable to virtually all climatic zones and all aquatic plants and animals regardless of ecosystem (marine, fresh, brackish water), AS-ISK comprises 49 basic questions on the taxon’s biogeographical and historical traits and its biological and ecological interactions. In compliance with the ‘minimum requirements’ for use with the new EU Regulation on invasive alien species of EU concern, AS-ISK includes a preamble of background information on the species as well as questions on its potential socio-economic impacts and those on ecosystem services, and an additional section (six questions) for the assessor to predict how forecasted changes in climate are likely to influence the risks of introduction, establishment, dispersal and impact of a species. Following a concise but detailed description of AS-ISK, an example assessment of the Manila clam Ruditapes philippinarum is provided, with the French coastline as the risk assessment area, to demonstrate use of this decision-support tool. AS-ISK is available for free download at:
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Distribution records (historical, contemporary) for native and non-native freshwater fish species from 105 hydrographic basin areas were compiled and analysed in order to develop a nation-wide inventory (including transboundary river basins). Overall, 162 species, including diadromous and euryhaline, with documented occurrence records in freshwaters, and taxa of unclarified taxonomic status, are accommodated in the distributional compilation. An annotated checklist summarises the confirmed ichthyofauna of Greek freshwaters (161 species); a provisional supplementary list contains species recorded in brackish waters (55 species). In comparison to the last published (1991) checklist of freshwater fish of Greece, the present checklist shows an increase in species number of 53% (56 species). This increase has resulted mainly from taxonomic re-evaluations of existing taxa on the basis of new information and adoption of a new systematic concept. The current trend, as reflected in recent ichthyological publications, is towards abandonment of the biological species concept (BSC) and adoption of the phylogenetic species concept (PSC) for the delineation of species boundaries. The practical implications of the change in species concept on biodiversity conservation and watershed management are discussed. An overview of the composition and characteristics of the freshwater fish fauna of Greece is provided, especially with regard to the native and introduced status of species, and the spatial patterns of species richness and endemism. This systematic inventory may assist in efforts to develop nation-wide surface water bioassessment tools within the demands of the Water Framework Directive (WFD); it may further promote biodiversity conservation and biologically-orientated fishery management approaches.
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Lake Prespa, Lake Ohrid, and Lake Skadar are the biggest lakes in the Balkan Peninsula. In this paper are presented the researches of the fish populations qualitative composition in Lake Prespa, Lake Ohrid and Lake Skadar. In those three lakes as result of negative anthropogenic impact there are changes in fish biodiversity (with more presence of alochtonous species). In this way, unfortunately autochthones populations of fishes (which are rich by endemic and relict species) are endangered. By reason of inserting news species, the fish populations are endangered, especially the populations of particular zoographically significant species. So, it is necessary to proceed the procedure to their inserting in the Red list of endangered species. The abundance of the fish populations in the three biggest lakes in the Balkan Peninsula is in dependence from of their different altitudes, surfaces and depths. Also, the qualitative composition of the fish populations in those lakes depend from the different physic-chemical conditions, biological communities (phytoplankton, zooplankton, bottom fauna), and especially from the macrophyte vegetation.
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In Albania, alien freshwater fish are continuing to steadily increase in number of species (reported in this paper to be more than 17), abundance, and distribution. In general however, their impacts are not well quantified in either environmental or economic terms and current management to reduce their impacts is limited and lacking direction. From around the middle of the 19th century, international transfers of fish species, especially for sporting purposes and the provision of an additional food supply increased apace. After the end of the Second World War the number of introductions of alien fish species increased still further, helped by the development of advanced artificial spawning techniques (Elvira 2001). The fact that European countries are important recipients of alien fish is ascribed by Welcomme (1992) to the fact that they have generally impoverished fish faunas and that introductions have been made, with a variety of motives, to increase their ichthyological biodiversity. The naturalization of some of the alien fish species that are able to reproduce successfully in the wild has had catastrophic consequences. There is the case of well established Lepomis gibbosa in Macro Prespa Lake. Species associated with high impact tend to have a broad diet and abundant populations in native and disturbed habitats. Likewise, host aquatic environments resistant to impact tend to be heavily managed or disturbed, productive, and inhabited by complex communities. In Albania, it was central government until 1990, owner of the all fish farming centers, with a total surface of 215 ha, to occupy on the restocking of the reservoirs, natural and artificial lakes. In this paper we describe the presence and riks of the following species: Ameiurus melas, Carassius auratus, Megalobrama amblycephala, Ctenopharyngodon idella, Cyprinus carpio, Gambusia affinis, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Oncorhynchus mykiss, Parabramis pekinensis, Poecilia reticulate, Peudorasbora parva, Silurus glanis, Lepomis gibbosus, Stizostedion lucioperca, Perca fluviatilis, Tinca tinca, etc. Looking towards the concerns for the environmental flow–sustainable action at the protected area, biodiversity conservation, preserving the internationally important species of flora and fauna and recreation– those can be reflected into a regulatory and policy measures, local actions that strives to preserve the biotope conditions. The aim of this paper was to reveal the rapid invasion of introduced fishes and its possible effects on native freshwater fish species in Albania.
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The pumpkinseed Lepomis gibbosus, an omnivorous, nest guarding North American sunfish, was introduced into European waters about 100 years ago. To assess growth performance following introduction, we reviewed the available data for North American and European populations of pumpkinseed and compared the back-calculated age-specific growth for juveniles (standard length, SL, at age two) and adults (age two to five increment) as well as adult body size (SL at age five), von Bertalanffy growth model parameters and the index of growth (in length) performance (φ′). For continental comparisons of growth trajectory, mean growth curves for North American and Europe were calculated with the von Bertalanffy model using pooled data sets for each continent. Juvenile growth rate did not differ between European and North American pumpkinseed, but mean adult body size and adult growth rate were both significantly greater in North American than European populations. Adult body size decreased with increasing latitude (ANOVA) in North American populations, but this was not observed with adult growth rate. In contrast, adult body size tended to increase with latitude in European populations. Adult body size correlated significantly with φ′. The von Bertalanffy model described the overall growth patterns of North American and European populations reasonably well, but on the individual population level, length asymptotes were unrealistic (estimates that were > 20 % of the mean back-calculated size for the oldest age class) for a third of European populations and 80% of the North American populations. In contrast to North American pumpkinseed populations, somatic growth in European populations appears to be compromised by limited, but adequate, food resources, probably due to strong intraspecific interactions. This appears to be especially acute in adults, having potential ramifications for life span and reproductive allocation.
Environmental changes due to non-native species introductions and translocations are a global concern. Whilst understanding the causes of bioinvasions is important, there is need for decision-support tools that facilitate effective communication of the potential risks of invasive non-native species to stakeholders. Decision-support tools have been developed mostly in English language only, which increases linguistic uncertainty associated with risk assessments undertaken by assessors not of English mother tongue and who need to communicate outcomes to local stakeholders. To reduce language-based uncertainty, the ‘ecology-of-language’ paradigm was applied when developing the Aquatic Species Invasiveness Screening Kit (AS-ISK), a decision-support tool that offers 32 languages in which to carry out screenings and communicate outcomes to stakeholders. Topics discussed include uncertainty related to language-specific issues encountered during the AS-ISK translation and the potential benefits of a multilingual decision-support tool for reducing linguistic uncertainty and enhancing communication between scientists, environmental managers, policy and decision makers.