268
H. Dutta
resulted in high local extinction of endemic species (Ding et al. 1995). For instance,
the endemic aquatic plant Ottelia acuminate faced local extinction due to alien plant
invasion in the plateau lakes of China (Xiang et al. 2013). On the other hand, the
expansion of invasive macrophytes has led to the greatest decrease in fish abundance
(Gallardo et al. 2016).
An example of an invasive aquatic plant is the Eurasian water milfoil, which can
displace and outnumber native aquatic plants as well as reduce their habitat and
diversity in lakes (Zhang and Boyle 2010). Hydrocotyle ranunculoides, Ludwigia
grandiflora and Myriophyllum aquaticum are important invasive plants of Belgium.
Their introductions have led to severe ecological alterations in native vegetation
and detritus community in the ponds of Belgium and this has negatively affected
invertebrate abundance in affected ponds (Stiers et al. 2011). On the other hand,
Vallisneria spiralis, Azolla filiculoides and Elodea nuttallii are the most abundant
non natives of Serbia. Most of the aquatic invasive plants of Serbia are native to the
Americas. (An -
delkovi´ c et al. 2016). However, there are 152 invasive aquatic plant
species in China and the majority were introduced from South America followed by
North America, Asia, Africa, and Oceania (Wang et al. 2016). But there is a lack of
adequate information on such plants in both China (Wang et al. 2016) and Serbia
(An -
delkovi´ c et al. 2016). In fact, biological invasions in aquatic ecosystems have also
been mostly overlooked in China, even though their negative effects are frequently
observed (Chen et al. 2017). This can be exemplified by species such as mosquito
fish (Gambusia affinis) and water hyacinth, which have caused great ecological and
economic problems in the Three Gorges Dam Reservoir in China (Xiong et al. 2018).
Apart from plants, molluscs, fishes and decapods also invade freshwater ecosystems and impose their own respective negative effects depending upon their role and
function (Strayer 2010). Nonnative crayfish is another example in this regard. Invasive crayfish affects biodiversity and ecosystem functioning and leads to negative
consequences on basal resources, invertebrates, amphibians and fish (Twardochleb
et al. 2013). Greater numbers of non-indigenous crayfish of pet trade origin are
becoming established particularly in Europe and their negative effects are expected
on freshwater ecosystems (Kotovska et al. 2016).
The Common carp Cyprinus carpio is a major invasive fish of the freshwater
ecosystem (Bajer et al. 2015). The introduction of this species led to severe reduction in plant cover and richness in several Great Plains lakes and Eastern Temperate
Forests lakes in North America. It illustrates the consequences of introducing nonnative ecosystem engineers to lakes (Bajer et al. 2016). On the other hand, in England
introduced Ruffe (Gymnocephalus cernuus) and cyprinid roach (Rutilus rutilus) have
become invasive. Vice versa, native Coregonid whitefish (Coregonus lavaretus) is
an example of a fish negatively affected by alien fish species in Loch Lomond in
Scotland (Winfield et al. 2011). Several negative associations have been identified
between native and introduced nonnative species of trout in Western United States
(Dunham et al. 2004). This has also led to indirect effects, as evident from the fact
that the reductions in the native cutthroat trout in and around Yellowstone Lake has
resulted in changes the distribution, diet, survival and abundance of river otters (Crait
H. Dutta
resulted in high local extinction of endemic species (Ding et al. 1995). For instance,
the endemic aquatic plant Ottelia acuminate faced local extinction due to alien plant
invasion in the plateau lakes of China (Xiang et al. 2013). On the other hand, the
expansion of invasive macrophytes has led to the greatest decrease in fish abundance
(Gallardo et al. 2016).
An example of an invasive aquatic plant is the Eurasian water milfoil, which can
displace and outnumber native aquatic plants as well as reduce their habitat and
diversity in lakes (Zhang and Boyle 2010). Hydrocotyle ranunculoides, Ludwigia
grandiflora and Myriophyllum aquaticum are important invasive plants of Belgium.
Their introductions have led to severe ecological alterations in native vegetation
and detritus community in the ponds of Belgium and this has negatively affected
invertebrate abundance in affected ponds (Stiers et al. 2011). On the other hand,
Vallisneria spiralis, Azolla filiculoides and Elodea nuttallii are the most abundant
non natives of Serbia. Most of the aquatic invasive plants of Serbia are native to the
Americas. (An -
delkovi´ c et al. 2016). However, there are 152 invasive aquatic plant
species in China and the majority were introduced from South America followed by
North America, Asia, Africa, and Oceania (Wang et al. 2016). But there is a lack of
adequate information on such plants in both China (Wang et al. 2016) and Serbia
(An -
delkovi´ c et al. 2016). In fact, biological invasions in aquatic ecosystems have also
been mostly overlooked in China, even though their negative effects are frequently
observed (Chen et al. 2017). This can be exemplified by species such as mosquito
fish (Gambusia affinis) and water hyacinth, which have caused great ecological and
economic problems in the Three Gorges Dam Reservoir in China (Xiong et al. 2018).
Apart from plants, molluscs, fishes and decapods also invade freshwater ecosystems and impose their own respective negative effects depending upon their role and
function (Strayer 2010). Nonnative crayfish is another example in this regard. Invasive crayfish affects biodiversity and ecosystem functioning and leads to negative
consequences on basal resources, invertebrates, amphibians and fish (Twardochleb
et al. 2013). Greater numbers of non-indigenous crayfish of pet trade origin are
becoming established particularly in Europe and their negative effects are expected
on freshwater ecosystems (Kotovska et al. 2016).
The Common carp Cyprinus carpio is a major invasive fish of the freshwater
ecosystem (Bajer et al. 2015). The introduction of this species led to severe reduction in plant cover and richness in several Great Plains lakes and Eastern Temperate
Forests lakes in North America. It illustrates the consequences of introducing nonnative ecosystem engineers to lakes (Bajer et al. 2016). On the other hand, in England
introduced Ruffe (Gymnocephalus cernuus) and cyprinid roach (Rutilus rutilus) have
become invasive. Vice versa, native Coregonid whitefish (Coregonus lavaretus) is
an example of a fish negatively affected by alien fish species in Loch Lomond in
Scotland (Winfield et al. 2011). Several negative associations have been identified
between native and introduced nonnative species of trout in Western United States
(Dunham et al. 2004). This has also led to indirect effects, as evident from the fact
that the reductions in the native cutthroat trout in and around Yellowstone Lake has
resulted in changes the distribution, diet, survival and abundance of river otters (Crait