International Journal of Aquaculture, 2024, Vol.14, No.4, 174-183 http://www.aquapublisher.com/index.php/ija 176 Carp's feeding habits can reduce the abundance of zooplankton and benthic invertebrates, which are crucial components of the aquatic food web (Rolls et al., 2107). This reduction in prey availability can have cascading effects throughout the food web, impacting higher trophic levels, including native fish species. Additionally, the presence of carp can increase phytoplankton abundance due to reduced grazing pressure from zooplankton, further altering the food web structure (Carey and Wahl, 2010). 3.3 Impact on water quality and sediment Common carp significantly impact water quality and sediment composition in invaded ecosystems. Their foraging behavior increases water turbidity and nutrient concentrations, leading to eutrophication and degraded water quality (Marshall et al., 2019). In shallow lakes, carp have been shown to increase suspended solids, phytoplankton, and nutrient levels, contributing to a shift from clear to turbid water states (Carey and Wahl, 2010). These changes in water quality can have far-reaching consequences for the entire aquatic ecosystem, affecting both biotic and abiotic components. 4 Economic and Social Consequences 4.1 Impact on commercial and recreational fishing The invasion of common carp (Cyprinus carpio) has significant repercussions on both commercial and recreational fishing sectors. In Germany, for instance, specialized carp anglers' catch rates exceed commercial harvests by up to 2500%, indicating a substantial impact on the fishing industry. This overabundance of carp can lead to decreased populations of native fish species, thereby reducing the overall biodiversity and altering the ecosystem balance, which in turn affects commercial fishing yields (Busst et al., 2017). Additionally, the presence of carp can shift ecosystems from macrophyte-dominated clear water states to turbid water states dominated by phytoplankton, further complicating fishing activities and reducing the quality of fishing experiences (Gallardo et al., 2016). 4.2 Economic costs of management and control Managing and controlling the spread of common carp incurs significant economic costs. Invasive species like the common carp have been responsible for economic losses amounting to at least US$37.08 billion globally, with North America bearing the highest costs (Haubrock et al., 2021). These costs are associated with damage and resource losses, as well as expenses related to management actions and environmental restoration. In Australia, for example, the control of carp populations in dryland rivers involves substantial investments in biocontrol measures, which are necessary to mitigate their adverse effects on native fish biomass and ecosystem health (Marshall et al., 2019). Moreover, the implementation of continuous removal efforts and novel control approaches is essential to prevent the unintended consequences of increased carp condition and reproductive potential (Coulter et al., 2018). 4.3 Social perceptions and cultural significance The social perceptions and cultural significance of common carp vary across different regions. In some areas, carp are valued for recreational fishing, contributing to local economies through tourism and related activities (Veer and Nentwig, 2015). However, the negative ecological impacts of carp invasions, such as increased water turbidity and reduced native fish populations, can lead to negative social perceptions and a demand for effective management strategies (Figure 1). Policymakers must consider these social welfare implications when deciding on conservation policies and mitigation efforts (Brockmann et al., 2021). Additionally, the cultural significance of carp in certain communities may influence the acceptance and success of management programs, highlighting the need for culturally sensitive approaches to invasive species control. 5 Case Studies of Common Carp Invasions 5.1 North America In North America, the introduction of common carp (Cyprinus carpio) has led to significant ecological changes in various aquatic ecosystems. The carp's presence has been linked to a decline in aquatic plant richness and cover, particularly in the Great Plains and Eastern Temperate Forests ecoregions. Studies have shown that as carp biomass increases, submersed plant cover and species richness decline exponentially, with plant cover reduced to
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