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7QUANTIFYING THE ECONOMIC COSTS OF INVASIVE SPECIES ON
NATIVE BIODIVERSITY AND ECOSYSTEM FUNCTIONING IN NIGERIA.
EKWERIKE EMMANUEL CHINEDU 1
Department of Cell Biology and Genetics University of Lagos, Nigeria.
NWANKWO NNABUEZE KALU 2
PhD candidate, Institute of Environmental Engineering RUDN University, Moscow, Russia.
Abstract: Invasive species have become a global challenge due to their detrimental impact on native biodiversity and ecosystem performance. This study aims to quantify the economic costs associated with invasive species on native biodiversity and ecosystem functioning in Nigeria. The article studied the direct and indirect economic costs incurred as a result of invasive species' effects on native species and ecosystem services. The findings reveal that invasive species have severely impacted native biodiversity, leading to declines in species richness and disruptions in ecosystem functioning. Understanding the economic costs of invasive species is vital for formulating effective management approaches and policies to mitigate their impact. This study provides valuable awareness of the urgent need for proactive measures and resource allocation to lessen the economic problems caused by invasive species and preserve Nigeria's unique biodiversity and ecosystems.
Keywords: Invasive species, Native biodiversity, Ecosystem functioning, Economic costs, Nigeria, Management strategies, Mitigation measures
Introduction:
Invasive species create a major threat to native biodiversity and ecosystem functioning worldwide. Nigeria, renowned for its plentiful biodiversity and vibrant ecosystems, is not protected from this phenomenon. The introduction and establishment of non-native species have led to the alteration of ecosystem structure and function, leading to potential economic costs and ecological differences. Thus, quantifying the economic impacts of invasive species is crucial for effective management and conservation strategies.
The economic costs of invasive species result from a variety of factors, including direct damage to crops, livestock, and infrastructure, as well as indirect effects on ecosystem services, human health, and tourism revenues. In Nigeria, invasive species such as water hyacinth (Eichhornia crassipes), giant African snail (Achatina fulica), and the red-bellied piranha (Pygocentrus nattereri) have been acknowledged as predominantly problematic. These species have shown a rapid increase, outcompeting native flora and fauna, resulting in severe ecological and economic effects.
Assessing the economic impacts of invasive species necessitates a comprehensive understanding of the ecological interactions between invasive and native species, as well as the quantification of associated economic losses. Economic calculations can help estimate the direct costs incurred from crop harvest losses, livestock ruin, damage to infrastructure, and the costs of control and eradication efforts. Furthermore, indirect costs can be evaluated by assessing the impact of invasive species on ecosystem services, such as water quality. The purpose of this research work was to determine the economic costs of invasive species on native biodiversity and ecosystem functioning in Nigeria.
To achieve this goal, the following tasks were set
1. Collecting data on invasive species impact in the study areas.
2. Utilizing the demography of the study area and distribution to envisage the emergence of inversive.
3. Calculating the Total Economic Impact
4. Analyzing the results and justification of the studied area.
This research aims to quantify the economic costs of invasive species on native biodiversity and ecosystem functioning in Nigeria, providing policymakers, land managers, and conservationists with valuable insights to prioritize management interventions. By integrating ecological and economic analyses, we can better understand the full extent of the problem and develop strategies to mitigate the impacts of invasive species, protect native biodiversity, and ensure the sustainable functioning of Nigeria's valuable ecosystems. Research result and discussion: Materials and Methods
The quantitative method was used to collect data and information about inversive species and their impact on native biodiversity and ecosystem functioning in Nigeria. Data were collected through secondary data collection quantitative method, to better understand the socio-demographic characteristics of the study areas. Full reports and PDF articles that met the criteria of being used for the descriptive statistical input method were considered.
This article aims at analyzing the socioeconomic impacts of invasive species and evaluating cost-effective management strategies. The objective is to create a higher level of awareness and understanding for the reader to see the ecological interactions between invasive and native species. The assessment study was carried out in June 2023.
Invasive species in Nigeria
Nigeria faces numerous notable invasive species that pose dangers to its native ecosystems. Some prominent examples include the water hyacinth (Eichhornia crassipes), the giant African land snail (Achatina fulica), and the Nile perch (Lates niloticus).
Dispersal and Spread of Invasive Species in Different Ecosystems: The water hyacinth, has quickly spread across Nigeria's water bodies, including rivers and lakes, creating dense mats that impede water flow and disrupt aquatic ecosystems. The giant African land snail has invaded agricultural areas, causing damage to crops and rivalry with native species for resources. The Nile perch, introduced for fisheries, has transformed the dynamics of native fish populations in certain aquatic ecosystems. The exposure of ecosystems to invasion by species transported by humans, either purposefully or unintentionally threatens native species mostly as a result of competition and predation by non-indigenous species [2] Case Studies of Specific Invasive Species and Their Impacts:
• Water Hyacinth (Eichhornia crassipes): Distribution: Found in rivers and lakes across Nigeria.
Impact: Creates dense mats, leading to reduced sunlight penetration and oxygen depletion, harming aquatic life and affecting local fishing activities.
• Giant African Land Snail (Achatina fulica):
Distribution: Invades agricultural areas and urban environments. It is a gastropod animal that is often found under plant debris, in certain agricultural areas [5].
Impact: Damages crops, competes with native snails and can transmit diseases to humans.
• Nile Perch (Lates niloticus):
Distribution: Introduced to various freshwater bodies for fisheries. The Nile perch (Lates niloticus) is a notorious invasive species [3]
Impact: Alters the balance of native fish populations, posing a threat to biodiversity and affecting local fisheries.
Impacts of invasive species on native biodiversity
1. Changes in Species Composition and Diversity: Invasion and eutrophication are considered to pose serious threats to freshwater biodiversity and ecosystem function [4]. Invasive species in Nigeria contribute to shifts in the composition and
diversity of native ecosystems. The introduction of non-native species often leads to the outcompeting of indigenous flora and fauna, resulting in a reduced variety of native species.
Invasive species often alter the alpha and beta diversity of ecosystems. This can be measured using ecological indices such as the Shannon-Wiener index, which considers both species richness and evenness. Monitoring changes in species composition requires methods like quadrat sampling and transect surveys to quantify the abundance and distribution of native and invasive species over time.
2. Displacement and Extinction of Native Species:
The aggressive nature of some invasive species can lead to the displacement and, in extreme cases, the extinction of native species. For example, invasive plants may outcompete native vegetation, disrupting established ecological balances and causing a decline in indigenous plant species.
The displacement of native species can be analyzed through ecological niche modelling, examining the overlapping niches of invasive and native species to understand competitive interactions. Extinction risk assessments, employing tools like the IUCN Red List criteria, help evaluate the vulnerability of native species in the face of invasive threats.
3. Altered Ecological Interactions and Disruptions in Food Webs:
Invasive species can disrupt intricate ecological interactions by either preying on native species, competing for resources, or introducing new diseases. This disruption can lead to imbalances in local food webs. For instance, the introduction of a predatory invasive species may cause a decline in the population of native prey species, affecting the entire trophic structure of an ecosystem.
Studying trophic interactions in ecosystems impacted by invasive species involves stable isotope analysis to trace nutrient flows and understand how these interactions change. Network analysis, using methods like food web models, helps quantify the structural changes in interaction networks, highlighting the impact of invasive species on trophic relationships. Economic costs of invasive species Quantifying Direct and Indirect Economic Damages: Direct Economic Damages:
Case Study: Crop Damage by Fall Armyworm (Spodoptera frugiperda):
The monetary loss by assessing the reduction in crop yield (Yield Loss Percentage x Market Price per ton).
20% yield loss on a 100-ton maize field with a market price of 150,000 Naira/ton results in direct economic damage of 3,000,000 Naira. Indirect Economic Damages:
Case Study: Impact of Water Hyacinth (Eichhornia crassipes) on Fisheries: The loss in revenue by assessing the decline in fish catch (Reduced Catch x Market Price per unit). 30% reduction in fish catch with a market price of 250 Naira/kg results in indirect economic damage of 75,000 Naira for every 1,000 kg of fish lost
Economic modelling to assess the cumulative costs of crop damage, pesticide use, and the impact on farm incomes.
Case Study: Impact of Giant African Land Snail (Achatina fulica) on Agriculture Crop Damage:
Assess the economic impact of Giant African Land Snail on crops, considering reduced yields and quality.
15% reduction in maize yield with a market price of 150,000 Naira per ton results in a crop damage cost of 2,250,000 Naira for a 100-hectare farm. Pesticide Use:
The costs associated with increased pesticide application to control the snail population. An additional 2,000,000 is spent on pesticides per year to manage the snail infestation on the farm. Impact on Farm Incomes:
The overall impact on farm incomes, considering both reduced crop yields and increased pesticide costs. Would be the combination of reduced yield and increased pesticide cost, Integrated Economic Impact Calculation:
2,500,000 Naira (CropDamage)+ 2,000,000 Naira (PesticideUse) = 4,500,000 Naira Economic Modeling for Water Resources Impacted by Water Hyacinth:
Reduced Water Flow:
Assess the economic impact of reduced water flow on irrigation and hydropower generation. A 20% reduction in water flow leads to a 10% decrease in agricultural productivity, resulting in a combined economic loss of 5,000,000 Naira per year. Health-related Costs:
Consider the impact on public health due to contaminated water, leading to increased healthcare expenses.
Increased incidence of waterborne diseases results in an estimated additional 50,000,000 Naira in indirect healthcare costs annually.
Integrated Economic Impact:
Total Economic Impact = Economic Impact of Reduced Water Flow + Indirect Health-related Costs 5,000,000 Naira (Reduced water flow) + 50,000,000 Naira (health-related cost) = 55,000,000 Naira
Economic Factor Impact (%) Economic Loss (Naira)
Reduced Water Flow 20 5,000,000
Indirect Health-related - 50,000,000
Costs
Total Economic Impact - 55,000,000
Table compiled by the authors
This table breaks down the economic factors, the percentage change in each factor, and the resulting economic losses. The total economic impact includes the costs associated with reduced water flow and the indirect health-related impacts due to waterborne diseases. Management strategies for invasive species
Invasive species management has mainly focused on eradication to limit proliferation using different control methods (e.g., mechanical control, physical removal of species through cutting or pulling, chemical control, use of herbicides to kill and suppress regrowth, and biological control [1] Strategic Measures: Implement stringent biosecurity protocols at national borders, ports, and transportation hubs to mitigate unintentional introductions. Strengthen regulatory frameworks and enforcement mechanisms to control the importation and movement of potentially invasive species. Early Detection and Rapid Response Measures:
Surveillance and Monitoring: Establish comprehensive surveillance programs to detect invasive species at an early stage. Utilize advanced monitoring technologies and engage local communities in reporting mechanisms. Develop rapid response protocols, including targeted containment and eradication efforts upon detection. Control and Eradication Techniques:
Integrated Pest Management (IPM): Adopt IPM strategies that integrate biological, chemical, and mechanical control methods. Prioritize environmentally sustainable approaches to minimize nontarget impacts. Invest in research and development for innovative and species-specific control measures.
Restoration and Rehabilitation of Affected Ecosystems:
Ecological Restoration Plans: Develop and implement ecosystem-specific restoration plans that prioritize native species reintroduction and habitat rehabilitation. Apply adaptive management principles to assess the effectiveness of restoration efforts over time. Engage local communities in restoration initiatives to ensure long-term success. Cross-cutting Considerations:
Capacity Building: Invest in training programs for stakeholders, including government agencies, local communities, and relevant industries, to enhance capacity in invasive species management.
Public Awareness: Implement educational campaigns to raise public awareness about the risks associated with invasive species and promote responsible behaviour to prevent further introductions Conclusion
The management of invasive species in Nigeria requires a wide-ranging and adaptive approach, considering the diverse ecological, economic, and social impacts. Key findings emphasize the insistence on implementing robust prevention strategies, early detection measures, and effective control techniques to lessen the spread and impact of invasive species on native ecosystems. The case studies highlight the diverse ecological and economic impacts of invasive species in Nigeria, stressing the significance of effective management approaches to mitigate their spread and protect native ecosystems.
The economic modelling calculations demonstrated the tangible financial consequences of invasive species, highlighting the value of resource allocation for mitigation efforts. The health-related costs associated with waterborne diseases and the agricultural losses due to the Giant African Land Snail additionally draw attention to the interconnectedness of invasive species impacts across different sectors.
Implications of these results extend past immediate economic losses, including broader ecological disorders, threats to biodiversity, and challenges to sustainable resource management. The summary of management approaches emphasizes the need for an all-inclusive and interdisciplinary approach, integrating biosecurity measures, surveillance systems, and ecosystem-specific restoration plans.
Moving forward, successful invasive species management in Nigeria involves continued research, community engagement, and the combination of adaptive management principles. The study provides a foundation for policymakers, researchers, and practitioners to develop targeted interventions that protect and preserve native ecosystems, promote sustainable agriculture, and protect public health. It is imperative to accept the dynamic nature of invasive species challenges and encourage a proactive and collaborative approach to ensure the resilience and integrity of Nigeria's ecosystems in the face of invasive threats.
REFERENCES
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