Setting the scene for achievable post-2020 convention on biological diversity targets: A review of the impacts of invasive alien species on ecosystem services in Africa

Abstract

Invasive alien species (IAS) are known to pose a serious threat to biodiversity, and reduce the ability of ecosystems to provide benefits to humans. In recognition of this threat and to address the impacts of IAS, Parties to the Convention on Biological Diversity (CBD) adopted Aichi Biodiversity Target 9, which is dedicated to the control or eradication of priority IAS and the management of their introduction pathways by 2020. The achievement of Target 9 relies strongly on the commitment and ability of Parties to set ambitious national or regional targets and achive them, the availability of information and the requisite expertise on invasion biology. Now that the global community is gearing for the post-2020 Biodiversity Framework, it is time to take stock and identify opportunities to improve the performance of the African region beyond 2020. We approached this task by reviewing information on the impacts of IAS on ecosystem services in Africa, as a large proportion of Africans directly rely on ecosystem services, particularly in rural areas. Furthermore, we assessed the expertise on IAS in Africa. Our data sources were National Reports of African countries to the CBD, as well as peer-reviewed scientific literature. National Reports under the CBD provide information on measures taken to implement the Convention at country level, as well as progress towards the achievement of set targets. We found National Reports for 48 (about 90%) countries of which 73% provided feedback on IAS indicating commitment to fight IAS. However, there were few studies within peer-reviewed scientific literature looking at impacts of IAS on ecosystem services in Africa and almost half of the authors were non-Africans. This alludes to limited scientific expertise to inform and support IAS management on the continent. Both the National Reports and scientific literature showed that provisioning services were the most negatively affected by IAS. Also, more than 100 species were listed as problematic. More efforts and resources are needed to document IAS impacts across different realms (e.g. marine, terrestrial and freshwater) and for sub-regional bodies so that more integrated strategies and approaches can be developed. This information is also needed to support the development and implementation of national legislative and regulatory initiatives, as well as to report on international obligations such as the Aichi Biodiversity Targets.

Ecological and potential socioeconomic impacts of two globally-invasive crayfish

“…High consumption of native resources, relative to that of a native analogue, is regarded as indicative of high impact IAS according to the Resource Consumption Hypothesis (Ricciardi et al 2013;Paterson et al 2015;Dick et al 2017;Laverty et al 2017). Understanding these impacts on specific ecosystem services is necessary, not only for the regulation and management of these IAS, but also to guard against detriment to human well-being, especially important in areas where food security and water resources are already precarious (Egoh et al 2020). Here, we compare temperature-and resource-specific feeding rates by invasive crayfish and a native freshwater crab to infer ecological and potential economic impacts on fisheries.…”

A Review of Freshwater Crayfish Introductions in Africa

“…Understanding crayfish impacts on specific ecosystem services is necessary not only for their regulation and management, but also to guard against detriment to human wellbeing in a continent where food security and water resources are already precarious (Egoh et al 2020). This is particularly relevant as some of the crayfish species were introduced for aquaculture and there are ongoing requests for the use of crayfishes, and indeed other species, in both inland fisheries and for aquaculture (Nunes, Zengeya, Measey et al 2017;Moshobane et al 2020).…”

Environmental Degradation by Invasive Alien Plants in the Anthropocene: Challenges and Prospects for Sustainable Restoration

“…In this respect, UN-IPBES-global indicators target (i.e., 15.8) aimed to achieve SDGs through implementation of effective management strategies to control the IAPs by 2020 (IPBES 2019a, b;McGeoch and Jetz 2019;Rai and Singh 2021). Especially, in relation to IAPs management, CBD adopted Aichi Biodiversity Target 9 to effectively restore and revitalize the ecosystem services (Egoh et al 2020). In this aspect, UNCCD advocated the adoption of land degradation neutrality (LDN) as a solution to stop further environmental degradation and concomitantly revitalize various ecosystem services and livelihood prospects.…”