Functional groups of Afrotropical EPT (Ephemeroptera, Plecoptera and Trichoptera) as bioindicators of semi-urban pollution in the Tsitsa River Catchment, Eastern Cape, South Africa

We examined the distribution patterns of Ephemeroptera, Plecoptera, and Trichoptera functional feeding groups (EPT FFGs) in five streams that drain semi-urban landscapes in the Tsitsa River catchment, Eastern Cape Province of South Africa. We undertook macroinvertebrate and physicochemical analysis over four seasons between 2016 and 2017 at eight sites in three land-use categories (Sites 1, 2 and 3), representing an increasing gradient of semi-urban pollution. Five EPT FFGs (shredders, grazers/scrapers, predators, collector-gatherers and collector-filterers) were fuzzy coded and analyzed using RLQ-R (environmental characteristics of samples), L (taxa distribution across samples) and Q (species traits) and fourth-corner analyses. Physicochemical variables, including phosphate-phosphorus, total inorganic nitrogen and temperature, were the most influential variables that significantly influenced the distribution patterns of EPT FFGs in the Tsitsa River. RLQ and the fourth-corner model revealed varying responses of FFGs to semi-urban pollution. Of the five FFGs, collectors were the most abundant EPT FFGs in the study area, exhibiting disparate responses to disturbances, with collector-gatherers associated with impacted sites and significantly associated with phosphate-phosphorus. On the other hand, collector-filterers decreased with increasing semi-urban disturbance and exhibited a significant negative association with phosphate-phosphorus, total inorganic nitrogen and temperature. Overall, this study provides further insights into the environmental factors that influence the distribution patterns of FFGs in Afrotropical streams and the potential use of FFGs as indicators of anthropogenic pollution in tropical streams and rivers

Governance and Institutional Drivers of Ecological Degradation in Urban River Ecosystems: Insights from Case Studies in African Cities

The degradation of rivers in urban landscapes is alarming and impaired their ecological functions and the services they provide to society. In African cities, urban rivers are among the most degraded ecosystems, yet ecologically sustainable utilisation of river resources can contribute to and support sustainable urban development. In this paper, we identify and analyse key governance and institutional drivers of ecological change in urban river systems in the Swartkops catchment in South Africa and the Federal Capital Territory (FCT) in Nigeria. Our results indicate that poor ecological conditions of rivers in the two urban landscapes can be attributed to: (1) a lack of system view of the water value chain and associated infrastructure, (2) ambiguity in roles, responsibilities, and poor accountability, (3) prioritizing short-term social–economic–political agenda over long-term environmental sustainability goals, (4) institutional silos and failure of cooperative governance, and (5) over-centralised, top-down, state-centric governance processes. Strengthening the interactions between actors in the science, policy and practice domains, mainstreaming planning with rivers in integrated urban development plans, and strengthening cooperative and polycentric governance across administrative scales are key governance and institutional processes needed to address the trajectory of urban ecological degradation. Our paper sheds light on the fundamental role of strengthening governance and institutional processes for steering urban rivers toward sustainable paths for city resilience