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Dr. Tatenda Dalu
University of Venda, South Africa

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0 Biological Control
0 Wetlands
0 Trophic ecology
0 environmental monitoring and modeling
0 Biodiversity and Conservation

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Short Biography

I am interested in the general aquatic ecology of wetlands, reservoirs and rivers/estuaries. I have a strong interest in trophic, plankton and invasion ecology, environmental assessment, biodiversity and conservation.

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Journal article
Published: 07 June 2021 in African Journal of Aquatic Science
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Irrigation ponds are increasingly abundant globally, particularly in water-stressed countries with limited natural surface waters, yet knowledge of their ecology is limited. Here, we assessed zooplankton, macroinvertebrate, and littoral fish communities from irrigation ponds located in the Sundays River Valley in South Africa. This study assessed the seasonal community patterns in response to physico-chemical and biotic components. Water temperature, water depth, Secchi depth, and ammonium concentrations differed significantly across seasons. Similarly, Chlorophyll-a concentrations differed seasonally, with water transparency identified as the main driver. Zooplankton was dominated by Rotifera, Copepoda and Cladocera. Seasonal changes in temperature and subsequent fluctuations in water levels resulted in changes in zooplankton community. Macroinvertebrates were dominated by insects, notably the families Corixidae and Naucoridae. The littoral fish community comprised of Glossogobius callidus, Oreochromis mossambicus and Gambusia affinis. Zooplankton, macroinvertebrates and littoral fish abundances, species richness, diversity and assemblage composition differed significantly across seasons with temperature identified as the main driver of these differences. This study demonstrates that bottom-up processes are the dominant drivers of the irrigation pond communities in the Sundays River Valley and highlights the relevance of seasonal abiotic drivers in structuring these communities, particularly G. callidus and G. affinis.

ACS Style

L Mofu; T Dalu; Rj Wasserman; Dj Woodford; D Khosa; Olf Weyl. Seasonal variation and drivers of zooplankton, macroinvertebrate and littoral fish communities from irrigation ponds in a semi-arid region in the Eastern Cape (South Africa). African Journal of Aquatic Science 2021, 1 -12.

AMA Style

L Mofu, T Dalu, Rj Wasserman, Dj Woodford, D Khosa, Olf Weyl. Seasonal variation and drivers of zooplankton, macroinvertebrate and littoral fish communities from irrigation ponds in a semi-arid region in the Eastern Cape (South Africa). African Journal of Aquatic Science. 2021; ():1-12.

Chicago/Turabian Style

L Mofu; T Dalu; Rj Wasserman; Dj Woodford; D Khosa; Olf Weyl. 2021. "Seasonal variation and drivers of zooplankton, macroinvertebrate and littoral fish communities from irrigation ponds in a semi-arid region in the Eastern Cape (South Africa)." African Journal of Aquatic Science , no. : 1-12.

Journal article
Published: 21 May 2021 in Journal of Thermal Biology
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Large branchiopods are specialist crustaceans adapted for life in temporary, thermally dynamic wetland ecosystems. Certain large branchiopod species are, however, restricted to specific temporary wetland types, exemplified by their physico-chemical and hydroperiod characteristics. Here, we contrasted the thermal preference and critical thermal maxima (CTmax) and minima (CTmin) of southern African anostracans and spinicaudatans found exclusively in either temporary rock-pool or pan wetland types. We hypothesized that environment of origin would be a good predictor of thermal preference and critical thermal limits. To test this, Branchiopodopsis tridens (Anostraca) and Leptestheria brevirostris (Spinicaudata) were collected from rock-pool habitats, while Streptocephalus cafer (Anostraca) and a Gondwanalimnadia sp. (Spinicaudata) were collected from pan habitats. In contrast to our hypothesis, taxonomic relatedness was a better predictor of CTmax and temperature preference than environment of origin. Spinicaudatans were significantly more tolerant of high temperatures than anostracans, with L. brevirostris and Gondwanalimnadia sp. median CTmax values of 45.1 °C and 44.1 °C, respectively, followed by S. cafer (42.8 °C) and B. tridens (41.4 °C). Neither environment or taxonomic relatedness were good predictors of CTmin trends, with B. tridens (0.9 °C) and Gondwanalimnadia sp. (2.1 °C) having the lowest median CTmin values, followed by L. brevirostris (3.4 °C) and S. cafer (3.6 °C). On the contrary, temperature preferences differed according to taxa, with spinicaudatans significantly preferring higher temperatures than anostracans. Leptestheria brevirostris and Gondwanalimnadia sp. both spent most time at temperatures 30–32 °C, S. cafer at 18–20 °C and B. tridens at 21–23 °C. Constrained thermal traits reported here suggest that the studied anostracans might be more susceptible to projected climatic warming than the spinicaudatans, irrespective of habitat type, however, these taxa may also compensate through phenotypic plasticity.

ACS Style

Murphy Tladi; Ryan J. Wasserman; Ross N. Cuthbert; Tatenda Dalu; Casper Nyamukondiwa. Thermal limits and preferences of large branchiopods (Branchiopoda: Anostraca and Spinicaudata) from temporary wetland arid zone systems. Journal of Thermal Biology 2021, 99, 102997 .

AMA Style

Murphy Tladi, Ryan J. Wasserman, Ross N. Cuthbert, Tatenda Dalu, Casper Nyamukondiwa. Thermal limits and preferences of large branchiopods (Branchiopoda: Anostraca and Spinicaudata) from temporary wetland arid zone systems. Journal of Thermal Biology. 2021; 99 ():102997.

Chicago/Turabian Style

Murphy Tladi; Ryan J. Wasserman; Ross N. Cuthbert; Tatenda Dalu; Casper Nyamukondiwa. 2021. "Thermal limits and preferences of large branchiopods (Branchiopoda: Anostraca and Spinicaudata) from temporary wetland arid zone systems." Journal of Thermal Biology 99, no. : 102997.

Journal article
Published: 18 April 2021 in Ecological Indicators
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The poor understanding of changes in mollusc ecology along rivers, especially in West Africa, hampers the implementation of management measures. We used a self–organizing map, indicator species analysis, linear discriminant analysis and a random forest model to distinguish mollusc assemblages, to determine the ecological preferences of individual mollusc species and to associate major physicochemical variables with mollusc assemblages and occurrences in the Sô River Basin, Benin. We identified four mollusc assemblages along an upstream–downstream gradient. Dissolved oxygen (DO), biochemical oxygen demand (BOD), salinity, calcium (Ca), total nitrogen (TN), copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd) and mercury (Hg) were the major physicochemical variables responsible for structuring these mollusc assemblages. However, the physicochemical factors responsible for shaping the distribution of individual species varied per species. Upstream sites (assemblage I) showed high DO and low BOD and mineral compounds (i.e., TN, salinity, and Ca), which are primarily responsible for structuring the occurrences of bivalves (Afropisidium pirothi, Etheria elliptica, Sphaerium hartmanni) and the gastropod Lanistes varicus. Sites along the middle reach (assemblage II) were characterised by a high degree of organic pollution but low heavy metal pollution; we detected no specific mollusc indicator species. Downstream sites (assemblage III) displayed high mineral and heavy metal concentrations and a fauna without specific indicator species. Finally, downstream sites associated with brackish water (assemblage IV) displayed important levels of organic and heavy metal pollution. These sites are dominated by diverse gastropods (i.e., Bulinus spp., Gabbiella africana, Indoplanorbis exustus, Pachymelania fusca, Radix natalensis, Stenophysa marmorata and Tympanotonos fuscatus). Our results highlight that mollusc communities in the Sô River Basin are structured by key physicochemical variables related to the river–estuary continuum. Habitats that are progressively more downstream are confronted with increasing anthropogenic stress. Conservation and management plans should focus on downstream habitats.

ACS Style

Zinsou Cosme Koudenoukpo; Olaniran Hamed Odountan; Prudenciène Ablawa Agboho; Tatenda Dalu; Bert Van Bocxlaer; Luc Janssens de Bistoven; Antoine Chikou; Thierry Backeljau. Using self–organizing maps and machine learning models to assess mollusc community structure in relation to physicochemical variables in a West Africa river–estuary system. Ecological Indicators 2021, 126, 107706 .

AMA Style

Zinsou Cosme Koudenoukpo, Olaniran Hamed Odountan, Prudenciène Ablawa Agboho, Tatenda Dalu, Bert Van Bocxlaer, Luc Janssens de Bistoven, Antoine Chikou, Thierry Backeljau. Using self–organizing maps and machine learning models to assess mollusc community structure in relation to physicochemical variables in a West Africa river–estuary system. Ecological Indicators. 2021; 126 ():107706.

Chicago/Turabian Style

Zinsou Cosme Koudenoukpo; Olaniran Hamed Odountan; Prudenciène Ablawa Agboho; Tatenda Dalu; Bert Van Bocxlaer; Luc Janssens de Bistoven; Antoine Chikou; Thierry Backeljau. 2021. "Using self–organizing maps and machine learning models to assess mollusc community structure in relation to physicochemical variables in a West Africa river–estuary system." Ecological Indicators 126, no. : 107706.

Preprint content
Published: 15 April 2021
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Biological invasions are one of the top drivers of the ongoing biodiversity crisis. An underestimated consequence of invasions is the enormity of their economic impacts. Knowledge gaps regarding economic costs produced by invasive alien species (IAS) are pervasive, particularly for emerging economies such as India — the fastest growing economy worldwide. To bridge this gap, we synthesised data on economic costs of IAS in India. Specifically, we examine how IAS costs are distributed spatially, environmentally, sectorally, taxonomically, temporally and across introduction pathways; and discuss globally how IAS costs vary with socioeconomic indicators. We found that IAS have cost the Indian economy between at least US$ 127.3 billion to 182.6 billion (Indian Rupees ₹ 8.3 trillion to 11.9 trillion) over 1960–2020, and these costs have increased with time. Most recorded costs were not assigned to specific regions, environments, sectors, cost types and causal IAS. When costs were specifically assigned, maximum costs were incurred in west, south and north India, by invasive alien insects in semi-aquatic ecosystems, incurred mainly by the public and social welfare sector, and were associated with damages and losses rather than management expenses. Our findings indicate that the reported economic costs grossly underestimate the actual costs, especially when considering the expected costs given India's population size and gross domestic product (GDP). This cost analysis improves our knowledge of the negative economic impacts associated with biological invasions in India and the burden they can represent for its development. We hope that this study motivates policymakers to address socio-ecological issues, especially since economic growth will be accompanied by greater impacts of global change.

ACS Style

Alok Bang; Ross Cuthbert; Phillip Haubrock; Romina Fernandez; Desika Moodley; Christophe Diagne; Anna Turbelin; Achyut Kumar Banerjee; David Renault; Tatenda Dalu; Franck Courchamp. Fragmented yet high economic costs of biological invasions in India. 2021, 1 .

AMA Style

Alok Bang, Ross Cuthbert, Phillip Haubrock, Romina Fernandez, Desika Moodley, Christophe Diagne, Anna Turbelin, Achyut Kumar Banerjee, David Renault, Tatenda Dalu, Franck Courchamp. Fragmented yet high economic costs of biological invasions in India. . 2021; ():1.

Chicago/Turabian Style

Alok Bang; Ross Cuthbert; Phillip Haubrock; Romina Fernandez; Desika Moodley; Christophe Diagne; Anna Turbelin; Achyut Kumar Banerjee; David Renault; Tatenda Dalu; Franck Courchamp. 2021. "Fragmented yet high economic costs of biological invasions in India." , no. : 1.

Journal article
Published: 12 April 2021 in Sustainability
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With ~70% of the sub-Saharan population living in rural areas, more than 90% of rural African households depend on natural forest products. Although several studies in other parts of South Africa have looked into the use of natural forest products in poverty alleviation, little is known on the roles and relative contribution of natural forest products as daily and safety nets specifically within the Vhembe Biosphere Reserve, South Africa. This study assessed the different roles played by natural forest products in households and the patterns of their relative contribution to households both as sources of income and direct consumption within differing household compositions as well as socio-economic factors. These included employment and income diversification role and the monetised value of natural resources in the rural livelihoods of households in Sambandou and Mavunde, Vhembe Biosphere Reserve, Limpopo Province, South Africa. The study inter alia compared a wide use of natural resources by two villages and determined on which forest products they most relied for their economic welfare. Their relative contributions to livelihoods were assessed by identifying factors that affected their contributions. Findings of the study showed that Sambandou had a high number of people with formal jobs and females, and fewer old-age pensioners. Differences in employment and education between villages were observed. In all villages, the most frequently used or harvested resource was fuelwood, wild edible fruits, herbs, grass/shrub hand sweepers, insects for food, thatch grass/reeds and poles for fencing and housing. Overall, Mavunde village households were found to be more dependent on natural resource harvesting both for income and subsistence substitution. Findings suggest that this may have been a consequence of socio-economic factors such as income and employment, as well as general underdevelopment in the village. This study’s findings could contribute to further studies into how these results compare to other parts of the country and region, as well as their respective developmental implications.

ACS Style

Mwazvita Dalu; Ashley Gunter; Mulweli Makatu; Gregory Dowo; Farai Dondofema; Tatenda Dalu. Contribution of Natural Forest Products to Rural Livelihoods at Mavunde and Sambandou Villages, Vhembe Biosphere Reserve, South Africa. Sustainability 2021, 13, 4252 .

AMA Style

Mwazvita Dalu, Ashley Gunter, Mulweli Makatu, Gregory Dowo, Farai Dondofema, Tatenda Dalu. Contribution of Natural Forest Products to Rural Livelihoods at Mavunde and Sambandou Villages, Vhembe Biosphere Reserve, South Africa. Sustainability. 2021; 13 (8):4252.

Chicago/Turabian Style

Mwazvita Dalu; Ashley Gunter; Mulweli Makatu; Gregory Dowo; Farai Dondofema; Tatenda Dalu. 2021. "Contribution of Natural Forest Products to Rural Livelihoods at Mavunde and Sambandou Villages, Vhembe Biosphere Reserve, South Africa." Sustainability 13, no. 8: 4252.

Original research
Published: 30 March 2021 in Ecology and Evolution
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Predation is a critical ecological process that directly and indirectly mediates population stabilities, as well as ecosystem structure and function. The strength of interactions between predators and prey may be mediated by multiple density dependences concerning numbers of predators and prey. In temporary wetland ecosystems in particular, fluctuating water volumes may alter predation rates through differing search space and prey encounter rates. Using a functional response approach, we examined the influence of predator and prey densities on interaction strengths of the temporary pond specialist copepod Lovenula raynerae preying on cladoceran prey, Daphnia pulex, under contrasting water volumes. Further, using a population dynamic modeling approach, we quantified multiple predator effects across differences in prey density and water volume. Predators exhibited type II functional responses under both water volumes, with significant antagonistic multiple predator effects (i.e., antagonisms) exhibited overall. The strengths of antagonistic interactions were, however, enhanced under reduced water volumes and at intermediate prey densities. These findings indicate important biotic and abiotic contexts that mediate predator–prey dynamics, whereby multiple predator effects are contingent on both prey density and search area characteristics. In particular, reduced search areas (i.e., water volumes) under intermediate prey densities could enhance antagonisms by heightening predator–predator interference effects.

ACS Style

Ross N. Cuthbert; Tatenda Dalu; Ryan J. Wasserman; Arnaud Sentis; Olaf L. F. Weyl; P. William Froneman; Amanda Callaghan; Jaimie T. A. Dick. Prey and predator density‐dependent interactions under different water volumes. Ecology and Evolution 2021, 11, 6504 -6512.

AMA Style

Ross N. Cuthbert, Tatenda Dalu, Ryan J. Wasserman, Arnaud Sentis, Olaf L. F. Weyl, P. William Froneman, Amanda Callaghan, Jaimie T. A. Dick. Prey and predator density‐dependent interactions under different water volumes. Ecology and Evolution. 2021; 11 (11):6504-6512.

Chicago/Turabian Style

Ross N. Cuthbert; Tatenda Dalu; Ryan J. Wasserman; Arnaud Sentis; Olaf L. F. Weyl; P. William Froneman; Amanda Callaghan; Jaimie T. A. Dick. 2021. "Prey and predator density‐dependent interactions under different water volumes." Ecology and Evolution 11, no. 11: 6504-6512.

Journal article
Published: 09 March 2021 in Chemistry and Ecology
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Anthropogenic pressures on standing waterbody systems potentially result in changes to sediment and water qualities, and thus ecological community characteristics. We tested effects of drawdown on physical, water and sediment variables, as well as their effects on littoral macroinvertebrate community composition in two subtropical reservoirs. Water levels differed significantly between reservoirs and over time, with significant effects on several water chemistry parameters (e.g., pH, conductivity, Mg, Fe), whilst sediment properties were less affected. Significant effects of water level, site and macrophyte cover on macroinvertebrate community structures were not detected, however macroinvertebrate community structuring differed significantly over time. Redundancy analysis (RDA) highlighted that the first and second axes accounted for 45.6% of the total macroinvertebrate community and environmental variables relationship variance. Most of the sediment variables, such as Cu, Mg, Na and Pb and water chemistry (i.e., HCO3-), were positively associated with the first axis, while water temperature and pH were negatively associated with the first axis. The RDA variation partitioning showed that water and sediment chemistry variables accounted for 40.3% and 30.3%, respectively, of the total macroinvertebrate variation. The present study contributes to understandings of the interplays between water level, physico-chemical properties and community compositions in human-altered aquatic ecosystems.

ACS Style

Tatenda Dalu; Pretty Dlamini; Ryan J. Wasserman; Matjutla J. Mokgoebo; Thendo Mutshekwa; Farai Dondofema; Ross N. Cuthbert. Effects of environmental variables on littoral macroinvertebrate community assemblages in subtropical reservoirs. Chemistry and Ecology 2021, 37, 419 -436.

AMA Style

Tatenda Dalu, Pretty Dlamini, Ryan J. Wasserman, Matjutla J. Mokgoebo, Thendo Mutshekwa, Farai Dondofema, Ross N. Cuthbert. Effects of environmental variables on littoral macroinvertebrate community assemblages in subtropical reservoirs. Chemistry and Ecology. 2021; 37 (5):419-436.

Chicago/Turabian Style

Tatenda Dalu; Pretty Dlamini; Ryan J. Wasserman; Matjutla J. Mokgoebo; Thendo Mutshekwa; Farai Dondofema; Ross N. Cuthbert. 2021. "Effects of environmental variables on littoral macroinvertebrate community assemblages in subtropical reservoirs." Chemistry and Ecology 37, no. 5: 419-436.

Journal article
Published: 08 March 2021 in Environmental Science and Pollution Research
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Global freshwaters are increasingly threatened by pollutants emanating from human activities around watersheds. Microplastic pollution is an increasing problem for rivers worldwide, potentially threatening ecological integrity, ecosystem services and human health. We present quantifications and characterisations of sediment microplastic pollution in a subtropical river system in southern Africa, and relate distributions to wastewater treatment works, abiotic variables and urban environments. We additionally apply several diversity indices to decipher how microplastic types differ across the river system seasonally. Over two thousand microplastic particles were found across five sites and three seasons in the river system, comprising microbeads of various colours and microfibres. Microplastic concentrations were highest and most diverse in the hot–wet (mean range 76.0 ± 10.0–285.5 ± 44.5 microplastic kg−1) season as compared to the cool–dry (16.5 ± 4.5–27.0 ± 5.0 microplastic kg−1) and hot–dry (13.0 ± 4.0–29.0 ± 10.0 microplastic kg−1) seasons, and were mostly dominated by microfibres. However, no clear patterns were found in relation to wastewater treatment operations spatially, or in relation to abiotic variables in the river system. This study therefore finds a diverse range of microplastic types widely distributed in the river system that differ across seasons. Our results provide important, novel insights into plastic pollution in an understudied area of the Global South, and point to extensive pollution from sources outside of wastewater treatment works.

ACS Style

Tatenda Dalu; Thabiso Banda; Thendo Mutshekwa; Linton F. Munyai; Ross N. Cuthbert. Effects of urbanisation and a wastewater treatment plant on microplastic densities along a subtropical river system. Environmental Science and Pollution Research 2021, 28, 1 -10.

AMA Style

Tatenda Dalu, Thabiso Banda, Thendo Mutshekwa, Linton F. Munyai, Ross N. Cuthbert. Effects of urbanisation and a wastewater treatment plant on microplastic densities along a subtropical river system. Environmental Science and Pollution Research. 2021; 28 (27):1-10.

Chicago/Turabian Style

Tatenda Dalu; Thabiso Banda; Thendo Mutshekwa; Linton F. Munyai; Ross N. Cuthbert. 2021. "Effects of urbanisation and a wastewater treatment plant on microplastic densities along a subtropical river system." Environmental Science and Pollution Research 28, no. 27: 1-10.

Primary research paper
Published: 20 February 2021 in Hydrobiologia
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The physical properties of habitats are crucial determinants of community structure with significant effects on food web dynamics. We examined the effects of rock pool physical properties (e.g. pool size, water depth) and short-term temporal (seasonal) change (e.g. temperature, nutrients) on food web structure at small spatial scales (c. 500 m) on the warm temperate coast of South Africa. Using stable carbon and nitrogen isotope signatures, we characterised food web structure with Layman metrics and quantified food web size, defined as the total area in isotopic space occupied by consumer species. The effects of rock pool physical properties and seasonal changes on species counts and food web structure were evaluated using a Bayesian generalised linear mixed model approach. Substratum type, water depth, pool size, phosphate concentrations, salinity and temperature all influenced overall food web dynamics. A winter reduction of sand cover led to a more heterogeneous substratum and a significant increase in species counts, while consumer niche similarity decreased with increasing pool size in summer. The range of δ15N values, or trophic height, was negatively and positively affected by salinity and phosphate levels, respectively. Overall, the effects of pool physical properties on food web structure were moderated by seasonality.

ACS Style

Molline N. C. Gusha; Tatenda Dalu; Christopher D. McQuaid. Interaction between small-scale habitat properties and short-term temporal conditions on food web dynamics of a warm temperate intertidal rock pool ecosystem. Hydrobiologia 2021, 848, 1517 -1533.

AMA Style

Molline N. C. Gusha, Tatenda Dalu, Christopher D. McQuaid. Interaction between small-scale habitat properties and short-term temporal conditions on food web dynamics of a warm temperate intertidal rock pool ecosystem. Hydrobiologia. 2021; 848 (7):1517-1533.

Chicago/Turabian Style

Molline N. C. Gusha; Tatenda Dalu; Christopher D. McQuaid. 2021. "Interaction between small-scale habitat properties and short-term temporal conditions on food web dynamics of a warm temperate intertidal rock pool ecosystem." Hydrobiologia 848, no. 7: 1517-1533.

Short notes
Published: 17 February 2021 in Marine Biology
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Invasive alien species impacts might be mediated by environmental factors such as climatic warming. For invasive predators, multiple predator interactions could also exacerbate or dampen ecological impacts. These effects may be especially pronounced in highly diverse coastal ecosystems that are prone to profound and rapid regime shifts. We examine emergent effects of warming on the strength of intraspecific multiple predator effects from a highly successful invasive gammarid Gammarus tigrinus, using a functional response approach towards larval chironomids (feeding rates under different prey densities). Single predator maximum feeding rates were three-times higher at 24 °C compared to 18 °C overall, with potentially prey destabilising type II functional responses exhibited. However, pairs of gammarids exhibited intraspecific multiple predator effects that were in turn mediated by temperature regime, whereby synergisms were found at the lower temperature (i.e. positive non-trophic interactions) and antagonisms detected at the higher temperature (i.e. negative non-trophic interactions) under high prey densities. Accordingly, warming scenarios may worsen the impact of this invasive alien species, yet implications of temperature change are dependent on predator–predator interactions. Emergent effects between abiotic and biotic factors should be considered in ecological impact predictions across habitat types for invasive alien species.

ACS Style

Ross N. Cuthbert; Ryan J. Wasserman; Tatenda Dalu; Elizabeta Briski. Warming mediates intraspecific multiple predator effects from an invasive crustacean. Marine Biology 2021, 168, 1 -7.

AMA Style

Ross N. Cuthbert, Ryan J. Wasserman, Tatenda Dalu, Elizabeta Briski. Warming mediates intraspecific multiple predator effects from an invasive crustacean. Marine Biology. 2021; 168 (3):1-7.

Chicago/Turabian Style

Ross N. Cuthbert; Ryan J. Wasserman; Tatenda Dalu; Elizabeta Briski. 2021. "Warming mediates intraspecific multiple predator effects from an invasive crustacean." Marine Biology 168, no. 3: 1-7.

Mitogenome announcement
Published: 01 February 2021 in Mitochondrial DNA Part B
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Spinicaudatan clam shrimp are a widespread and diverse group of branchiopod crustaceans, yet few mitochondrial genomes have been published for this taxonomic group. Here, we present the mitogenome of Leptestheria brevirostris from a rock pool ecosystem in Botswana. Massively parallel sequencing of a single specimen facilitated the reconstruction of the species’ 15,579 bp circularized mitogenome. The reconstructed phylogenetic tree confirms that L. brevirostris forms a monophyletic group with other diplostracan branchiopods, and that these are the sister taxon to Notostraca. The mitogenome reconstructed here is the first to be reported from a leptestherid clam shrimp.

ACS Style

Arsalan Emami-Khoyi; Murphy Tladi; Tatenda Dalu; Peter R. Teske; Bettine Jansen van Vuuren; D. Christopher Rogers; Casper Nyamukondiwa; Ryan J. Wasserman. The complete mitogenome of Leptestheria brevirostris Barnard, 1924, a rock pool clam shrimp (Branchiopoda: Spinicaudata) from Central District, Botswana. Mitochondrial DNA Part B 2021, 6, 608 -610.

AMA Style

Arsalan Emami-Khoyi, Murphy Tladi, Tatenda Dalu, Peter R. Teske, Bettine Jansen van Vuuren, D. Christopher Rogers, Casper Nyamukondiwa, Ryan J. Wasserman. The complete mitogenome of Leptestheria brevirostris Barnard, 1924, a rock pool clam shrimp (Branchiopoda: Spinicaudata) from Central District, Botswana. Mitochondrial DNA Part B. 2021; 6 (2):608-610.

Chicago/Turabian Style

Arsalan Emami-Khoyi; Murphy Tladi; Tatenda Dalu; Peter R. Teske; Bettine Jansen van Vuuren; D. Christopher Rogers; Casper Nyamukondiwa; Ryan J. Wasserman. 2021. "The complete mitogenome of Leptestheria brevirostris Barnard, 1924, a rock pool clam shrimp (Branchiopoda: Spinicaudata) from Central District, Botswana." Mitochondrial DNA Part B 6, no. 2: 608-610.

Journal article
Published: 20 January 2021 in Science of The Total Environment
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Much research effort has been invested in understanding ecological impacts of invasive alien species (IAS) across ecosystems and taxonomic groups, but empirical studies about economic effects lack synthesis. Using a comprehensive global database, we determine patterns and trends in economic costs of aquatic IAS by examining: (i) the distribution of these costs across taxa, geographic regions and cost types; (ii) the temporal dynamics of global costs; and (iii) knowledge gaps, especially compared to terrestrial IAS. Based on the costs recorded from the existing literature, the global cost of aquatic IAS conservatively summed to US$345 billion, with the majority attributed to invertebrates (62%), followed by vertebrates (28%), then plants (6%). The largest costs were reported in North America (48%) and Asia (13%), and were principally a result of resource damages (74%); only 6% of recorded costs were from management. The magnitude and number of reported costs were highest in the United States of America and for semi-aquatic taxa. Many countries and known aquatic alien species had no reported costs, especially in Africa and Asia. Accordingly, a network analysis revealed limited connectivity among countries, indicating disparate cost reporting. Aquatic IAS costs have increased in recent decades by several orders of magnitude, reaching at least US$23 billion in 2020. Costs are likely considerably underrepresented compared to terrestrial IAS; only 5% of reported costs were from aquatic species, despite 26% of known invaders being aquatic. Additionally, only 1% of aquatic invasion costs were from marine species. Costs of aquatic IAS are thus substantial, but likely underreported. Costs have increased over time and are expected to continue rising with future invasions. We urge increased and improved cost reporting by managers, practitioners and researchers to reduce knowledge gaps. Few costs are proactive investments; increased management spending is urgently needed to prevent and limit current and future aquatic IAS damages.

ACS Style

Ross N. Cuthbert; Zarah Pattison; Nigel G. Taylor; Laura Verbrugge; Christophe Diagne; Danish A. Ahmed; Boris Leroy; Elena Angulo; Elizabeta Briski; César Capinha; Jane A. Catford; Tatenda Dalu; Franz Essl; Rodolphe E. Gozlan; Phillip J. Haubrock; Melina Kourantidou; Andrew M. Kramer; David Renault; Ryan J. Wasserman; Franck Courchamp. Global economic costs of aquatic invasive alien species. Science of The Total Environment 2021, 775, 145238 .

AMA Style

Ross N. Cuthbert, Zarah Pattison, Nigel G. Taylor, Laura Verbrugge, Christophe Diagne, Danish A. Ahmed, Boris Leroy, Elena Angulo, Elizabeta Briski, César Capinha, Jane A. Catford, Tatenda Dalu, Franz Essl, Rodolphe E. Gozlan, Phillip J. Haubrock, Melina Kourantidou, Andrew M. Kramer, David Renault, Ryan J. Wasserman, Franck Courchamp. Global economic costs of aquatic invasive alien species. Science of The Total Environment. 2021; 775 ():145238.

Chicago/Turabian Style

Ross N. Cuthbert; Zarah Pattison; Nigel G. Taylor; Laura Verbrugge; Christophe Diagne; Danish A. Ahmed; Boris Leroy; Elena Angulo; Elizabeta Briski; César Capinha; Jane A. Catford; Tatenda Dalu; Franz Essl; Rodolphe E. Gozlan; Phillip J. Haubrock; Melina Kourantidou; Andrew M. Kramer; David Renault; Ryan J. Wasserman; Franck Courchamp. 2021. "Global economic costs of aquatic invasive alien species." Science of The Total Environment 775, no. : 145238.

Original article
Published: 18 January 2021 in Lakes & Reservoirs: Research & Management
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The stratification of a lentic water system is an important factor regulating its biotic activities and processes. The present study investigated changes in temperature and oxygen stratification regimes in Mazvikadei Reservoir 27 years after the first study was conducted during its filling phase. The FLake‐Global model was also tested as a predictive tool for the first time to analyse annual limnological trends in a subtropical reservoir. The lake‐modelling tool FLake‐Global enables an instantaneous estimation of the seasonal cycle of temperature and mixing conditions in shallow freshwater lakes around the world. The results of the present study illustrate that the reservoir was weakly stratified, with the overall thermal stratification patterns somewhat similar to those recorded during the filling phase (1992). The oxygen stratification patterns observed in the present study correspond well to those of thermal stratification. The depth‐integrated oxygen profiles for both the deep and shallow sampling sites exhibited the same pattern, with higher concentrations from July to September. The water column was well oxygenated, indicating the reservoir has matured since its filling phase in 1992, when there was significant hypolimnetic deoxygenation. The FLake‐Global model exhibited good results in predicting annual trends, with the results also indicating no differences in stratification levels in the reservoir for the current and Masundire (1992) filling phase studies. The model predicted lower surface and bottom temperatures, however, compared to those measured in the reservoir. There was lowering of the mixed layer depth from the hot‐wet (November–April) months through the cool‐dry (May–August) season. Latent heat fluxes agreed with the net longwave (LW) predictions for Mazvikadei Reservoir, which exhibited an overall net cooling effect. The stratification has not changed significantly since the previous study in 1988. The FLake‐Global model proved a useful predictive tool when tested in a subtropical system.

ACS Style

Tamuka Nhiwatiwa; Chipo Mungenge; Lindah Mhlanga; Tatenda Dalu. Stratification regimes and thermodynamic modelling of a subtropical African reservoir. Lakes & Reservoirs: Research & Management 2021, 1 .

AMA Style

Tamuka Nhiwatiwa, Chipo Mungenge, Lindah Mhlanga, Tatenda Dalu. Stratification regimes and thermodynamic modelling of a subtropical African reservoir. Lakes & Reservoirs: Research & Management. 2021; ():1.

Chicago/Turabian Style

Tamuka Nhiwatiwa; Chipo Mungenge; Lindah Mhlanga; Tatenda Dalu. 2021. "Stratification regimes and thermodynamic modelling of a subtropical African reservoir." Lakes & Reservoirs: Research & Management , no. : 1.

Magazine
Published: 04 December 2020 in Fisheries
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Olaf LF Weyl, 48, Chief Scientist at the South African Institute for Aquatic Biodiversity (SAIAB) passed away on the Wolf River in Hogsback, South Africa on 14 November. Born in Giessen, Germany, Olaf was raised in southern Africa, where his parents served as development workers. Driven by a passion for fishes and tireless work ethic, Olaf devoted his career towards understanding freshwater ecosystems across southern Africa and became a global authority in fish conservation, biology, and ecology, as well as fisheries and invasion biology.

ACS Style

John S. Hargrove; Micheal S. Allen; Ryan J. Wasserman; Darragh J. Woodford; Bruce R. Ellender; Tatenda Dalu. In Memoriam. Fisheries 2020, 46, 47 -47.

AMA Style

John S. Hargrove, Micheal S. Allen, Ryan J. Wasserman, Darragh J. Woodford, Bruce R. Ellender, Tatenda Dalu. In Memoriam. Fisheries. 2020; 46 (1):47-47.

Chicago/Turabian Style

John S. Hargrove; Micheal S. Allen; Ryan J. Wasserman; Darragh J. Woodford; Bruce R. Ellender; Tatenda Dalu. 2020. "In Memoriam." Fisheries 46, no. 1: 47-47.

Journal article
Published: 01 December 2020 in Parasites & Vectors
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Background Predators play a critical role in regulating larval mosquito prey populations in aquatic habitats. Understanding predator-prey responses to climate change-induced environmental perturbations may foster optimal efficacy in vector reduction. However, organisms may differentially respond to heterogeneous thermal environments, potentially destabilizing predator-prey trophic systems. Methods Here, we explored the critical thermal limits of activity (CTLs; critical thermal-maxima [CTmax] and minima [CTmin]) of key predator-prey species. We concurrently examined CTL asynchrony of two notonectid predators (Anisops sardea and Enithares chinai) and one copepod predator (Lovenula falcifera) as well as larvae of three vector mosquito species, Aedes aegypti, Anopheles quadriannulatus and Culex pipiens, across instar stages (early, 1st; intermediate, 2nd/3rd; late, 4th). Results Overall, predators and prey differed significantly in CTmax and CTmin. Predators generally had lower CTLs than mosquito prey, dependent on prey instar stage and species, with first instars having the lowest CTmax (lowest warm tolerance), but also the lowest CTmin (highest cold tolerance). For predators, L. falcifera exhibited the narrowest CTLs overall, with E. chinai having the widest and A. sardea intermediate CTLs, respectively. Among prey species, the global invader Ae. aegypti consistently exhibited the highest CTmax, whilst differences among CTmin were inconsistent among prey species according to instar stage. Conclusion These results point to significant predator-prey mismatches under environmental change, potentially adversely affecting natural mosquito biocontrol given projected shifts in temperature fluctuations in the study region. The overall narrower thermal breadth of native predators relative to larval mosquito prey may reduce natural biotic resistance to pests and harmful mosquito species, with implications for population success and potentially vector capacity under global change.

ACS Style

Mmabaledi Buxton; Casper Nyamukondiwa; Tatenda Dalu; Ross N. Cuthbert; Ryan J. Wasserman. Implications of increasing temperature stress for predatory biocontrol of vector mosquitoes. Parasites & Vectors 2020, 13, 1 -11.

AMA Style

Mmabaledi Buxton, Casper Nyamukondiwa, Tatenda Dalu, Ross N. Cuthbert, Ryan J. Wasserman. Implications of increasing temperature stress for predatory biocontrol of vector mosquitoes. Parasites & Vectors. 2020; 13 (1):1-11.

Chicago/Turabian Style

Mmabaledi Buxton; Casper Nyamukondiwa; Tatenda Dalu; Ross N. Cuthbert; Ryan J. Wasserman. 2020. "Implications of increasing temperature stress for predatory biocontrol of vector mosquitoes." Parasites & Vectors 13, no. 1: 1-11.

Review
Published: 24 November 2020 in Journal of Crustacean Biology
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We review the current knowledge surrounding the Triops granarius morphological species group globally, and present a revision of the southern African T. granarius forms based on collections from southern Africa and Madagascar. We also provide comparisons with other material of T. granarius from outside this region. We revise the morphological descriptions of T. numidicus (Grube, 1865) and T. namaquensis (Richters, 1886) using modern standards, and resurrect T. sakalavus Nobili, 1905 from synonymy, using both morphological and molecular techniques. Morphological definitions focus primarily on the form of the apical portion of the thoracopod II endite. Differential diagnoses are presented for the three species, including characters that separate them from the other members with similar morphology. Furthermore, we treat T. dybowskii (Braem, 1893), T. orientalis (Tiwari, 1951), and T. mavliensis (Tiwari, 1951), which had been recently resurrected, as species inquirenda.

ACS Style

D Christopher Rogers; Martin Schwentner; Tatenda Dalu; Ryan J Wasserman. A review of Triops granarius (Lucas, 1864) sensu lato (Notostraca: Triopsidae) of southern Africa and Madagascar, with comments on the group. Journal of Crustacean Biology 2020, 41, 1 .

AMA Style

D Christopher Rogers, Martin Schwentner, Tatenda Dalu, Ryan J Wasserman. A review of Triops granarius (Lucas, 1864) sensu lato (Notostraca: Triopsidae) of southern Africa and Madagascar, with comments on the group. Journal of Crustacean Biology. 2020; 41 (1):1.

Chicago/Turabian Style

D Christopher Rogers; Martin Schwentner; Tatenda Dalu; Ryan J Wasserman. 2020. "A review of Triops granarius (Lucas, 1864) sensu lato (Notostraca: Triopsidae) of southern Africa and Madagascar, with comments on the group." Journal of Crustacean Biology 41, no. 1: 1.

Journal article
Published: 20 November 2020 in African Journal of Aquatic Science
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South Africa is in the process of developing a National Freshwater (Inland) Wild Capture Fisheries Policy. A properly focused research strategy is essential to guide the policy development process, and thus a dedicated ‘Inland Fisheries’ workshop was convened by the South African Society for Aquatic Scientists in June 2018 to update and further develop a list of priority knowledge requirements for inland fisheries in the country. The main themes that emerged during the workshop were developed and contextualised as ten research questions. These were: (1) What is the exploitation potential of inland fisheries? (2) What are the health risks from consuming freshwater fishes? (3) Who currently uses inland fisheries and what are their harvests? (4) What can we learn from historical constraints to inland fisheries development? (5) How will governance of fisheries have to change in an evolving sectoral environment? (6) What are the options for fisheries enhancement? (7) What are the most appropriate fisheries technologies? (8) What value chains and employment opportunities are associated with inland fisheries? (9) What is the impact of water level fluctuations on fish production? (10) What are the impacts of pathogenic diseases on fish populations?

ACS Style

Olf Weyl; L Barkhuizen; K Christison; T Dalu; Ha Hlungwani; D Impson; K Sankar; Ne Mandrak; Sm Marr; Jr Sara; Nj Smit; D Tweddle; Ng Vine; V Wepener; M Zvavahera; Ig Cowx. Ten research questions to support South Africa’s Inland Fisheries Policy. African Journal of Aquatic Science 2020, 46, 1 -10.

AMA Style

Olf Weyl, L Barkhuizen, K Christison, T Dalu, Ha Hlungwani, D Impson, K Sankar, Ne Mandrak, Sm Marr, Jr Sara, Nj Smit, D Tweddle, Ng Vine, V Wepener, M Zvavahera, Ig Cowx. Ten research questions to support South Africa’s Inland Fisheries Policy. African Journal of Aquatic Science. 2020; 46 (1):1-10.

Chicago/Turabian Style

Olf Weyl; L Barkhuizen; K Christison; T Dalu; Ha Hlungwani; D Impson; K Sankar; Ne Mandrak; Sm Marr; Jr Sara; Nj Smit; D Tweddle; Ng Vine; V Wepener; M Zvavahera; Ig Cowx. 2020. "Ten research questions to support South Africa’s Inland Fisheries Policy." African Journal of Aquatic Science 46, no. 1: 1-10.

Dissertation
Published: 29 October 2020
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Mwazvita Tapiwa Beatrice Dalu. Unpacking the link between adaptive capacity, assets and responses of rural livelihoods facing multiple stressors in the Eastern Cape. 2020, 1 .

AMA Style

Mwazvita Tapiwa Beatrice Dalu. Unpacking the link between adaptive capacity, assets and responses of rural livelihoods facing multiple stressors in the Eastern Cape. . 2020; ():1.

Chicago/Turabian Style

Mwazvita Tapiwa Beatrice Dalu. 2020. "Unpacking the link between adaptive capacity, assets and responses of rural livelihoods facing multiple stressors in the Eastern Cape." , no. : 1.

Journal article
Published: 29 October 2020 in Scientific African
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Increased fishing pressure from artisanal and recreational fishing has led to the collapse of some important fish stocks around the world over the past years. There is currently limited understanding of the impacts of recreational and artisanal fishing on tigerfish Hydrocynus vittatus populations in Lake Kariba and the socioeconomic factors behind them. Hence, this study investigated socioeconomic factors that act as drivers of the recreational and artisanal fishery industry and what sort of impact this would likely have on tigerfish H. vittatus populations using qualitative approaches. Eight three percent of the artisanal fishers interviewed recorded high catches during the summer season (October–February), which also coincides with the breeding season for tigerfish when it migrates up the rivers. Recreational anglers mainly caught females during the tigerfish tournament which is likely to have a significant effect on the tigerfish population in the long term through changes in tigerfish recruitment and other life history traits. Tigerfish size at sexual maturity and catch per unit effort which are all indicators of overexploitation were found to have decreased over the past years. Results further demonstrated increased fishing activities from artisanal and recreational fishing. It can be implied that the population of tigerfish may inadvertently be affected, but direct evidence that both recreational and artisanal fishing were having impacts on tigerfish populations was limited. It is therefore recommended that effective conservation measures such as preventing fish poaching during the tigerfish breeding season are put in place to protect the population and that of other fishes (i.e. potential prey).

ACS Style

Terence Magqina; Tamuka Nhiwatiwa; Mwazvita T.B. Dalu; Lindah Mhlanga; Tatenda Dalu. Challenges and possible impacts of artisanal and recreational fisheries on tigerfish Hydrocynus vittatus Castelnau 1861 populations in Lake Kariba, Zimbabwe. Scientific African 2020, 10, e00613 .

AMA Style

Terence Magqina, Tamuka Nhiwatiwa, Mwazvita T.B. Dalu, Lindah Mhlanga, Tatenda Dalu. Challenges and possible impacts of artisanal and recreational fisheries on tigerfish Hydrocynus vittatus Castelnau 1861 populations in Lake Kariba, Zimbabwe. Scientific African. 2020; 10 ():e00613.

Chicago/Turabian Style

Terence Magqina; Tamuka Nhiwatiwa; Mwazvita T.B. Dalu; Lindah Mhlanga; Tatenda Dalu. 2020. "Challenges and possible impacts of artisanal and recreational fisheries on tigerfish Hydrocynus vittatus Castelnau 1861 populations in Lake Kariba, Zimbabwe." Scientific African 10, no. : e00613.

Journal article
Published: 09 October 2020 in Inland Waters
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Ryan J. Wasserman; Sia Sanga; Mmabaledi Buxton; Tatenda Dalu; Ross N. Cuthbert. Does invasive river red gum (Eucalyptus camaldulensis) alter leaf litter decomposition dynamics in arid zone temporary rivers? Inland Waters 2020, 11, 104 -113.

AMA Style

Ryan J. Wasserman, Sia Sanga, Mmabaledi Buxton, Tatenda Dalu, Ross N. Cuthbert. Does invasive river red gum (Eucalyptus camaldulensis) alter leaf litter decomposition dynamics in arid zone temporary rivers? Inland Waters. 2020; 11 (1):104-113.

Chicago/Turabian Style

Ryan J. Wasserman; Sia Sanga; Mmabaledi Buxton; Tatenda Dalu; Ross N. Cuthbert. 2020. "Does invasive river red gum (Eucalyptus camaldulensis) alter leaf litter decomposition dynamics in arid zone temporary rivers?" Inland Waters 11, no. 1: 104-113.