Dataset on macroinvertebrates occurrence across different stretches of an urban Palmiet River in Durban, South Africa
Three hypotheses were tested: 1. Macroinvertebrate communities would exhibit spatial variation along the longitudinal gradient of the Palmiet River, with a site within an industrial area showing lower taxa richness and abundance. 2. Macroinvertebrates assemblage would be strongly associated with the physical habitat and water quality. 3. The presence of anthropogenic solid waste materials would increase the abundance of some macroinvertebrates. Sampling was conducted seasonally from March 2017 (Autumn) to January-February 2018 (Summer). Water was collected using acid-treated water sampling bottles and kept in a cooler box with ice. Habitat assessment was carried out following McMillan (1998) protocol where habitats were given scores based on their conditions (Appendix 1). Macroinvertebrates were sampled following Dickens and Graham (2002) protocol where vegetation, stones, and gravel sand and mud biotopes were sampled. Samplings were carried out at six sites along the longitudinal gradient of an Urban Palmiet River, at the headwaters (Site 6), industrial area (Site 5), few kilometeres downstream industrial area (Site 4), before Palmiet Nature Reserve (Site 3), in the Palmiet Nature Reserve (Site 2), and few kilometers downstream Palmiet Nature Reserve, within the University of KwaZulu-Natal (Site 1). These data show variation on macroinvertebrates assemblage across 6 sites and the site 5 which was hypertrophic has shown low taxa richness and abundance. Sensitive taxa were recorded at Site 6. Generally, these data show a clear association between macroinvertebrates assemblage, water quality and physical habitat condition. Moreover, anthropogenic litter showed to provide habitat for some taxa.
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This data was collected at 6 sites along the longitudinal gradient of an urban river. The sites were at the headwaters (Site 6), industrial area (Site 5), few kilometeres downstream industrial area (Site 4), before Palmiet Nature Reserve (Site 3), in the Palmiet Nature Reserve (Site 2), and few kilometers downstream Palmiet Nature Reserve, within the University of KwaZulu-Natal (Site 1). Water samples were collected using acid-treated water bottles and kept in a cooler box with ice. Habitat assessment was carried following McMillan (1998) protocol where habitat scores were assigned based on the physical condition as well as water quality and quantity (Appendix 1). Macroinvertebrates were collected following a protocol adapted Dickens and Graham (2002). Three habitats, stones, vegetations, and gravel, sand and mud (GSM). Macroinvertebrates were collected using a deep net. For stone biotope, the bottom substrate was disturbed for about 3 minutes and a net was placed about 1.5m downstream of the disturbed place. Some stones were picked up and scrapped for those inhabiting underneath. For GSM biotope, the net was placed about a meter downstream of the disturbed place to allow sand to sink before it gets into the net. For vegetation biotope, the net was pushed repeatedly against the vegetation for approximately 2 meters to dislodge the attached organisms and this continued for about 3 minutes. Organisms from all stone biotopes were combined and treated as one entity, stone biotope, whereas those from marginal and aquatic vegetations were also combined and treated as vegetation biotope, and same thing happened for the GSM biotope. An illustration guide and a field guide by Gerber and Gabriel (2002a,b) were used for the identification of macroinvertebrates to family levels. A magnifying glass was used in the field. Some macroinvertebrates were preserved in 70% alcohol for quality control in the lab.