https://commons.ufh.ac.za/vital/access/manager/Index en-us 5 https://commons.ufh.ac.za/vital/access/manager/Repository/vital:50006 Wed 21 Sep 2022 19:03:08 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:50129 Mon 10 Oct 2022 08:54:24 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:49988 20 μg Chl-a l-1) that result in instances of bottom water oxygen depletion (< 4 mg/l). During the present study in the Sundays Estuary, low oxygen waters were recorded in the middle reaches (Site S5) mostly during summer (four months of low DO conditions). In the Swartkops Estuary, low dissolved oxygen was recorded in the upper reaches during spring. The lowest dissolved oxygen concentration recorded was 0.5 mg/l and 2.4 mg/l in the bottom waters of the Sundays and Swartkops estuaries, respectively. Selected dominant species were only absent from areas where dissolved oxygen was < 1 mg/l and present in the adjacent sites (for example Site S4, and S3) where DO was higher mostly during January 2019. As such, the low dissolved oxygen concentrations recorded in the Swartkops Estuary did not have a noticeable impact on fish distribution, although the total abundance of species did show a slight decline when dissolved oxygen was < 3 mg/l. This study demonstrates the importance of concurrently examining estuarine and nearshore marine habitats in order to identify ecologically important habitats, which has important implications for the development of effective management strategies for coastal fish populations, particularly in the light of anthropogenic change. In addition, in order to identify nursery hotspots it is crucial to correctly identify all the species occupying these areas. As such, this study confirms the importance of also using DNA barcoding for fish identification, particularly for the early life history stages of cryptic species (e.g. Argyrosomus inodorus and Argyrosomus japonicus).]]> Mon 10 Oct 2022 08:22:49 SAST ]]>