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The improved representation of freshwater and estuarine ecosystems and associated data was a key component of the 2018 National Biodiversity Assessment, and is an essential step in enhancing defensible land use planning and decision making. This paper reports on the enhancement of the National Wetland Map (NWM) version 5 for South Africa and other data layers associated with the South African Inventory of Inland Aquatic Ecosystems. Detail is provided on (i) the extent of wetlands mapped in NWM5, compared to previous versions of the NWMs; (ii) the improved extent of inland wetlands mapped in focus areas in NWM5 relative to NWM4; (iii) the type of cover associated with the wetlands (inundated, vegetated or arid); (iv) the ecotone between rivers and estuaries; and (v) level of confidence for the inland wetlands in terms of how well the extent and hydrogeomorphic units were captured for each sub-quaternary catchment of South Africa. A total of 4 596 509 ha (3.8% of South Africa) of inland aquatic ecosystems and artificial wetlands have now been mapped, with NWM5 delineating 23% more inland wetlands (2 650 509 ha or 2.2% of SA) compared with NWM4. The estuarine functional zone, which encapsulates all estuarine processes, and associated habitats and biota, was refined for 290 systems totalling 200 739 ha, with the addition of 42 micro-estuaries totalling 340 ha. Nearly 600 000 ha (0.5% of SA) of artificial wetlands were mapped in SA. Inland wetlands are predominantly palustrine (55%), with some arid (34%) and a few inundated systems (11%). Ecotones between rivers and estuaries, ecotones where biota and processes continuously vary from freshwater to estuarine, formed a small fraction (<1.5%) of river total extent (164 018 km). Most inland wetlands (~70%) had a low confidence ranking for designation of extent and typing, because they were not mapped by a wetland specialist and not verified in the field. Future improvements of the map should be focused on catchment-based improvements, particularly in strategic water-source areas, areas of high development pressure and those with low confidence designation.

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There remains considerable debate over the impact of predation upon Atlantic salmon, Salmo salar L., populations. The pattern and prevalence of predator damage on salmon returning to a river system in North-east Scotland were recorded. Overall, 214 (19.5%) out of 1099 fish sampled were damaged, and 10 distinct categories of damage were identified. Measurements of scratches indicated that the damage was caused by a number of different factors. In particular, damage typically attributed to seals was suggested to be the result of attacks by odontocete cetaceans. These results highlight the multispecies nature of interactions between salmon and their predators, but suggest that damage levels may be of limited use in assessing the impact of different predators on salmonid population dynamics. K E Y w 0 R DS : Atlantic salmon, dolphins, management, predators, S a h o salur L., seals. ; R u x y P.A. I tWh) C'omparative distnbution. movements and diet of harbour and grey s u l r fmm the h t m y Firth. NE Scoiland. o w tl-hl.. tlunmond P S & hlackay A. (1997) Estimnting harbour seal abundance and status in an estuannc hahitrt in norrhea Scotland Journal o/ Applrd Ecolngv 34, 43-52. Witkinson L.. Hill h1.-A.. Wclna J.P. & Birkenbcuel G.K. (19921 S Y S T A T lor Il'rndnnr Stutrtrrcc. li.nrron 5. Evanston, IL: SYSTAT, inc.. 750 pp Wilson B.. Thompson P.M. & tlammond P S . (1997) tlabitat u s e by bottlenose dolphins, vawnrl distnbution and stratified movement patterm in thc h f m y Firth. Scnrland Jnurnol to/ App'plrc-cl Ecnlngv 34. 1365-1 374.