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    Zandvlei: Lower Estuary (34071828)

    Western Cape
    Card 510049
    Compiler 10691
    Location code 34071828Zandvlei: Lower Estuary (Western Cape)
    Start date 2023-04-15
    Season OOther
    Start time 08:45
    End time 11:45
    Shoreline covered 90
    Openwater covered 95
    Total Species 23
    Total Count 542
    Wetland Condition 3Very little standing water (low tide for estuaries
    Wetland Threats 0
    Count Condition 4Good
    Count Type 5Mixed
    Nil Count (No birds present) 0There were CWAC species present
    Notes "There were very few birds on the main waterbody today. Something we noticed with the water level so low was the growth of black mussels along the western concrete wall or revetment. This indicates that the salinity has been kept very high for an extended time for these mussels to establish and flourish (see the photos). These mussels extend from the estuary mouth concrete walls and the rubble weir all the way to the yacht basin. Speculation is the mussels are establishing themselves onto the Marina canals revetments as well as the Caravan Park and Park Island revetments on the eastern side of the main waterbody. 10 years ago they were not in evidence, so it is a short term management intervention result in keeping the salinity levels of the estuary very high. Another indicator is the new range of the sand prawn holes which were exposed due to the low water level. The sandy bottom of the estuary between the Royal Road Bridge and the 2nd bend was exposed with two shallow streams towards the mouth. The estuary mouth was mechanically closed, and when done, it must have been at a low tide. There has not been any rainfall run off from the catchment in the last week. A Purple Heron flew out of the reeds and landed nearby on the sand spit, when we were counting all the gulls on at ""the cookie cutter"" (the old radio controlled sailing yacht basin) near Thesens bridge. Kyran (Reserve Manager)used the inflatable motor boat (it is very quiet) to count the southern Marina canals. Park Island and the Caravan Park were counted as well. "
    Survey notes


    Add additional observers
    Observer NumberNameOptions
    0Barbara Currin
     
    0C A Wright
     
    0Gigi Laidler
     
    0Josred Vaughen
     
    0Kyran Wright
     
    0Linda Hibbin
     
    0Marian Hoole
     

    Current data
    Ref #SpeciesCountBreeding
    Pairs    		Breeding
    indicator
    4Grebe, Great Crested
    (Podiceps cristatus)    		30
    47Cormorant, White-breasted
    (Phalacrocorax lucidus)    		30
    48Cormorant, Cape
    (Phalacrocorax capensis)    		40
    50Cormorant, Reed
    (Microcarbo africanus)    		570
    52Darter, African
    (Anhinga rufa)    		480
    57Heron, Purple
    (Ardea purpurea)    		10
    59Egret, Little
    (Egretta garzetta)    		70
    69Night Heron, Black-crowned
    (Nycticorax nycticorax)    		20
    81Ibis, African Sacred
    (Threskiornis aethiopicus)    		220
    84Ibis, Hadada
    (Bostrychia hagedash)    		70
    85Spoonbill, African
    (Platalea alba)    		130
    89Goose, Egyptian
    (Alopochen aegyptiaca)    		1130
    96Duck, Yellow-billed
    (Anas undulata)    		160
    212Coot, Red-knobbed
    (Fulica cristata)    		680
    245Lapwing, Blacksmith
    (Vanellus armatus)    		50
    274Thick-knee, Water
    (Burhinus vermiculatus)    		20
    287Gull, Kelp
    (Larus dominicanus)    		1310
    289Gull, Hartlaub's
    (Chroicocephalus hartlaubii)    		30
    290Tern, Caspian
    (Hydroprogne caspia)    		20
    394Kingfisher, Pied
    (Ceryle rudis)    		70
    686Wagtail, Cape
    (Motacilla capensis)    		100
    1016, Mallard
    (Anas platyrhynchos)    		110
    10015Mallard, Hybrid
    (Anas hybrid)    		70


    FITZ logo Ramsar Wetlands International http://www.sanbi.org/

    Thursday 21 November 2024 06:30
    FitzPatrick Institute of African Ornithology
    Department of Biological Sciences - University of Cape Town

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