Cormorant

Phalacrocorax carbo (probably) phalacrocorax lucidus (unlikely)

Great Cormorant

https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/cormorant/

"A large, black, and conspicuous waterbird, the cormorant has an almost primitive appearance with its long neck making it appear reptilian. It is often seen standing with its wings held out to dry. Regarded by some as sinister and greedy, cormorants are supreme fishers which can bring them into conflict with anglers, thus causing them to be persecuted in the past. The UK holds internationally significant wintering numbers."

White breasted? The cormorant at Charlotte's Pool has a significant white breast but I think that this is because is it is a juvenile rather than a white breasted cormorant whose normal distribution is in southern Africa.

Birdforum information about cormorants and sub-species