It's a river dolphin. The water is probably dark with tannins.https://en.m.wikipedia.org/wiki/River_dolphin
Sure, but it's an article in a British paper and you're referencing an American dictionary. Brits can use it for the nefarious connotation, but they very commonly use it to mean an officially organized plan / program.https://dictionary.cambridge.org/dictionary/english/scheme
It's a river dolphin. The water is probably dark with tannins.
https://en.m.wikipedia.org/wiki/River_dolphin