The fresh water will float on top. The exposure of rock to weathering and the release of glacial sediments will produce a major algal bloom that could augment the Atlantic’s carrying capacity significantly. I can’t see anything but good from that.
Plus, Iceland’s a third world leftwing hellhole which happens to have a decent level of income/dole — so who cares what they say or think about anything. ❄
MBARI gave John an office 3 doors from mine:
https://mlml.sjsu.edu/2020/06/18/30-years-the-iron-hypothesis-is-no-more/