The next day we did another CTD cast during high tide and the oxygen situation improved significantly – the oxygen saturation dropped to 85-95%, back to the level for the 7th August CTD cast. The Chlorophyll a concentration level also dropped to 7-14ug/L.
The change in the oxygen regime was reflected in the presence of a two-layer stratification with a thermocline at a depth of 1.5 m, apparently “fresh” water mass came with a flood and NW wind, pushing more water into the harbour from the Gulf of St.Lawrence. Yesterday we had SW wind, which blew from the land, preventing the renewal of water in the harbour.

CTD cast at high tide and NW wind

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