Happy New Year!
Through mid-December river flow continued to be very low. The high salinity record (11.9) that was set at station 0 (Streets Ferry Bridge) in late November was smashed by a 13.4 reading at the bottom on 14 December. The rest of the estuary was really salty too with bottom waters at the mouth near 25. The upper estuary was strongly stratified based on salinity. In the upper estuary (stations 0-30) bottom waters were 3-4 degrees C warmer than surface waters and dissolved oxygen was lowest (~ 4 mg/L) in these warmer, isolated bottom waters. For the rest of the estuary, dissolved oxygen was 8 mg/L or more. Chlorophyll was 10 ug/L or less except near the surface at station 50 where chlorophyll was ~25 ug/L. Microscopic examination revealed the peak in phytoplankton biomass at this station was due to a combination of small cryptophytes and the cool-weather dinoflagellate, Heterocapsa rotundata. These phytoplankton haven’t been associated with fish kills or toxin production. We finally got some rain associated with the strong cold front before Christmas. I imagine that the high salinity upstream of New Bern has probably been pushed downstream. I think we’ll find out next week if the weather cooperates.
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