Category: ModMon Neuse (page 1 of 2)

Neuse River Update

Hi all,
The estuary is extremely well stratified from New Bern to the mouth. The salinity difference is the major driver of the stratification, but a temperature difference of ~4 degrees C is playing an unusually strong role in reinforcing the stratification. Bottom waters were hypoxic from New Bern to the mouth. There were no reports of rotten egg smell from the bottom waters. So the bottom waters were probably hypoxic rather than anoxic. A zone of high surface chlorophyll occurred from New Bern (station 30) to where the estuary widens at stations 60 and 70. From there downstream there was also a subsurface chlorophyll maximum along the pycnocline. I haven’t looked to see what was blooming.
Nathan

Neuse River Update

Hi all,
The estuary looks almost exactly like it did two weeks ago. The upper region above New Bern is very turbid as flows are still much higher than normal for this time of year.  Surface waters are basically fresh to near the bend at Cherry Branch. The tip of the salt wedge is at station 50 just downstream of the HWY 17 bridge and the estuary is highly stratified ,and bottom waters were hypoxic from station 50 to the mouth. A broad zone of elevated chlorophyll a occurred from stations 100 to 160. Depth-wise the high phytoplankton biomass was maximum at about 1 m depth. This vertical patchiness is a tell-tale sign that the phytoplankton producing the peak is likely a flagellate seeking optimum light levels for photosynthesis. Our surface sample is collected at 0.2 m and missed the peak. I suspect it’s probably still an ongoing bloom of Gyrodinium instriatum.
Best regards,
Nathan

Neuse River Forecast

Midsummer Neuse River Forecast Shows Greater Potential for Fish Kills

Neuse Update

Hi all,
The estuary continues to freshen with the 2020 spring deluge. Surface water salinity at station 140 near Oriental is only about 5. The tip of the salt wedge is still just below New Bern at station 50, and the estuary is highly stratified from there to the mouth. Bottom waters were hypoxic from station 50 to 140. A broad surface bloom extended from station 60 to 120. This is likely the same dinoflagellate bloom of Gyrodinium instriatum from two weeks ago. I’ll take a look when I’m in the lab next and will post a correction with the next report if I’m wrong. With the rain still falling, the estuary will likely stay very fresh, and the hypoxic zone may expand without some serious wind mixing.
Best regards,
Nathan

Neuse River Update- An early start to hurricane season with Tropical Storms Arthur and Bertha

Hi all,
The estuary is fresher now due to all the rain from Arthur and Bertha but the tip of the salt wedge still extends almost to New Bern. A strong pycnocline occurred at about 4 m depth at stations upstream of station 120 and at about 5 m at the lower stations. Bottom waters were hypoxic (< 2 mg/L) at station 50 -120, and were <4 mg/L at the lower stations. There was a zone of high surface chlorophyll from stations 70 to 120. Microscopic examination of station 120 surface water where chlorophyll was greatest showed that the bloom was dominated by the dinoflagellate, Gyrodinium instriatum (more correctly known as Lavanderina fissa). This dinoflagellate is our most common summer-time bloom former in the Neuse and is not known to produce toxins. The other phytoplankton in the sample were a mix of cryptophytes, small diatoms, and smaller dinoflagellates.
Nathan

Neuse River Update

Hi all,
Since I’ve last reported on conditions in the Neuse River Estuary our world has changed a lot more than it has. Nothing exceptional to report water quality-wise. The high chl-a at stations 120 and 140 during March were likely remnants of the dinoflagellate bloom noticed in February. I’ll find out once I’m able to get back to the lab. Y’all stay safe and well.
Best,
Nathan

ModMon Neuse River Estuary Conditions

Hi all,
That line of strong storms with torrential rains on Feb 6 and 7th has increased Neuse River flows to about five times their average for this time of year. The turbid (>20 NTU) flood waters are clearly evident upstream of New Bern (stations 0-30).  Downstream of New Bern, the estuary was highly stratified. Waters are quite warm for this time of year and bottom water DO was well below saturation from station 50 to 100. A near surface zone of elevated chl-a (~30 ug/L) occurred at station 160.
Best regards,
Nathan

IMS scientists, give close-up look at Neuse River research

Faculty members from UNC-Chapel Hill got a first-hand look at the work done by the school’s Institute for Marine Sciences (IMS) in Morehead City during a tour of the Neuse River Thursday.

Dr. Nathan Hall demonstrates monitoring water quality on the Neuse River

Click the link below to read the full article!

https://www.newbernsj.com/news/20191017/ims-scientists-give-close-up-look-at-neuse-river-research?fbclid=IwAR3PdRwz9FELR7GFcMwekhrH59T-KlZCOT3MTt0T8Zo0ADlJI7bA6eQofiI

Hans and The Conversation

Click the link below to find out what The Conversation is about

More frequent and intense tropical storms mean less recovery time for the world’s coastlines

What happening on the Neuse?

Hi all,
Catching up again. Attached are the three figures showing conditions from mid-July to the end of August. Up until the last Neuse run conditions were typical for summertime under low/moderate flows. Salinity was 5ish around New Bern and 15-20ish at the mouth. Stratification was strong and bottom water hypoxia was present throughout much of the estuary. Conditions looked very different on 27 Aug following three days of brisk NE winds and cooler temperatures associated with an offshore subtropical low. Waters throughout the estuary were mixed up and cooled significantly. A small pocket of warm, hypoxic bottom water remained in the upstream area around New Bern that was sheltered from the NE winds (my guess). There were no significant bloom events.
Best,
Nathan
« Older posts

© 2020 The Paerl Lab

Theme by Anders NorenUp ↑