Category: ModMon Neuse (page 1 of 2)

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

What’s Happening in the Neuse!

Hi all,

I’m a little behind but here are the results from the last Neuse run on 9 July. It’s crazy how things have changed since spring when the estuary was basically a river. Salinities in the bottom waters of the lower estuary are as high as I remember seeing. The only other time that bottom waters at 180 have been this high was on 5 Oct 2002. Neuse river flows do not indicate that we are in as significant of a drought as in 2002. So, I think something on the ocean-side of the estuary might be playing a role in the high salinities and plan to see what our physical oceanographers think. The estuary was strongly stratified from New Bern to the mouth. Bottom waters were anoxic along much of the transect as evidenced by a strong sulfide smell. The crew will be out again next week.

Best,

Nathan

What’s Happening on the Neuse 2019Jun17

Hi all,

Salinity in the lower estuary is average for this time of year but the upstream section is a little fresher than normal. The basin saw quite a bit of rain in the second week of June and river flows are about four times higher than the seasonal average.  The salt wedge penetrated upstream to station 50 just downstream of the HWY 17 bridge. Bottom water dissolved oxygen was low from the tip of the salt wedge through the length of the estuary but was only below 2 mg/L (acutely lethal to fish) at stations 50-70. A subsurface peak in chlorophyll a at about 1 meter depth occurred from stations 60 -100. Microscopic examination of the surface water sample from station 60S revealed high concentrations of the dinoflagellate, Gyrodinium instriatum. This dinoflagellate is a common bloom former during the warmer months in the Neuse and is not known to produce toxins or negative food web related impacts.  Photosynthesis produced a zone of supersaturated dissolved oxygen at the stations with high chlorophyll. pH data are not shown due to probe failure.

Best,    Nathan

Scientists predict fewer stresses on Neuse Ecosystem | Public Radio East

Less Stress for The Neuse River

 

What’s Happening on the Neuse 2019June04

Hi all,

For two and a half decades, ModMon has provided valuable information on water quality and habitat conditions in the Neuse River Estuary and Pamlico Sound. These data are crucial for evaluating how conditions are changing in response to human and climatic pressures. ModMon has also served as a platform to support research projects aimed at figuring out how estuaries work from ecological, geological, physical, and biogeochemical perspectives.

Conditions on 4 June 2019 were pretty typical for this time of year. Salinities ranged from zero above New Bern to a maximum of about 15 in the bottom waters near the mouth.  Stratification was not particularly intense except at station 160 which was influenced by saltier bottom water likely from the Intracoastal Waterway. Hypoxic conditions occurred throughout most of the length of the estuary but were confined to a thin, ~1 m thick, layer near the bottom. A zone of high DO, high pH, and high chlorophyll a was observed at station 30 near New Bern. Microscopic examination of surface waters from station 30 revealed a high concentration of cryptophytes that are generally good food for higher trophic levels, and don’t cause problems.

Best,

Nathan

 

What’s Happening on the Neuse 2019May21

Hi all,

A couple of weeks without rain and the estuary is looking almost normal. The salt wedge is at New Bern and surface water salinity near the mouth was about 10. Most of the estuary was strongly stratified and bottom waters were hypoxic from stations 60 to 160. There was a peak in DO at station 50 that was likely due to high phytoplankton production. Microscopic observation of the station 50 surface sample showed a high concentration of small (3-5 um) centric diatoms. Chlorophyll data are not shown due to a failed probe. During the previous trip on 7 May, the chlorophyll probe of the YSI data sonde started to malfunction but the malfunction was not noticed until this trip on 21 May 2019. The bloom level chlorophyll a concentrations observed at station 50 on 7 were an artifact of this malfunction. The probe has been replaced and in vivo chlorophyll a data from both dates have been flagged in the data set.

A fish kill was observed a few days following this trip on 21 May, but no dead fish were noticed during a boat run from New Bern to station 100 on yesterday, 28 May. Based on the reports that I saw, the dead fish were mostly menhaden and had sores consistent with ulcerative mycosis caused by Aphanomyces invadans. This fungus is most virulent when salinities are low and temperatures are in the low to mid 20’s C; conditions observed during the fish kill. Fish that are already stressed, e.g. due to hypoxia, are more likely to suffer from the infection. I’ve attached a couple good papers for those interested.

Best,

Nathan

 

Kiryu et al. 2002-induction of menhaden ulcers by exposure

Oidtmann 2011-review of A invandans

What’s Happening in the Neuse 2019May07

Hi all,

The Neuse is an estuary again, a strongly salinity, stratified estuary with hypoxic bottom waters. The hypoxic zone stretched from just downstream of New Bern to the mouth. A zone of high chlorophyll with a subsurface maximum at ~1 m depth was detected from stations 20 to 70. Microscopic examination of surface waters from station 50 revealed a community dominated by freshwater diatoms, primarily Aulacoseira.

Until the next trip,

Nathan

What’s Happening in the Neuse River 2019Apr16?

Hi all,

Not much has changed on the Neuse. It’s still much fresher than normal. There is a small bolus of high salinity bottom water at station 160, but that’s likely intruding from the intercoastal waterway. High chlorophyll (~30 ug/L) and turbidity  occurred near the surface at station 100, and microscopy identified high concentrations of the diatom Aulacoseira sp., and a high concentrations of several cryptophyte species. These phytoplankton are non-toxic and considered “good” phytoplankton that tend to contribute energy to higher trophic levels.

Best regards,

Nathan  Hall

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