These data include carbonate chemistry, nutrient concentration, and dissolved oxygen concentration for discreet water samples collected within Galveston Bay, TX. Eight single day cruises were conducted quarterly aboard the R/V Lithos or R/V Trident from June 2017 through September 2018. In addition, discreet water samples were collected at sites 10 - 60 km outside the mouth of the bay and up to 15m deep to characterize incoming seawater to the bay. These samples were collected on three cruises (WTX1 - R/V Manta, WTX3 - R/V Manta, WTX4 - R/V Pelican) in June, August, and November 2017. Discreet water samples were collected for total alkalinity and dissolved inorganic carbon, dissolved oxygen, and dissolved nutrients. CTD profiles were collected at each sampling site. Stochastic coastal acidification events in response to high volume rainfall and runoff that often accompanies tropical cyclone events has the potential to represent a significant threat to valuable calcifying reef ecosystems. Understanding acidification response and recovery to such events is critical to improving conservation and protection of coastal ecosystems, like oyster and coral reefs, particularly as climate change continues and tropical cyclone rainfall intensity increases. These data assess the impact of the rainfall and runoff from Hurricane Harvey on the acidification levels in Galveston Bay, TX. Samples were collected and analyzed primarily by Tacey Hicks, with assistance from other students in Dr. Katie Shamberger ’s research group, at Texas A&M University.

Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

Methods & Sampling:

Samples were collected at 14 different sites quarterly from June 2017 through September 2018 in Galveston Bay and at 10 sites along the Texas coast in the Gulf of Mexico in June, August, and November of 2017 to investigate changes in water chemistry following Hurricane Harvey.

For cruises in Galveston Bay, discrete water samples were collected with a Niskin (General Oceanics) bottle at the surface (0.5 m) and ~1.2 m off the bottom. Samples collected for carbonate chemistry analysis (TA/DIC) were transferred from the Niskin to 250 mL narrow-mouth borosilicate glass bottles using a 0.2 mm polypropylene Whatman Polycap 36 Tissue Culture Grade (TC) in-line filter for total alkalinity (TA) and dissolved inorganic carbon (DIC) analysis, leaving approximately 5 mL headspace for thermal expansion. Some samples in September and November 2017 were collected using 0.2 mm Whatman Polycap 36 Aqueous Solution (AS) filters. However, no significant difference was found in the carbonate chemistry analysis for samples using either filter, therefore no distinction is made. Conductivity, temperature, and depth (CTD, SonTek Castaway™) profiles were conducted concurrently with Niskin samples at each station. Discrete water samples for TA/DIC on WTX cruises (WTX1/WTX2/WTX4) were collected using Niskin bottles (6L/6L/10L) on a Seabird CTD rosette. Carbonate chemistry water samples (TA/DIC) were collected similar to those from Galveston Bay, but no in-line filter was used. All TA/DIC samples was poisoned with 100 mL saturated mercuric chloride solution immediately after collection to inhibit biological activity, and then sealed with silicone-free type L Apiezon grease and ground glass stoppers with rubber bands and plastic clamps. TA and DIC were analyzed simultaneously on a Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity (VINDTA) 3C in Dr. Kathryn Shamberger’s lab at Texas A&M University. The VINDTA uses coulometric titration for DIC analysis and an open cell potentiometric titration for TA analysis. Dissolved inorganic nutrient samples from all fieldwork operations were transferred from the Niskins to a a polycarbonate flask using a GF/C 0.2 micron filter, frozen, and analyzed by the Geophysical Environmental Research Group at Texas A&M University on an Astoria Analyzer.

Cruises:

Galveston Bay Cruises: 8 single-day trips on R/V Lithos or R/V Trident; conducted quarterly in Galveston Bay, TX June 2017 - September 2018. (Cruise IDs: GB0617, GB0917, GB1117, GB0318, GB0618, GB0918).

Gulf of Mexico Research cruises: aboard R/V Manta and R/V Pelican (see "Deployments" section for multi-day cruise details,  Cruise IDs: WTX1, WTX2, WTX4).

Instruments:

Galveston Bay: 

• 5L General Oceanics Niskin bottles: Dissolved seawater samples collected using 2 individual 5L General Oceanics Niskin bottles
• Sontek Castaway: CTD profiles were recorded at each site in Galveston Bay at the time of Niskin deployment using a Sontek Castaway. Data processed using Sontek processing software.

WTX 1 and 2: 

• 6 x 5L Niskin rosette: dissolved seawater samples collected using a 6-bottle rosette equipped with 6 5L-Niskin bottles and Sea-Bird SBE 25 CTD.

WTX 4: 

• 12 x 10L Niskin rosette: dissolved seawater samples collected using 12-bottle rosette equipped with 12 10L-Niskin bottles and Sea-Bird SBE 911 CTD.
   

MARIANDA VINDTA 3C

Funding note:
See "Awards" section for details of NSF-OCE funding (OCE-1760381; OCE-1800913). Additional funding from TAMU T3 Triad Grant; Texas A&M University Department of Oceanography; Texas Governor’s Fund through Texas OneGulf Center of Excellence; Texas Commission on Environmental Quality.

DIC and TA measurements were calibrated using certified reference materials (CRMs) obtained from Dr. Andrew Dickson at Scripps Institute of Oceanography (Dickson et al., 2007). 

BCO-DMO Data Manager Processing Notes:
* Sheet "Data" from Galveston_CarbonateChemistry.xlsx imported into BCO-DMO data system.
* Renamed columns to meet BCO-DMO naming conventions (to support broader interoperability, see Data Processing Conventions https://www.bco-dmo.org/page/bco-dmo-data-processing-conventions)
* Added ISO 8601 formatted datetime with timezone (UTC)

Data version 2 replaces data version 1:
* replaced outlier lat,lons with values provided by the data submitter :

original file lines 47,48  (29.45,-140.62)  corrected to (29.45, -94.78)

original file lines55,56 (60.52,-94.88)  corrected to (29.53, -94.88)

Coverage: Gulf Mexico, Louisiana and Texas coast

In late August 2017, Category 4 Hurricane Harvey made landfall on Coastal Texas, 2017 and stalled bringing 125 cm of rain to Southeastern Texas over a five-day period resulting in catastrophic flooding along most of the Gulf coast of Texas as well as the metropolitan Houston area and 18 surrounding counties. Dams and reservoirs filled and even on September 1st ? 3rd releases from these dams continued to flood the area releasing even more water. Approximately 11 trillion gallons were estimated to have fallen and eventually this freshwater will be released onto the broad Texas continental shelf. In the US alone there has never been so much fresh water impacting a coastal area other than the discharge of the Mississippi River, which divides between the Atchafalaya River and the Birdfoot Delta to the east and injects freshwater into a much narrower shelf and into much deeper water in the north-central Gulf. The main hypothesis of the Rapid response project is that freshwater from Hurricane Harvey has 1) reduced coastal water quality by increasing stratification, and thereby inhibiting ventilation of atmospheric oxygen to sub-surface waters and 2) increased respiration by transporting nutrients from terrestrially derived sources leading to increased biomass and microbial activity. Secondly, the ocean heat content of the Texas Bight region contributed to the intensification of Hurricane Harvey by supplying thermal heat to the storm as it passed from the deep Gulf of Mexico to the shelf region. This project will provide critical information on how freshwater runoff from hurricane Harvey is impacting the stratification, oxygen, nutrient budgets of the coastal waters and whether this could lead to hypoxia and other long-term ecological impacts along the Texas shelf. The data will be made available rapidly to other researchers, students and the public.

This project aims to answer two questions of importance which could not be answered without a major flood. Is the freshwater from Hurricane Harvey reducing coastal water quality by increasing stratification, thereby inhibiting ventilation of atmospheric oxygen to subpycnocline water and is it increasing respiration by transporting nutrients from terrestrially derived sources leading to increased biomass and microbial activity? The project will also seek to determine if the ocean heat content of the Texas Bight region contributed to the intensification of Hurricane Harvey by supplying thermal heat to the storm as it passed from the deep Gulf of Mexico to the shelf region. This Rapid response project will conduct two research cruises on the R/V Pelican, one in late September and one in mid-November to quantify the effects and potential impacts of the freshwater run-off from Hurricane Harvey along the southern coast of Texas. In addition to the two cruises using a suite of oceanographic physio-chemical measurements, an autonomous Wave Glider will sample a grid to follow the freshwater plume and a buoyancy-controlled ocean glider will determine the depth and characteristics of the freshwater intrusion and its evolution between cruises and after data from two cruises in June and August 2017 prior to Hurricane Harvey. The research cruises will use existing offshore observing systems, i.e., the Texas Automated Buoy System, the Texas HF Radar network, and the Texas A&M University buoyancy-controlled glider program, to integrate the observations into a comprehensive picture of how the coastal region responded to the impulsive freshwater resulting from the unprecedented terrestrial flooding event in southeastern Texas.