| Contributors | Affiliation | Role |
|---|---|---|
| Villareal, Tracy A. | University of Texas at Austin (UT Austin) | Principal Investigator, Contact |
| Gegg, Stephen R. | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
CTD Data with Chemical and Biological Discrete Samples
Biological survey of phytoplankton in the northern Gulf of Mexico
Comments on parameter names, definitions and units:
Depth (m)
Salinity: practical salinity units
Fluorescence: ~micrograms per liter. Calibrated by the ship's technician
PE (phycoerthrin): micrograms per L. Not considered reliable, provided by the ship
CDOM: mg per meter cubed. Provided by ship, not considered reliable.
Oxygen: ship's sensor, ml or mg per L. calibrated by Technician.
Beam attenuation: ship's equipment
Chlorophyll: micrograms per liter
Nutrient concentrations: micromoles per liter
cell counts: cells per liter for all but Trichodesmium
Trichodesmium: filaments per liter
Nutrients: run fresh, unfiltered on a Seal QuAAtro nutrient analyzer. Standards were made daily in artificial seawater, baseline was artificial seawater. Samples were corrected for residual contamination in the baseline. Values are the mean of two samples (±10%). Level of detection is -0.1 µM N and P. Si is 0.5µM.
chl: filtered onto either 0.4 or 10 µm pore size polycarbonate filters, extracted in MeOH overnight in the freezer and then run on a Turner TD-700 with the Welschmeyer (1994) non-acidification filters. The instrument was calibrated prior to each batch with a solid standard calibrated against pure chlorophyll a. Results are the average of two duplicates, variation is ±10%.
Cell counts: preserved in 1% hexamine buffered formalin. 25-50 ml of sample was settled overnight in a Utermohl settling chamber and then counted on a Zeiss ICM-405 inverted microscope. A single sample from each depth was counted.
Related files and references:
Welschmeyer NA (1994) Fluorometric analysis of chlorophyll a in the presence of chlorophyll b and pheopigments. Limnology and Oceanography 39: 1985-1992.
Knapke, E. (2012) Influence of Mississippi River Plume on Distributions of Diazotrophs in the Northern Gulf of Mexico During Summer 201. M.S., University of Texas at Austin. http://hdl.handle.net/2152/ETD-UT-2012-08-6107
CTD raw data was processed on board ship using the standard Seabird package.
BCO-DMO Processing/Edits
- Generated from file: "GoM2011_Master_ch0711.xlsx" contributed by Tracy Villareal
- Parameter names modified to conform to BCO-DMO conventions (blanks to underscores, etc.)
- "nd" (no data) inserted in black cells
| File |
|---|
CTD_Bot_Chem_Bio.csv (Comma Separated Values (.csv), 7.93 MB) MD5:59edd5782e4472096375cdb25492bd0b Primary data file for dataset ID 3805 |
| Parameter | Description | Units |
| CruiseId | Cruise Id | text |
| Station | Station Id | integer |
| Latitude | Station Latitude (South is negative) | decimal degrees |
| Longitude | Station Longitude (West is negative) | decimal degrees |
| Type | Station Type | text |
| Date | Date | YYYYMMDD |
| Depth | Depth | m |
| Temp | Temp | Degrees Celsius |
| Salinity | Salinity | psu |
| Density | Density | Kg/m^3 |
| Fluorescence | Fluorescence | micrograms per liter |
| CDOM | CDOM | mg/m^3 |
| PE | Phycoerthrin | micrograms per L |
| Oxygen_Saturation | Oxygen Saturation | ml/l |
| Oxygen | Oxygen | mg/l |
| Pressure | Pressure | db |
| Beam_Attenuation | Beam Attenuation | 1/m |
| Trichodesmium_Colonies_per_L | Trichodesmium Colonies (L-1) | L-1 |
| NO3_to_NO2 | NO3/NO2 | umol L-1 |
| PO4 | PO4 | umol L-1 |
| SiO2 | SiO2 | umol L-1 |
| NH4plus | NH4+ | umol L-1 |
| Total_chl | Total chl | µg per L |
| gt_10_um_chl | >10 um chl | µg per L |
| percent_Chl_above_10 | % Chl above 10 | percentage |
| Prochlorococcus | Prochlorococcus | cells/mL |
| Synechococcus | Synechococcus | cells/mL |
| PicoEukaryotes | PicoEukaryotes | cells/mL |
| Trichodesmium_Colonies_per_M | Trichodesmium Colonies (m-2) | m-2 |
| Acantharian | Acantharian | L-1 |
| Asterolampra | Asterolampra | L-1 |
| Asteromphalus | Asteromphalus | L-1 |
| Bacteriastrum | Bacteriastrum | L-1 |
| Cerataulina_pelagica | Cerataulina pelagica | L-1 |
| Ceratium_Gr_1 | Ceratium Gr. 1 | L-1 |
| Ceratium_Gr_2 | Ceratium Gr. 2 | L-1 |
| Ceratium_Gr_3 | Ceratium Gr. 3 | L-1 |
| Ceratium_praelongum | Ceratium praelongum | L-1 |
| Ceratium_spp_Total | Ceratium spp. Total | L-1 |
| Ceratocorys | Ceratocorys | L-1 |
| Chaetoceros | Chaetoceros | L-1 |
| Chaetoceros_messanensis | Chaetoceros messanensis | L-1 |
| Chaetoceros_peruvianus | Chaetoceros peruvianus | L-1 |
| Chaetoceros_spp_Total | Chaetoceros spp. Total | L-1 |
| Coscinodiscus | Coscinodiscus | L-1 |
| Cylindrotheca | Cylindrotheca | L-1 |
| Dictyocha | Dictyocha | L-1 |
| Dinophysis_caudata | Dinophysis caudata | L-1 |
| Dinophysis_Gr_1 | Dinophysis Gr. 1 | L-1 |
| Dinophysis_Gr_2 | Dinophysis Gr. 2 | L-1 |
| Dinophysis_schuettii | Dinophysis schuettii | L-1 |
| Dinophysis_spp_Total | Dinophysis spp. Total | L-1 |
| Foraminifera | Foraminifera | L-1 |
| Glossleriella | Glossleriella | L-1 |
| Gonyaulax | Gonyaulax | L-1 |
| Guinardia | Guinardia | L-1 |
| Guinardia_delicatula | Guinardia delicatula | L-1 |
| Guinardia_striata | Guinardia striata | L-1 |
| Guinardia_spp_Total | Guinardia spp. Total | L-1 |
| Hemiaulus_hauckii | Hemiaulus hauckii | L-1 |
| Hemiaulus_membranaceous | Hemiaulus membranaceous | L-1 |
| Hemiaulus_sinensis | Hemiaulus sinensis | L-1 |
| Hemiaulus_spp_per_L | Hemiaulus spp. (L-1) | L-1 |
| Odontella | Odontella | L-1 |
| Ornithocercus | Ornithocercus | L-1 |
| Pennate | Pennate | L-1 |
| Phalacroma | Phalacroma | L-1 |
| Planktoniella_sol | Planktoniella sol | L-1 |
| Pleurosigma | Pleurosigma | L-1 |
| Podolampas | Podolampas | L-1 |
| Proboscia_alata | Proboscia alata | L-1 |
| Prorocentrum | Prorocentrum | L-1 |
| Protoperidinium | Protoperidinium | L-1 |
| Pseudo_nitzchia | Pseudo nitzchia | L-1 |
| Pseudosolenia | Pseudosolenia | L-1 |
| Pyrophacus | Pyrophacus | L-1 |
| Radiolarian | Radiolarian | L-1 |
| Rhizosolenia | Rhizosolenia | L-1 |
| Rhizosolenia_plus_Symbiont_per_L | Rhizosolenia + Symbiont (L-1) | L-1 |
| Rhizosolenia_spp_Total | Rhizosolenia spp. Total | L-1 |
| Silicoflagellate | Silicoflagellate | L-1 |
| Thalassionema | Thalassionema | L-1 |
| Thalassionema_nitzschioides | Thalassionema nitzschioides | L-1 |
| Thalassionema_spp_Total | Thalassionema spp. Total | L-1 |
| Tintinnid | Tintinnid | L-1 |
| Trichodesmium_Filaments_per_L | Trichodesmium Filaments (L-1) | L-1 |
| Unknown_1 | Unknown 1 | L-1 |
| Unknown_2 | Unknown 2 | L-1 |
| Unknown_3 | Unknown 3 | L-1 |
| Unknown_4 | Unknown 4 | L-1 |
| Vorticella | Vorticella | L-1 |
| DDAs_per_L | DDAs (L-1) | L-1 |
| DDAs_per_M | DDAs ( m-2) | m-2 |
| Trichodesmium_Filaments_per_M | Trichodesmium Filaments (m-2) | m-2 |
| Rhizosolenia_plus_Symbiont_per_M | Rhizosolenia + Symbiont (m-2) | m-2 |
| Hemiaulus_spp_per_M | Hemiaulus spp. (m-2) | m-2 |
| Dataset-specific Instrument Name | CTD Sea-Bird |
| Generic Instrument Name | CTD Sea-Bird |
| Dataset-specific Description | R/V Cape Hatteras Research Instrumentation and Technical Support |
| Generic Instrument Description | Conductivity, Temperature, Depth (CTD) sensor package from SeaBird Electronics, no specific unit identified. This instrument designation is used when specific make and model are not known. See also other SeaBird instruments listed under CTD. More information from Sea-Bird Electronics. |
| Dataset-specific Instrument Name | Turner TD-700 |
| Generic Instrument Name | Fluorometer |
| Dataset-specific Description | Turner TD-700 |
| Generic Instrument Description | A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. The instrument is designed to measure the amount of stimulated electromagnetic radiation produced by pulses of electromagnetic radiation emitted into a water sample or in situ. |
| Dataset-specific Instrument Name | Zeiss ICM-405 inverted microscope |
| Generic Instrument Name | Inverted Microscope |
| Dataset-specific Description | Zeiss ICM-405 inverted microscope |
| Generic Instrument Description | An inverted microscope is a microscope with its light source and condenser on the top, above the stage pointing down, while the objectives and turret are below the stage pointing up. It was invented in 1850 by J. Lawrence Smith, a faculty member of Tulane University (then named the Medical College of Louisiana).
Inverted microscopes are useful for observing living cells or organisms at the bottom of a large container (e.g. a tissue culture flask) under more natural conditions than on a glass slide, as is the case with a conventional microscope. Inverted microscopes are also used in micromanipulation applications where space above the specimen is required for manipulator mechanisms and the microtools they hold, and in metallurgical applications where polished samples can be placed on top of the stage and viewed from underneath using reflecting objectives.
The stage on an inverted microscope is usually fixed, and focus is adjusted by moving the objective lens along a vertical axis to bring it closer to or further from the specimen. The focus mechanism typically has a dual concentric knob for coarse and fine adjustment. Depending on the size of the microscope, four to six objective lenses of different magnifications may be fitted to a rotating turret known as a nosepiece. These microscopes may also be fitted with accessories for fitting still and video cameras, fluorescence illumination, confocal scanning and many other applications. |
| Dataset-specific Instrument Name | Niskin bottle |
| Generic Instrument Name | Niskin bottle |
| Dataset-specific Description | R/V Cape Hatteras Research Instrumentation and Technical Support |
| Generic Instrument Description | A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc. |
| Dataset-specific Instrument Name | Seal QuAAtro nutrient analyzer |
| Generic Instrument Name | Nutrient Autoanalyzer |
| Dataset-specific Description | Seal QuAAtro nutrient analyzer |
| Generic Instrument Description | Nutrient Autoanalyzer is a generic term used when specific type, make and model were not specified. In general, a Nutrient Autoanalyzer is an automated flow-thru system for doing nutrient analysis (nitrate, ammonium, orthophosphate, and silicate) on seawater samples. |
| Website | |
| Platform | R/V Cape Hatteras |
| Start Date | 2011-07-04 |
| End Date | 2011-07-29 |
| Description | This cruise was funded by NSF OCE-0928495. Cruise information and original data are available from the NSF R2R data catalog. The science plan called for sampling in the Gulf of Mexico during the summer, when large populations of N2-fixing organisms are known to be present and the Mississippi plume tends to extend the furthest offshore. The cruise plans included stable isotope (15N, 13C) tracer experiments; one meter MOCNESS tows for zooplankton sampling; and plans to sample Trichodesmium and large diatoms using SCUBA gear. |
From the NSF proposal abstract
This project will study the interplay of physical, chemical, and biological factors in supplying nitrogen, an essential nutrient, to temperate coastal and offshore waters of the Gulf of Mexico. The Gulf is an economically important but understudied marginal sea with major commercial and recreational fisheries as well as extensive fossil fuel deposits. Diazotrophic (N2-fixing) cyanobacteria bloom regularly in offshore and coastal waters of the Gulf and the limited data suggest that they contribute significant quantities of both nitrogen and carbon to the pelagic food web. These diazotrophs may play also a critical role in supplying N to other organisms, including the ichthyotoxic red tide dinoflagellate Karenia brevis. Despite its importance, little is currently known of the factors that promote N2-fixation in the Gulf or the relative significance of different physical and biological processes in creating conditions that favor N limitation in the water column. The Gulf of Mexico is strongly influenced by both riverine inputs and advective processes, providing an excellent model system for studying nutrient dynamics, physical forcing of productivity, terrestrial-oceanic linkages, and the potential impact of land use and climate change on marine ecosystems.
The relatively small basin of the Gulf of Mexico provides an opportunity to quantify and study interactions among physical, chemical, and biological processes relevant to a broad range of other coastal and oceanic systems. Land-use and climate change are likely to affect the circulation and hydrography of the Gulf, as well as the magnitude and nature of riverine inputs, all with uncertain impacts on the biogeochemistry of the Gulf of Mexico. This research will provide timely insights into these processes and will generate a baseline of understanding for evaluating and predicting the impact of future land use and climate changes in the system. This project will make an important contribution to our understanding of the factors that regulate N2-fixation and its role in supporting the biota in temperate waters. The following specific goals are included in the work:
1. Identify the major diazotroph groups in the Gulf of Mexico and characterize their distribution and activity in different regions and water masses.
2. Quantify the impact of advective processes, mesoscale features, and riverine inputs on nutrient limitation and N2-fixation in the Gulf, and evaluate the controls on N2-fixation and the degree of spatial and temporal niche differentiation among diazotroph assemblages in different regions affected by these processes.
3. Use satellite data and physical models to scale up our measurements spatially and to evaluate the regional significance of N2-fixation in the Gulf of Mexico. The researchers will also use a coupled physical/biological model to explore variability in the physical forcing and the potential impact of likely land use and climate change scenarios in altering nutrient dynamics and N2-fixation in the Gulf of Mexico.
The investigators and their institutions have a strong commitment to undergraduate and graduate education. This project includes support for graduate students, a technician, and undergraduates. In addition to peer-reviewed papers and websites, workshops aimed at K-12 teachers, and a program involving high school teachers in research will be used to disseminate the results of this project broadly in the local community. The investigators are committed to increasing the diversity of the ocean science community and are active in recruiting and training efforts at their institutions.
GOM - Broader Impacts
The need to understand the impact of this largest oil spill to date on ecosystems and biochemical cycling is self evident. The consequences of the disaster and accompanying clean up measures (e.g. the distribution of dispersants) need to be evaluated to guide further mediating measures and to develop and improve responses to similar disasters in the future. Would it be advantageous if such oil aggregates sink, or should it rather remain suspended? Possibly measures can be developed to enhance sinking or suspension (e.g. addition of ballast minerals) once we understand their current formation and fate. Understanding the particle dynamics following the input of large amounts of oil and dispersants into the water is a prerequisite to develop response strategies for now and in the future.
The Ocean Carbon and Biogeochemistry (OCB) program focuses on the ocean's role as a component of the global Earth system, bringing together research in geochemistry, ocean physics, and ecology that inform on and advance our understanding of ocean biogeochemistry. The overall program goals are to promote, plan, and coordinate collaborative, multidisciplinary research opportunities within the U.S. research community and with international partners. Important OCB-related activities currently include: the Ocean Carbon and Climate Change (OCCC) and the North American Carbon Program (NACP); U.S. contributions to IMBER, SOLAS, CARBOOCEAN; and numerous U.S. single-investigator and medium-size research projects funded by U.S. federal agencies including NASA, NOAA, and NSF.
The scientific mission of OCB is to study the evolving role of the ocean in the global carbon cycle, in the face of environmental variability and change through studies of marine biogeochemical cycles and associated ecosystems.
The overarching OCB science themes include improved understanding and prediction of: 1) oceanic uptake and release of atmospheric CO2 and other greenhouse gases and 2) environmental sensitivities of biogeochemical cycles, marine ecosystems, and interactions between the two.
The OCB Research Priorities (updated January 2012) include: ocean acidification; terrestrial/coastal carbon fluxes and exchanges; climate sensitivities of and change in ecosystem structure and associated impacts on biogeochemical cycles; mesopelagic ecological and biogeochemical interactions; benthic-pelagic feedbacks on biogeochemical cycles; ocean carbon uptake and storage; and expanding low-oxygen conditions in the coastal and open oceans.
| Funding Source | Award |
|---|---|
| NSF Division of Ocean Sciences (NSF OCE) |