Dataset: Ichthyoplankton Density - MOCNESS
Deployment: PE18-21

Ichthyoplankton density and plankton displacement volume data collected using MOCNESS plankton nets on the NSF RAPID Plankton Cruises in the Northwestern Gulf of Mexico in 2017-2018

Principal Investigator:

Simon Geist (Texas A&M, Corpus Christi, TAMU-CC)

Co-Principal Investigator:

Kelly L. Robinson (University of Louisiana at Lafayette)

Astrid Schnetzer (North Carolina State University, NCSU)

Beth Stauffer (University of Louisiana at Lafayette)

Student:

Shannan McAskill (Texas A&M, Corpus Christi, TAMU-CC)

Stormy Paxton (Texas A&M, Corpus Christi, TAMU-CC)

Contact:

Kelly L. Robinson (University of Louisiana at Lafayette)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Collaborative Research: RAPID-HARVEY: Response of plankton assemblages and trophodynamics to a historic, hurricane-induced floodwater plume in a subtropical, pelagic environment (RAPID Plankton)

Deployment Synonyms:

RPD-3

Data URL:

https://www.bco-dmo.org/dataset-deployment/829557/data

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Description

Methods & Sampling

Dataset acquisition description

The MOCNESS Plankton Net was deployed over the aft to horizontally sample three discrete depth strata in the water column: (1) Under Chla maximum layer above bottom, (2) within the Chla maximum layer, (3) Above Chla maximum layer underneath the surface. Ship speed was 1.5-2.0 knots and was adjusted according to online flowmeter readings.

One net per sampled stratum was analyzed for ichthyoplankton (net # 1, 5, 7). Nets were rinsed and processed on board and samples were preserved in 200 proof Ethanol (ETOH) according to NOAA SEAMAP Operations Manual upon retrieval of nets. After 24 hours, ETOH was exchanged with fresh ETOH. Plankton samples were stored in 1000ml plastic jars until processing in the Geist Early Life History Research Laboratory at Texas A&M University Corpus Christi during 2017 and 2020. Total Zooplankton Displacement Volume was determined using a calibrated 1000ml measuring cylinder by subtracting the volume of ethanol without sample from the volume of ethanol with sample. The plankton sample was separated from ethanol using a concentrator sieve with a mesh size < than the net mesh size. Then the plankton sample was resuspended in Ethanol. Larval fish were picked under dissecting microscopes using feather steel tweezers. Every sample was looked through twice for quality check purposes.

Data Processing Description

Dataset Processing Description

Data Processing:
Filtered Volume was calculated automatically by MOCNESS software. Total Plankton Displacement Volume and Total Larval Fish Density was standardized per 100m³ filtered water volume.

Problems/Issues:
On the RAPID Plankton 1 cruise (PS1813), at shallow bottom depths, deployment time was shortened, which resulted in less than 3 nets available for analyses.
On the RAPID Plankton 2 cruise (PE18-18), rough weather did not allow deployment at station 1. At other shallow bottom depth stations, deployment time was shortened, which resulted in less than 3 nets available for analyses.
On the RAPID Plankton 3 cruise (PE18-21), MOCNESS was not deployed at station 1. At other shallow bottom depth stations, deployment time was shortened, which resulted in less than 3 nets available for analyses.

BCO-DMO Processing:
- concatenated separate files into one dataset;
- converted date format to YYYY-MM-DD;
- added ISO date-time fields;
- added Cruise_ID numbers.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1760674	NSF Division of Ocean Sciences

Instruments

CTD MOCNESS

Supplied Name: in situ CTD

Supplied Description:

MOCNESS Plankton Net (1x2m), equipped with 10 nets of 333µm mesh widths, in situ CTD and online flowmeters. Nets # 1, 5, and 7 were analyzed for this dataset.

Instrument Type

Generic Name: CTD MOCNESS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/131/

Generic Description:

The CTD part of the MOCNESS includes 1) a pressure (depth) sensor which is a thermally isolated titanium strain gauge with a standard range of 0-5000 decibars full scale, 2) A Sea Bird temperature sensor whose frequency output is measured and sent to the surface for logging and conversion to temperature by the software in the MOCNESS computer (The system allows better than 1 milli-degree resolution at 10 Hz sampling rate), and 3) A Sea Bird conductivity sensor whose output frequency is measured and sent to the surface for logging and conversion to conductivity by the software in the computer (The system allows better than 1 micro mho/cm at 10 Hz sampling rate). The data rate depends on the speed of the computer and the quality of the cable. With a good cable, the system can operate at 2400 baud, sampling all variables at 2 times per second. One sample every 4 seconds is the default, although the hardware can operate much faster. (From The MOCNESS Manual)

Microscope - Optical

Supplied Name: Dissecting microscope

Supplied Description:

Larval fish were picked under dissecting microscopes using feather steel tweezers.

Instrument Type

Generic Name: Microscope - Optical

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB05/

Generic Description:

Instruments that generate enlarged images of samples using the phenomena of reflection and absorption of visible light. Includes conventional and inverted instruments. Also called a "light microscope".

MOCNESS

Supplied Name: MOCNESS Plankton Net (1x2m)

Supplied Description:

MOCNESS Plankton Net (1x2m), equipped with 10 nets of 333um mesh widths, in situ CTD and online flowmeters. Nets # 1, 5, and 7 were analyzed for this dataset.

Instrument Type

Generic Name: MOCNESS

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/NETT0097/

Generic Description:

The Multiple Opening/Closing Net and Environmental Sensing System or MOCNESS is a family of net systems based on the Tucker Trawl principle. There are currently 8 different sizes of MOCNESS in existence which are designed for capture of different size ranges of zooplankton and micro-nekton Each system is designated according to the size of the net mouth opening and in two cases, the number of nets it carries. The original MOCNESS (Wiebe et al, 1976) was a redesigned and improved version of a system described by Frost and McCrone (1974).(from MOCNESS manual) This designation is used when the specific type of MOCNESS (number and size of nets) was not specified by the contributing investigator.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Date	Date; format: YYYY-MM-DD	unitless	date
Cruise_ID	Cruise identifier	unitless	cruise_id
CR_N	Project Internal Cruise Name	unitless	cruise_name
P_SN	Project Internal Station Number	unitless	station
NOAA_SN	Respective NOAA SEAMAP/GOMECC Station Number	unitless	station
GEAR_T	Plankton Net Gear Type	unitless	instrument
MESH_W	Plankton Net Mesh Width	micrometers (um)	net_mesh
NET_NO	Net number, if gear has more than 1 net	unitless	net
STA_LAT	Generalized Station Latitude	decimal degrees	lat
STA_LON	Generalized Station Longitude	decimal degrees	lon
BOT_D	Assigned Bottom Depth	meters (m)	depth_bottom
MAX_ND	Max Net Depth	meters (m)	depth_max
MIN_ND	Min Net Depth	meters (m)	depth_min
D_TW	Depth of Tow FD_TW = MAX_ND - MIN_ND	meters (m)	depth
TGI_GMT	Time Gear In (GMT), Net starting fishing; format: hh:mm	unitless	time
TGO_GMT	Time Gear Out (GMT), Net stopping fishing; format: hh:mm	unitless	time
TGI_CST	Time Gear In (CST), Net starting fishing; format: hh:mm	unitless	time
TGO_CST	Time Gear Out (CST), Net stopping fishing; format: hh:mm	unitless	time
TT	Time towed, Duration of Net fishing; format: hh:mm:ss	unitless	time_elapsed
FIL_V	Filtered volume	cubic meters (m³)	vol_filt
EV_WP	ETOH with Plankton (ml)	milliliters (ml)	sample_volume
EV_WOP	ETOH without Plankton (ml)	milliliters (ml)	sample_volume
PLA_D	Plankton Displacement Volume = ETOH with Plankton - ETOH without Plankton	milliliters (ml)	disp_vol
PLA_DD	Total Plankton Displacement Volume Density per 100 cubic meters filtered water volume	milliliters per 100 cubic meters (ml/100m3)	disp_vol
TFILA	Total Larval Fish Number in sample	number of larval fish	abundance
TFILA_DV	Total Larval Fish Density per filtered water volume	larval fish per 100 cubic meters	abundance
TGI_ISO_DateTime_GMT	Date and Time Gear In (GMT), Net starting fishing; formatted to ISO8601 standard: YYYY-MM-DDThh:mmZ	unitless	ISO_DateTime_UTC
TGO_ISO_DateTime_GMT	Date and Time Gear Out (GMT), Net stopping fishing; formatted to ISO8601 standard: YYYY-MM-DDThh:mmZ	unitless	ISO_DateTime_UTC

Database

Contribute Data

Dataset: Ichthyoplankton Density - MOCNESS
Deployment: PE18-21

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Ichthyoplankton Density - MOCNESSDeployment: PE18-21

Dataset acquisition description

Dataset Processing Description

Dataset: Ichthyoplankton Density - MOCNESS
Deployment: PE18-21