Dataset: Inside and Outside Kelp Forest Mooring

Name: Data from moored instruments (pH, dissolved oxygen, temperature, salinity, PAR, pressure) at 9 depths outside and inside the kelp canopy at Hopkins Marine Station, recorded between June and October 2018.
Published: 2020-09-02
Keywords: ocean acidification, kelp forest, biogeochemistry, spatiotemporal variability, upwelling, pH, oxygen, temperature, salinity, PAR, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.822549.1

Spatial Extent: N:36.6224 E:-121.9008 S:36.6216 W:-121.9017

Temporal Extent: 2018-06-07 - 2018-10-04

Project:

Collaborative Research: RUI: Building a mechanistic understanding of water column chemistry alteration by kelp forests: emerging contributions of foundation species (Kelp forest biogeochemistry)

Principal Investigator:

Kerry J. Nickols (California State University Northridge, CSUN)

Co-Principal Investigator:

Robert B. Dunbar (Stanford University)

Scientist:

Heidi Hirsh (Stanford University)

Stephen G. Monismith (Stanford University)

David Mucciarone (Stanford University)

Yuichiro Takeshita (Monterey Bay Aquarium Research Institute, MBARI)

Sarah Traiger (United States Geological Survey, USGS)

Project Coordinator:

Kerry J. Nickols (California State University Northridge, CSUN)

Contact:

Heidi Hirsh (Stanford University)

BCO-DMO Data Manager:

Karen Soenen (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2020-09-02

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Data from moored instruments (pH, dissolved oxygen, temperature, salinity, PAR, pressure) at 9 depths outside and inside the kelp canopy at Hopkins Marine Station, recorded between June and October 2018.

Abstract:

Data from moored instruments (pH, dissolved oxygen, temperature, salinity, PAR, pressure) at 9 depths outside (36° 37.342’ N, 121° 54.049’ W) and inside the kelp canopy (36° 37.297’ N, 121° 54.102’ W.) at Hopkins Marine Station, recorded between June and October 2018. The tidal depth of the kelp canopy mooring ranges from 8 to 11 meter. The outside mooring is located 115m north and offshore from the kelp forest, the tidal range is 16 to 9 meters.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2020-09-02	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.822549.1	2020-10-16

Description

These data are published in Hirsh et al., see related publications section.

Methods & Sampling

The moorings were deployed from June to October 2018. The moorings consisted of a subsurface mooring buoy anchored to a weight so that it was approximately 1 m below the surface at spring low tide. A 5 m line connected the subsurface buoy to a small float at the surface.

Inside Kelp Forest Mooring Instruments:

3 MiniDO2T dissolved oxygen loggers (Precision Measurement Engineering (PME), 5 minute sampling frequency)
3 SBE 56 thermistors (Sea-Bird Electronics, 1 minute sampling frequency)
2 HOBO Pro v2 temperature loggers (Onset Data Loggers, 1 minute sampling frequency)
1 HOBO U20L pressure sensor (Onset Data Loggers, 1 minute sampling frequency)
1 miniPAR sensor (PME, 1 minute sampling frequency). PME miniPAR sensors were paired with PME miniWIPERs set to wipe the PAR sensors every six hours to prevent biofouling.
7 pH loggers were deployed on the kelp mooring between July and October. The kelp mooring configuration included two SeapHOx instrument packages (Bresnahan et al., 2014) deployed 1 meter above the bottom (mab) and just below the subsurface mooring buoy. Each SeapHOx consisted of a Honeywell Durafet pH electrode (Martz et al., 2010), an Aanderaa 4835 oxygen optode, and an SBE-37 MicroCAT CTD equipped with a pressure sensor. The other 5 pH loggers (mFETs) were custom built at the Monterey Bay Aquarium Research Institute utilizing Honeywell Durafet electrodes (Martz et al., 2010). SeapHOxes measured pH, O2, temperature, salinity and pressure every 10 minutes, whereas mFETs measured pH and temperature every 5 minutes.
An SBE 37-SM MicroCAT CTD recorder was deployed at mid depth on the mooring beginning in mid-August with sampling frequencies of 5 minutes.
A miniDO2T sensor was installed on a surface buoy located ~50 m from the kelp mooring between July 18 and August 1. This two-week miniDO2T deployment provided the only in situ surface O2 data inside the kelp forest.

Outside Kelp Forest Mooring Instruments:

3 MiniDO2T dissolved oxygen loggers (Precision Measurement Engineering (PME), 5 minute sampling frequency)
3 SBE 56 thermistors (Sea-Bird Electronics, 1 minute sampling frequency)
2 HOBO Pro v2 temperature loggers (Onset Data Loggers, 1 minute sampling frequency)
1 HOBO U20L pressure sensor (Onset Data Loggers, 1 minute sampling frequency)
1 miniPAR sensor (PME, 1 minute sampling frequency). PME miniPAR sensors were paired with PME miniWIPERs set to wipe the PAR sensors every six hours to prevent biofouling.
1 pH logger (mFET) was deployed between July and October and measured pH and temperature
every 5 minutes. The mFET was custom built at the Monterey Bay Aquarium Research Institute
utilizing Honeywell Durafet electrodes (Martz et al., 2010).
An SBE 37-SM MicroCAT CTD recorder was deployed at 13.5 man beginning in mid-August with
sampling frequencies of 5 minutes.

Calibration by taking discrete samples alongside sensors in situ can lead to relatively large uncertainties, especially in highly dynamic coastal environments (Bresnahan et al. 2014); therefore, we decided to calibrate sensors in a flow through tank where the pH is more stable, and multiple discrete samples for DIC and TA analysis could be collected. Prior to deployment, the mFET sensors logged in a tank for 6 days (3 discrete samples) and the SeapHOxes logged in an adjacent tank for 1 day (2 discrete samples). We estimate the accuracy of the pH sensor data to be ± 0.015.

Oxygen sensors were calibrated by making measurements in a black bucket filled with freshwater while bubbling air for 8 hours. We assumed 100% saturation and applied a gain correction to the raw sensor output (Bittig & Körtzinger, 2015; Bushinsky & Emerson, 2013; Johnson et al., 2015). Because the air-stone was placed at the bottom of the bucket, elsewhere we would expect slight over-saturation. However, since the depth of the bucket was < 40 cm, we estimate the accuracy of this calibration to be better than 1-2%. Post-deployment calibration indicated no drift in the oxygen sensors.

Data Processing Description

Sensor data were quality controlled with several steps. First, obviously erroneous data such as spikes were removed. When bubbles were present on the sensors they led to clearly erroneous data; for instance, pH values typically changed in a large, stepwise manner (usually >0.3 or more) with no correlation to temperature or O2.

Second, the sensors were deployed facing downwards on the mooring line, and bubbles from divers were sometimes trapped on the sensing surface for several hours, leading to incorrect sensor readings. The data bias by bubbles was clearly evident. Sensor data that showed short, stepwise shifts when divers were near the mooring were manually removed.

Finally, the first day of sensor data is not included in this data set to ensure that the instruments were fully equilibrated with environmental conditions.

BCO-DMO Processing notes:

Adjusted column headers to comply with database requirements
Converted Timestamp to ISO format, and timezone from Pacific Standard Time (PST) to UTC

Data Files

File
mooring_inside_outside.csv (Comma Separated Values (.csv), 51.28 MB) MD5:41b9a9f1c221740ea4378298a924bf9d Primary data file for dataset ID 822549

Supplemental Files

File
Sensor deployment details for the kelp and outside mooring filename: KelpMooring_Outside_DeploymentDetails.pdf (Portable Document Format (.pdf), 54.27 KB) MD5:92adbabbf47ac77dd462d38d86c70d16 Sensor deployment details for the kelp and outside mooring for datasets related to the Kelp forest biogeochemistry project.

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1737176
NSF Division of Ocean Sciences	OCE-1737096

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
KELP	Protected Kelp, PK, Inner, Kelp	2018-06-08	Mooring - Hopkins Marine Station	Kerry J. Nickols (Chief Scientist) Heidi Hirsh (Contact)	data info
OUTSIDE	Outside Kelp, PO, Outer	2018-06-07	Mooring - Hopkins Marine Station	Kerry J. Nickols (Chief Scientist) Heidi Hirsh (Contact)	data info

Instruments

CTD Sea-Bird MicroCAT 37

Supplied Name: SBE 37-SM MicroCAT CTD

Supplied Description:

An SBE 37-SM MicroCAT CTD recorder was deployed at mid depth on the mooring beginning in mid-August with sampling frequencies of 5 minutes.

Instrument Type

Generic Name: CTD Sea-Bird MicroCAT 37

Acronym: CTD MicroCAT 37

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/350/

Generic Description:

The Sea-Bird MicroCAT CTD unit is a high-accuracy conductivity and temperature recorder based on the Sea-Bird SBE 37 MicroCAT series of products. It can be configured with optional pressure sensor, internal batteries, memory, built-in Inductive Modem, integral Pump, and/or SBE-43 Integrated Dissolved Oxygen sensor. Constructed of titanium and other non-corroding materials for long life with minimal maintenance, the MicroCAT is designed for long duration on moorings.

In a typical mooring, a modem module housed in the buoy communicates with underwater instruments and is interfaced to a computer or data logger via serial port. The computer or data logger is programmed to poll each instrument on the mooring for its data, and send the data to a telemetry transmitter (satellite link, cell phone, RF modem, etc.). The MicroCAT saves data in memory for upload after recovery, providing a data backup if real-time telemetry is interrupted.

Onset HOBO Pro v2 temperature logger

Supplied Name: HOBO Pro v2 temperature logger

Supplied Description:

2 HOBO Pro v2 temperature loggers (Onset Data Loggers, 1 minute sampling frequency)

Instrument Type

Generic Name: Onset HOBO Pro v2 temperature logger

Acronym: HOBO U22-001

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/134/

Generic Description:

The HOBO Water Temp Pro v2 temperature logger, manufactured by Onset Computer Corporation, has 12-bit resolution and a precision sensor for ±0.2°C accuracy over a wide temperature range. It is designed for extended deployment in fresh or salt water.

Operation range: -40° to 70°C (-40° to 158°F) in air; maximum sustained temperature of 50°C (122°F) in water
Accuracy: 0.2°C over 0° to 50°C (0.36°F over 32° to 122°F)
Resolution: 0.02°C at 25°C (0.04°F at 77°F)
Response time: (90%) 5 minutes in water; 12 minutes in air moving 2 m/sec (typical)
Stability (drift): 0.1°C (0.18°F) per year
Real-time clock: ± 1 minute per month 0° to 50°C (32° to 122°F)

Additional information (http://www.onsetcomp.com/)
Onset Computer Corporation
470 MacArthur Blvd
Bourne, MA 02532

Onset HOBO U20L water level logger series

Supplied Name: HOBO U20L pressure sensor

Supplied Description:

1 HOBO U20L pressure sensor (Onset Data Loggers, 1 minute sampling frequency)

Instrument Type

Generic Name: Onset HOBO U20L water level logger series

Acronym: HOBO U20L

Generic Description:

The HOBO U20L is designed for monitoring changing water levels in a variety of applications including tidal areas, streams, lakes, wetlands, and groundwater. It outputs pressure, water level, and temperature data. The instrument can record samples, sensor measurements at each logging interval, and events data, occurrences such as a bad battery or host connected. The samples are recorded as absolute pressure values, which are later converted to water level readings using software. Absolute pressure is atmospheric pressure plus water head. The deployment of an additional HOBO U20L at the surface can be used to compensate for barometric pressure changes. Each instrument is individually calibrated. They require a coupler and optic base station or HOBO waterproof shuttle to connect to a computer. The instrument is operated with a 3.6 V lithium battery.

This series contains 3 models, U20L-01, U20L-02, and U20L-04, with different operation ranges, calibrated ranges, and burst pressures. The pressure sensor is temperature compensated between 0 and 40 degrees Celsius (C), and calibrated between 69 and a maximum of 400 kPa (depending on the model). Its accuracy is within 0.3 % of the full scale for absolute pressure, and 0.1 % FS for water level readings. The temperature sensor operates between -20 and 50 degrees C, with an accuracy of 0.44 deg C, and a resolution of 0.1 deg C. The drift is 0.1 deg C per year.

Oxygen Sensor

Supplied Name: MiniDO2T dissolved oxygen logger

Supplied Description:

3 MiniDO2T dissolved oxygen loggers (Precision Measurement Engineering (PME), 5 minute
sampling frequency)

Instrument Type

Generic Name: Oxygen Sensor

Acronym: Dissolved Oxygen Sensor

Generic Description:

An electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed

Photosynthetically Available Radiation Sensor

Supplied Name: miniPAR sensor

Supplied Description:

1 miniPAR sensor (PME, 1 minute sampling frequency). PME miniPAR sensors were paired with
PME miniWIPERs set to wipe the PAR sensors every six hours to prevent biofouling.

Instrument Type

Generic Name: Photosynthetically Available Radiation Sensor

Acronym: PAR sensor

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/122/

Generic Description:

A PAR sensor measures photosynthetically available (or active) radiation. The sensor measures photon flux density (photons per second per square meter) within the visible wavelength range (typically 400 to 700 nanometers). PAR gives an indication of the total energy available to plants for photosynthesis. This instrument name is used when specific type, make and model are not known.

SeapHOx/SeaFET

Supplied Name: SeapHOx instrument package

Supplied Description:

The outside kelp mooring included one mFET pH sensor and the kelp mooring included 2 seapHOx sensors and 5 mFET pH sensors.

Instrument Type

Generic Name: SeapHOx/SeaFET

Generic Description:

The SeapHOx and SeaFET are autonomous sensors originally designed and developed by the Todd Martz Lab at Scripps Institution of Oceanography. The SeaFET was designed to measure pH and temperature. The SeapHOx, designed later, combined the SeaFET with additional integrated sensors for dissolved oxygen and conductivity. Refer to Martz et al. 2010 (doi:10.4319/lom.2010.8.172).

The SeapHOx package is now produced by Sea-Bird Scientific and allows for integrated data collection of pH, temperature, salinity, and oxygen. Refer to Sea-Bird for specific model information.

Thermistor

Supplied Name: SBE 56 thermistor

Supplied Description:

3 SBE 56 thermistors (Sea-Bird Electronics, 1 minute sampling frequency)

Instrument Type

Generic Name: Thermistor

Generic Description:

A thermistor is a type of resistor whose resistance varies significantly with temperature, more so than in standard resistors. The word is a portmanteau of thermal and resistor. Thermistors are widely used as inrush current limiters, temperature sensors, self-resetting overcurrent protectors, and self-regulating heating elements.

Thermistors differ from resistance temperature detectors (RTD) in that the material used in a thermistor is generally a ceramic or polymer, while RTDs use pure metals. The temperature response is also different; RTDs are useful over larger temperature ranges, while thermistors typically achieve a higher precision within a limited temperature range, typically 90C to 130C.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
MAB	Meters above bottom	meters (m)	altitude
Mooring_ID	Mooring name: KELP = inside kelp forest mooring; OUTSIDE = mooring outside kelp forest	unitless	buoy_id
ISO_DateTime_UTC	Timestap (date and time) in ISO format, UTC (yyyy-mm-ddThh:mmZ)	yyyy-MM-dd'T'HH:mm:ss'Z'	ISO_DateTime_UTC
Latitude	Latitude of mooring location, south is negative	decimal degrees	lat
Longitude	Longitude of mooring location, west is negative	decimal degrees	lon
DO	Dissolved oxygen	micromoles per kilogram (umol/kg)	O2
DOSAT	oxygen saturation	percentage (%)	O2
PAR	Photosynthetic Active Radiation	micromoles photons per square meter per seconds (umol/m2/s)	PAR
pH	pH of water	unitless	pH
Pressure	Pressure. Pressure at bottom (0 mab, depth_i=9) provides mab for surface (depth_id=1)	meter (m)	press
Salinity	Salinity	unitless	sal
Depth_ID	ID to distinguish depth	unitless	Site_ID
Temperature	Water temperature	degrees Celsius (°C)	temperature

Database

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Dataset: Inside and Outside Kelp Forest Mooring