Metadata Report for BODC Series Reference Number 2025897

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

EK188 CTD Quality Control Report

Chlorophyll-a (CPHLPS01)

Flags have been applied to a number of suspect data values in the chlorophyll-a channels for 26 out of the 56 casts.

Irradiance (IRRDUV01, IRRDSV01, PCTIRRXX)

The entire surface irradiance (SPAR) channel has been flagged as suspect for casts 004 (IPSNO: 82900) and 031 (IPSNO: 85600) as the data recordings are very high. For this reason, flags have also been applied by BODC to the entire corrected irradiance (CPAR) channel on these casts because the SPAR data was used to derive CPAR.

Cycle recordings are constant in all of the PAR channels in 20 out of the 56 CTD casts. This occurs on stations where the CTD has been deployed at night and is likely due irradiance levels being below the detection capabilities of the sensors. Flags have been applied by BODC to these channels on the casts where this has occurred.

Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

Narrative Documents

Sea-Bird Dissolved Oxygen Sensor SBE 43 and SBE 43F

The SBE 43 is a dissolved oxygen sensor designed for marine applications. It incorporates a high-performance Clark polarographic membrane with a pump that continuously plumbs water through it, preventing algal growth and the development of anoxic conditions when the sensor is taking measurements.

Two configurations are available: SBE 43 produces a voltage output and can be incorporated with any Sea-Bird CTD that accepts input from a 0-5 volt auxiliary sensor, while the SBE 43F produces a frequency output and can be integrated with an SBE 52-MP (Moored Profiler CTD) or used for OEM applications. The specifications below are common to both.

Specifications

Further details can be found in the manufacturer's specification sheet.

EK188 SOLSTICE-WIO CTD Instrument Description

CTD Unit and Auxiliary Sensors

A Seabird 911+ V2 CTD system was used on the EK188 cruise. This was coupled with a Seabird 32 Carousel/Rosette which had 12 8L Niskin bottles fitted.

The CTD was fitted with the following scientific sensors:

A Biospherical Instruments QSR-2200 series SPAR sensor was mounted on the foremast and used to measure the ambient atmospheric light during dips. This was used in conjunction with the Biospherical Instruments QSP-2350 PAR sensor to calculate the PAR ratio.

Sea-Bird Electronics SBE 911 and SBE 917 series CTD profilers

The SBE 911 and SBE 917 series of conductivity-temperature-depth (CTD) units are used to collect hydrographic profiles, including temperature, conductivity and pressure as standard. Each profiler consists of an underwater unit and deck unit or SEARAM. Auxiliary sensors, such as fluorometers, dissolved oxygen sensors and transmissometers, and carousel water samplers are commonly added to the underwater unit.

Underwater unit

The CTD underwater unit (SBE 9 or SBE 9 plus) comprises a protective cage (usually with a carousel water sampler), including a main pressure housing containing power supplies, acquisition electronics, telemetry circuitry, and a suite of modular sensors. The original SBE 9 incorporated Sea-Bird's standard modular SBE 3 temperature sensor and SBE 4 conductivity sensor, and a Paroscientific Digiquartz pressure sensor. The conductivity cell was connected to a pump-fed plastic tubing circuit that could include auxiliary sensors. Each SBE 9 unit was custom built to individual specification. The SBE 9 was replaced in 1997 by an off-the-shelf version, termed the SBE 9 plus, that incorporated the SBE 3 plus (or SBE 3P) temperature sensor, SBE 4C conductivity sensor and a Paroscientific Digiquartz pressure sensor. Sensors could be connected to a pump-fed plastic tubing circuit or stand-alone.

Temperature, conductivity and pressure sensors

The conductivity, temperature, and pressure sensors supplied with Sea-Bird CTD systems have outputs in the form of variable frequencies, which are measured using high-speed parallel counters. The resulting count totals are converted to numeric representations of the original frequencies, which bear a direct relationship to temperature, conductivity or pressure. Sampling frequencies for these sensors are typically set at 24 Hz.

The temperature sensing element is a glass-coated thermistor bead, pressure-protected inside a stainless steel tube, while the conductivity sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Thermistor resistance or conductivity cell resistance, respectively, is the controlling element in an optimized Wien Bridge oscillator circuit, which produces a frequency output that can be converted to a temperature or conductivity reading. These sensors are available with depth ratings of 6800 m (aluminium housing) or 10500 m (titanium housing). The Paroscientific Digiquartz pressure sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.

Additional sensors

Optional sensors for dissolved oxygen, pH, light transmission, fluorescence and others do not require the very high levels of resolution needed in the primary CTD channels, nor do these sensors generally offer variable frequency outputs. Accordingly, signals from the auxiliary sensors are acquired using a conventional voltage-input multiplexed A/D converter (optional). Some Sea-Bird CTDs use a strain gauge pressure sensor (Senso-Metrics) in which case their pressure output data is in the same form as that from the auxiliary sensors as described above.

Deck unit or SEARAM

Each underwater unit is connected to a power supply and data logging system: the SBE 11 (or SBE 11 plus) deck unit allows real-time interfacing between the deck and the underwater unit via a conductive wire, while the submersible SBE 17 (or SBE 17 plus) SEARAM plugs directly into the underwater unit and data are downloaded on recovery of the CTD. The combination of SBE 9 and SBE 17 or SBE 11 are termed SBE 917 or SBE 911, respectively, while the combinations of SBE 9 plus and SBE 17 plus or SBE 11 plus are termed SBE 917 plus or SBE 911 plus.

Specifications

Specifications for the SBE 9 plus underwater unit are listed below:

Further details can be found in the manufacturer's specification sheet.

WETLabs ECO FLNTU(RT)D combined fluorometer and turbidity sensor

This optical sensor is available in combinations of backscattering, turbidity, and fluorescence measurements. It records in real-time and does not store data. ECOs feature optional active anti-fouling and internal batteries for long-term deployments. This instrument has a user-selectable sample rate up to 8 Hz The fluorometer can typically measure pigment concentrations in the range 0-75 ug/l, with a sensitivity of 0.037 ug/l, at wavelengths of 470 or 695 nm. The turbidity sensor can measure within the range 0-200 NTU, with a sensitivity of 0.098 NTU, at a wavelength of 700 nm. The instrument is stable over a temperature range of 0-30 degC and is rated to a depth of 6000 m.

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/datasheet_ECO_FLNTU.pdf

Biospherical Instruments QCP-2200 [underwater] PAR sensor

A cosine-corrected PAR quantum irradiance profiling sensor. For use in underwater applications with a 16 bit or higher analog-to-digital converter. Measures light available for photosynthesis on a flat surface. Operation is by a linear analog output voltage that is proportional to the log of incident PAR (400-700 nm) irradiance. The sensor is designed for operation in waters to depths of up to 2,000 m (standard) or 6,800 m (high-pressure standard option) or 10,000 m (high-pressure user-specific option).

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/Biospherical_QCP_2000_series_brochure.pdf

Biospherical Instruments QSP-2350 underwater PAR sensor

Quantum Scalar Irradiance PAR Sensor. Developed for data loggers with limited dynamic range. It uses a scalar irradiance collector to obtain a uniform directional response over 3.6-pi steradians. A stainless���steel encased optical light pipe guides flux from the collector to a filtered silicon pho���todetector, resultng in a flat quantum response over the PAR spectral region (400���700 nm). The sensor produces a logarithmically compressed analog voltage output and BH���4���MP connector Operates in waters depths up to 2000 m.

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/Biospherical_QSP_2300_2350_series_brochure.pdf

WETLabs Single-angle Backscattering Meter ECO BB

An optical scattering sensor that measures scattering at 117°. This angle was determined as a minimum convergence point for variations in the volume scattering function induced by suspended materials and water. The measured signal is less determined by the type and size of the materials in the water and is more directly correlated to their concentration.

Several versions are available, with minor differences in their specifications:

• ECO BB(RT)provides analog or RS-232 serial output with 4000 count range
• ECO BB(RT)D adds the possibility of being deployed in depths up to 6000 m while keeping the capabilities of ECO BB(RT)
• ECO BB provides the capabilities of ECO BB(RT) with periodic sampling
• ECO BBB is similar to ECO BB but with internal batteries for autonomous operation
• ECO BBS is similar to ECO BB but with an integrated anti-fouling bio-wiper
• ECO BBSB has the capabilities of ECO BBS but with internal batteries for autonomous operation

Specifications

Further details can be found in the manufacturer's specification sheet.

WETLabs C-Star transmissometer

This instrument is designed to measure beam transmittance by submersion or with an optional flow tube for pumped applications. It can be used in profiles, moorings or as part of an underway system.

Two models are available, a 25 cm pathlength, which can be built in aluminum or co-polymer, and a 10 cm pathlength with a plastic housing. Both have an analog output, but a digital model is also available.

This instrument has been updated to provide a high resolution RS232 data output, while maintaining the same design and characteristics.

Specifications

Further details are available in the manufacturer's specification sheet or user guide.

EK188 SOLSTICE-WIO CTD Data: Originator's Processing

Sampling strategy

A total of 56 CTD casts were carried out during the EK188 Cruise. These included 50 CTD profile and rosette sampling stations where the twelve 8L water sampling bottles mounted on the Seabird 32 Rosette were triggered remotely. In addition, a single CTD profile was taken at each of the four ADCP Mooring sites during the recovery of these arrays and a further CTD deployment took place at each of the recovery sites of the two gliders at the end of the cruise.

Data processing

Data were acquired through Seasave version 7.23.2. The data from casts CTD001 to CTD054 were acquired at 24Hz but unintentionally averaged to 1Hz by the deck unit and recorded at 1Hz. Raw 24 Hz data were not recorded. Data from casts CTD055 and CTD056 were acquired and recorded at 24Hz. Data processing was performed using the Seabird SBEDataProcessing software(Seasave Version 7.26.7) and the following steps were then performed consecutively on the raw data:

• DatCnv: A conversion routine to read in the raw CTD data file (.hex) containing data in engineering units output by the CTD hardware.
• Wild Edit: Removal of pressure spikes.
• Filter: Run on the pressure channel to smooth out high frequency data Low pass filter time B: 0.15 seconds
• Align CTD: conductivity and oxygen values (V) are shifted in time to compensate for sensor time lags.
• CellTM: Removes the effect of thermal inertia on the conductivity cells.
• Derive: After the dynamic corrections have been applied (Filter, Align, thermal inertia correction), oxygen and salinity are derived.
• Bottle Summary: This step created a .btl file containing the average, standard deviation, min and max values at bottle firings.
• Bin Average: Only performed on casts CTD_055 & CTD_056 since casts CTD_001 to CTD_054had 1Hz averaging applied on collection
• Matlab Processing

Calibration

Oxygen

The oxygen sensor has been calibrated against Winkler titration samples collected from CTD Niskin bottles taken during the cruise. A total of 106 samples were collected during the cruise of which 30 were duplicates from the same bottle. The slope between dissolved oxygen concentrations taken from the CTD sensor and the Winkler samples was calculated as 0.98425302 (R² = 0.9999)

Chlorophyll-a

After removal of samples taken during daylight in the surface the following calibrations were applied to the fluorometer:

Chlorophyll-a fluorescence samples [mg m^-3] = (CTDfluor_raw [V] - 0.07393) x 14.47046 (R² = 0.7393)

Salinity

A total of 98 salinity samples were taken from Niskin bottles throughout the cruise. The salinities of samples taken ranged from 34.742 psu to 35.528 psu. The slope between salinity samples taken from the CTD sensor and the discrete bottle samples was calculated as:

Portasal bottle salinity [PSU] = 1.01300 x CTDsalinity [PSU] - 0.31878 (R² = 0.90767)

EK188 SOLSTICE-WIO CTD Data: Processing by BODC

The CTD data were submitted to BODC as 1 NetCDF file and converted to the BODC internal format.

During transfer the originator's variables were mapped to unique BODC parameter codes. The following table shows the parameter mapping:

Following transfer, the data were screened using BODC in-house visualisation software. Suspect data values were assigned the appropriate BODC data quality flag. Missing data values, where present, were changed to the missing data value and assigned a BODC data quality flag.

Parameters that have not been transferred can be provided on request.

Project Information

SOLSTICE-WIO: Sustainable Oceans, Livelihoods and food Security Through Increased Capacity in Ecosystem research in the Western Indian Ocean

Introduction

SOLSTICE-WIO is a four-year collaborative project funded by the UK Global Challenges Research Fund (GCRF). Launched in October 2017, it brings together recent advances in marine technologies, local knowledge and research expertise to address challenges facing the Western Indian Ocean region in a cost-effective way via state-of-the-art technology transfer, collaborative environmental and socio-economic research and hands-on training.

Over 100 million people in the Western Indian Ocean (WIO) region live within 100km of the coast, with over 1 million working in the fisheries sector. The WIO is highly dependent on the ocean for economic stability, food security, and social cohesion. In recent years, the region has seen dramatic and often poorly understood reductions in key fisheries, due to the combined effects of climate change, natural ecosystem variability, overfishing and degradation of key marine habitats. Until the mechanisms behind the collapse are understood, there is little potential for aiding recovery or guiding adaptation. The key to stability of living marine resources lies in an ecosystem approach to fisheries (EAF), which sees human-natural systems as a whole, integrated entity rather than separately considering individual target species. Understanding and managing WIO fisheries and the impacts of recent and future changes requires a mature capacity to implement an ecosystem approach to fisheries management (EAF) that is built on sound environmental and socio-economic information.

The core strength of SOLSTICE-WIO lies in its integral approach to food security, drawing on UK expertise in physical oceanography, marine ecology, autonomous observations, environmental economics and the human dimension,and WIO expertise in fisheries, the marine economy and regional policy development. SOLSTICE will provide the region with the state-of-the-art technology to deliver cost-effective marine research and provide the information needed to achieve maximum potential from the region's living marine resources. In the UK marine robotics, ocean models and novel data products from satellite observations have developed rapidly in the last decade, and now underpin Blue Economies and Ocean Governance in Europe. These technologies are highly agile and ready to be applied in the developing world as cost-effective ways to maximise understanding and sustainable exploitation of living marine resources. Such "technology leapfrogging" can overcome the severe lack of research ships in the WIO and save decades of effort in developing predictive modelling systems from scratch.

Scientific Objectives

SOLSTICE-WIO main objectives are to:

1. Grow marine environmental research capability to address challenges facing the WIO region in a cost-effective way via state-of-the-art technology transfer, collaborative environmental and socio-economic research, and hands-on training.
2. Strengthen the capacity of UK marine scientists to apply leading-edge technologies in developing countries, and work with regional and local experts to ensure that their research addresses local and regional needs.
3. Strengthen the ability of WIO scientists to effectively deliver evidence-based environmental and socio-economic information to support policy development and implementation at national and regional levels.
4. Ensure future sustainability of marine research capability in the region by training and mentoring early career scientists and post-graduate students from the WIO and by developing on-line resources for use in distance learning and hands-on training of marine scientists outside the partner organisations and beyond the duration of the project.
5. Ensure on-going support for an Ecosystem Approach to Fisheries in the WIO by building lasting strategic research partnerships between UK marine science and regional centres of excellence, between these centres and other WIO research organisations, and between marine scientist and government agencies and NGOs mandated to deliver sustainable development and exploitation of marine living resources in the WIO.

Fieldwork

SOLSTICE-WIO will demonstrate its approach to strengthening research capacity through three case studies in Kenya, Tanzania and South Africa. These have been selected by SOLSTICE-WIO partners in each of the three countries.

• Tanzania Case Study: Pemba Channel small pelagic fishery under climate threat.

  The small pelagic fishery is important for local communities in Zanzibar and mainland Tanzania as a source of food security, nutrition and livelihood support. This diverse group includes mackerel, sardines and anchovies â?? found in schools over the continental shelf, in bays and deep lagoons with nutrient rich waters. They are more abundant during the southeast monsoon, when stronger winds drive upwelling that brings nutrient rich water to the surface.

  Despite its importance for coastal economies, there is a lack of data and information about the fishery, which hampers effective management. Using robotics, modelling, remote sensing, field observations and socio-economic studies, SOLSTICE will identify key environmental and anthropogenic drivers of the main species and address climatic pressures on this fishery.

• Kenya Case Study: Emerging fishery of the North Kenya Bank, an opportunity for coastal populations.

  The North Kenya Bank fishery is expected to spur economic growth for local communities. If well managed, it could help achieve national development goals, including poverty alleviation and wealth creation. Sustainability requires informed management interventions, but there is only scant information on the ecological status and drivers of the fishery.

  Using modelling, remote sensing, field observations and socio-economic studies, SOLSTICE will explore processes related to productivity and resilience of the ecosystems supporting the fishery, identify the main drivers of variability and change, and advise the fishery and government on how to optimise use of this important resource.

• South Africa Case Study: Environmental drivers and socio-economic consequences of the South African Chokka squid fishery collapsing.

  The collapse of the Chokka squid fishery in 2013 had a devastating effect on the Eastern Cape, one of the poorest provinces in South Africa. The reasons for the collapse are unknown, although local fishermen believe it happened as a result of environmental change.

  SOLSTICE will address key environmental and anthropogenic factors controlling the ecosystem dynamics of the Agulhas Bank. The results will help explain why the fishery collapsed, and inform the fishery and government as to whether the current recovery is stable, or whether similar collapses are likely in the future.

Project Collaborators

The science delivered as part of SOLSTICE-WIO is greatly enhanced by the collaboration of the following institutions:

• National Oceanography Centre (NOC)
• Plymouth Marine Laboratory (PML)
• Scottish Association for Marine Science (SAMS)
• Heriot-Watt University
• Imperative Space
• Nelson Mandela University (NMU)
• South African Squid Management Industry Association
• Rhodes University
• South African Environmental Observation Network
• University of Cape Town
• Institute of Marine Sciences (IMS)
• Western Indian Ocean Marine Science Association
• Tanzania Fisheries Research Institute (TAFIRI)
• Environment for Development - Tanzania (EfDT)
• WWF Tanzania
• Kenya Marine and Fisheries Research Institute (KMFRI)
• Coastal Oceans Research and Development â?? Indian Ocean
• University of Seychelles
• Mozambique National Institute of Fisheries Research
• Institut Halieutique et des Sciences Marines (IH.SM)

SOLSTICE-WIO Leadership Team

Directors

• Prof Mike Roberts (Nelson Mandela University (NMU), South Africa)
• Dr Katya Popova (National Oceanography Centre (NOC), UK)

Members

• Prof Julius Francis (Western Indian Ocean Marine Science Association (WIOMSA), Tanzania)
• Dr Yohana W. Shaghude (Institute of Marine Sciences (IMS), Tanzania)
• Dr Baraka Sekadende (Tanzania Fisheries Research Institute (TAFIRI), Tanzania)
• Dr Joseph Kamau (Kenya Marine and Fisheries Research Institute (KMFRI), Kenya)
• Prof Warwick Sauer (Rhodes University (Rhodes), South Africa)
• Dr Eleni Papathanasopoulou (Plymouth Marine Laboratory (PML), UK)
• Dr Matthew Palmer (National Oceanography Centre (NOC), UK)
• Dr Val Byfield (National Oceanography Centre (NOC), UK)
• Sofia Alexiou (National Oceanography Centre (NOC), UK)

Funding

This is a NERC funded research project. The total value of the grant is £6,934,488 and the period of award is from September 4th 2017 to March 3rd 2020. NERC Reference: NE/P021050/1

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle: