Water Quality and Analysis

Gardline has extensive experience in undertaking water profiling and analysis, and either integrating the subsequent results into Environmental Baseline Survey (EBS) reports, or producing stand alone water quality assessment reports. The quality of all chemical analysis is covered by laboratory accreditation (UKAS, EPA) and Gardline’s ISO: 9001 guidelines which approve all data prior to despatch to clients. Standard analyses undertaken includes total hydrocarbons and polynuclear aromatic hydrocarbons (gas chromatography), metals, total organic carbon, nutrients, total suspended solids, total dissolved solids, pH and total chlorophyll. In addition, Gardline has experience conducting phytoplankton and zooplankton sampling, and the subsequent analysis.

Water quality covers a vast array of parameters: from basic descriptors of a water body (such as salinity, temperature, dissolved oxygen and depth) to targeted parameters associated with potential impacts (such as hydrocarbons, metals and other chemicals). 

Gardline’s expertise covers a corresponding wide range: from coastal water quality surveys associated with waste water treatment infrastructure, to collecting data on the baseline chemical levels present in a region prior to an oil and gas development.

Backed up with its own equipment pool for reliability, Gardline can offer the right package for each circumstance, or advice on the most appropriate samples and measurements to collect.


Gardline own and operate a variety of water samplers and profiles including 5 litre Niskin bottles, which offer discrete water samples at desired depths throughout the water column. In deep water environments Niskin sampling bottles can be ‘daisy chained’ to provide a more efficient means of sampling. 

Direct measurements of the temperature, conductivity/salinity, pH, dissolved oxygen and turbidity will be directly profiled in the water column using a multi-parameter probe, from sea surface to bottom, or as required. Our CTD probes rated to 6000m can be adapted with a range of industry standard sensors including temperature, salinity, pH, dissolved oxygen, turbidity, chlorophyll concentrations, redox, photosynthetically available radiation and pressure measurements. 

In addition to our standalone Niskin bottles for seawater sampling, we offer our new Rosette oceanographic water sampler capable of deploying 12 Niskin bottles of 5 or 10 litres in volume. Niskin bottles will be deployed in a rosette and triggered at pre-determined depth in real time. This system integrates the existing CTD with the water sampler allowing for specific water column features to be targeted, and discrete water samples collected at a variety of depths. Our Rossette has a rack manufactured from AISI 316 Stainless Steel, capacity of up to twelve Niskin water samplers. Niskin bottles are non-metallic construction, so the interior is totally free from metal parts. 

There are a number of sampling techniques recommended for the acquisition of different size classes of plankton.  The objectives of the survey will determine the most appropriate method used, whether spatial composition is required or more routinely an indication of the presence / absence of species, using an integrated sample (i.e. vertical trawl from one specified depth).  Gardline can offer both discrete water sampling to target phytoplankton and subsequent filtering as well as vertical trawls through the water column for zooplankton and icthoplankton utilising a variety of mesh sizes.

For more information, please Contact Us.