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Sediment surveys

The condition and diversity of the benthic sediments and fauna close to discharge locations will often provide an indication of the operational and environmental status of a site.

Åkerblå categorizes the benthos through performing accredited B- and C-surveys. In addition, services for other forms of sediment investigations, environmental studies, monitoring and research are also performed.


A B-survey (Previously known as «MOM-B") is conducted as an operational and / or trend survey, monitoring the environmental condition in the immediate vicinity of the site. B-surveys examine the degree of impact on the seabed. B-surveys are an accredited service following the requirements laid down in the Norwegian Standard (NS 9410:2007). Reports combine a description of the survey results and any recommendations regarding required changes in production.

  • «Baseline sample» is conducted before any activity at the site starts. Sampling before operations begin makes it possible to evaluate the effects of operations in the area and to determine the potential environmental impact. This survey is also routinely a part of the application for a new aquaculture site.
  • «Maximum production» surveys are conducted when production is at maximum biomass in order to investigate the full effects on the benthic environment.
  • «Monitoring» is conducted when requested by customers, or due to external requirements for a thorough monitoring of the area.

Sediment sampling is conducted using a Van Veen grab. The samples are evaluated according to type of sediment, chemical parameters (pH/Eh), sensory properties (odor, gas, color, volume, sludge and consistency) and biodiversity. The results provide an indication of the condition of site (table 1).

Table 1. The frequency of B-surveys depends on the condition of the site. In addition, a survey is always conducted at the time of maximum biomass production.

ConditionSurvey inteval
1 – Very goodBiannual
2 – GoodAnnual
3 – BadWithin six months
4 – Very badWithin two months of a survey an extended B-survey is conducted with additional measurement locations and chemical analysis of the sediment samples.



While the “B-survey” examines the immediate vicinity around and under the site, the C-survey is a more thorough type of survey. It analyzes the level of impact close to the site, an intermediate zone some distance from the site and at one remote zone some distance from the site.

The survey is conducted using a larger Van Veen Grab to collect the sediment, while a CTD instrument measures different hydrographic parameters within the water column.

Sediment survey: grain size, total organic carbon (TOC), amount of phosphorus and heavy metals.
Faunal survey: sediment samples are washed, animals preserved and sent to our laboratory for identification and quantification.

C-surveys are often an important part of the environmental monitoring program at any marine production site or other discharge areas.

ASC investigations

Åkerblå plans the sampling program, conducts the fieldwork and thereafter the species identification as part of the requirements of the ASC (Aquaculture Stewardship Council – Salmon Standard) – approval.  An ASC approval provides the fish farmers with a certification of environmentally responsible operations for a particular site.