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Survey methods

Geological survey methods

Geological surveys are mainly conducted using acoustic methods, particularly multibeam echo sounding.

Geological survey methods

Geological survey methods used in VELMU. Photo: H. Kutvonen, Geological Survey of Finland





Biological survey methods

Diving allows for direct observation of species and habitats and sampling of hard-bottom fauna. For sampling of soft-bottom fauna, grab samplers are operated on board small boats or research vessels.

Most of the observations under VELMU are carried out using video photography methods. With video photography, data on species and habitats can be collected in a timely fashion and cost efficiently. Both drop video cameras and remotely operated vehicles (ROV) are used.


A drop video A van Veen sampler
A drop video camera. Photo: Tiina Asp, Metsähallitus 2012. A van Veen sampler. Photo: SYKE.

Researcher operating an ROV

Saduria entomon captured in an ROV image from the Eastern Gulf of Finland. Photo: Anna Downie SYKE.

Methods for surveying fish breeding grounds


Sampling with a white plateSampling with a white plate. Photo: Meri Kallasvuo, LUKE 2010.

Under VELMU, data on fish spawning and larval areas in coastal regions are also collected. The collection methods used include, among others, scooping, white plate, Gulf-Olympia sampler and remote sensing.



Because it is not possible to monitor all sea areas, species and communities distribution models are developed based on species observations and environmental factors. Models are developed for vascular plants, macroalgae, benthos and fish species. Maps produced from data generated by models can be used, for instance, for comparison purposes and in planning.

Method development

New methods are being developed under the work package on Methodological Development. These methods include, among others, LIDAR (Light Detection and Ranging – a radar technique using red and green laser light), remote sensing and aerial photography in inventories, development of equipment for carrying drop video cameras in shallow areas, and sensors attached to cameras.

Published 2015-04-07 at 15:06, updated 2020-04-22 at 13:50