Large and experienced field team

With offices throughout the UK we have both nationwide coverage and the ability to mobilise large field teams to any location. This allows us to respond rapidly according to weather and environmental conditions.

As well as carrying out walkover surveys, our field team also provides expert advice on the design of the surveys and strategies for delivering them.

Walkover survey experience

  • Fish habitat assessments, both coarse and salmonid fish.
  • Ecological habitat assessments.
  • Sediment and diffuse pollution tracing in urban and rural areas.
  • Geomorphological and fluvial walkover surveys.
  • River habitat surveys.
  • Lake habitat surveys.
  • Fish passage and barrier assessments.
  • Protected and invasive species walkovers.
  • River restoration walkover surveys.

  • Field scientist gathering samples from a stream

Key walkover survey projects

Ecological Habitat Assessment

Walkover surveys of river habitats using field mapping techniques provide a detailed representation of the precise location and extent of various habitat features.

River habitat survey (RHS) is a classification system to describe the physical features that occur in different river types to provide a standard multifunctional habitat assessment technique for rivers.

We have undertaken 500 baseline River habitat surveys across England and Wales on behalf on the Environment Agency to ensure compliance with the EU Habitats Directive.

Diffuse pollution tracing and mitigation

Catchment-wide diffuse pollution and deposition of excessive fine sediment are major pressures on freshwater ecology and water quality. APEM collaborated with the Environment Agency to develop a standardised methodology for the identification and classification of diffuse pollution sources.

This method involved a walkover survey of priority waterbodies and surrounding landscape to identify sources of fine sediment and other diffuse contaminants, encompassing more than 25,000 potential sources on over 10,000 km of river.

Fish population habitat and mapping

APEM conducts salmonid and coarse fish habitat walkover mapping to generate a baseline of habitat availability.

Field walkover maps are transcribed into GIS to provide user-friendly data showing the relative abundance and spatial distribution of the various habitats identified. The information also shows features of note, such as in-river obstructions that are potential barriers to migrating fish and river flow.

Our teams have undertaken coarse fish habitat mapping surveys on the rivers Mease, Wensum and Cleddau and salmonid habitat mapping on the rivers Tyne, Otter, Tamar, Trent, Vyrnwy, Conwy, Wyre, Avon, Mersey and many others throughout the UK.

If you have any queries, please contact Peter Dennis, principal aquatic scientist.
Alternatively you can email us here. Or call 0161 442 8938.