What is habitat mapping?
Habitat mapping is defined by the MESH Project to be:
Plotting the distribution and extent of habitats to
create a map with complete coverage of the seabed showing
distinct boundaries separating adjacent habitats.
Throughout the MESH Guide, the term 'seabed' refers
to both intertidal and subtidal areas; the habitat mapping process
applies equally to both areas.
Habitat mapping within this MESH Guide
specific methodology: seabed habitat maps show the distribution of
habitats by interpreting physical data layers, often derived from
remote sensing, using biological information about habitats
obtained from direct sampling and observation of the seabed. Only a
small proportion of the seabed can be observed or sampled and the
complete coverage of habitats is inferred from the association
between the physical habitat data and the seabed samples so the
final maps predict
the distribution of
seabed habitats. The physical habitat factors act as a proxy
biological habitat data.
A summary of the habitat mapping process
promoted by the MESH Project. It is important to remember that the
final map predicts the distribution of habitats.
Full coverage maps of physical habitat factors (the proxy
data) are obtained either directly from some form of remote sensing
(e.g. bathymetry from acoustic surveys) or derived from
mathematical models of the marine environment (e.g. wave energy
from weather prediction models). The inferential process to link
the sample data with the physical maps is loosely termed modelling.
In some cases this may be a simple process of using expert
judgement whilst, in other cases, the modelling
take the form of a multi-step process of transforming and combining
many datasets to derive the final maps.
In summary the habitat mapping process involves surveying,
collating information, analysing and modelling data to derive the
habitat distribution and then designing the layout of habitat
maps that are clear and fit for their intended purpose.
The present Chapter introduces the topic of marine habitat
mapping by laying the foundations needed for the user to fully
understand the basic concepts, uses and limitations of marine
habitat mapping and sets the scene for subsequent Chapters. It
- Habitat mapping in MESH - outlines the process
of mapping, including how this can be tackled over a range of
scales and levels of detail. The relationship between what can be
detected by survey techniques and habitat variability is discussed.
The types of data needed to make maps, linking environmental
variables to the physical and biological characteristics of the
seabed, are outlined.
- Why do we need habitat maps? -
provides an overview of the main uses for habitat maps and some key
policy drivers which rely on this information.
are habitats? - describes the concept of a habitat and their
variability in space and scale, together with an introduction to
schemes for their classification.
- What do you want to map? - explains some of the
basic concepts of habitat mapping, concentrating on the need to
clearly establish the level of habitat detail required, and the
geographic area to map. It also explain why some habitats
cannot be mapped, or not displayed on maps of the chosen
- How do you map habitats? - describes some
of the different approaches to habitat mapping and explains what
type of data are required for different types of habitat.
- What are the limitations of habitat
mapping? - explains what can be displayed on a map, suggests
what maps can and cannot do, and explains why some habitats cannot
be mapped. It also introduces the concepts of accuracy and
confidence, and how maps need to change over time to reflect
improved data and temporal changes in the environment.
management - introduces the needs for sound data management,
and the requirements for metadata throughout the mapping
- How do you plan for habitat mapping? -
describes the basic considerations required to effectively plan a
habitat mapping project. It sets out the main steps in the planning
cycle and provides links to the relevant sections in the MESH Guide
that offer further more detailed information on each topic.
Links to other sections: