Background to the MESH Project

The seas around north-west Europe support an exceptionally wide range of seabed habitats and rich biodiversity. These provide important food resources (fish, shellfish), contribute to essential ecosystem functioning (such as nutrient recycling) and yield valuable natural resources (oil, gas, aggregates). In addition the seabed is subject to increasing pressures from new developments, such as for renewable energy (e.g. wind-farms) and coastal developments for leisure activities and coastal defences.

These multiple uses bring ever-growing pressures on our seas and coasts, leading to increased risk of conflict between users with a greater potential for degradation of the marine environment and the essential physical, chemical and biological processes that maintain our marine ecosystem. We are responding to this challenge through recognising the need for much improved integrated spatial planning for our seas (where traditionally planning has been very piecemeal or sectoral), as reflected by the new requirement for Strategic Environmental Assessments (SEAs) and issues raised recently within the developing EU Marine Strategy, by the OSPAR Commission and by national governments (e.g. the UK's Marine Stewardship Report). Additionally there are new and increasing international commitments (from the EC Habitats Directive and OSPAR) to protect certain marine habitats, including through the designation of a network of marine protected areas, whilst the EC Water Framework Directive and OSPAR require periodic assessment of ecosystem health, including its seabed biological communities. The assessment of coastal sensitivity to oil spills is currently hampered by the lack of proper data on habitats, as has been shown by the recent Prestige case in France.

Mapping EUNIS habitats in the MESH study area

All this creates a substantial demand for information about intertidal and seabed habitats, but is set against a background of patchy, inconsistent and poorly collated information on their distribution, extent and quality. There are few national programmes in the north-west Europe region which collate such information (except in France) and the information which is available is difficult to access, making very poor use of data which are expensive to collect. The recent increase in demand, coupled with advances in remote-sensing technologies over the past ten years, has led to a burgeoning of seabed mapping studies. These are undertaken using a variety of techniques, for a range of end needs (e.g. fisheries, commercial, nature conservation) and at various scales. The lack of international standards for these studies means the resulting data cannot readily be compared or aggregated and leads to an absence of regional, national and international perspectives on the seabed resource in spatial planning and decision-making.

What is MESH doing?

The intention of the MESH project is not to go out and map the entire North West Europe seabeds (this would be a huge job in terms of both time and cost). Instead, our first task was to bring together and collate all the existing maps held in Europe (some dating back to 1870) and to harmonise them into the standard European classification scheme. This information is now available through an interactive web-based mapping system.

Alongside this have worked to set standards and protocols for the use of surveying and sampling methods and technologies in marine habitat mapping. This will help improve the quality and consistency of future survey work.

During the process of setting these standards we needed to do some field study work in order to test them for both quality and practicality. Doing this testing work also contributed data to help fill in gaps in the information we have managed to gather together.

Once we had gathered together and assessed all existing data as well as setting and testing standards the results revealed large gaps in the information that we have. Ideally we would have liked to survey all these areas, but as before, cost is a large factor. Instead, we developed methods to predict habitats based on many factors including; depth, temperature and underlying rock type, i.e. use the existing information we had access to predict the seabed habitats. As well as filling in gaps in the information coverage this also helped us understand the processes determining the existence of a particular habitat in a particular location.

MESH has addressed the above issues in the following key ways:

Compiling available seabed habitat mapping information across north-west Europe and harmonising it according to European habitat classification schemes (the European Environment Agency's EUNIS system and the EC Habitats Directive types) to provide the first seabed habitat maps for north-west Europe (see map).
Existing studies were of variable quality and, more importantly, did not cover the entire study area. Habitat models were developed to predict the distribution of habitats in unsampled areas from the more widely available geophysical and hydrographic data. The final maps are presented with a quality rating so that end-users can determine their adequacy for their decision-making, and future survey effort can be strategically directed to areas with relatively low quality maps or little existing information.
A set of internationally agreed Recommended Operating Guidelines (ROGS) for habitat mapping have been developed following a review of protocols and standards, drawing upon the best available expertise across Europe and elsewhere, to help ensure that future mapping programmes yield quality assured data that can be readily exchanged and aggregated to further improve the initial maps. The protocols were tested through a range of field-testing scenarios involving trans-national co-operation to ensure they are robust and the results repeatable.
Both the protocols and the habitat maps have been made available through the website. The maps are displayed using an interactive Geographical Information System (GIS) that allows users to customise the map view by selecting layers of their choice and zooming to their location of interest. The website provides ready access to the information for a wide range of end-users at local, regional, national and international levels (e.g. spatial planners and managers; governments and other regulatory authorities, research institutions, educational establishments).
A wide spectrum of potential end-users have been engaged from the start of the project to help gain a better understanding of their requirements, and to encourage the supply of relevant data to the project. End-users are encouraged to use the mapping information in their spatial planning, management issues and for environmental protection. The network of stakeholders will continue to be valuable in helping to forge strategies within each country for the maintenance and further improvement of the seabed maps beyond the end of this project.

A separate guide is available for the non-scientist.

* © Crown copyright, all rights reserved. This photograph was produced as part of the UK Department of Trade and Industry's offshore energy Strategic Environmental Assessment programme. The SEA programme is funded and managed by the DTI and coordinated on their behalf by Geotek Ltd and Hartley Anderson Ltd.