Healthy & Biologically Diverse Seas Evidence Group: Evaluation and gap analysis of current and potential indicators for Deep Sea Habitats
(August 2010)
A Benn, J A Hughes and T FitzGeorge-Balfour



A range of national and international legislation, obligations and commitments aim to promote and maintain a healthy and biologically diverse marine environment from intertidal waters to the deep sea. These require sustained and routine observations to achieve their objectives. This report evaluates the applicability of twenty seven potential environmental indicators, identifies gaps, and suggests indicators that could be used to monitor and assess the state of UK deep-sea habitats. These indicators are reviewed against potential anthropogenic pressures, together with ecosystem structure and function.  Of these twenty seven indicators, eighteen were assessed as “recommended”, and can be mapped to the assessment framework and may be used within an integrated monitoring programme. Of the eighteen recommended, twelve are indicators of ecosystem structure/function, three of pressure, two of state change/impact and one is an indicator of activity.


The deep sea is the largest ecosystem on earth, and is thought to contain more species than any other habitat.  While attaching a monetary value to the deep sea is difficult, it provides a number of important ecosystem functions which may alter in response to anthropogenic pressures. The deep sea also provides a range of ecosystem goods and services (i.e. human benefits directly or indirectly derived from ecosystem functions). In particular, maintenance of biodiversity is thought to be essential to ecosystem stability, so that loss of species may detrimentally influence ecosystem function, and therefore the provision of goods and services.  The principal anthropogenic pressures that may have an impact on UK deep-sea habitats are identified as demersal fisheries, oil and gas industry activities, land-based/shipping pollution and climate change. At present, there are no routine UK deep-sea environment monitoring programmes and the only protected area in UK deep waters is the Darwin Mounds region.  Regional and international statutory obligations are therefore not being fully addressed or fulfilled.


While a number of indicators address aspects of ecosystem structure of deep-sea benthic ecosystems, there are major gaps in indicators of ecosystem function, underpinned by our lack of knowledge of deep-sea ecosystems in general.  While this lack of knowledge is being addressed by researchers, it is unlikely that ongoing research efforts will lead to the development of relevant indicators in the near future.  The development of an effective monitoring programme will require improved knowledge of deep-sea habitats in UK waters, together with more research on the impacts of different pressures. Also, monitoring should not focus only on ‘charismatic’ species (e.g. corals and sponges); while these may act as “umbrella species”, a huge number of small, poorly known species live in the deep sea, forming the major component of the biodiversity and playing an important role in ecosystem functioning. Less charismatic species should not be overlooked from either a monitoring or conservation perspective.




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A4, soft back, 54 pp
ISBN 978-1-86107-623-6
Please cite as: A Benn, J A Hughes and T FitzGeorge-Balfour, (August 2010), Healthy & Biologically Diverse Seas Evidence Group: Evaluation and gap analysis of current and potential indicators for Deep Sea Habitats, A4, soft back, 54 pp, ISBN 978-1-86107-623-6