Defining and sustaining healthy seas
Submitting InstitutionEdinburgh Napier University
Unit of AssessmentEarth Systems and Environmental Sciences
Summary Impact TypeEnvironmental
Research Subject Area(s)
Earth Sciences: Oceanography
Environmental Sciences: Environmental Science and Management
Biological Sciences: Ecology
Summary of the impact
Managing and conserving the marine environment requires defining what
constitutes healthy ecosystems and understanding the effects of pollution.
Edinburgh Napier University (ENU) research defining `undesirable
disturbance' allowed the United Kingdom (UK) to mount a successful defence
at the European Court of Justice in 2009 against alleged infraction of UK
obligations under the Urban Waste Water Treatment Directive. This saved UK
taxpayers £6 billion in estimated additional costs. The European Union
(EU) Marine Strategy Framework Directive uses a definition of good status
for pelagic habitats derived from work at ENU, which benefits policy
makers and marine stakeholders by facilitating the establishment of Marine
ENU has a long history of applied marine research including the first UK
Master's degree in the biology of water resource management (1979), and
early work on pollution in the Forth. Three related questions underpin
this work from these origins until today: 1) How do we know what
conditions are `natural' or `healthy'? 2) How can we detect changes from a
healthy state? 3) How can we predict the impacts of pollution and
disturbance on marine systems? Answering these questions for phytoplankton
communities was the main focus of the group led by Professor Paul Tett
(ENU, 1996 - 2009, when the research underpinning this case was
conducted). Using modelling, field sampling and laboratory approaches, the
Tett group explored the relationships between nutrient inputs and
phytoplankton growth. They explained seasonal cycles under natural
conditions in Scotland (e.g. with J. Lee, ENU, 1996 - 2002)3.4
and in Northern Ireland (with E. Capuzzo, 2005 - 2011 funded by the Loughs
Agency), and under conditions of enhanced nutrient inputs (with V.
Edwards, 1997 - 2001, co-supervised with the Scottish Environment
Protection Agency; (SEPA))3.5.
This work modelled the `assimilative capacity' of water bodies. The
concept of assimilative capacity informs policy on pollution control. It
assumes that there are acceptable quantities of pollution that can be
absorbed by natural environments. Exceeding these limits results in
detectable impacts that should be avoided. For example, inputs of
nutrients that exceed limits can lead to eutrophication. The core
predictive model developed and refined by the Tett team (with the Scottish
Association for Marine Science, (SAMS)) is known as the CSTT (after the
`Comprehensive Studies Task Team' established by the UK Government). This
predicts plankton biomass given nutrient and light conditions. Model
predictions were validated, by ENU, SAMS and others, against observations
from the Mediterranean to the Arctic in the European project OAERRE3.3,
and in Loch Creran by ENU-SAMS PhD student C. Laurent 3.2.
Applying biological understanding to policy required clear definitions of
terms. The Urban Waste Water Treatment Directive (EEC 1991) gives the
following definition of eutrophication: "The enrichment of waters by
nutrients... causing an accelerated growth of algae... to produce an undesirable
disturbance to the balance of organisms present in the water". Hence
defining `undesirable disturbance' is of crucial importance in applying
this directive. Work led by Prof. Tett, funded by the UK Government
(Department for Environment, Food and Rural Affairs; DEFRA) and with other
permanent ENU staff (Mark Huxham, 1995 — present, Teresa Fernandes, 1994 - 2012 and Linda Gilpin, 1996 — present), and colleagues from SAMS, the
Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Hull
University and elsewhere, produced a working definition of this term that
has since been used by policy makers3.1.
The latest developments in using phytoplankton science to inform policy
have come from the Tett team's invention of the Phytoplankton Community
Index (PCI). Work on undesirable disturbance showed how biomass
alone was an insufficient indicator: the balance of types of organisms is
also crucial. The PCI applies life form theory to phytoplankton modelling
which allows an understanding of when ecosystems are moving towards less
desirable states, without the burdensome requirement to identify all taxa
to species level.
References to the research
Selected peer reviewed papers:
3.1 Tett, P., R. Gowen, D. Mills, T. Fernandes, L. Gilpin, M.
Huxham, K. Kennington, P. Read, M. Service, M. Wilkinson and S. Malcolm
(2007) Defining and detecting Undesirable Disturbance in the context of
Eutrophication. Marine Pollution Bulletin 55, 282-297.
3.2 Laurent, C., P. Tett, T. Fernandes, L. Gilpin and K. J.
Jones (2006) A dynamic CSTT model for the effects of added nutrients in
Loch Creran, a shallow fjord. Journal of Marine Systems 61,
3.3 Tett, P., L. Gilpin, H. Svendsen, C. P. Erlandsson, U.
Larsson, S. Kratzer, E. Fouilland, C. Janzen, J.-Y. Lee, C. Grenz, A.
Newton, J. G. Ferreira, T. Fernandes and S. Scory (2003) Eutrophication
and some European waters of restricted exchange. Continental Shelf
Research 23, 1635-1671.
3.4 Lee, J.-Y., P. Tett and K.-R. Kim (2003)
Parameterising a Microplankton Model. Journal of the Korean Society of
Oceanography 38, 185-210.
3.5 Edwards, V. R., P. Tett and K. J. Jones (2003) Changes in
the yield of chlorophyll a from dissolved available inorganic nitrogen
after an enrichment event — applications for predicting eutrophication in
coastal waters. Continental Shelf Research 23, 1771-1785.
3.6 Gowen, R.J., P. Tett, K. Kennington, D.K. Mills, T.M.
Shammon, B.M. Stewart, N. Greenwood, C. Flanagan, M. Devlin and A. Wither
(2008) The Irish Sea: is it eutrophic? Estuarine, Coastal and Shelf
Science 76, 239-254.
Key grants related to research covered in this case study:
S.N.I.F.F.E.R. `Yield of marine phytoplankton chlorophyll from dissolved
inorganic nitrogen under eutrophic conditions' ($35579 for 3 years from
October 1997, a research studentship jointly supervised by P. Tett, K.
Jones (Natural Environment Research Council Dunstaffnage Marine
Laboratory) and R. Park (SEPA).
DEFRA `Understanding of Undesirable Disturbance in the context of
eutrophication, and development of UK assessment methodology for coastal
and marine waters' (£45,992 in 2004, to a consortium led by ENU: other
members were, Heriot-Watt University, Liverpool University, CEFAS, and the
Department of Agriculture and Rural Development).
DEFRA /CEFAS: `Research supporting the development of eutrophication
monitoring and assessment' (CEFAS contract leader was Dr D. Mills,
Subcontract ME2202 from CEFAS to ENU for £57,818, September 2004 to
February 2007; extended into 2009, and used as a vehicle for providing
advice to DEFRA in relation to the `Scientific analysis and contributions
to UK evidence and arguments concerning eutrophic status of estuaries and
coastal waters in UWWTD case 1998/2265'.
DEFRA/CEFAS: `Development of a phytoplankton trophic index'. (CEFAS, CSA
6754 contract leader was Dr D. Mills; subcontract ME2204 to ENU for
£35,700, December 2004 to March 2006).
Details of the impact
The most significant impact arising from this work was the role it played
in determining UK policy in response to the Urban Waste Water Treatment
Directive (UWWTD). Specifically, the work led by Professor Tett saved the
UK approximately £6 billion (as estimated by the Environment Agency) with
UK taxpayers as the ultimate beneficiaries.
The UWWTD governs how member states should treat sewage discharges into
coastal waters. It requires the application of tertiary treatment to
remove nutrients when discharges occur into eutrophic waters. In 1999, the
European Commission (EC) accused the UK of infracting the UWWTD by failing
to identify certain coastal waters in England and Wales as eutrophic, and
the case came before the European Court of Justice (ECJ) in 2007.
Defending the case involved empirical work on the relationships between
nutrients and algal growth and conceptual clarity around what was meant by
the key term undesirable disturbance taken from the UWWTD
definition of eutrophication.
In anticipation of this case, in 2004, DEFRA commissioned a review of
'undesirable disturbance in the context of eutrophication' from a group
led by Tett. The group (see Tett et al., 2007)3.1
concluded that `an undesirable disturbance is a perturbation of a
marine ecosystem that appreciably degrades the health or threatens the
sustainable human use of that ecosystem', and proposed methods for
detecting such disturbance. The methods were applied by a team including
Tett and colleagues from SAMS, CEFAS, the Agri-Food and Biosciences
Institute, and elsewhere, to show lack of undesirable disturbance in the
Irish Sea, one of the contested areas (Gowen et al., 2008)3.6.
During the defence, the UK was able to cite the undesirable disturbance
work and the arguments were accepted by the Court (e.g. para. 330, 332 — they refer to the paper as the Gowen report 2007)5.1,5.2. In
addition, evidence from Tett and Gowen on the biology of phytoplankton
growth was presented orally to court in April 2009. This drew on the CSTT
work and demonstrated that most UK coastal waters were light limited
because of turbidity, which was crucial in winning the case5.1.
In December 2009, it was announced that the UK had won the relevant part
of its case (ECJ, 2009), thus avoiding fines, and the necessity for very
expensive tertiary sewage treatment plants. The work has influenced other
areas of UK response to EU legislation, for example the EU's Marine
Strategy Framework Directive (adopted in June 2008). This aims to protect
the marine environment across Europe by achieving `good environmental
status' of the EU's marine waters by 2020, and to protect the resource
base upon which marine-related economic and social activities depend. As
in the case of the UWWTD, implementing the legislation requires conceptual
clarity about key terms and the scientific tools and procedures to measure
the relevant variables. In particular, it requires that the commission
should lay down criteria and methodological standards to allow consistency
of approach in evaluating the extent to which Good Environmental Status
(GES) is being achieved. The Commission established Task Groups of experts
to achieve this for each of the descriptors in the directive. Task group 5
reported on eutrophication in 20105.3. It included Tett as one
of the expert authors, and drew on the work on undesirable disturbance and
the plankton community index to establish standards that will be used in
implementing the directive across the EU, thus helping to maintain and
enhance the health of the marine environment within the EU.
Impacts of the work in defining assimilative capacity and undesirable
disturbance included policy on aquaculture, in particular on the siting of
finfish and shellfish farms5.4. Tett and Fernandes were authors
on the Huntington et al. 2006 report to the Directorate-General
for Fish and Maritime Affairs of the EC on `Some Aspects of the
Environmental Impact of Aquaculture in Sensitive Areas'. This has been
used by the EC to inform policy on aquaculture. It has also informed the
application of the Marine Stewardship Council (MSC) sustainable fisheries
certification in Scottish waters. For example, the Shetland and Scottish
Mainland Rope Grown mussel Enhanced fishery was certified by the MSC in
April 2012, using Huntington et al. 2006 to support their
`principle 2 — ecosystem sustainability'5.5. This industry is
growing rapidly, with more than 7,000 tonnes produced in 2010. Its further
growth will be supported by the MSC accreditation.
Hence, the ENU work on healthy seas has established a strong tradition of
interpreting fundamental ecological concepts, such as ecosystem health,
and facilitating their application by policy makers in settings from
pollution control to ecosystem restoration.
Sources to corroborate the impact
5.1Corroboration from key individual: Science Leader at CEFAS.
This person can corroborate the impacts of the UWWTD related work.
5.2ECJ (2009). Commission of the European Communities v United
Kingdom supported by Portuguese Republic. Judgement of the European Court
of Justice (3rd chamber) on 10 December 2009, In Case C-390/07, under
Article 226 EC for failure to fulfil obligations, pursuant to Articles
3(1) and (2) and 5(1) to (3) and (5) of, and Annex II to, Council
Directive 91/271/EEC of 21 May 1991 concerning urban waste water treatment
(OJ 1991 L 135, p. 40).
A link to this judgement from the European court — note paragraphs 330
and 332 as examples of references to the work described here:
5.3Report of the Marine Strategy Framework Directive task
group 5 on eutrophication, with Tett as an expert author:
5.4Programme manager for Marine Spatial Planning with Marine
Science Scotland. This individual can corroborate the importance of the
aquaculture impacts and siting work.
5.5For evidence of the use of assimilative capacity in
aquaculture see, e.g. p 94 from the Marine Stewardship Council