Responses of estuaries to natural and ... - University of Hull

Responses of estuaries to natural
and anthropogenic changes:
perspectives and a global view
Mike Elliott (* 1 ) and Victor N. de Jonge (* 1,2 )
* 1 Institute of Estuarine & Coastal Studies, University of Hull,
UK
* 2 Dept Marine Biology, University of Groningen, Netherlands
mike.elliott@hull.ac.uk, v.n.de.jonge@biol.rug.nl
http://www.hull.ac.uk/iecs

Content:
• Framework for assessing change
• Science direction and framework
• Threats & challenges
• Data and information for management
• Health, resilience, vigour & organisation
• Scale of change and indicators
• Carrying capacity, habitat loss & creation
• Biodiversity changes & challenges
• Society, eco-change & management

DPSIR Approach
Driving forces (human activities and economic sectors
responsible for the pressures);
Pressures (particular stressors on the environment in the
form of direct pressures such as emissions);
State Changes (environmental variables
(geo/physical/chemical/biological) which describe the
characteristics and conditions of the coastal zone);
Impact (changes in the ecosystem, resources, human
health);
Response (measurement of different policy options as a
response to the environmental problems).
(see Elliott, 2002, Mar. Poll. Bull.)

RESPONSES
Measurement of Policy Options
- Administration
- Legislation
- EU Urban Waste Water Treatment Dir.
- EU Nitrates Dir.
(4) Socio-
Economics
(3) Admin &
Legislation
IMPACT
Changes to the System
- Impact on human health
- Impact on tourism/recreation
- Changes to ecosystem processes
- Changes to ecosystem functions
- Changes to ecosystem structure
DRIVING FORCES
Human Activities Responsible
- Agricultural intensification
- Increasing human populations
(3) Admin &
Legislation
(2) Ecological
Modelling
(1) Ecological
Impacts
NATURAL CHANGE
PRESSURES
e.g. Emissions to the Environment
- Increased nutrients from agriculture
(diffuse pollution)
- Increased nutrients from UWWT plant
(point source)
(2) Ecological
Modelling
(1) Ecological
Impacts
STATE CHANGES
Environmental Variables
- Changes in nutrient loads
- Increased occurrence of
eutrophic signs/symptoms
(1) Ecological
Impacts
Application of the DPSIR approach e.g. to the problem
of eutrophication (NB cyclical to helical)

The endless loop
Ecology
Fysische
systeem
Fysischchemische
systeem
Biologische systeem
effect on
human
environment
changes
Economische systeem
choices
Hoofdfactor 1
Productiemogelijkheden
Hoofdfactor 2
Prijsverhoudingen
Economy
appreciation
environment
well-being
perspective and
potential
Human desires
technical
developments

The endless loop
State change & impact
Ecology
Fysische
systeem
Fysischchemische
systeem
Biologische systeem
effect on
human
environment
changes
Economische systeem
Impact & response
choices
Hoofdfactor 1
Productiemogelijkheden
Hoofdfactor 2
Prijsverhoudingen
Economy
State change & impact
appreciation
environment
Driver 2
well-being
Driver 2
perspective and
potential
Driver 1
Human desires
technical
developments

Science, information & data needs
for understanding and management:
• Explicit and implicit
• Adequacy of understanding and the
available data
• Adequacy of generic conceptual models
and then to quantify the processes
• Ability to upscale, hindcast & predict
• Ability to translate to other systems

An example of the adequacy of our
scientific understanding:
• Underlying processes
• Conceptual models
• Predictive (empirical, deterministic,
stochastic models)
• Ecosystem models

atural factors
natural variation
(noise)
Physical
system
Physicochemical
system
The integral system
Ecological
system
Biological
system
process
structure
Ecological quality:
-absolute species numbers
-diversity
-community structure
-landscape
Judgement of the environmental
quality by the social community
Consumer preferences
(DEMAND)
Judgement of the
environmental quality by
the social community
Economic
system
(COST)
Production possibilities
Economic quality:
(AVAILABILITY)
Judgement of the
economical quality by
the social community
Anthropogeni
plans & activities
de Jonge et al. 2003

Interaction between man and nature
Anthropogenic
factors =
man induced variation
Physical system
influencing
- morphological change
- turbidity change
- modification of area
Chemical factors
influencing:
- nutrient loads &
concentrations
Direct ecosystem
influence:
- habitat change
Natural factors
natural variation
Determining physical
factors
Determining chemical
factors
Judgement of the
natural environment
Physical
Physicochemical
Process level
Ecological
system
system
Biological
Ecological quality
at different levels:
de Jonge et al. 2003

Wind & SPM:
‘noise’ to the one is ‘signal’ to the other
Suspended matter concentrations
de Jonge 1995

Water discharge & SPM:
L. Ametistova & I.S.F. Jones 2004
SPM
(mg l -1 )
180
160
140
120
100
80
60
40
20
0
y = 23.674e 0.0006x
R 2 = 0.6985
Herbert river estuary
0 500 1000 1500 2000 2500 3000
Discharge (m 3 s -1 )
non linear response
local resuspension, density circulation, transport capacity ?

Response area
(> 100 km away)
Marsdiep (1)
oswal Noord-west
ump site
River Scheldt
Vlie (2)
Dantzig Gat (5)
Blauwe Slenk (6)
Doove Balg oost (4)
Doove Balg west (3)
Ems estuary
River Rhine
Other non-linear
response curves
from
The Netherlands
de Jonge & de Jong, 2003

SPM
(g m -3 )
120
100
80
60
40
20
0
red: y = 1.11x + 28.49
R 2 = 0.83
de Jonge & de Jong, 2003
black: y = 36.90e 0.02x
R 2 = 0.89
0 10 20 30 40 50 60
km dredging

36.9 e
non-linear
> 2-fold increase
Y= 36.9e 0.016x
R 2 = 0.89
R = 0.94
NIET MEEGENOMEN
Dredging &
SPM:
Non-linear
system response
Possibly due to
amplified
erosion-sedimentation
cycle
de Jonge 1983

SPM
(g m -3 )
120.0
100.0
80.0
60.0
40.0
20.0
0.0
Mean annual suspended matter concentration at station
Marsdiep plotted as function of spoil disposal at Loswal N
and NW
y = 12.42e 0.0816x
5-fold increase
Non-linear
R 2 = 0.6274
0 5 10 15 20 25 30
disposed dredge spoil
(x 10 6 m 3 a -1 )
isposal of dredge spoil & SPM ‘at distance’:

SPM
SPM
(g m -3 g m
100
)
-3 )
120.0
100.0
80.0
60.0
40.0
20.0
0.0
80
60
40
20
SPM Mean as annual function suspended of dredge matter disposal concentration at station
Marsdiep plotted as function of spoil disposal at Loswal N
and NW y = 12.841e 0.0787x
5-fold increase
Non-linear
y = 12.42e 0.0816x
R 2 = 0.6274
y = 14.097e 0.0594x
y = 11.711e 0.0542x
0 5 10 15 20 25 30
0
disposed dredge spoil
(x 10 6 m 3 a -1 )
0 5 10 15 20 25 30
Sediment disposed (10 6 m 3 .a -1 )
isposal of dredge spoil & SPM ‘at distance’:

SPM
(g m
120.0
100.0
80.0
60.0
40.0
20.0
0.0
-3 )
Mean annual suspended matter concentration at station
Marsdiep plotted as function of spoil disposal at Loswal N
and NW
y = 12.42e 0.0816x
R 2 = 0.6274
0 5 10 15 20 25 30
disposed dredge spoil
(x 10 6 m 3 a -1 )
response
weakening
SPM
(g m -3 )
de Jonge & de Jong, 2003
80.0
60.0
40.0
20.0
0.0
Mean annual suspended matter concentration at station Vlie
plotted as function of spoil disposal at Loswal N and NW
y = 14.752e 0.0579x
R 2 = 0.5092
0 5 10 15 20 25 30
disposed dredge spoil
(x 10 6 m 3 a -1 )
SPM
(g m -3 )
60.0
40.0
20.0
Non-linear response of the the Wadden Sea
to spoil dump from Rotterdam harbours
possibly due to amplified density driven
sediment accumulation in relation to river
Mean annual suspended matter concentration at station
Doove Balg West plotted as function of spoil disposal at
Loswal N and NW
y = 12.33e 0.0525x
R 2 = 0.4692
0.0
0 5 10 15 20 25 30
disposed dredge spoil
(x 10 6 m 3 a -1 )
SPM
(g m -3 )
60.0
40.0
20.0
plume size
Mean annual suspended matter concentration at station
Doove Balg Oost plotted as function of spoil disposal at
Loswal N and NW
y = 24.979e 0.0224x
R 2 = 0.1723
0.0
0 5 10 15 20 25 30
disposed dredge spoil
(x 10 6 m 3 a -1 )
SPM
(g m -3 )
150.0
120.0
90.0
60.0
Mean annual suspended matter concentration at station
Blauwe Slenk plotted as function of spoil disposal at Loswal
N and NW
y = 48.321e 0.0128x
R 2 = 0.0363
30.0
0.0
0 5 10 15 20 25 30
disposed dredge spoil
(x 10 6 m 3 a -1 )

North Sea
tidal import & accumulation
residual transport
&
coastal accumulation
stuarine circulation,
iver and tidal import
SPM accumulation
ud supply from
trait of Dover &
lemish Banks
Wadden Sea
TIDE & DENSITY DOMINATED de Jonge & de Jong, 2003
WIND DOMINATED
river supply

140
120
100
80
60
40
20
20
18
Seagrass
Critical Loads (mg-N m -2 d -1 )
6
16
40 60 80 100 120 140 160 180 200
8
14
10
14
12

ocess level

oundaries between fresh and brackish
rticle 2: definitions: boundaries of transitional area
1. Suggested criterion is clear
2. Implications of criterion are not clear because of
sedimentological impact to the tidal fresh water area
‘real’ river
phosphate concentration
river sea
De Jonge & Elliott 2001
salinity
Process level

De Jonge & Elliott 2001

traits of Dover
r away from
y backyard’
DIN
Process level
DIP
2-fold
3-fold
winter values
start of P-decline
Wadden Sea

ue to management
easures in 1990 the
ake IJsselmeer DIP
as lower than that of
he Straits of Dover
his may have
onsequences for
efining ‘targets’

Defining goals:
Natural North background Sea data (before the introduction of extra P & N)
Straits of Dover
tP 0.45
tN 5.5
North Sea
tP 0.7
tN 10
North Sea coast
tP 0.6 - 0.8
tN 7 - 13
Dutch Wadden Sea
tP 0.7 - 0.9
tN 8 - 15
rivers Rhine & Ems
tP 1.8
tN 45
van Raaphorst et al. 2000
van Raaphorst & de Jonge 2004

Concentration (mg-N m -2 )
Hysteresis in response to N loads
2500
2000
1500
1000
500
0
Large Phytoplankton
Seagrass
No
denitrification
Rising Load
0 10 20 30 40
Load (mg-N m -2 d -1 )
Yes
Anoxia

Enhanced production in tropical
estuarine systems is usually
controlled by strong
pulse of freshwater
Chlorophyll may increase in
coastal/shelf environments with
increased nutrient loading due to
less light limitation
ut, what about intertidal seagrasses
ke eelgrass?
Twilley 2004
Phytoplankton
Seagrasses
Mangroves
Productivity
1.0
0.5
0.0
Light Availability
Residence Time (months)
Nutrient Inputs
Reef Lagoon Estuary Delta
(Low energy Wind/Tides River/Tides Ri
Geomorphological Setting
Terrigenous Sediment Input
Eutrophication

Stable versus unstable conditions
Simple Plankton Model
From Huisman and
Weissing, 2001

Simple Plankton Model
Findings
Complex behaviour might be possible in plankton
systems
(occurrence sensitive to community structure)
Large hydraulic disturbances may suppress complex
behaviour
Complex behaviour, when possible, may be robust
Roelke 2004

oelke et al.
004
Biovolume, µm 3 liter -
Biovolume, µm 3 liter -1
1.40E+11
1.20E+11
1.00E+11
8.00E+10
6.00E+10
4.00E+10
2.00E+10
Others
Francheia Droescheri
Centric sp.
Trebauria sp.
Tetraedron minimum
Ankistrodesmus sp.
Navicula sp.
Nitzschia sp.
0.00E+00
3 6 9 12 15 18 21 24 27 30 33
1.40E+11
1.20E+11
1.00E+11
8.00E+10
6.00E+10
4.00E+10
2.00E+10
0.00E+00
Others
Tetraedron minimum
Chrysidiastrum sp.
Centric sp.
Trebauria sp.
Ankistrodesmus sp.
Navicula sp.
Nitzschia sp.
Days
3 6 9 12 15 18 21 24 27 30 33

One challenge is to link knowledge on
ystem ‘structure’ to that of system ‘functioning’
11184
Energy Flows (kcal m -2 y-1 )
300
Plants
1
2003
8881
635
-fluxes
nformation flows
lows of currency
Detritus
2
3109
860 5205
167
1600
Bacteria
3
3275
2309
200
Carnivores
5
203
75
225
Detrivore
4
370
1814
Tilly, 196

Ascendency vs. Overhead
(“Organization” vs. “disorder”)
Ascendency = (developmental capacity – overhead)
Organization = (developmental capacity – disorder)
Organization
– Growth and development
“Disorder”
– Redundancy
– Dissipation
– Export
De Jonge 2004

Ascendency
(“organization”)
Measure of efficiency of energy flow
Low Ascendency High Ascendency
Fig. Ann Krause

Overhead
(“disorder”)
Measure of inefficiency of energy flow
through the food web
Redundancy
+ Dissipation
Fig. Ann Krause

Simple connections
& efficiency?
Connectivity needs to be made operational
1
2 2
3 3 3 3
4 4 4 4 4 4 4 4
Complex connections
& confusion?
mathematically so that we can apply it
1
2 2
3 3 3 3
4 4 4 4 4 4 4 4
Linear model Hypercoherent model
dapted from:
lannery KV, 1972. The Cultural Evolution of Civilizations, Annual Review of Ecology and
ystematics, pp. 399-426.
Why is this all so interesting??
P Dale 2004

• High variability intrinsic to tidal ecosystems
i.e. no reference ‘state‘, but a reference ‘dynamic‘
- Unpredictability is a key property of tidal zones
and estuaries (Costanza et al. 1993)
- Predictability of spatial dynamics (patterns) in tidal
ecosystems (Grimm et al. 1999)
- Understanding of development of bio-diversity
(Huisman & Weissing 1999 2000 2001ab 2002,
Roelke et al. 2004)
• Identification of stability properties dependant on
spatial and temporal scale of observation
• Timeframe of most projects too short to assess
reference dynamic and resilience
Changed after
Dittmann 2004

Why is it difficult to assess reference states
and resilience?
• High variability intrinsic to tidal ecosystems
i.e. no reference ‘state‘, but a reference ‘dynamic‘
- Unpredictability is a key property of tidal zones
and estuaries (Costanza et al. 1993)
- Predictability of spatial dynamics (patterns) in tidal
ecosystems (Grimm et al. 1999)
- Understanding of development of bio-diversity
(Huisman & Weissing 1999 2000 2001ab 2002,
Roelke et al. 2004)
• Identification of stability properties dependant on
spatial and temporal scale of observation
• Timeframe of most projects too short to assess
reference dynamic and resilience
Changed after
Dittmann 2004

undamental & Applied Sciences Policy/Management
EU-WFD
cientific research & theoretical framework Management application
ystem theory
Network Analysis
knowledge graph theory)
e Jonge et al. 2003
Computer simulation model
Cellular automata
(process oriented)
‘Appealing’ results
(proper scaling in time and space)
Ecological network analysis
(process & species oriented)
Decision making
Conceptual
model
Images
‘Valuation
of nature’
‘Weighing’
Final choice

de Jonge et al. 2003
Fundamental & Applied Sciences Policy/Management
EU-WFD; EU-MS
Scientific research & theoretical framework Management application
Management Tool Kit
Decision making
Network Analysis
(Knowledge Graph Theory)
Computer Simulation Model
Cellular Automata
(process oriented)
‘Appealing’ results
(proper scaling in time and space)
Ecological Network Analysis
(process & species oriented)
Conceptual
model
Images
‘Valuation
of nature’
‘Weighing’
Final choice

ppealing results: Convert in
. indices at different scales
. species indicators
. landscape/ habitat elements
de Jonge et al. 2003
Fundamental & Applied Sciences Policy/Management
EU-WFD; EU-MS
Scientific research & theoretical framework Management application
Management Tool Kit
Network Analysis
(Knowledge Graph Theory)
Dutch
Rijkswaterstaat
Computer Simulation Model
Cellular Automata
(process oriented)
‘Appealing’ results
(proper scaling in time and space)
Ecological Network Analysis
(process & species oriented)
e.g.
AMOEBA approach
Species as indicators
Decision making
Conceptual
model
Images
‘Valuation
of nature’
‘Weighing’
Final choice
To protect ‘structure’ and ‘functioning’ according to EU-WFD

ONCLUSIONS
undamental & Applied Sciences Policy/Management
de Jonge 2004
EU-WFD
esponses of estuaries to natural and anthropogenic changes:
ystem erspectives theory and a global view
Decision making
cientific research & theoretical framework Management application
Network Analysis
nowledge Graph Theory)
further develop
CIENCE:
. variations
. threats
. noise-signal
Computer simulation model
Cellular automata
(process oriented)
maintain
‘Appealing’ results
(proper scaling in time and space)
work on
Ecological network analysis
(process & species oriented)
challenge ?
‘flexible functional indicators’
for variable coastal systems
Conceptual
model
Images
work on
‘Valuation
of nature’
‘Weighing’
Final choice

Traditional Threats (a) vs. Emerging
Issues (b)
(a)
• Contaminant levels
• Physical & chemical
Pollutants
• Water quality
• Toxicity
• Fisheries
• Land claim
• Land use
• Microbial pollutants
(b)
• Irreversible habitat change – loss
• Reduction in productivity and
biodiversity
• Nutrient cycling modification
• Land change and use
• Climate variability and global
change
• Macro-biological pollution
• Sustainable fishing
• Marine energy
• Trace organics, POPs, EDS,
antibiotics
(modified & expanded from Boesch & Paul 2001)

Threats & Challenges: what can be
managed and what cannot?
focus both on:
• large-scale causes (exogenic unmanaged pressures)
such as global climate change
• localised and more manageable change such as
through land-use, resource exploitation and pollution
(*).
(* diffuse inputs, such as the production of
eutrophication signs and symptoms, and point source
inputs, from industry and urban areas.)

Soluble (a) vs Insoluble (b) problems?
(a)
Input of discharges:
• reduction/treatment
• waste minimisation
• diffuse/point sources,
• control by national and
international legislation
(b)
Habitat loss –
• temporary (water quality
barriers/change, dredging,
sea-ice),
• permanent (land claim,
barriers, sea level rise) –
examples of loss and gain
of habitats

Pollutants (old vs. new)
Chemical:
• Heavy metals O
• Organic matter O
• Radioactivity O
• Hydrocarbons O
• Heat O
• Nutrients N
• Persistent organics N
Physical:
Biological:
• Micropathogens O
• Ballast water migrants O
• Invasive macrophytes N
• Introduced parasites N
• GMO’s N
• Inert solids (sediment) O
• Thermal deformations O
• Litter/garbage N
• Large structures N
• Escapees from culture N

Obtaining Data & Information for
Management
• surveillance, compliance, condition and diagnostic
monitoring systems and their outputs against
indicators of change
• To be interpreted against a background of the
resilience of highly variable systems (e.g. estuaries),
the recovery period from different types of stressor
and the differences in that variability and resilience
with latitude
but …...

H&SD
surveillance
Surveillance & Monitoring Terminology
(= added complication)
UK H&SD
surveillance
condition
monitoring
compliance
monitoring
WFD
surveillance
monitoring
operational
monitoring
investigative
monitoring
ME/VNdeJ et al
surveillance:
assessment of status and
features with a posteriori
detection of
changes/trends
monitoring:
determination of specific
features against a preconceived
end-point
applied research:
diagnostic study,
trigger-exceedance study

Threats & Challenges e.g. #1:
• localised and more manageable change e.g.
through land-use, resource exploitation and
pollution;
• manage the causes and consequences on a
local scale.

Organophosphates
(total)
Atrazine
Simazine
Dieldrin
Aldrin
Endrin
Isodrin
DDE
DDT
Endosulfan
HCB
Alpha-HCH
Beta-HCH
Gamma-HCH
Trifluralin
Seawater ng l -1
(median)
5
10
11
5
5
10*
5*
0.005
5
10*
5
5
5
5
5
Sediment mg kg -1 DW
(75 th %ile)
0.0019*
0.0019
0.0038*
0.0019*
0.0019
Severn
Estuary UK
pesticides in
water and
sediments
1995099
(Allen et al 2000)
* possible
tentative
exceedences of
EQS or interim
marine sediment
quality guidelines
(ISQG)
Q. – any biological effects?

Cumulative Species Nos.
120
100
80
60
40
20
0
CUMULATIVE FISH SPECIES RECORDED IN
TIDAL THAMES (FULHAM - TILBURY)
1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002
Year
Example of rehabilitated estuary – the Thames,
London – low level data with high public value (source:
Environment Agency)

10000
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
1985 1989 1990 1991 1992 1993 1994 1995 1996 1997
Year
(b) phosphorus
Tons
600
500
400
300
200
100
0
Agriculture
Natural loading
Atmospheric deposition
Rural communities
Aquaculture
Industry
Rainwater
Sewage treatment plants
Annual inputs to the
Randers Fjord during
1985 and 1989-1997
(data taken from Sømod et al.,
1999)
(a) nitrogen
1985 1989 1990 1991 1992 1993 1994 1995 1996 1997
Agriculture
Natural loading
Atmospheric deposi
Rural communities
Aquaculture
Industry
Rainwater
Sewage treatment p

CONDITIONS SYMPTOMS CONSEQUENCES
LIGHT
atural light
onditions
TRIENT INFLUX
vels
d ratios
& P
SIDENCE TIME
Maintaining high
nitrogen levels
Shading
Increased
primary
production
Maintaining high
phosphorus levels
Species shift in
plants
Reduced
denitrification
Increased
turbidity
Growth of
epiphytes
Species shift of
phytoplankton
Species shift of
vascular plants
Increased
organic matter
decomposition
Reduced
nitrification
Shading of
vascular plants
Harmful and
toxic blooms
Changes in
community
structure
Temporal
hypoxia/
anoxia
Internal
phosphorus
flux
Loss of habitat
Direct human health
problems by toxin
Indirect human health
problems by toxin
accumulation
Fish kills
Reduced habitat for
life stages (spawning)
Mephitic waters
‘Black spots’
intertidal flats
Implications to
fisheries
Implications to
human health
(PSP, ASP, DSP)
Loss of recreational
use
de Jonge & Elliott 2001

uses of
trophication
mary Effects
Primary Symptoms(**) of Eutrophication
Value of tick-list
approach
Increased nutrient inputs
High residence time / slow flushing rate /
poor levels of dilution
Occurrence of blooms of toxic or tainting
phytoplankton forms
Increasing plant/algal biomass production,
both at the micro and/or macro level,
leading to elevated chlorophyll-a
concentrations
Occurrence of blooms of micro-algae which
may be a nuisance (and cause aesthetic
pollution) through foaming (e.g.
Phaeocystis, Chaetoceros socialis)
Decline or disappearance of certain
perennial plants, often replaced by annual,
fast growing opportunistic species such as
foliose or filamentous green algae (e.g.
Ulva, Enteromorpha)
Reduced diversity of the flora (and
associated fauna)
Changes to photic regime through shading
Including Hevring Bay.
Unclear from the literature.
No information identified within the literature sourced.
Inner
Fjord
�
�
�
?
�
�
�
Randers
Fjord
Outer
Fjord*
�
Short retention
time 13 days
�
�
?
�
�
?
Estuary
Plume
�
�
�
�
�
�
-
Lower
Estuary
�
�
�
�
�
�
�
Scheldt
Upper
Estuary
High residence time of the water masses; up
to 70 days for water in upstream areas
�
�
�
�
�
�
�
Fluvial
Estuary
�
�
�
�
�
�
�
Bay of Palma
Inshore
�
Wind driven, poor
turnover ratio
(** also for secondary symptoms)
�
�
�
�
?
�
Offshore
�
�
?
�
?
?
?

Changes as a response
to management actions
EU Nitrates Directive
Re-designation of Nitrate
Vulnerable Zones in
response to EU
recommendation
Tackling diffuse
pollutants – requires
changes to agricultural
systems and society

Inputs
Industry
Sewage - STW
Sewage - CSO
Natural vegetation [*]
Diffuse sources via
freshwater (FWsewage)
Total
Humber Estuary (tentative)
organic budget pre- and
post land-claim
t C yr -1
(

Determining Unhealthy Systems?
Medical (*1) –
• Diagnosis
• Prognosis
• Treatment
• Prevention
(*1 Steevens et al 2001 - Human Ecol. Risk Ass.)
Environmental –
• Assessment (*2)
• Prediction
• Remediation/Creation/
Restoration
• Prevention
(* 2 using extension of
symptoms for the diagnosis
of ecosystem pathology)

Attributes for the diagnosis of ecosystem
pathology: ⇒ 7 indicators for general
application:
• primary production
• nutrients (fate & effects)
• species diversity (abiotic areas)
• community instability (biotic composition)
• size and biomass spectrum
• disease/anomaly prevalence
• contaminant uptake and response

Ecosystem health – V-O-R Approach, to
include:
• Vigour – turnover, throughput or productivity
of the system
• Organisation – species diversity, degree of
connectiveness (food webs, trophic
interactions, predator-prey relationships)
• Resilience – ability to maintain structure and
function despite stress; ability to withstand
sustained or repeated stress
(modified from Boesch & Paul 2001, Human Ecol. Risk Ass)

Conceptual diagram -
ecosystem health
(i.e. vigour x
organisation (=
ascendancy) vs.
resilience
V-O-R properties of
different estuaries with
temporal change (t 1 to
t 5) (from Costanza &
Mageau 1999)
Challenge – quantifying the
model?

Example hypotheses for future study:
• That larger, stable systems are more predictable, and
therefore easier for the use of indicators/objectives
setting and meeting cf. smaller, more variable
systems.
• That the more variable systems such as estuaries are
more resilient to change (greater environmental
homeostasis).
• That the adoption of a reference condition or
favourable conservation status really does imply a
healthy ecosystem.
• Q. – does resilience = assimilative capacity?

Determine, Quantify and Express the
Scale of Change:
• Indicators – pressure/change – morphological,
environmental quality, pressure indicators;
• Challenge – weighting of indicators;
• List of pressures/threats – which involve habitat loss,
species loss;
• Need to define, determine and quantify carrying
capacity;
• Signal-to-noise ratios for given stressors;
• Detection of wide and narrow spatial change (extent
of effect) and long and short term temporal change
(duration of effect).

Define conceptual
models of change (I)
Derive common standards
and reference conditions (I)
Definition of estuary,
coastal systems and
features
Determine appropriate
monitoring (condition,
compliance, diagnostic and
investigative) (I)
Application and assessment – identify
actual and potential threats
Reporting and communication (presentations,
public participation, action plans, awareness) (I)
Define management implications
(infrastructure, socio-economic basis,
navigation, pollution control, etc.)
Define
data needs
Definition of
geographical
area boundaries
Model development: deterministic
(physico-chemical) and
empirical/descriptive (biological)
Comparison against
reference conditions (I)
Carry out
management
Data collection for standard units
(physical, chemical and biological)
Agree legal definitions
Derivation and
production of legal and
administrative
frameworks
Initial estuary
classification (I)
Further categorise
unmodified and modified
areas (I)
Further development
(identify priorities, research
and development)
Implementation of legal
and administrative
frameworks
Generic framework for indicator use (I = need for indicators)

Indicators of change:
• Relate types and nature of indicators of
change to the DPSIR philosophy
• Increasing use of qualitative and quantitative
indicators
but:
• also consider the use of flexible indicators –
(required in highly dynamic systems such as
estuaries cf. less variable terrestrial and
freshwater systems)

From Indicators to Classification Schemes:
• Use of single indicators for biology, chemistry,
aesthetics (Aust., SA, UK, NL, etc.)
• Combining into EEI (Environmental
Integrative Indicators – EEI1 Pressures, EEI2
Physical Modification, EEI3 Env. Quality)
• Weighting, mapping, use as performance
indicators & socio-economic assessment (e.g.
EU WFD)

Carrying Capacity:
• Environmental aim – maintenance;
• Socio-economic aim – exploitation (relate to
assimilative capacity);
• Big questions – what is lost and how to regain
it;
• Increase by habitat creation;

Habitat Loss:
• Permanent – removal of wetland/
polderisation (Northern problem?) – solved by
creation/restoration
• Temporary – by increase or decrease in
water and sediment quality (e.g. salinity,
temperature, DO, turbidity) (Northern
problem?) or by decrease in water quantity
(Southern problem?) – solved by remediation

Sunk Island, north bank of the Humber: piecemeal reclamation

Land Claim – still
occurring: Encroachment
Pressures in the Thames
Estuary
Marginal habitats provide:
(a) specialized refuge and feeding grounds
for juvenile fish, hence loss of these
habitats reduces the carrying capacity of
the estuary,
(b) migration routes during STST and a
continuous foreshore is vital for these
migrations.
(Ackn. Dr S Colclough, Env. Agency)

Examples of Temporary Habitat Loss:
• E.g. DO barrier at
estuarine upper
reaches
• Dredging sediment plume
+
• Salinity rise through abstraction
• Sea-ice cover

Threats & Challenges #2:
• large-scale causes (exogenic unmanaged
pressures (EUP)) such as global climate
change, isostatic rebound
• manage the consequences on a local scale

‘Ready for
immigrating to
Australia’
National level

Priority – ‘dry feet’ first then worry
about the environment?
© Elliott
he storm-surge Delta works SW Netherlands
© de Jonge
© Rijkswaterstaat

Thames Estuary, UK –
barrier protection
Source: Environment Agency
Humber Estuary, UK
– flood risk (relative
SLR – SLR +
isostatic rebound

coastal
adjustment
set-back/
managed
retreat
wetland/habitat
creation
increase in
refugia
fisheries
support
Climate Change - Effects on Habitats
relative sea level rise
“coastal
squeeze”
tidal area
reduction
loss of prey/
feeding area
reduction in
carrying
capacity
fisheries
repercussions
marine
incursion
salinity/depth
alteration
community
displacement
e.g.
movement
of brackish
species
erosion
increased
storminess
loss of
habitat
substratum
change
change in
prey
availability
increase
need fo
refugia

Combatting sea level rise - Contrasts: Hard defences

‘Win-win-win situation’
Photos: Environment Agency
Habitat Creation:
Restoration / setback
/ managed
realignment /
depolderisation

Biodiversity changes & challenges:
• Biological pollution – introduced species
• Effects of global warming – changing
distributions (e.g. Red Sea migrations)
• Examples of habitat modification effects
e.g. Eriocheir, Caulerpa

Future – biodiversity change:
• Determine what’s there and what’s been lost
• Quantify niche creation
• Quantify rate & processes of filling niches
• Determine sequence depending on time of start
• (Fulfil management actions in these)
(Elliott, 2002, Mar. Poll. Bull.;
McLusky & Elliott, 2004, OUP)

Turning pressures into
gains?
e.g. artificial structures

Challenge – not just assessing negative
effects?
Aerogenerator monopiles as artificial reefs –
mitigation, compensation or problem source?
• Introduction/creation of new
habitat
• Change (increase?) in species
diversity
• Facilitate spread of fouling
organisms and invasive
species (biological pollution?)
• Recreation or production
possibilities

Challenge – not just assessing negative
effects?
Aerogenerator monopiles as creators of no-take
zones and fish/shellfish refuges – mitigation,
compensation or problem source?
• Prevention of a
deleterious activity
• Creation of new
habitat
• Knock-on effects in
surrounding area
• Production
possibilities

Challenge - to determine relative effects
(footprint) at 5 spatial levels:
• Microscale: on a structure
• Mesoscale: with type and alignment of
material
• Macroscale: heterogenity within the area
• Megascale: between structures
• Metascale: integration of data and knowledge
[can also give the same for temporal responses]

Society & Eco-change - 6 tenets for
successful, sustainable and acceptable
environmental management:
• Environmentally sustainable
• Technologically feasible
• Economically viable
• Socially desirable/tolerable
• Legally permissible
• Administratively achievable
(modified from Elliott, 2002, Mar. Poll. Bull.)

Policy strategies, development, merging &
overlap
⇒ addressing concerns by policy action:
• 1960’s - realise there is a problem of pollution;
• 1970’s – no problem, dilution as solution;
• 1980’s – not sufficient, end of pipe controls;
• 1990’s – realise there is a bigger problem than just
pollution; EMS, holistic, ecosystem approach;
• 2000’s – realise there are problems - diffuse, habitat,
catchment and open sea solutions and strategies
(e.g. EEA, OSPAR, US NOAA, ANZ EQO).

Direction of Estuarine Management:
• Upscaling - larger and collective systems
(e.g. the EU Water Framework Directive, the
US NOAA eutrophication assessment, and
the Australian and New Zealand estuarine
management plans and quality objectives);
• Multi- & cross disciplinary approach;
• Statutory remit to include cost-benefit
appraisal (eg. CVA, WTP) (e.g. Randers
estuary)

US - Level of expression of symptoms per category of
eutrophic condition (NOAA 1999) – value of expert view
approach where no hard data

The Framework for Applying the Australian/New Zealand
Water Quality Guidelines (from National Water Quality
Management Strategy, 2000)
Define: PRIMARY MANAGEMENT AIMS
(incl. environmental values, management goals and level of protection)
⇓
Determine appropriate: WATER QUALITY GUIDLEINES
(tailored to local environmental conditions)
⇓
Define: WATER QUALITY OBJECTIVES
(specific water quality to be achieved)
taking account of social, cultural, political and economic concerns where
necessary
⇓
Establish: MONITORING AND ASSESSMENT PROGRAMME
(focussed on water quality objectives)
after defining acceptable performance or decision criteria
⇓
Initiate appropriate: MANAGEMENT RESPONSE
(based on attaining or maintaining water quality objectives)

Mitigation (‘to make less severe’)
Measures in Management – examples:
• Segregate the wastes
• Provide an area for the degradation of wastes
• Re-use the wastes
• Separate the activities/uses in space
• Separate the activities/uses in time
• Reduce the wastes/land-use
(Mitigation/compensation for change but need to determine their
success)

Compensation Measures in Management
(where mitigation is not possible/costeffective):
• Economic compensation (e.g. pay the
fishermen)
• Resource compensation (e.g. improve the
fishery)
• Ecological compensation (‘creative
conservation’ – e.g. wetland creation)
(Mitigation/compensation for change but need to determine their
success)

The Estuary & Coast - Major Legislative /Administrative/Policy
Drivers – Statutory Requirements
EU Directives - Sectoral:
• Urban Waste-water
Treatment
• Integrated Pollution
Prevention & Control
• Titanium Dioxide
• Shellfish Growing Waters &
Health
• Shellfish Harvesting
• Bathing Waters
• Dangerous Substances +
Daughters
• Freshwater Fishes
EU Directives –
Ecosystemic/Holistic:
• Environmental Impact
Assessment
• Habitats & Species
• Wild Birds
• Nitrates – level, control, use
• Strategic Environmental
Assessment
• Water Framework
• Freshwater Fishes
• Integrated Coastal Zone
Management?
• Marine Strategy?

Understanding & Managing Estuarine
Change: the future (1)
♦ Know the problem: widespread surveillance (low
level) to identify targeted monitoring;
♦ Greater focussed research: role of survey,
experiment, theoretical approaches;
♦ Good science: hypothesis generation & testing;
♦ Lateral thinking: think out of the box/silo;
embrace even the socio-economists;
♦ Big questions: ‘how is it’, ‘what if’, ‘so what’;
♦ Catchment & whole enclosed sea approaches &
management: watershed, river basin to oceanic
& climatic drivers;

Understanding & Managing Estuarine
Change: the future (2)
♦Test the rationale: define the characteristics of the
ecosystem � define the objectives, standards,
indicators � define the monitoring strategy � define
monitoring protocol � determine compliance;
♦ Feedback loops: scientists and their information into
management decisions (& vice versa);
♦Question the need: for detailed assessment vs.
educated guess (what information is required by
managers);
♦Simplify the debate/approach: harmonise terms and
approaches across initiatives; beware of ‘gold-plating’.

‘Joined-up Environmental Thinking’:
♦Ecological Integration: habitat integrity, fit-forpurpose;
♦User/Use Integration: move from sectoral approach;
♦Management Integration: WFD / HSD / IMO(PSSA) /
OSPAR(Annex V) / BAP / WBD / ICES;
♦Monitoring Integration: joint programmes for costeffectiveness;
♦Environmental Integration: from site-based to wider
study (sites influencing and being influenced by
events remote from the site);
♦Scientific Integration: responses to multiple stressors
at several levels of biological organisation.

Ultimate Aim:
“Give us the tools and
we’ll finish the job”
(Churchill) – not
vice versa!
Optimism
(the SWFC Factor!)
http://www.hull.ac.uk/iecs

elected references:
llen et al., 2000.
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oyes et al., 2004.
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ostanza R and Mageau M (1999) What is a healthy ecosystem? Aquatic Ecology 33: 105-115.
ale, P., 2004. Connectivity: opportunity, constraint and impact of change. Presentation ECSA
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ittman, S, V. Grimm & H. Hildenbrandt, 2004. Assessing reference states and changes in tidal
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