Eutrophication Lecture 1Definition and History
DPSIR framework
Alice NewtonF. Colijn
Ana Cristina Cardoso
Defining Eutrophication
Some etymology…
Eu: Greek prefix “good” and “well”Troph: Greek “nourishment”
“nutrition” “feeding”
Eutrophic: Positive connotation Eutrophication: Negative
connotation
Definition...in context Eutrophication means ...
Nixon, S. W. 1995.
Coastal marine eutrophication: A definition, social causes, and future concerns
Ophelia 41: 199-219
Medicine:"healthy or adequate nutrition“,Ecology: “an increase in the rate of supply of
organic matter to an ecosystem“
Definitions...Eutrophication means ...
Jørgensen B.B. and Richardson K. (eds.). 1996
Eutrophication in Coastal Marine Ecosystem.
Coastal and Estuarine Studies, vol. 52
American Geophysical Union, Washington, D.C. 272 pp, ISBN 0-87590-266-9
‚... a process of changing the nuritional status of a given water body by increasing the nutrient resources‘ (Jørgensen and Richardson 1996) ...natural
‚...the increase in trophic state of a water through anthropogenic influences‘ (Sommer 1998)
Ecological definition…~ Eutrophication: organic and nutrient
enrichment of natural waters~ Natural eutrophication in regions of
upwelling: cold, deep, nutrient-rich waters rise to surface e.g. Chile
~ Anthropogenic eutrophication is result of nutrient pollution of natural waters e.g. lakes, rivers, aquifers, estuaries, bays, coastal waters, mainly from sewage and/or agriculture
Natural Science definition of Eutrophication…the good?
~ “Stimulation of algal growth by enrichment of the aquatic environment with mineral nutrients” (Richardson, 1989)
~ Natural processes are the agents of enrichment: includes naturally eutrophic coastal waters, such as upwelling regions
The Primary Productivity of the oceans varies both spatially and seasonally
Courtesy of Gay Mitchelson–Jacob
The Atlantic is much more nutrient-rich and more productive than the
Mediterranean
Courtesy of Gay Mitchelson–Jacob
Mediterranean Chlorophyll CZCS composite
Courtesy of Gay Mitchelson–Jacob
Upwelling regions are especially productive, e.g. the coast of Chile
Coastal Upwelling
off W. Africa
Courtesy of Gay Mitchelson–Jacob
Chlorophyll Concentrations (CZCS), Cape Verde Islands
Management definition of Eutrophication… the Bad?
~ Anthropogenic Eutrophication: mankind is the agent responsible for nutrient and/or organic enrichment
DefinitionEutrophication means ...
‚...the enrichment of water by nutrients causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of the organisms present in the water and to the quality of the water concerned, and therefore refers to the undesirable effects resulting from anthropogenic enrichment by nutrients as described in the Common Procedure.‘
OSPAR
DefinitionEutrophication means ...
‚...the process of enrichment of waters with plant nutrients, primarily nitrogen and phosphorus, that stimulates aquatic primary production and in its most serious manifestations leads to visible algal blooms, algal scum, enhanced benthic algal growth and, at times, to massive growth of submersed and floating macrophytes‘
(Vollenweider 1992)
Vollenweider, R. A., R. Marchetti and R. Viviani (eds.). 1992.
Marine Coastal Eutrophication. The Response of Marine Transitional Systems to Human Impact: Problems and Perspectives for Restoration.
Proceedings, International Conference, Bologna, Italy, 21-24 March 1990. Elsevier, Amsterdam.
DefinitionEutrophication means ...
“The enrichment of waters by inorganic plant nutrients which results in the stimulation of an array of symptomatic changes.
These include the increased production of algae and/or other aquatic plants, affecting the quality of the water and disturbing the balance of organisms present within it.
Such changes may be undesirable and interfere with water uses.” UK Environment Agency
DefinitionEutrophication means ...
“Enhanced primary production due to excess supply of nutrients from human activities, independent of the natural productivity level for the area in question”
EEA-European Environment Agency definition
Nutrients & Eutrophication~ The main nutrients causing eutrophication are N
in the form of nitrate, nitrite or ammonium and P in the form of ortho-phosphate.
~ In addition, supply of bioavailable organic P and N cause eutrophication
~ Silicate is essential for diatom growth, but it is assumed that silicate input is not significantly influenced by human activity.
~ Enhanced primary productivity may exhaust silicate and change the phytoplankton community from diatoms to flagellates.
EEA-European Environment Agency
DefinitionEutrophication means ...
‘The enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the water balance of organisms present in the water and to the quality of the water concerned’
(cf. Art. 2(11) of the UWWTD Directive 91/271/EEC).
DefinitionEutrophication is ...
‘the accelerated production of organic matter, particularly algae, in a water body. It is usually caused by an increase in the amount of nutrients being discharged to the water body. As a result of accelerated algal production, a variety of impacts may occur, including nuisance and toxic algal blooms, depleted dissolved oxygen, and loss of submerged aquatic vegetation. These impacts are interrelated and usually viewed as having a negative effect on water quality and ecosystem health.”
Bricker et al 2003
Conceptual Models of Eutrophication
DPSIR framework
~ Some definitions…
~ DPSIR + eutrophication
~ Evolving concepts of Eutrophication
DPSIR
~ Drivers: socio-economic, e.g. tourist development
~ Pressures: e.g. increase nutrient runoff
~ State: quantifiable metrics, e.g. Dissolved Oxygen, chlorophyll a concentration
~ Impacts: ~ environmental e.g. increase turbidity,~ ecological, e.g. loss of biodiversity, ~ economic e.g. lower fish catches, ~ social e.g. loss of fishing jobs
~ Responses: of society, e.g. new management criteria, new infrastructure, new policy
DPSIR + eutrophication
BODDONutrients
O.E.C.D. 1993, 2004
Pressures
State variables
Responses
DPSIR + Eutrophication
Borja, A. et al 2006, after Bricker et al 1999
DPSIR + eutrophication
Drivers•Agriculture•Aquaculture•Industry•Urban development•Global change
Aliaume et al 2007Aliaume, C., Do Chi, T, Viaroli, P., and Zaldivar, J.M.,2007. Coastal lagoons of Southern Europe: Recent changes and future scenarios. Transitional Waters Monographs 1: 1-12.
DPSIR in coastal and transitional waters
Borja, A. et al 2006
Main pressure categories
~ Pollution
~ Hydrological alterations
~ Morphology
~ Biology and biomass extraction
Borja, A., Galparsoro, I., Solaun, 0., Muxika, I., Tello,E.-M., Uriarte, A. , Valencia, V. 2006
The European Water Framework Directive and the DPSIR, a methodological approach to assess the risk of failing to achieve good ecological status.
Estuarine, Coastal and Shelf Science 66, 84-96.
Common PRESSURES
•Organic and chemical pollution (e.g. from agricultural and agrochemical activities, animal rearing and food industry)
•Μodification of hydrological regime (hydroelectric dams, fresh water abstraction, etc)
•Urban development•Fishing and aquaculture
Eutrophication process UK EA
Pressure
State
Impact
Early Eutrophication Model
Nutrient loading
Responses: Changes in
ChlorophyllPrimary ProductionSystem Metabolism
Oxygen
Early conceptual models focused on direct responses of coastal waters, such as stimulation of phytoplankton blooms.
Note : different use of “response”
Contemporary conceptual model
Nutrient loading Filter
DirectResponses Chlorophyll
Primary ProductionMacroalgal biomass
Sedimentation of O CSystem MetabolismPhyto. community
Si:N N:P Oxygen
HAB
IndirectResponses
Benthic biomassPelagic biomassVascular plants
Habitat diversityWater transparency
O C in sedimentsSediment biogeochemistry
Bottom-water oxygenSeasonal cycles
MortalityBiodiversity
Cloern, J.E. 2001. Review. Our evolving conceptual model of the coastal eutrophication problem. Mar. Ecol. Prog. Ser. 210: 223-253.
Note : different use of “response”, substitute “effects” for clarity
Contemporary conceptual model
~ Growing awareness of the complexity of the problem
~ Attributes of specific bodies of water create enormous variations in their responses
~ Cascade of direct and indirect consequences
~ Appropriate management actions to reduce nutrient inputs can reverse some of the degradation caused by enrichment.
Eutrophication concept Direct EffectsPhytoplankton
communityHAB ChlorophyllMacroalgal biomassPrimary ProductionSedimentation of OCSi:NN:P
Indirect EffectsBenthic communityPelagic communityVascular plantsTransparencyBottom water OxygenOC in sedimentsSediment biogeochemistryHabitat diversitySeasonal cyclesMortalitiesBiodiversity
adapted from Cloern, J.E. 2001.
BQEBQE METRICSPh-Ch QE
Effectsinclude
some State and
Impacts
STATE ECOLOGICAL IMPACTSupporting elements:
Nutrient concentrationsSi:NN:PTransparencyBottom water OxygenBQE metricsChlorophyll aCell countsHAB Opportunist algae biomassBiodiversity of benthosAMBI
Biological Quality Elements
PhytoplanktonOther plantsBenthosFish
Annex V of WFD and Intercalibration
Impacts
~ Environmental
~ Ecological
~ Economic
~ Social
~ Poor water quality
~ Loss of seagrass
~ Loss of fishing catch and revenues
~ Loss of fishing jobs
Drivers: need to update, maybe price of oil will be a major driver with increased biofuels
Pressures: need to consider “difficult” aspects such as loss of denitrifying wetlands, atmospheric deposition
State: need to test the metrics for the physico-chemical supporting quality elements and the Biological Quality Elements and move towards INTEGRATIVE ASSESSMENT
Impact: must link economic impact to ecological impacts, NOT consider them separately. Clearly shows the value of ecosystem services
Response: is building UWWT plants the only answer? What about CAP and farming practices?
– Require a conceptual framework which has it’s foundations in the Pressure-State-Response (PSR and/or DPSIR) context
– Should be “comprehensive” enough
– Should allow for discrimination between natural and anthropogenic pressures
– As starting point it was adopted the conceptual framework proposed by OSPAR
EU Common Conceptual Framework
Internal nutrient load- sedim ent- N-fixation
Transboundarynutrient fluxes
External nutrientload
Inc rease in nutrientconcentration or
change in N/Pratio
Environm ental fac torse.g. Hydrom orphology,c lim ate, alkalinity, toxicsubs tances .
PhytoplanktonC hang e in b iomass,b loom frequency ,co mpo sition ( toxic spp )
PhytobenthosC hange in biom ass orcom pos ition.
M acrophytesC hange in biom ass ,com pos ition, or depthdis tribution.
Top dow ncontrol
Inc reased turbidity,dec reased light
trans perancy
O rganicmatte r
Inc rease inbac teria
O xygendeficiency
(+ )
M acroinvertebratesC h a n g e in co m p o s itio n o ra b u n d a n ce
F ishC h a n g e in co m p s itio n ,a b u n d a n ce , a g e s tru ctu re .Fis h k il ls .
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River-specific factors Lake-specific factors Coastal and transitional waters specific factors
Causative factors
Nutrient enrichment ( P concentration)
Nutrient enrichment( P concentration)
Nutrient enrichment (nitrate (DIN) and phosphate (DIP)concentrations and loadings
Supporting factors
Hydromorphological conditions (water flow, substrate type, water depth, flood frequency)Typology factors: alkalinity, colour, size of catchment
Stratification, flushing, retention timeTypology factors: alkalinity, colour, size, depth
Upwelling, salinity gradients,Typology factors: salinity, wave exposure, others
Causative parameters
River-specific factors Lake-specific factors Coastal and trasititonal waters specific factors
Microphytobenthosincreased biomass and primary production, increased areal cover on substrateShifts in species composition from diatoms to chlorophytes and cyanobacteria
Phytoplankton shifts in species compositionfrom chrysophytes and diatoms to cyanobacteria and chlorophytes
Phytoplankton shifts in species composition from diatoms to flagellatesMacrophytes (and macroalgae)shift from long-lived species to short-lived species, some of which are nuisance species (Ulva, Enteromorpha)
Effect on macrofloramacroflora
Chlorophyll-aconcentration
Effect on algae
Direct effects of nutrient enrichment
River-specific factors Lake-specific factors Coastal and transitional waters specific factors
Oxygen more extreme diurnal variationFish disruption of migration or movementBenthic heterotrophic organisms increased biomass and areal cover of fungi and bacteria
Oxygen more extreme diurnal variation in surface waters. Occurrence of anoxic zones at the sediment surface (“black spots”)Fish mortalities resulting from low oxygen concentrationsInternal loading of phosphorusIncreased ammonia concentration in bottom waters
Organic carbon/organic matter occurrence of foam and/or slimeOcurrence and magnitude of Paralytic Shellfish Poisoning (PSP)Oxygen occurrence of anoxic zones at the sediment surface (“black spots”)Release of nutrients and sulphide from sedimentChanges in fauna
Algal scums Oxygen deficiency Shellfish poisoning
Indirect effects of nutrient enrichment
History of Eutrophication
Historical fertilizer shortage~18th Century England “mined” battlefields and catacombs
~19th Century USA used bones from buffalo killing fields
Guano deposits minedNavassa guano trench
GuanoProduction!
Haber-Bosch Process
~ Fritz Haber (Nobel prize winner) described chemical process to produce NH3 from N2 & CH4
~ Carl Bosch (Nobel prize winner) perfected commercial manufacture
Industrial N fixation
N2 from atmosphere mixed with CH4 and heated under pressure with a metallic catalizer produces CO2 and NH3 (82%N)
Mean plant production is 1.5 million kg ammonia per day
History of Eutrophication
Eutrophication first noticed in lakes where P is the main problem
Eutrophication of lakes
Eutrophication worldwide (Lakes).pdf
Eutrophication also noticed in riversRiver Neuse
Eutrophication noticed Estuaries: eg Chesapeake bay
Bays and coastal waters affected: eg Gulf of Mexico“dead zone”
-94 -93.5 -93 -92.5 -92 -91.5 -91 -90.5 -90 -89.5
28.5
29
29.5
30L. Calcasieu Atchafalaya R.
Mississippi R.
Terrebonne Bay
Sabine L.
100 km
70 % of world population lives in coastal plains, increasing Pressure
Global Distribution of Documented Oxygen Depletion, Diaz
2007
n = 146
(Diaz et al., 2004)
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