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

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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

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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)