FunctionsFunctions andand behaviourbehaviour ofof mudmud inin estuarineestuarine andand coastalcoastal ecosystemsecosystems

Prof.Prof. Dr.Dr. VictorVictor N.N. dede JongeJonge DScDSc

Dept. Ocean Ecosystems, University of , The Dept. Biological Sciences, University of Hull, UK [email protected] to keep 1 warf at place …. 1. A ‘storm surge barrier’ was built, (mainly to up Ems river water when a newly built giant cruiser had to float to the sea…) 2. river deepening and canalisation was executed & 3. river dredging takes place continuously Resulting in 3. a tremendous change in the river and estuarine light climate SPM concentration Sa linity 12 00 35 …. (m g/l) (P S U)

10 00 2005-2006 30

25 80 0 20 60 0 1975-1976 15 40 0 10

20 0 5

0 0 0 20 406080 100 120 di sta nce from He rbrum (km )

S P M 19 75 -197 6 S P M 20 05 -200 6 s alini ty 19 75 -197 6 s alinity 20 05 -200 6

Oxygen 10.0 concentration m( g/l) 8.0 6.0 No fish species 4.0 can take this barrier 2.0 2.5 mg/l 0.0

0 200 400 600 800 1000 1200

Thanks to N-Ports Emden, (Rewert Wurpts) for help in sampling! River Ems: ‘Yellow river’ Power failure hits Europe [04-11-2006] Danna Avsec Created: 11/5/2006 2:20:56 PMUpdated:11/5/2006 2:21:34 PM

4. About half of W Europe without power for 1 hour because this high voltage power cable over the river Ems was shut down (AP) -- A German electric company says it may know the cause of yesterday's chain-reaction blackout that hit parts of Europe.

The company says systems may have become overloaded after a high-voltage transmission line was shut down over a river to let a ship pass.

‘The river’ was the river Ems and ‘a ship’ was a giant cruiser ‘Norwegian Pearl’ [01-11-2006] 305 cm (+ 2m)

410 cm (+ 3m)

483 cm (+ 3.5m)

‘Ems Sperrwerk’ was needed! Highest water level ever measured in the Ems estuary: 01-11-2006 Groningen Together with the channel maintenance dredging in the Ems estuary, the scale of the activity and its impact is large +

Meyer warf WhyWhy thisthis exampleexample ??

1.1.LightLight isis aa resourceresource forfor algaealgae whichwhich areare responsibleresponsible forfor creatingcreating thethe foodfood forfor thethe aquaticaquatic systemsystem

2.2.LightLight isis easilyeasily andand heavilyheavily influencedinfluenced byby humanhuman activitiesactivities

3.3.LightLight isis anan emergingemerging problemproblem!!!! OtherOther functionsfunctions ofof mudmud •• SuspendedSuspended ‘‘particlesparticles’’ // ‘‘solidssolids’’ •• ExtinctingExtincting lightlight •• SubstrateSubstrate •• HabitatHabitat •• SourceSource ofof compoundscompounds •• AdsorbanceAdsorbance forfor chemicalchemical compoundscompounds •• SubstrateSubstrate forfor benthicbenthic diatomsdiatoms andand bacteriabacteria •• CarrierCarrier forfor transportingtransporting micromicro--organismsorganisms •• ByBy--productproduct ofof foodfood •• ResourceResource forfor brickbrick productionproduction TheThe underwaterunderwater lightlight climateclimate inin transitionaltransitional ANDAND coastalcoastal waterswaters isis anan emergingemerging issueissue whichwhich isis insufficientlyinsufficiently recognizedrecognized byby WFDWFD && MSDMSD atat presentpresent tootoo muchmuch acknowledgedacknowledged asas aa naturalnatural boundaryboundary conditioncondition WhatWhat mattersmatters basicallybasically inin anyany ecosystemecosystem andand forfor modellingmodelling it:it: 1.1. Resources:Resources:

106CO2 + 106H2O + 16NH4 + 1PO4 (CH2O)106(NH4)16PO4 + 106O2 + 16 (SiO4) a. Light a. System functioning b. Nutrients: N, P, Si b. Species structure c. Species interactions 2.2. EnvironmentalEnvironmental conditionsconditions:: Related to spiritspirit ofof WFD & MS a. temperature b. dilution rate (τf ) 3.3. BalanceBalance betweenbetween channelschannels && intertidalintertidal flatsflats a. sediment - water interaction We understand part of the general functioning level: e.g. the primary production process

We do not understand the general structure level: e.g. systems quality by its species composition

HowHow doesdoes (systems(systems ecology)ecology) thethe combinationcombination ofof e.g.e.g. lightlight,, nutrientsnutrients,, temperaturetemperature regulateregulate

1.1. functioningfunctioning ofof thethe systemsystem 2.2. speciesspecies structurestructure ofof thethe systemsystem CanCan wewe explain,explain, eveneven predict,predict, thethe temporaltemporal developmentdevelopment ofof a.a. SpeciesSpecies compositioncomposition ?? b.b. StructureStructure ofof thethe ecosystemecosystem foodfood webweb ??

underunder varyingvarying conditionsconditions ofof -- lightlight intensityintensity -- lightlight qualityquality

FocusFocus onon speciesspecies--richrich partpart ofof ecosystemecosystem representedrepresented byby fastfast developingdeveloping micromicro--algaealgae asas cancan bebe foundfound inin thethe WaddenWadden SeaSea

Groningen

Variation in what is available 1990 – 2003 = 14 years

O = Monitoring stations 30 km apart Deep coastal Shallow coastal

Relative cell density 4.0 (Zuidoost Lauwers/ 14 year average Huibertgat Oost) 3.0

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a a a ii is n m ra m l n is m im ri u tu tu n u us ns n a ri ge a a a st ni ri e i e ti c cy a in m t e st li m idi n m a s o e s r li lo s d ck eo er la a a c ia a c ro a p se l v r ia h to s te ta en m b P o n i Pa ca e en la hu o r e ol n l l Pr c th o o ie y au o os s pt Od la iz let o nn o dr e iz n el in Rh k ti nt l S Rh kma c Cy c A do ro O B Species Brockmanniella brockmannii mean abundance (cells l-1)

300000 250000 200000 150000 (13 yr average) 100000 50000 0 T ND GT OT O D D TZ W G GN RS N OL B OT A DA ID HUI O M ZU GR

Skeletonema costatum mean abundance (cells l-1)

700000 600000 500000 400000 Rhizosolenia delicatula 300000 200000 mean abundance (cells l-1) 100000 0 T T T 80000 ND G O O ND D TZ W G G 70000 RS N OL IB OT A DA ID HU O 60000 M ZU GR 50000 40000 30000 20000 10000 0 T ND GT OT O D D TZ W G GN RS N OL B OT A DA ID HUI O M ZU GR Strong variations in time and space Brockmanniella brockmannii mean abundance (cells l-1)

300000 250000 200000 150000 (13 yr average) 100000 50000 0 T ND GT OT O D D TZ W G GN RS N OL B OT A DA ID HUI O M ZU GR

Skeletonema costatum mean abundance (cells l-1)

Options: 700000 600000 500000 400000 1. MathematicalRhizandosolenia statisticaldelicatula analysis as description300000 for what has been 200000 mean abundance (cells l-1) observed 100000 0 T T T 80000 ND G O O ND D TZ W G G 70000 RS N OL IB OT A DA ID HU O 60000 M ZU GR 2. Searching50000 for concepts with general applicability behind the observed 40000 30000 picture20000 to support 10000 - stochasticity0 T ND GT OT O D D TZ W G GN RS N OL B OT - determinismA DA (mechanisID HUI Otic explanations for observed developments in M ZU GR Strong variations in time and space space and time) HowHow dodo conceptuallyconceptually algaealgae respondrespond to:to:

A.A. ResourcesResources ((sunsun,, lightlight,, nutrientsnutrients))

B.B. EnvironmentalEnvironmental conditionsconditions ((tidetide,, wind,wind, T,T, ττf )) C.C. EquilibriumEquilibrium betweenbetween channelschannels && tidaltidal flatsflats ((humanshumans)) Top specialist Top generalist

Temperature fluctuations around the average The factor temperature could also have been LIGHT Average temperature or LIGHT QUALITY due to changed spectrum by humic substances or …. Fluctuations of 2 oC around 20 oC

top specialist

top generalist

Fluctuations of 8 oC around 20 oC de Jonge & Brauer, in press. MPB Different species are in a different Surprisingly, after mixing the 2 BS species way adapted to light conditions. with a Tolypothrix species, the last one They have different pigments and adapt to the new light conditions by thus different light absorption changing its pigment composition. This spectra. ‘adaptive behaviour’ improves its competition for the new situation.

Stomp, M. et al. 2004. Adaptive divergence in pigment composition promotes phytoplankton biodiversity. Nature, 432, 104 – 107. DoesDoes thisthis helphelp usus inin understanding,understanding, exploringexploring andand predicting?predicting?

II thinkthink soso givengiven nextnext example.example. Predictability by external disturbances simulated by models and tested experimentally (Roelke et al. 2003) 2x3 replicates Stable conditions Additions in pulses brought under different conditions.

1. Steady input of medium. 2. Pulse-wise input of medium.

Result: Series 1: unpredictable development of spp composition Series 2: predictable development of spp composition PulsePulse frequencyfrequency && pulsepulse intensityintensity maymay bothboth determinedetermine diversitydiversity developmentdevelopment

PulsePulse:: lightlight,, N,N, P,P, Si,Si, tt oror riverriver dischargedischarge ThusThus atat thethe generalgeneral levellevel thethe occurrenceoccurrence ofof speciesspecies assemblagesassemblages andand theirtheir abundanceabundance mightmight bebe atat leastleast ‘‘understandableunderstandable’’ !!

WeWe shouldshould taketake thethe chancechance toto integrateintegrate thethe modernmodern scientificscientific ‘state‘state ofof thethe art’art’ withwith currentcurrent environmentalenvironmental monitoringmonitoring practicepractice byby authoritiesauthorities andand thethe requirementsrequirements byby e.g.e.g. thethe WFDWFD && MS.MS. Because light is ecologically of utmost importance l move to the most important impact in coastal waters wind, dredging, sludge disposal, mining, extraction, fisheries, …as a source for changes in light climate. TheThe EmsEms estuaryestuary

TheThe underwaterunderwater lightlight climateclimate inin transitionaltransitional ANDAND coastalcoastal waterswaters isis anan emergingemerging issueissue whichwhich isis insufficientlyinsufficiently recognizedrecognized byby MarineMarine StrategyStrategy Channel maintenance dredging: 1.Changes morphology, flow current field & tidal wave 2.Increases erosion – sedimentation cycle

Situation before 1980, thus excluding all the river changes & river dredging

SPM as function of volume dredged SPM as function > 2-fold increase Y= 36.9e0.016x of R2= 0.89 distance dredged R = 0.94

Exponential ! de Jonge, V.N., 1983. Relations between annual dredging activities, suspen-ded matter concentrations, and the development of the ti-dal regime in the Ems estu-ary. Can. J. Fish. Aquat. Sci. 40 (Suppl. 1): 289-300. System is more sensitive to dredging the tidal inlet (outer and inner delta) than further upstream TheThe RhineRhine -- WaddenWadden SeaSea systemsystem TheThe underwaterunderwater lightlight climateclimate inin transitionaltransitional ANDAND coastalcoastal waterswaters isis anan emergingemerging issueissue whichwhich isis insufficientlyinsufficiently recognizedrecognized byby MSDMSD Turbidity: an important problem

Time series of mean annual suspended matter in Marsdiep and Vlie SPM (g m-3) 100.0 InMarsdiep 1986 a three to fourfold 80.0 increase was observed in 60.0 the suspended matterVlie 40.0 concentrations of 20.0 Marsdiep & Vlie tidal inlet 0.0 1970 1975 1980 1985 1990 1995 2000 2005 year Now the time series was as follows:

Time series of mean annual suspended matter in Marsdiep and Vlie -3 In 1990 the situation was SPM (g m ) completely different 100.0 Marsdiep 80.0 60.0 Vlie 40.0 20.0 0.0 1970 1975 1980 1985 1990 1995 2000 2005 year r

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S - - Mud supply Strait Flemish estuarine river & SPM accumulation salinity Salinity gradient Rhine estuary 40 30 20 10 0 100 50 0 distance from 0 PSU (km)

Average salinity distribution (PSU) Van Dixhoorn triangle (land reclmation) Estuary has disappeared.

Europoort 29012006 © V.N. de Jonge Dutch Delta 29012006 © V.N. de Jonge Depth profile

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Meuse mouth

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-26 m 1975 Dantzig Gat (5) Vlie (2) River Ems

Blauwe Slenk (6)

Doove Balg oost (4) Marsdiep (1) Doove Balg west (3)

Lake IJsselmeer Loswal Noord-west Loswal Noord

Maassluis Spijk

River Meuse

River Rhine

River Scheldt Apart from variation in SPM in Wadden Sea also long term variation in 1. river discharge discharge River Rhine discharge at Spijk and Maassluis (m3 s-1) y = 4.3593x - 6355.8 4000 R2 = 0.0192 R = 0.139 3000

2000

1000 y = 3.8818x - 6314.2 R2 = 0.0352 0 R = 0.188 1950 1960 1970 1980 1990 2000 year Apart from variation in SPM in Wadden Sea also long term variation in 1. river discharge 2. dredging in channels and harbours

Dredged sediments from navigation route and volume harbour basins (x 106 m3 a-1) 25.0 20.0 channels 15.0 10.0 5.0 harbours 0.0 1970 1975 1980 1985 1990 1995 2000 year Apart from variation in SPM in Wadden Sea also long term variation in 1. river discharge 2. dredging in channels and harbours 3. disposal of harbour sludge in coastal zone Dredge spoil disposed at Loswal Noord and volume Noord-west (x 106 m3 a-1)

30.0 25.0 20.0 15.0 10.0 5.0 0.0 1950 1960 1970 1980 1990 2000 year There are patterns recognizable! dredging seems a function of river discharge and may thus be ‘global change’ related! volume Dredged volume from main navigation route in the dredged period 1973-1999 as function of river Rhine discharge (x 106 m3 a-1) (Spijk) y = 4.0257e0.0005x 25.0 R2 = 0.3353 20.0 R = 0.579

15.0

10.0

5.0

0.0 0 500 1000 1500 2000 2500 3000 3500

discharge (m3 s-1) disposed harbour sludge seems also a (weaker) function of river discharge, but part is brought on land due to heavy pollution

Dredge spoil disposed at Loswal N and NW plotted as volume function of river Rhine discharge (Spijk) (x 106 m3 a-1)

30 y = 6.2351e0.0003x 25 R2 = 0.2511 R = 0.501 20

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0 0 500 1000 1500 2000 2500 3000 3500

discharge (m3 s-1) Most interesting are the 5 plots where SPM is plotted as a function of the dredge spoil disposal

Mean annual suspended matter concentration at station Marsdiep plotted as function of spoil disposal at Loswal N SPM -3 and NW (g m ) y = 12.42e0.0816x 2 120.0 R = 0.6274 R = 0. 792 100.0 5-fold increase 80.0

60.0 40.0 Exponential ! 20.0 0.0 0 5 10 15 20 25 30 disposed dredge spoil (x 106 m3 a-1) Mean annual suspended matter concentration at station Marsdiep plotted as function of spoil disposal at Loswal N SPM -3 and NW Jonge, V.N. & D.J. de Jong, 2002. (g m ) y = 12.42e0.0816x 2 120.0 R = 0.6274 100.0 ‘Global Change’ impact of inter-annual 80.0 60.0 variation in water discharge as a driving factor Marsdiep 40.0 20.0 0.0 to dredging and spoil disposal in the river 0 5 10 15 20 25 30 disposed dredge spoil (x 106 m3 a-1) Rhine system and of turbidity in the Wadden

SPM Mean annual suspended matter concentration at station Vlie (g m-3) plotted as function of spoil disposal at Losw al N and NW Sea.

0.0579x 80.0 y = 14.752e R2 = 0.5092 Estuarine Coastal Shelf Science 55: 969-991. 60.0 Vlie 40.0 20.0

0.0 0 5 10 15 20 25 30 disposed dredge spoil (x 106 m3 a-1)

Mean annual suspended matter concentration at station SPM Doove Balg West plotted as function of spoil disposal at (g m-3) Loswal N and NW y = 12.33e0.0525x 60.0 R2 = 0.4692 Doove Balg west 40.0 20.0

0.0 0 5 10 15 20 25 30 disposed dredge spoil (x 106 m3 a-1)

Mean annual suspended matter concentration at station SPM Doove Balg Oost plotted as function of spoil disposal at response (g m-3) Loswal N and NW

0.0224x 60.0 y = 24.979e weakening R2 = 0.1723 Doove Balg oost 40.0 20.0

0.0 0 5 10 15 20 25 30 disposed dredge spoil (x 106 m3 a-1)

Mean annual suspended matter concentration at station SPM Blauwe Slenk plotted as function of spoil disposal at Loswal (g m-3) N and NW

y = 48.321e0.0128x 150.0 R2 = 0.0363 120.0

90.0 Blauwe Slenk 60.0 30.0

0.0 0 5 10 15 20 25 30 disposed dredge spoil (x 106 m3 a-1) Weekening of the slope is suggesting:

1. In tidal inlets mainly the spoil + tide 2. In the shallow basins mainly the wind mean annual mean annual suspended matter Marsdiep as function of SPM river Rhine discharge Marsdiep 100 80 0.0008x 60 y = 5.8339e 2 40 R=R 0.45 = 0.3305 20 0 0 1000 2000 3000 4000 discharge river Rhine For station Marsdiep the relationship between SPM and dredge spoil disposal (r = 0.8; P<0.001) SPM and river discharge (r = 0.4; 0.01

This suggests that both play a role Mean annual suspended matter Marsdiep as function of dumps at Loswal Noord SPM -3 (g m ) 100 Marsdiep tidal inlet 80 y = 13.523e0.1312x 60 R2 = 0.7435 40 20 0 0 5 10 15 20 sediment dumped 6 -1 (x10 tons dry weight a )

mean annual suspended matter Vlie as function of dumps at Loswal Noord SPM (g m-3) 100 y = 19.326e0.0754x Vlie tidal inlet 80 R2 = 0.5913 60 40 20 0 0 5 10 15 20 sediment dumped (x106 tons dry weight a-1) Mean annual suspended matter Marsdiep as function of dumps at Loswal Noord SPM -3 (g m ) 100 Marsdiep tidal inlet 80 y = 13.523e0.1312x 60 R2 = 0.7435 40 20 0 0 5 10 15 20 sediment dumped 6 -1 (x10 tons dry weight a )

mean annual suspended matter Vlie as function of dumps at Loswal Noord SPM (g m-3) 100 y = 19.326e0.0754x Vlie tidal inlet 80 R2 = 0.5913 60 40 20 0 0 5 10 15 20 sediment dumped (x106 tons dry weight a-1) Some conclusions: Natural background concentration <20 mg l-1 Mean increase in SPM about 250% Max increase about 700%

Causes 1. River discharge 2. Dredge spoil disposal

Under expected 10% increase in river discharge further structural increase in SPM by about 15% How to explain this correlation?

Rotterdam harbour authorities do nothing else then recharging the coastal zone with mud which was accumulated by the tide and the estuarine density circulation. However, …….

Mud accumulated from an unknown large part of the brackish river Rhine (+ Meuse, Scheldt, etcetera) water plume is deposited at one point close to the coastline. It can not escape from that area!! site ispersal d sposal Brackish di water plume cated from ndi i ng New transport path

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Ecological Economic system system Channel maintenance dredging Physical system Consumer preferences Production possibilities (DEMAND) (AVAILABILITY) Natural factors Biological Anthropogenic natural variation system plans & activities (noise) process & structure Physico- (COST) chemical system Loads of nutrients and organic matter Fisheries If we do not know what If we do not know the the natural signal anthropogenic signal then drives and howTotalit system variationwe can not work= on the naturalbehavesvariationthen we+ can effects orestorationf anthropogenicor conservationstress not detect the of human influenced coastal anthropogenic signal. systems. ConclusionConclusion:: SEDNETSEDNET maymay taketake thethe opportunityopportunity toto focusfocus onon allall aspectsaspects relatedrelated toto ‘mud’‘mud’ ((alsoalso ‘clean’‘clean’ mud)mud) toto supportsupport thethe protectionprotection ofof functioningfunctioning && structurestructure ofof aquaticaquatic ecosystemsecosystems (WFD(WFD annexannex V)V)

ThankThank youyou