Limitations and solutions to the exchange of macrobenthos community data

Limitations and solutions to the exchange ofLimitations and solutions to the exchange ofmacrobenthos community data macrobenthos community data

between scientists and CZM managersbetween scientists and CZM managersin the frame of human impact monitoring studiesin the frame of human impact monitoring studies

in SW Netherlandsin SW Netherlands

NIOO, Netherlands Institute of Ecology, Centre for Estuarine and Marine EcologyKorringaweg 7, P.O. Box 140, 4400 AC Yerseke, The Netherlands

Herman Hummel, Bart Schaub, Wil Sistermans,Mieke Rietveld, Rinus Markusse, Ko Verschuure,

Olaf van Hoesel, Tom Ysebaert, Dick van Oevelen,Peter Bot & Peter Herman

RIKZRIKZ, , the Dutch Governmental Institute of Coasts and Seathe Dutch Governmental Institute of Coasts and Sea, Den Haag, the Netherlands, Den Haag, the Netherlands

RIKZRIKZ

http://infoserver/PR/naarhetnioo/NIEUWLOGO.htm

PresentationPresentation content: content:

1. W1. Why monitoring of macrobenthoshy monitoring of macrobenthos

2.2. PPresent-day problems regarding monitoringresent-day problems regarding monitoring

3. Problem 1: 3. Problem 1: Data stored but not analysedData stored but not analysed

6. Solution to problem 2:6. Solution to problem 2: Correspondence analysesCorrespondence analyses Adjustment of sampling strategyAdjustment of sampling strategy Example: GrevelingenExample: Grevelingen - impact abiotic factors - impact abiotic factors

4. Solution to problem 1:4. Solution to problem 1: Analyses of data - time series, ordinationAnalyses of data - time series, ordination Example: GrevelingenExample: Grevelingen - - major changesmajor changes, , not observed beforenot observed before

5. Problem 2: 5. Problem 2: Causal relationshipsCausal relationships Mismatch of data-seriesMismatch of data-series


Benthic organisms are suitable indicators for Benthic organisms are suitable indicators for changes in environmental quality, because of :changes in environmental quality, because of :- their sessile character- their sessile character- relatively long life-span- relatively long life-span

Thereby, benthic organismsThereby, benthic organisms- integrate environmental fluctuations and influences- integrate environmental fluctuations and influences- at a particular place over a relatively long time span- at a particular place over a relatively long time span



The aim of the long-term studies on benthosThe aim of the long-term studies on benthos is to obtainis to obtain insight ininsight in::- natural development of estuarine and coastal areas- natural development of estuarine and coastal areas- the anthropogenic influences in those areas- the anthropogenic influences in those areas

Such in order to help coastal managers:Such in order to help coastal managers:- saveguard natural resources- saveguard natural resources- allow optimal use of a system’s potentials- allow optimal use of a system’s potentials



As most monitoring programma’s this kind of continuous As most monitoring programma’s this kind of continuous long-term assessment (= many data) is perfect to detect:long-term assessment (= many data) is perfect to detect:- small deviations from a standard or norm- small deviations from a standard or norm- over a long-term- over a long-term- in a large area- in a large area

Year-to-year changes may not be significantYear-to-year changes may not be significant, but, butlonger series of data may reveal trendslonger series of data may reveal trends



In the Netherlands TWO major PROBLEMS arise in the In the Netherlands TWO major PROBLEMS arise in the present-day evaluation and use of the monitoring datapresent-day evaluation and use of the monitoring data

(mainly because of restricted funding).(mainly because of restricted funding).

2.2. PPresent-day problems regarding monitoringresent-day problems regarding monitoring


Basic data are stored by funding governmental agencies Basic data are stored by funding governmental agencies often often withoutwithout any further processing and any further processing and analysesanalyses..

By that the benefit of monitoring-programmes is debated:By that the benefit of monitoring-programmes is debated:- projects were costly- projects were costly- yet did not yield a proper end-product for the end-users- yet did not yield a proper end-product for the end-users(managers and the public in large) (managers and the public in large)

The The first problemfirst problem is: is:

3. Problem 1: data storage and analysis3. Problem 1: data storage and analysis


Use new techniques which allow us to analyse and visualise Use new techniques which allow us to analyse and visualise monitoring data in a limited time and at (relatively) limited costs:monitoring data in a limited time and at (relatively) limited costs:- advanced databases- advanced databases- statistical analyses (e.g. ordination, correspondence analyses)- statistical analyses (e.g. ordination, correspondence analyses)- internet communication (web-pages)- internet communication (web-pages)

Solution to problem 1: data storage and analysis

4. Solution to problem 1: data storage and analysis4. Solution to problem 1: data storage and analysis


The Grevelingen exampleThe Grevelingen example

Visualisation of a long-term (10-year) data-set showed forVisualisation of a long-term (10-year) data-set showed forthe brackish lake Grevelingenthe brackish lake Grevelingen

dramatic changes in macrobenthos species compositiondramatic changes in macrobenthos species composition--

4. Grevelingen example 1: data storage and analysis4. Grevelingen example 1: data storage and analysis


0 tot 2m diep2 tot 6m diep6 tot 45m diep

Grevelingen - Westelijk deel - plot 1Mytilus edulis

Campagnes

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aar

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eid

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- without having been noticed before by managers.- dramatic changes in macrobenthos species compositiondramatic changes in macrobenthos species composition


Grevelingen - Westelijk deel - plot 1Cerastoderma edule

Campagnes

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Bio

mas

sa m

g/m

25,000

4,500

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2,000

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500

0


Grevelingen - Westelijk deel - plot 1Hydrobia ulvae

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Grevelingen - Westelijk deel - plot 1Littorina littorea

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Grevelingen - Westelijk deel - plot 1ACTINIARIA

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Grevelingen - Westelijk deel - plot 1Heteromastus filiformis

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Grevelingen - Westelijk deel - plot 1Nereis succinea

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In case of “ so what ?! “ remarksIn case of “ so what ?! “ remarksit may be helpful to communicate on changes in commercial speciesit may be helpful to communicate on changes in commercial species


0.1

1.0

10.0

100.0

1990 1991 1993 1994 1995 1996 1997 1998 1999 2000

Year

Nu

mb

ers

(n·m

-2)

Cerastoderma edule Mytilus edulis

Ostrea edulis Crassostrea


Next step is a statistical Next step is a statistical analysis of the data by analysis of the data by means of correspondence means of correspondence analysesanalyses

Showed influence of :Showed influence of :

- year- year- season- season- depth- depth

6-45 m 0-2 m

Spring

Autumn


Next step is a statistical Next step is a statistical analysis of the data by analysis of the data by means of correspondence means of correspondence analysesanalyses

Showed influence of :Showed influence of :

- season- season- depth- depth

19901999

- year (independent of- year (independent of depth and season)depth and season)

33

11

556677

4422

88



Thus a strong Thus a strong temporal evolutiontemporal evolution



Our Our second problemsecond problem therefore is: therefore is:- coastal managers nowadays ask for causal relationships- coastal managers nowadays ask for causal relationships- relations to (changes in) environmental quality- relations to (changes in) environmental quality

The question arises: The question arises: What are the causes What are the causes of the changes of the changes ??

Whereas we have only information onWhereas we have only information onlarge-scale long-term processeslarge-scale long-term processes

5. Problem 2: Causal relationships5. Problem 2: Causal relationships


Solution to problem 2: causal relationshipsSolution to problem 2: causal relationships

More detailed information is needed on:More detailed information is needed on:- temporal and spatial dynamics in distribution of benthic- temporal and spatial dynamics in distribution of benthic populations (short-term / small scale)populations (short-term / small scale)- environmental variables- environmental variables

6. Solution to problem 2: causal relationships6. Solution to problem 2: causal relationships


Possible relationships, i.e. Possible relationships, i.e. causes causes for the changes in Grevelingen for the changes in Grevelingen ??

- sedimentation of organic matter and silt (esp- sedimentation of organic matter and silt (esp. . in the deeper parts)in the deeper parts) more sediment surface feeders, more wormsmore sediment surface feeders, more worms

- higher salinity, - higher salinity, disappearance of seagrass-bedsdisappearance of seagrass-beds disappearance associated faunadisappearance associated fauna

- - high concentrationhigh concentration of pollutants of pollutants decrease in numbers / biomass of sensitive speciesdecrease in numbers / biomass of sensitive species

- - lower light penetrationlower light penetration change of primary productionchange of primary production decrease of suspension feeders or grazersdecrease of suspension feeders or grazers

6. Grevelingen example 2: causal relationships6. Grevelingen example 2: causal relationships

1990-2002West

1990-2002East1982-2002

Dreischor

Benthos

environmental variables

Mismatch between benthos and environmental dataMismatch between benthos and environmental data

1972-1985data


Canonical correspondentie analyse Macrobenthos Grevelingen (1990 - 2000)

As 1

As

2

Chla

O2

pH

PO4

POC

Sal

s-NO

ZS

Zicht

NH4

lTBT

Polwa

DebBr

Cre forOLIGOCap cap

Cor ins

Pol cil

Mic gryMys bid

Tha marHet fil

Exo nai

Pla tduPol lig

Pyg ele

Hyd ulv

Spi marCor gib

Sco arm

Har imb

Ner suc

Pol sp

Lep cin

Mal sp

Nep homCor bon Ner virNEMERTACTINI

Syl armNas ret

Mic mac

Har sp

Ven pulMal ful

Abr nit

Asc asp

Syl gra

Are mar

Kef cir

Cor sp

Lit lit

Pse pul

Cer sp

Ostre

Myt edu

Mya are

Ner div

Abr alb

Neo fig

Har imp

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5


Nereis succineaNereis succinea

Hydrobia ulvaeHydrobia ulvae

Relation with light penetration Relation with light penetration and freshwater inflow from and freshwater inflow from

polderspolders

R2 = 0.52p<0.05

0

10

20

30

40

50

60

70

0 10 20 30 40 50

Freshwater inflow(from polders: 10^6 m^3 per half-year)

Lig

ht

pen

etra

tio

n (

Sec

chi

dis

c: d

m)

20

30

40

50

60

1982 1988 1994 2000

Year

Lig

ht

pe

ne

tra

tio

n (

dm

)


More freshwater from poldersMore freshwater from polders > Lower light penetration> Lower light penetration > Lower benthic> Lower benthic primary production primary production > Decrease of epiphytic grazers> Decrease of epiphytic grazers

Relation withRelation with TBT TBT

0

50

100

150

200

250

300

350

400

450

500

Jan-90

Jan-91

Jan-92

Jan-93

Jan-94

Jan-95

Jan-96

Jan-97

Jan-98

Jan-99

Jan-00

Jaar

TB

T (

ng

∙l-1

)

DN MD ZD Gem MTR (1 ng∙l-1)


All these relationships need further examination and verificationAll these relationships need further examination and verification

Decrease TBTDecrease TBT

Still high Still high TBTTBT levels levels > imposex in molluscs> imposex in molluscs > decrease in numbers> decrease in numbers

ConclusionConclusion::

In addition to In addition to

a better use and co-ordination betweena better use and co-ordination betweenexisting long-term large-scale monitoring programmesexisting long-term large-scale monitoring programmes

a different type of integrated monitoring,a different type of integrated monitoring,at short-term and small-scale is desirableat short-term and small-scale is desirable

Thank youThank you

Documents

Limitations and solutions to the exchange of macrobenthos community data