MiteMite letargo dletargo d’’acqueacque

Salvatore Quasimodo

MediterraneanMediterranean LimnologyLimnology: status, : status, gapsgaps

andand thethe futurefuture

Miguel Alvarez Cobelas

ParoleParole, , wordswords, , كلماتكلمات Fiumara (it)Torrente (it, sp)Rambla (sp)Uadi (arab)Limnowla (gr)Sel (tu)Abankor (ber)Billabong (aust)Sebkha (arab)Daya (arab)Delta (gr, it, sp)Enganes (fr)

Zajarich (arab)Lucio (sp)Bulvar (tu)Ojo (sp)Palude (it)Pigi (gr)Pantano (it, sp)Qa (arab)Salant (fr)Chott (arab)Tabla (sp)Corso (it)

Aiguamöll (cat, sp)Aguelman (ber)Playa lake (en)Marais (fr)Baisse (fr)Estero (sp)Stagno (it)Étang (fr)Várzea (pt)Élos (gr)Guelta (arab)

Letto (it)Sorgente (it)Kaynak (tu)Bega (sardo, it)Mallada (cat, sp)Ullal (cat, sp)Albufeira (pt)Nava (sp)Jeimarros (gr)Pan (en)Foum (arab)Limnothalassa (gr)

MediterraneanMediterranean climateclimate......

Mediterranean basin(s. str.)SW South AfricaSouthern CaliforniaCentral ChileS-SW Australia 0

20

40

60

J F M A M J J A S O N DR

ainf

all (

mm

)0

10

20

30

Aver

age

air t

empe

ratu

re

(ºC)

Rainfall:potentialRainfall:potential EvapotranspirationEvapotranspiration = 0.12= 0.12--1.001.00

......andand waterwater availabilityavailability toto inlandinland limnosystemslimnosystemsSTREAMS

2

4

6

8

10

12

J F M A M J J A S O N D

Dis

char

ge (m

3 s-1

)

0

1

2

Permanent

Temporary

LAKES

16

17

18

J F M A M J J A S O N D

Lake

dep

th (m

)

0

1

2

3

Permanent

Temporary

CatchmentCatchment vsvs ecosystemecosystem areaarea......

0

20

40

60

80

100

Temperate Mediterranean

Cat

chm

ent:L

ake

ratio

p < 0.05

n = 31

n = 35

MannMannMann--- WhitneyWhitneyWhitney testtesttest

Data Data sourcessources: :

Cold Cold temperatetemperate

lakeslakes ((KalffKalff, , 2001);2001);

SicilianSicilian reservoirsreservoirs

(Calvo et al. , (Calvo et al. , 1993)1993)

......andand thethe importanceimportance ofof groundwatersgroundwaters

0

2

4

6

O N D J F M A M J J A S

Gro

undw

ater

inpu

ts (H

m3 )

0

40

80

120

160

Rai

nfal

l (m

m)

Rainfall

G. Inputs

AnnualAnnual growthgrowth periodperiod

0

0,2

0,4

0,6

Temperate Mediterranean Tropical

Mea

n:M

ax r

atio

of p

hyto

plan

kton

bi

omas

sn = 16

n = 10n = 5

Data Data sourcessources::

Cold Cold temperatetemperate andand tropical tropical

((LewisLewis, 1990), 1990)

MediterraneanMediterranean (Alvarez (Alvarez CobelasCobelas, ,

unpublishedunpublished data)data)

TPTP--ChlChl aa relationshipsrelationships

Straightforward response

Chl-aMAX = 0.74 TPAVE 0.97 r = 0.91 n = 20 OECD (1982), SLR Project

Chl-aMAX = 0.45 TPAVE 0.64 r = 0.62 n = 68 Alvarez Cobelas, unpublished

Including a loading term

Chl-aMAX = 0.54 TPL 0.72 r = 0.87 n = 20 OECD (1982), SLR Project

Chl-aMAX = 1.43 TPL 0.40 r = 0.65 n = 25 Ortiz Casas et al. (1984)

NutrientNutrient metabolismmetabolism in in streamsstreams

32 32 SpanishSpanish catchmentscatchments (20 (20 forestedforested, ,

12 12 agriculturalagricultural))

MannMann-- WhitneyWhitney U U testtest forfor TNTN

p = 0.0065p = 0.0065

TP TP nsns In cold In cold temperatetemperate streamsstreams, , thethe rulerule isis thethe oppositeopposite!!

Tota

l nitr

ogen

exp

ort (

kg/h

a/y)

-2

4

10

16

22

28

Forested Agricultural

SpeciesSpecies richnessrichness

R = 0,008 TP + 21,16R2 = 0,40

0

10

20

30

40

50

0 1000 2000 3000

Total Phosphorus (mg/L)

Phyt

opla

nkto

n sp

ecie

s ric

hnes

s

0

3

6

9

Oligo Meso Eu Hyper

Cru

stac

ean

spec

ies

richn

ess

TP

JeppesenJeppesen et al. (2000)et al. (2000)

SpeciesSpecies richnessrichness in in

DanishDanish lakeslakes

n = 71n = 71

PhytoplanktonPhytoplankton

CrustaceansCrustaceans

SpanishSpanish lakeslakes

Alonso (1998); n = 113Alonso (1998); n = 113Alvarez Alvarez CobelasCobelas, ,

unpublishedunpublished; n = 30; n = 30

FoodFood webswebs ((emphasizingemphasizing thethe significancesignificance ofof CyprinidsCyprinids andand thethe

sedimentsediment))

PNNPP

ResultsResults fromfrom laboratorylaboratory microcosmsmicrocosms, , 16 16 shallowshallow lakeslakes andand a a wetlandwetland (Rojo (Rojo et al., 2001, 2002; Alvarez et al., 2001, 2002; Alvarez CobelasCobelas et et

al., al., unpublishedunpublished))

PNNP

P

CurrentCurrent status status ofof MediterraneanMediterranean limnologylimnology

It is an underdeveloped branch of limnology that relies upon unsatisfactory models

GapsGapsThe role of cyprinids in foodwebs deserves more researchBacterial growth and diversityin wetlands and streams are unknownThe functioning of submergedand emergent vegetation ispoorly knownThe relationship betweengroundwaters and limnosystemshas hardly been exploredLimnosystem services have notbeen emphasized enough

Very few studies on temporarystreamsPlankton-benthos linkages are unknownAlmost no studies on wetlandbiogeochemistryVery few studies on hyporheicbiogeochemistryThe landscape approach is absentVery few models of MediterraneanlimnosystemsVery few long-term studiesClimate change effects hardlyenvisaged

TheThe futurefuture ((conflictsconflicts

betweenbetween waterwater

use use andand

ecosystemecosystem

survivalsurvival))

The very near future(roughly 100 years ahead) will be conditioned by climate changeIn Mediterranean areas, higher air temperatures, lower rainfall (but higherseasonal rainfallvariability) are expectedWater availability tosurface and aquifersystems will certainlydiminish

The socioeconomy of manyMediterranean areas depends onagriculture and/or tourismThose are very water-demanding sectorsIn the likely scenario ofdiminishing water availability, Mediterranean limnosystemshave the lowest societal priorityMediterranean limnosystemsare then highly threatened andthe survival of many is dubious

ClimateClimate changechange

STREAMS

-1

0

1

2

3

4

Persistence Size Biogeochemistry BiotaQua

litat

ive

chan

ges N = 6

LAKES

-1

0

1

2

3

4

5

Persistence Size Biogeochemistry Biota

Qua

litat

ive

chan

ges N = 7

WETLANDS

0

1

2

3

4

5

Persistence Size Biogeochemistry Biota

Qua

litat

ive

chan

ges

N = 13

RESERVOIRS

-1

0

1

2

3

4

5

Persistence Size Biogeochemistry Biota

Qua

litat

ive

chan

ges N = 5

MitigationMitigation ofof CC CC effectseffectsMediterranean limnosystems should be given more priorityin the societal needsWater-saving measures should be implementedinmediately in the Mediterranean tourist and agriculturalsectorsDeveloping and/or improving wastewater treatment andrecyclingIncreasing revegetation in catchments to mitigate pollutionIncrease environmental protection of valuable limnosystems, also enhancing aquatic connectivity amongthem

ConclusionsConclusions andand prospectsprospectsMediterraneanlimnosystem types are very rich, but most are poorly knownCurrent models of cold temperate limnosystemsare very restricted andMediterraneanlimnosystems do not fitinto themMore research is urgentlyneeded

More people and more funding must be devotedto MediterraneanlimnologyMany endangeredMediterraneanlimnosystems will surviveif, and only if, Mediterranean societiesappreciate them (which isnot the case right now)

I I fiumefiume sonosono mito e memoria, mito e memoria, ss’’apartengono ai apartengono ai ““verdi paradisiverdi paradisi””

delldell’’ infanziainfanziaLeonardo Sciascia (1983)

Le acque della Sicilia

OTHERWISE...OTHERWISE...

The lower Simeto floodplain