past experience and future research on diapause in uruguay iglesias limnologia2012 final
TRANSCRIPT
Past experiences and future research on diapause in Uruguay
Carlos Iglesias, Néstor Mazzeo, Nicolás Vidal, Miriam Gerhard, Matías Arim, Mariana Meerhoff & Erik Jeppesen
Special session: Diapause as invertebrate survival strategy in instable aquatic environments
SUMMARY:
Brief history
Our working questions
Where we are
Some results
Future research
Doubts!
Brief history
1984 creation of Limnology section at Facultad de Ciencias Research focus on aquatic communities principally in lakes
1998 Research Group in Ecology and Restoration of Aquatic Systems
Eutrophication and Restoration of Shallow Lakes Ecosystemic approach Paleolimnology International cooperation (Moss, Jeppesen, Reynolds, Scheffer)
2006 Split of the Research group (2 permanent posisitions)
SNI
2008 Move to CURE Maldonado (9 DT permanent positions)
Our working questions
From Hugie & Dill 1994
Resting egg banks are capable to
develop different zooplankton
community structure if
biomanipulation techniches are
applied?
Resting egg banks are capable to
develop different zooplankton
community structure if
biomanipulation techniches are
applied?
Do macrophytes (PVI & architecture)
influence fish- zooplankton
interactions?
Do macrophytes (PVI & architecture)
influence fish- zooplankton
interactions?
Do fish structure the zooplankton
community in subtropical shallow
lakes? (effects of eutrophication)
Do fish structure the zooplankton
community in subtropical shallow
lakes? (effects of eutrophication)
Where are we
Different approaches
• Empirical
• Experimental
• Modeling
• Comparative studies
• Gradient analyses
Different approaches
• Empirical
• Experimental
• Modeling
• Comparative studies
• Gradient analyses
Warm -
Gillooly & Dodson, 2000 L&O 45: 22-30
Lacerot, 2010
Cold +
• Lower richness
• 5.5x lower density in subtropical lakes
• Large-bodied zooplankters infrequent or absent.
Meerhoff et al 2007 FWB
• Lower richness
• 5.5x lower density in subtropical lakes
• Large-bodied zooplankters infrequent or absent.
Meerhoff et al 2007 FWB
Where are we
Temperature
WHY ARE THEY SMALLER?
WHY ARE THEY SMALLER?PREDATION
By fish &/or invertebratesJeppesen et al 2007, Meerhoff 2008 Lacerot 2010
PHYSIOLOGICAL Growth, reprod, respiration rates Moore et al 1996
FOOD QUANTITYFood threshold higher for large species in warmer lakes
Duncan, 1989
FOOD QUALITYCyanobacteria and inedible algae Elser et al 2000 De Mott et 2001
Zooplankton structure changes accross climates
Fish size
Zoop size
Food quality
Where are we
Experiments on the structuring role
of fish and cascading effects over other
communities in simple and more
strucutrated environments
Combined approaches
Field surveys for seasonal
dynamics on water and sediment
records in a large set of lakes
Experiments on the structuring role
of fish and cascading effects over other
communities in simple and more
strucutrated environments
Combined approaches
Field surveys for seasonal
dynamics on water and sediment
records in a large set of lakes
Some results
Iglesias et al FWB 2008
SP
EP
OW
LAKE BLANCALAKE BLANCA
MESOCOSM APPROACHMESOCOSM APPROACH
Some results
0
500
1000
1500
2000
2500
3000
3500
4000 LAKE RODOB
IO
MA
SS
(µg/L)
0
1000
2000
3000
4000
5000
10000
15000
20000
Brachionus urceolarisMetacyclops mendocinusMoina micrura
Brachionus urceolarisMetacyclops mendocinusMoina micruraDaphnia obtusa
Metacyclops mendocinusDaphnia obtusa
Brachionus rubensMetacyclops mendocinusDaphnia obtusa
Keratella tropicaKeratella cochlearisMetacyclops mendocinusDiaphanososma birgeii
Metacyclops mendocinusNotodiaptomus incompositusDaphnia obtusa
Keratella tropicaBrachionus calyciflorusMetacyclops mendocinusNotodiaptomus incompositus
Notodiaptomus incompositusMetacyclops mendocinusDiaphanososma birgeiiDaphnia obtusa
LAKE RIVERA
BIO
MA
SS
(µg/L)
SUMMER AUTUMN WINTER SPRING
SUMMER AUTUMN WINTER SPRING
ROTIFERS
COPEPODS
OTHER CLADOCERANS
Daphnia obtusa
Extense fish kill
Some results
Igleisias et al., 2011 Hydrobiologia 667:133-147
Extensive fish kill in Lake Rivera
Determined the appearence of Daphnia
and bigger than expected
Extensive fish kill in Lake Rivera
Determined the appearence of Daphnia
and bigger than expected
FISH EXCLUSION EXPERIMENTFISH EXCLUSION EXPERIMENT
Large sized cladocerans appeared after fish exclusion
When fish was added then they disappeared or their size was diminished
Large sized cladocerans appeared after fish exclusion
When fish was added then they disappeared or their size was diminished
Some results
Igleisias et al., 2011 Hydrobiologia 667:133-147
Some results50% of the lakes (9) Epphipia was found.
In 3 of them Daphnia also found in water samples
In 3 of them only in water
Overall Daphnia potentially in 75%
50% of the lakes (9) Epphipia was found.
In 3 of them Daphnia also found in water samples
In 3 of them only in water
Overall Daphnia potentially in 75%
Igleisias et al., 2011 Hydrobiologia 667:133-147
50 Temporary systems
Dryed during summer
Laguna de Castillos basin
50 Temporary systems
Dryed during summer
Laguna de Castillos basin
Some resultsTEMPORARY PONDSTEMPORARY PONDS
Five days sediment incubation with water from the ponds in 1L cubitainers continously aireated
Comparison with active comunity
from the ponds (50 µm)
(3 replicates x 10 ponds) + 30 controls (1xpond)
Some resultsTEMPORARY PONDSTEMPORARY PONDS
Some resultsTEMPORARY PONDSTEMPORARY PONDS
020406080100120140 0 20 40 60 80 100 120 140
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
020406080100120140 0 20 40 60 80 100 120 140020406080100120140 0 20 40 60 80 100 120 140
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
Charcos de Hidroperíoodo Corto Charcos de Hidroperíoodo Largo
*
*
*
**
*
*
*
0100200300400500600700 0 100 200 300 400 500 600 700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
0100200300400500600700 0 100 200 300 400 500 600 7000100200300400500600700 0 100 200 300 400 500 600 700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
Charcos de Hidroperíoodo Corto Charcos de Hidroperíoodo Largo
0100200300400500600700 0 100 200 300 400 500 600 700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
0100200300400500600700 0 100 200 300 400 500 600 7000100200300400500600700 0 100 200 300 400 500 600 700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
Charcos de Hidroperíoodo Corto Charcos de Hidroperíoodo Largo
* *
* *
050100150200250300350400450500550600650700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
050100150200250300350400450500550600650700 050100150200250300350400450500550600650700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
Charcos de Hidroperíoodo Corto Charcos de Hidroperíoodo Largo
*
*
*
**
*
*
*
050100150200250300350400450500550600650700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
050100150200250300350400450500550600650700 050100150200250300350400450500550600650700
Ostrácoda
Rotífera
Nauplios
Cyclopoides
Clad pelágico
Calanoides
Clad fitófilos
Charcos de Hidroperíoodo Corto Charcos de Hidroperíoodo Largo
*
*
*
**
*
*
*
Sediment incubation
Worked!!!
Active community
High correlation among Active and latent communities
Future research
EXPERiMENTAL
Lab microcosm Mesocosms “Whole lake”
Empirical evidence
Plants Fish Zooplankton
Empirical-experimenta approach
Empirical-experimenta approach
Study the “potential” zooplankton community vs anual varitation in the water colum
Miriam Gerhard MSc Thesis
Study the “potential” zooplankton community vs anual varitation in the water colum
Miriam Gerhard MSc Thesis
Future research
Investigate composition & abundanceCalculate saturation & rarefaction
Also invetigate correlation betweenActive and latent zooplankton
Laguna Blanca as “our case of study”, piscivorous fish recolonized the system. Daphnia registered in water samples vs. previous data
Laguna Blanca as “our case of study”, piscivorous fish recolonized the system. Daphnia registered in water samples vs. previous data
Future research
Latitudinal analyses of ephippia occurence and sediment incubation in samples from 88 lakes from SA 5 to 55 lat
Latitudinal analyses of ephippia occurence and sediment incubation in samples from 88 lakes from SA 5 to 55 lat
Future research
Future research
Emergence and ephippia production phenology
Emergence and ephippia production phenology
Future research
Future research
Emergence and ephippia production phenology
Emergence and ephippia production phenology
Future research
Plastic Tissue Culture Flask
Tygon Tubing
Friction fit: mouth of flask fits snuggly over tubing
Tubing attached to funnel and funnel to bottle with “hot glue”
Small plastic funnel
Plastic bottle from water cooler(with bottom cut off)Mesh windows attached with hot glue
Sheet-metal collar, with hole for bottle: rests on sediment surface
Metal tubing legs (we made them with electrical conduit)They project about 20 cm into sediment to hold trap in place
Photo by CM Kearns Draw by Nelson G. Hairston
Doubts!
SS4-0187-Iglesias Limnologia2012
How to induce eclosion in lake samples
To dry or not to dry
Cool or not, how long
Culture meddium vs lake water
Emergence Traps frequency of sampling, how many of them, where
Ephippia production traps…………..
How to induce eclosion in lake samples
To dry or not to dry
Cool or not, how long
Culture meddium vs lake water
Emergence Traps frequency of sampling, how many of them, where
Ephippia production traps…………..
Thanks!!
Thanks for finantial support to AU, NERI and the Ministry of Science, Technology and Innovation in DK. PDT, ANII, CSIC –Udelar in Uruguay
Gracias!!
Obrigado!!
Zooplancton Rotíferos
Copépodos
Cladóceros
Importantes consumidores primarios en los sistemas lénticos
Filtradores de gran tamañoSucesión estacional
Mecanismos de respuesta a condiciones adversas
Huevos de resistencia: EfipiosEscape temporal y espacial
Comunidad activa
Comunidad potencial
