Long-term impacts of extreme events on estuarine ecosystems

Filipe Martinho

Centre for Functional Ecology – CFEDepartment of Life SciencesUniversity of Coimbra

Overview

IPCC, 2001; 2007

One of the most recognized aspects of

climate change is the gradual increase

in air and water temperature around

the globe

Impact on Earth’s marine ecosystems

• Biology

• Oceanography

• Functioning

Smooth changes can be interrupted by

sudden drastic switches to a contrasting

state.

Overview

EXTREME WEATHER EVENTS

As a consequence of climate change, the loss

of resilience in biological communities

usually paves the way for a switch to an

alternative state.

Overview

Long-term datasets are among the most important tools for addressing the

impacts of climate change and extreme events on marine ecosystems

Rijnsdorp et al., 2009 ICES Journal of Marine Science

Overview

Mondego estuary one of the longest time-series in Portugal

2003 2016

Biological communities

• Benthic invertebrates

• Zooplankton and ichthyoplankton

• Fish

Extreme weather events

• Droughts

• Heat waves

• Floods

Impacts on fish communities

Martinho et al., 2007Estuarine, Coastal and Shelf Sci

Dolbeth et al., 2010Marine and Freshwater Research

Baptista et al., 2015Marine Pollution Bulletin

Prolonged drought resulted in:

• Changes in dominant functional groups

• Increase in species with marine affinities

• Lower species diversity

• Reduced functional diversity

• Lower production of key species

Impacts on fish communities

Baptista et al., 2015Marine Pollution Bulletin

Martinho et al., 2010Journal of Applied Ichthyology

Prolonged drought resulted in:

• Changes in species climate affinity

A. laterna

D. hexophthalma P. lascaris

B. luteum

Scaldfish Solenette

Sand soleOcellated wedge sole

Sub-tropical flatfishesPresent only during the drought

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Impacts on habitat use by marine fish

(+ correlation)(- correlation)

European sea bassDicentrarchus labrax

Martinho et al., 2009Estuarine, Coastal and Shelf Sci

Bento et al, 2016Submitted

Estuarine densities of D. labrax

• Lower densities during the drought

• Negatively correlated with salinity- higher salinity- lower river runoff- smaller extension of river plumes into coastal areas

• Positively correlated with NAO- global climate patterns influence growth and survival of early life stages

European flounderPlatichthys flesus

Sor ord

WaddenSea

Slack

Villaine

Mondego

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Seasurfacetemperature(ºC)

Meanhatchdate

Impacts on estuarine colonization by marine fish

Martinho et al., 2013Journal of Sea Research

Estuarine colonization of P. flesus

• Early life stages follow a latitudinal trend

• Growth and survival is mainly determined by prevailing water temperature

• Different populations have different thresholds to temperature regimes

• Extreme events can overrule the latitudinal trend and impose a mismatch between prey and predator, or between larvae and suitable hydrographic conditions

Take home message

The long-term impacts of extreme events on estuarine communities depend on:

• Extension in time and space of the extreme event(s)

• Resilience of specific communities/species/functional groups

• Ontogeny – life cycle stages tend to have different thresholds to changes

• Position relative to geographical distribution range

Prolonging existing long-term monitoring plans is mandatory for addressing climate/species relationships

MYTAG - PTDC/MAR-EST/2098/2014 Integrating natural and artificial tags to reconstruct fish migrations and ontogenetic niche shifts

Project - IF/01410/2012Estuarine areas as nursery grounds for marine fish in a global change scenario: combining local and large-scale approaches

Future work

Estuarine habitat colonization vs oceanic circulation and river plumes

Relationship between fish and zooplankton with large/meso-scale climate drivers

Future work

Acknowledgments

Portuguese Foundation for Science and Technology - FCT

Investigador FCT – IF/01410/2012

Centre for Functional Ecology (CFE), Coimbra, Portugal

Team members & funding

Homepage: cfe.uc.pt/fmartinho

E-mail: fmdm@ci.uc.pt