L. Seuront CNRS UMR 8187 LOG, Wimereux, France School of Biological Sciences, Flinders University, Adelaide, Australia South Australian Research and Development

L. SeurontCNRS UMR 8187 LOG, Wimereux, France

School of Biological Sciences, Flinders University, Adelaide, AustraliaSouth Australian Research and Development Institute, Aquatic Sciences, West Beach, Australia

Center for Polymer Studies, Department of Physics, Boston University, Bonston, USA

On the effects of hydrocarbon contamination on zooplankton behaviour

Approach and focus

Feeding and swimming behaviours intertwined in calanoid copepod, hence critical to understand

- trophodynamics

- population dynamics

- carbon fluxes

Approach and focus

Role of a range of ‘stressors’ on zooplankton behaviour

Approach and focus

- temperature and salinity

- biologically-induced viscosity

- anthropogenic pollutants, e.g. hydrocarbons


- natural contamination, e.g. HABs, diatom toxins

- food quality and quantity

Approach and focus

- temperature and salinity

- biologically-induced viscosity

- anthropogenic pollutants, e.g. hydrocarbons


- natural contamination, e.g. HABs, diatom toxins

- food quality and quantity

On (massive) hydrocarbon contaminations

On (pernicious) hydrocarbon contaminations

Oil leaked from a Nippon Petroleum Refining Co. oil factory float at Shiogama Bay, Miyagi prefecture, Japan

Source: http://www.toledoblade.com

Source: Google Earth

Petroleum leaking from a ship in Aden’s harbour

Sub-lethal effects of hydrocarbons on zooplankton:

- anomalous metabolism (Samain et al. 1980, 1981)

- decreased/inhibited feeding (Berdugo et al. 1977, Berman et al. 1980, Cowles & Remillard 1983, Barata et al. 2002)

- reduction in egg production (Ott et al. 1978)

- reduction in hatching rate (Cowles & Remillard 1983)

- increased mortality (Gajbhiye et al. 1995, Almeda et al. 2013)

- reduction in clutch size (Barata et al. 2005)

- behavioural changes (Seuront & Leterme 2007, Seuront 2010, 2011, 2012)

On pernicious hydrocarbon contaminations



Short-term exposure to low concentrationsno effects



Long-term exposure to low concentrationsvarious effects




Long-term exposure to low concentrationsvarious effects


Detrimental cumulative effects unidentifiable under standard short-term incubations…


Different tools are needed to assess the impact of pernicious ‘invisible’ contaminants

Objectives

1. ability of copepods to detect and avoid contaminated water

2. behavioural changes in contaminated water

3. effect of contaminated water on chemoreception

4. effect of contaminated water on mating strategies

Objectives

5. foraging behaviour as an end-point assessment and monitoring tool

1. ability of copepods to detect and avoid contaminated water

2. behavioural changes in contaminated water

3. effect of contaminated water on chemoreception

4. effect of contaminated water on mating strategies

Results: impact of pernicious contamination

Pollutants: - naphthalene - WSF of commercial diesel oil - always sub-lethal and very low concentrations

2 to 3 orders of magnitude below lethal concentrations (LC50)

Avoidance of WSF point source contamination:Temora longicornis and Eurytemora affinis

Seuront (2010) Zooplankton avoidance behaviour as a response to point sources of hydrocarbon-contaminated waterMarine and Freshwater Research, 61, 263-270.Seuront (2012) Hydrocarbon contamination and the swimming behavior of the estuarine copepod Eurytemora affinis

Results: detection and avoidance

















Water contamination and behavioural stress: - stress/sickness decrease behavioural complexity

(Bassingthwaighte et al. 1994; Escos et al. 1995; Alados et al. 1996)



Water contamination and behavioural stress: - stress/sickness decrease behavioural complexity

(Bassingthwaighte et al. 1994; Escos et al. 1995; Alados et al. 1996)

- fractal analysis reveals stress when standard behavioural metrics fail in dolphins (Seuront & Cribb 2011), snails (Seuront et al. 2007) and copepods

(Coughlin et al. 1992; Seuront & Leterme 2007; Seuront & Vincent 2008; Seuront 2011, 2012)


Naphthalene and behavioural stress: Centropages hamatus

Results: motion behaviour

From Seuront & Leterme (2007) Increased zooplankton behavioral stress in response to short-term exposure to hydrocarbon contamination. Open Journal of Oceanography, 1, 1-7.




Sp

ee

d (

mm

s-1)







Naphthalene and behavioural stress: Centropages hamatus vs. C. typicus - C. hamatus: inshore, i.e. more contaminated

- C. typicus: offshore, i.e. less contaminated


Naphthalene and behavioural stress: Centropages hamatus vs. C. typicus - C. hamatus: inshore - C. typicus: offshore

- stress: C. hamatus < C. typicus


Naphthalene and behavioural stress: Centropages hamatus vs. C. typicus - C. hamatus: inshore - C. typicus: offshore

- stress: C. hamatus < C. typicus

- vulnerability higher offshore than inshore


Results: more on motion behaviour

Successive displacements are intermittent

Highly non-Gaussian! Additional tools needed…


Successive displacements are intermittent

Highly non-Gaussian! Additional tools needed…

( )q qX

Intermittency in nutrients, phyto- and zooplankton(Seuront et al. 1996a, b, 1999, 2002; Seuront & Schmitt 2004; Seuront 2005, 2008; Yamazaki et al. 2006)

Seuront (2010) Fractals and Multifractals in Ecology and Aquatic Science, CRC Press.Seuront & Stanley (in press) Anomalous diffusion and multifractality enhance mating encounters in the ocean. PNAS.

( )q qX



Filtered seawater

q


Filtered seawaterFood-conditionned

seawater

q q



seawater

q q

q


PAH contamination


seawater

q q

q


PAH contamination

PAH contamination


Modified from Seuront (2013) Chemical and hydromechanical components of mate-seeking behaviour in the calanoid copepod Eurytemora affinis. Journal of Plankton Research, 35, 724-743.

Copepods mate-seeking strategies rely on chemosensory abilitities

150

mm

150 mm


Modified from Seuront (2013) Chemical and hydromechanical components of mate-seeking behaviour in the calanoid copepod Eurytemora affinis. Journal of Plankton Research, 35, 724-743.

Copepods mate-seeking strategies rely on chemosensory abilitities

150

mm

150 mm

WSF contamination and Temora longicornis mate-seeking and mating behaviour

- ability of males to detect, track and capture females

- control water vs. sub-lethal WSF concentration

Results: mating behaviour

From Seuront (2011) Hydrocarbon contamination decreases mating success in a marine planktonic copepod. PLoS ONE, 6(10), e26283.








WSF contamination and Temora longicornis mating behaviour

- decrease in male detection and tracking ability

- decrease in contact rates (2-fold)

- decrease in capture rates (3-fold)


Conclusions and Perspectives- copepod behaviour is very complex, hence specific tools are

needed

- hydrocarbon contamination may have a critical effect on reproduction, even at very low concentrations

- copepods are very sensitive to hydrocarbon contamination

Conclusions and Perspectives- copepod behaviour is very complex, hence specific tools are

needed

- hydrocarbon contamination may have a critical effect on reproduction, even at very low concentrations

- copepods are very sensitive to hydrocarbon contamination

- efficient tools to monitor water quality in quasi real-time

Thanks for your attention!

Thanks for your attention!

Special thanks to:

(financial support 2006-2012)

(financial support 1999-2000)

Documents

L. Seuront CNRS UMR 8187 LOG, Wimereux, France School of Biological Sciences, Flinders University, Adelaide, Australia South Australian Research and Development