Effect of Temperature on Alexandrium minutum Laboratory experiments - PowerPoint PPT Presentation

A. Chapelle, C. Labry, J. Quere, R.Verney, ANR Paralex, Roscoff, 15/2/ 2011 Effect of Temperature on Alexandrium minutum Laboratory experiments and Modelling

Temperature and dilution effects on blooms of Alexandrium minutum in the Penzé estuary ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ • PSP risk ∗ → > 1 M cells/L → • > 1 M cells/L Seawater temperature > 15° C Tidal Coeff < 60 (NT) or < 80 (ST) River runoff < 2 m 3 s -1 1993 2003 ∆ [ A. min cells] = Growth (T, I) – Dilution (tide, runoff) 2004 ∆ [ A. min cells] = Growth (T, I) – Dilution (tide, runoff) – parasitism ?

Hypothesis Blooms in Cork Harbour are controlled by the balance between the tidal dilution rate and the effects of temperature and irradiance on the growth rate Growth rate (T,I) > tidal dilution rate = bloom �������������������������� ���������������������������������������

Temperature and dilution effects on blooms of Alexandrium minutum in the Penzé estuary 1991 - 2003 ∆ [ A. min cells] = µ (T, I) - D (tide, runoff) T water (measured or extrapolated from Rephy, Pelagos data) Dilution calculated from Irradiance measured (meteorological Sibiril station) Hydrodynamic model µ = µmax ∗ f(T) ∗ f(I) D f(T) f(I) 1,2 d'après Probert (1999) 1,0 1,0 d'après Erard-Le Denn (1997) 0,9 Taux de croissance Taux de croissance 0,8 Modèle 0,8 0,7 relatif 0,6 relatif 0,6 d'après Probert (1999) 0,5 0,4 d'après Erard-Le Denn (non publié) 0,4 0,3 d'après Erard-Le Denn (1997) 0,2 0,2 Modèle 0,1 0,0 0,0 0 100 200 300 400 500 0 5 10 15 20 25 30 Température (° C) I (µE.m -2 .s -1 )

Temperature and dilution effects on blooms of Alexandrium minutum in the Penzé estuary 1991 - 2003

In ANR Paralex, new experiments on old strain (AM89BM) and more recent strain (AM06PZ 131) to reevaluate f(T) AM89BM 1997 AM89BM 1999 AM89BM model 2003 1,0 0,8 µ relatif (d-1) 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Temperature (° C)

In ANR Paralex, new experiments on old strain (AM89BM) and more recent strain (AM06PZ 131) to reevaluate f(T) AM89BM 1997 AM89BM 1999 AM89BM model 2003 AM89BM 2010 1,0 0,8 µ relatif (d-1) 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Temperature (° C)

In ANR Paralex, new experiments on old strain (AM89BM) and more recent strain (AM06PZ 131) to reevaluate f(T) AM89BM 1997 AM89BM 1999 AM89BM model 2003 AM89BM 2010 AM89BM model 2010 1,0 0,8 µ relatif (d-1) 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Temperature (° C) C : slope 0.07 ± 0.02 d -1 ° C -1 Linear relationship between 9 and 23 °

In ANR Paralex, new experiments on old strain (AM89BM) and more recent strain (AM06PZ 131) to reevaluate f(T) AM89BM 1997 AM89BM 1999 AM89BM model 2003 AM89BM 2010 AM89BM model 2010 1,0 0,8 µ relatif (d-1) 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Temperature (° C) C : slope 0.07 ± 0.02 d -1 ° C -1 Linear relationship between 9 and 23 ° Review de Montagnes et al. (2003) Sur 92 set de données 79 ⇒ relation linéaire 0.07 ± 0.005 d -1 ° C -1

In ANR Paralex, new experiments on old strain (AM89BM) and more recent strain (AM06PZ 131) to reevaluate f(T) AM89BM 1997 AM89BM 1999 AM89BM model 2003 AM89BM 2010 AM89BM model 2010 AM06PZ 131 1,0 0,8 µ relatif (d-1) 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Temperature (° C) C : slope 0.07 ± 0.02 d -1 ° C -1 Linear relationship between 9 and 23 ° Review de Montagnes et al. (2003) Sur 92 set de données 79 ⇒ relation linéaire 0.07 ± 0.005 d -1 ° C -1

In ANR Paralex, new experiments on old strain (AM89BM) and more recent strain (AM06PZ 131) to reevaluate f(T) AM89BM 1997 AM89BM 1999 AM89BM model 2003 AM89BM 2010 AM89BM model 2010 AM06PZ 131 1,0 0,8 µ relatif (d-1) 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Temperature (° C) Variability between strains in temperature effect Need to re-parametrize the temperature effect

In ANR Paralex, new experiments on old strain (AM89BM) and more recent strain (AM06PZ 131) to reevaluate f(T) AM89BM 1997 AM89BM 1999 AM89BM model 2003 AM89BM 2010 AM89BM model 2010 AM06PZ 131 A. min and A. tam Cork Cork model 1,0 0,8 µ relatif (d-1) 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Temperature (° C) Same linear relationship but a greater growth limitation by low temperatures in Penzé Why?

Similar temperature between Cork and Penzé. It isn’t a question of acclimatation.

Forecast of bloom occurrence period In Cork, the model simulates the bloom for the first neap tide of june

Forecast of bloom occurrence period 15 years simulated with only T, I, Dilution (tide and runoff) Interannual variability of the risk period reproduced (from beginning of june to mid july)

Forecast of bloom occurrence period - 1991 : Beginning of A. minutum apparition in Penzé, kystes explanation ?

Forecast of bloom occurrence period - 1998 : early bloom of A. minutum concentrations but….

2 High flows of Penzé river and Water temperature around the 15° C limit The model limits more heavily A. minutum development than in situ

Forecast of bloom occurrence period - 2005, 2006 : Good environmental conditions, the bloom begin early in June but does not reach high biomass -> control top down ?

Temperature and dilution effects on blooms of Alexandrium minutum in the Penzé estuary Perspectives Continue comparison between Alexandrium minutum blooms simulation between Penzé and Cork harbour Adjust the temperature effect with strain 06 experiments Apply the same approach to the Rance ? AM89BM 1997 AM89BM 1999 AM89BM model 2003 AM89BM 2010 f(T) : complete with temperature < AM89BM model 2010 AM06PZ 131 A. min and A. tam Cork Cork model 14° C (10, 12) 1,0 0,8 Test on new strains µ relatif (d-1) 0,6 Test with A . minutum infected by 0,4 0,2 Amoebophrya 0,0 0 5 10 15 20 25 30 Temperature (° C)