Growth performance of mussel recruits on raft culture after Prestige oil spill

Laura G. Peteiro, José MF Babarro, Uxío Labarta & María José Fernández ReirizInstituto de Investigaciones Marinas CSIC, 36208 Vigo Spain

Phone: +34986 231930 Fax: +34986 292762 Email: lpeteiro@iim.csic.es

From ENVISAT ASAR satellite on November 17 th, 2002

-PAH in mussel tissues -Physiological / Biochemical measurements (survival in air, biochemical composition)

Mussel characterization at seeding (February 2003) Labarta et al., MEPS 2005

Most affected area

Original locations ofmussel populations translated for experimental culture

Redes Miranda Pindo Bueu

Length (mm)

Total DW (g)

Length (mm)

Total DW (g)

Length (mm)

Total DW (g)

Length (mm)

Total DW (g)

Seeding 21,4±7.9 0,3±0.0 10,4±3.6 0,1±0.0 15,6±6.8 0,2±0.0 18,0±5.2 0,2±0.0

Thinning-out 50.6±10.1 4.1±0.3 46.8±6.2 3.2±0.0 44.7±7.5 2.5±0.0 52.2±7.2 4.8±0.4

Labarta et al., MEPS 2005

Corporal parameters at seeding and thinning-out

0 2 4 6 8 10 12

time (months)

0

10

20

30

40

50

60

70

80L

(mm

)

0 2 4 6 8 10 12

time (months)

0

2

4

6

8

10

12

tota

l DW

(g)

Growth curves in length and total dry weight fitted

to Gompertz model

Pt =P∞(e-e(-k*(t-t´)))

BueuRedesMirandaPindo

<2,4

**

0

2

4

6

8

10

Redes 1 Miranda 2 Pindo 3 Bueu 4

mm

/mon

th<2

<1,2,4

**

0

0,05

0,1

0,15

0,2

Redes 1 Miranda 2 Pindo 3 Bueu 4

g tis

sue

DW

/mon

th >1,2

>2

*

*

00,20,40,60,8

11,2

Redes 1 Miranda 2 Pindo 3 Bueu 4

g to

tal D

W/m

onth

<1,4

Seeding/Thinning-out

0

2

4

6

8

10

Redes 1 Miranda 2 Pindo 3 Bueu 4

mm

/mon

th

>3

* *

0

0,05

0,1

0,15

0,2

Redes 1 Miranda 2 Pindo 3 Bueu 4

g tis

sue

DW

/mon

th

>3,4

>1,3,4

* *

00,20,40,60,8

11,2

Redes 1 Miranda 2 Pindo 3 Bueu 4g

tota

l DW

/mon

th >3,4

Thinning-out/Harvest

Initial length/weight at seeding and thinning-out had no effect on growth rate (GR) (ANCOVA p>0.05)

Pindo showed the lowest weight GR in both phases of the culture (p<0.05)

Growth Rates

Seeding/Thinning-out Thinning-out/Harvest

0 2 4 6 8 10 12

time (months)

0

2

4

6

8

10

12

tota

l DW

(g)

DWt =DW∞(e-e(-k*(t-t´)))

<1,4

*

0

2

4

6

8

10

12

Redes 1 Miranda 2 Pindo 3 Bueu 4

DW∞

-0,9

-0,7

-0,5

-0,3

-0,1

0,1

Redes 1 Miranda 2 P indo 3 Bueu 4

<1,2

*

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

Redes 1 Miranda 2 P indo 3 Bueu 4

>2

*

*

00,20,40,60,8

11,2

Redes 1 Miranda 2 Pindo 3 Bueu 4

g to

tal D

W/m

onth

<1,4

>1,3,4

* *

00,20,40,60,8

11,2

Redes 1 Miranda 2 Pindo 3 Bueu 4

g to

tal D

W/m

onth >3,4

Pindo DW∞

(p<0.05) Bueu t´(p<0.05)

BueuRedesMirandaPindo

Growth rates in total dry weight

0

5

10

15

20

25

30

35C

I

0

1

2

3

4

5

6

7

8

9

Ch

l-a

BueuRedesMirandaPindoChl a

CI is a weak parameter to determine stress situations:

- Nutritional state- Reproductive cycle- Pollution

Condition Index evolution along the culture

0

10

20

30

40

50

60

70

80

<50 mm 50 mm≤N<70 mm N≥70mm

Bueu

Redes

Miranda

Pindo

% indiv≥70mm lowest for Pindo mussels (p<0.05)

Yield at harvest

Comparison among mussel populations showed the following remarks:

% individuals ≥ 70 mm, lowest values for Pindo mussels

Lowest Total DW values at harvest for Pindo mussels

A poor commercial classification in pieces/kg

-

-

- Population from Pindo showed the lowest growth rate values in weight in both phases of the culture.

Preliminary Remarks:

- The maintenance of lower growth rates along the culture resulted in poorer commercial yield at harvest for Pindo mussels.

- The latter growth performance of Pindo mussels would be a sub-lethal effect that might reflect its worse physiological and biochemicalconditioning (lipid classes, fatty acids)monitored at the onset of the culture by Labarta et al., (MEPS 2005).