Effects of Prestige fuel oil ingestion on growth of juvenile turbot (Scophtalmus maximus)

Effects of Prestige fuel oil ingestion on growth of juvenile turbot (Scophtalmus maximus)

Rosario Domínguez Petit

Instituto de Investigaciones Marinas, VigoRosario Domínguez Petit

Instituto de Investigaciones Marinas, Vigo

INTRODUCTION

• Prestige heavy fuel oil was poor in volatile and soluble components low degradation rates (Albaigés & Bayona, 2003).

• Models prediction (Gin et al, 2001) surface water

time

Sea bed sedimentsContamination of prey resourcesContamination of prey resources

Contamination of gills and skin

Degradation of natural environments

MATERIAL & METHODS

• 202 juvenile turbot (Scophtalmus maximus) from commercial hatchery

• One week before starting the experiment

Weight(0.01 g)

Total length (1mm; 90 mm aprox.)

Tagged (codified soft VI alfa tags)

Condition Factor (K = 100*W/L3)

MATERIAL & METHODS

TANKS

Capacity of 250 l

2 l/h filtered seawater

18º C

12L:12D photoperiod

FOOD

15.01 ± 0.02 g/day

3 times/day

Excess food was removed daily

0 mg/g

n = 33

2.4 mg/g

n = 32

5.6 mg/g

n = 34

16 mg/g

n = 33

29.5 mg/g

n = 35

48.2 mg/g

n = 35

CONTROL

MATERIAL & METHODS

Fuel

Dissolved fuel

Mixed

Dried

Pellets + Fuel (4ºC)

dichloromethane

pellets

Rotary evaporator

1 h 50º Cdichloromethane

Food preparation

RESULTS

ANOVA: Difference between mean length within treatment at the beginning and at the end of the experiment.

Treatment

1 2 3 4 5 6

Leng

th (

mm

)

90

95

100

105

110

115 Initial lengthFinal length

RESULTS

Treatment

1 2 3 4 5 6

We

igh

t (m

m)

10

15

20

25

30

Initial weightFinal weight

ANOVA: Difference between mean weight within treatment at the beginning and at the end of the experiment.

RESULTS

Relationship between weight increment and initial weight in each specimen for each treatment.

Relationship between length increment and initial length in each specimen for each treatment.

RESULTS

RESULTS

Length-weight relationships (main panel) and mean K (upper panel) for each treatment at the end of the experiment. Error bars = Mean ± 2*SE

Final length (mm)

60 80 100 120 140 160

Fin

al w

eig

ht

(g)

0

10

20

30

40

50

60

70

Treatment 1 Treatment 2Treatment 3Treatment 4 Treatment 5 Treatment 6

Treatment

1 2 3 4 5 6

Co

nd

itio

n f

acto

r

1.60

1.65

1.70

1.75

1.80

1.85

1.90

Ln [Fuel oil]

0.00 1.22 1.89 2.83 3.42 3.900.00 1.89 3.42 3.900.00 2.83 3.42 3.900.00 1.22 1.89 2.83 3.900.00 1.22 1.89 3.42 3.900.00 1.22 1.89 2.83 3.42 3.900.00 1.22 1.89 2.83 3.42 3.900.00 1.22 1.89 2.83 3.420.00 1.89 2.83 3.420.00 1.22 1.89 2.83 3.42 3.900.00 1.89 2.83 3.42 3.900.00 1.22 1.89 2.83 3.42 3.900.00 1.89 2.83 3.42 3.900.00 1.89 2.83 3.42 3.900.00 1.22 3.42 3.900.00 1.89 2.83 3.42 3.900.00 1.22 1.89 2.83 3.42 3.900.00 1.89 2.83 3.420.00 1.22 1.89 2.83 3.900.00 1.22 1.89 2.83 3.900.00 1.22 1.89 3.42 3.900.00 1.89 2.83 3.42 3.900.00 1.22 1.89 2.83 3.900.00 1.22 1.89 2.83 3.42 3.900.00 1.22 1.89 2.83 3.420.00 1.22 1.89 2.830.00 1.22 1.89 3.42 3.900.00 1.22 3.42 3.900.00 1.891.89 2.83 3.42 3.900.00 1.22 1.89 2.83 3.900.00 1.22 1.89 2.83 3.420.00 1.89 2.83 3.42 3.900.00 1.89 3.42 3.903.42 3.903.90

Gro

wth

ra

te (

% le

ng

th)

0

5

10

15

20

Gro

wth

ra

te (

% w

eig

ht)

0

20

40

60

80

100

Length, r2=0.97Weight, r2=0.99

Relationship between mean growth rate and oil concentration. Error bars = Mean ± 2*SE

BACKGROUNDS

- Crude oil components inhibit growth of several fish species, specially at earlier life stages as a result of ingestion of oil contaminated food (Schwartz 1985; Mortensen & Carls 1994; Carls et al. 1996).

- Reduction of feeding rate with increasing of oil concentration has been observed in other species (Schwartz 1985; Omeregie & Ufodike 2000)

- Reduction of energy assimilation can be derived from alteration in fish metabolism after assimilation of some oil components (Moles & Norcross 1997)

- Effects provoked by oil ingestion may remain well after the oil is no longer present, including any effect on feeding behaviour (Schwartz 1985; Heintz et al. 2000)

- Juvenile flatfishes do not avoid areas polluted with oil at low concentrations (Moles at al. 1994)

- Reduced growth may impact on the recruitment strength and the population dynamics, including maturation process (Heintz et al. 2000)

CONCLUSIONS

- Significant differences in somatic growth have been detected after 40 days providing fish with contaminated food within a range of oil concentration.

- At the end of the experiment, differences in growth performance could be explained because of the considerably mean fish body size differences between treatements (small fish fed at low rate).

- The growth reductions are probably the result of the reduction in feeding activity combined with a major reduction in the ability for food energy conversion.

- Care should be used in extrapolating these results to the field. While some of the concentrations used in this study are likely to be found after oil spill, others may be considered too high, although, there are a general lack of data about some oil components accumulation trough the food web.

Thank you very much