2nd workshop on Recirculating Aquaculture Systems 10-11 October 2013

Quantification of respiration and excretion rates in European lobster

(H. gammarus)

A. Drengstig, A. Bergheim, S. Westerlund & A.-L. Agnalt

Background

• Long traditions – Kvitsøy well known in Europe for its lobster fisheries

• European lobster is considered the most exclusive seafood product in the world

• Wild catches are negligible compared to market - high demand and high price

• A promising candidate for aquaculture

• Aquaculture features: – Cannibalism – Farming technology must be advanced – Individual compartments and monitoring – Optimum growth at 20 ºC – RAS is the required technology

Current knowledge base

• Produced semi-commercial volumes from egg to plate (value chain)

• Tested and documented farming technology

• Pelleted feed adjusted to nutritional needs

• Market potential, prices and product brand is documented

• Conducted successful attempts to develop genetic databank

• Conducted successful attempts for year-round hatching

4

Farming technology

• Utilising 3 dimensions • Individual cages • Distribution of water in and out of cages

Fully automatic solutions

• Feeding robot – Feeding with 5 different pellet sizes – Feeding accuracy is +/- 0.1 gram • Production planning tool – On site and/or remote control • Image processing – Daily control and registration of growth, moulting, mortality and determination of harvest time for each single lobster • Grading robot – I-III stage vs IV-stage juveniles – 2 larvae per second

Respiration and excretion rates for European lobster

• Knowhow regarding the range of optimal (not harmful) and critical levels of most water quality parameters for European lobster is lacking

• Available literature of metabolic rate in European lobster is sparse

– Thus, dimensioning criteria's for land-based RAS farms are sub-optimal

Initial test 2006

• Initial tests done by the University of Stavanger and Norwegian Lobster Farm in 2006 measured strongly fluctuating oxygen consumption in lobster of different size at 19ºC:

Small/fry 7 – 10 g: 0.8 – 6.3 mg O2/kg x min Medium-size 43 - 54 g: 0.5 – 3.5 “ Large 148 - 208 g: 0.7 – 2.1 “

8

Testing facility (IRIS’ Lab)

9

Excretion and respiration chamber (IRIS’ Lab)

Excretion and respiration chamber (IRIS’ Lab)

11

Online monitoring (IRIS’ Lab)

Excretion and respiration chamber (IRIS’ Lab)

13

Respiration rates – test 1

r = -0,64

0.0460.0977.788.0720.0-20.2208

0.0320.0807.938.0720.0-20.2122

0.0390.046 (0.031-0.061)7.908.0619.5-20.3121

0.0400.068 (0.042-0.094)7.898.0619.5-20.293.9Adults

0.0280.071 (0.059-0.082)7.948.0719.5-20.243.6

0.0340.110 (0.102-0.118)7.898.0719.5-20.220.4Youngsters

7.748.0819.9-21.01.76

0.0240.3497.998.0819.9– 21.00.0598Fry

N/O2 ratioExcretion mg TAN/kg x minpH endpH startTemp., °CInd. weight, gGroup

0.0460.0977.788.0720.0-20.2208

0.0320.0807.938.0720.0-20.2122

0.0390.046 (0.031-0.061)7.908.0619.5-20.3121

0.0400.068 (0.042-0.094)7.898.0619.5-20.293.9Adults

0.0280.071 (0.059-0.082)7.948.0719.5-20.243.6

0.0340.110 (0.102-0.118)7.898.0719.5-20.220.4Youngsters

7.748.0819.9-21.01.76

0.0240.3497.998.0819.9– 21.00.0598Fry

N/O2 ratioExcretion mg TAN/kg x minpH endpH startTemp., °CInd. weight, gGroup

Excretion rates - test 1

15

Respiration rates – test 2

y = -0.652ln(x) + 3.89 R² = 0.799

0

1

2

3

4

5

6

7

0 10 20 30 40 50 60

mg

O2

/kg

x m

in

Ind. weight (g)

Metabolic rate, fed lobster

Respiration rates – test 2

y = -0.111ln(x) + 1.91 R² = 0.091

0

1

2

3

4

5

6

7

0 10 20 30 40 50 60

mg

O2

/kg

x m

in

Ind. weight (g)

Metabolic rate, un-fed lobster

Excretion rates – test 2

y = -0.087ln(x) + 0.417 R² = 0.803

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

0 10 20 30 40 50 60

mg

TA

N/

kg x

min

Ind. weight (g)

Excretion rate , fed - unfed lobster

Respiration and excretion quotient – test 2

RQ

AQ

Mean 0.763 0.159

Max 1.260 0.284

Min 0.304 0.067

Respiration (RQ) and excretion quotient (AQ) in fed and unfed lobster of 0.126 – 59.15 g at 20 ºC. Unit: mole CO2/mole O2 and mole TAN/mole O2, respectively

Conclusions

• RAS is a proven technology suitable to grow lobster • Need more knowledge on optimum range for key water

quality parameters • Need more information with regard to excretion for

dimensioning of biofilter and investment costs

• Acknowledgement to VRI Rogaland for co-financing this work

2nd workshop on Recirculating Aquaculture Systems 10-11 October 2013

Thank you for your attention