Session 2 14h25 champenois_ceva

Sustainable Pathways for Algal Bioenergy

Design and trial of a new structure for seaweed production at sea
Jennifer Champenois, Fleuriane Fernandes

Situation CEVA is a demonstration pilot for seaweed production Focus of our research = how to improve the cost-effectiveness of the cultivation of kelp at sea
–Increase the productivity of the biomass (kg/m of rope)
–Optimize the occupation of the area at sea to increase the yield (kg/ha) Facility
–Inland hatchery
–6 ha at sea
•Depth 12-25 m
•Sheltered area with low wave action (1-1.5m)
•Current 3-4 knots at high tides period
Alt = 210 km
CEVA

Situation Since the 90’s, seaweed production was done on longlines Space between lines = 50 m because of strong water currents Even if a good productivity is achieved, the yield per ha would be low

Design of a new structure Design of « production units »
–20 m width
–50/100 m long Idea = semi-rigid framework to strengthen the structure so it’s possible to reduce the space between the lines
11 ropes/unit

Design of a new structure General concept
Tube PEHD Ø 315 mm = main tubes
Mooring
Space between lines = 2 m
50 or 100 m long
1000L buoy
Header rope Ø 32 mm
Tube PEHD Ø 90 mm = spacer
5L buoy

Design of a new structure General concept: cross-section view

Design of a new structure At scale view

Design of a new structure
Chaîne liège n°1 - Ø 14 mm – L = 3 m
Corps Mort n°2 - 2T
Corps Mort n°1 - 3,5T
Chaîne n°2 – Ø 25 mm – L =5 m
Ancre 200 Kg
Mooring line design
Aussière n°4 - Ø 32 mm – L = 20 m
Aussière n°5 - Ø 32 mm – L = 10 m
Anneau de liaison n°1 – CMU 14T
Anneau de liaison n°2 – CMU 14T
Mise en place d’une bouée tendeur de 300 L
Tube PEHD n°1 Ø 315 mm L = 20 m
Aussière n°2 - Ø 32 mm – L = 13m
M1
M2
M3
Bouée 1000 L n°1 -
M4
M5
M6
M7
M8
M10
M9
Chaîne n°3 – Ø 25 mm – L =10 m
M11
M12
M13
M14
M15
M16
M17 Mooring study

Design of a new structure Total cost = 40 000 €
–For the 4 production units (2 of 50 m long + 2 of 100 m long)
–Including feasibility study + PEHD tubes + anchoring equipment Pros & Cons Fall 2013 : set-up of the units at sea
Pros
Cons
Higher yield per ha
Strong tension
Less moorings to survey
Boat should be well-adapted: not too large

Cultivation trial Two species are grown
–Alaria esculenta (AE)
–Saccharina latissima (SL)
Dec 2013-Jun 2014: First trial at the new structure
Species
Origin
Density 1 (spores/m)
Density 2 (spores/m)
Date of seeding
Date of transfer at sea
Time at hatchery (days)
AE
Ile Grande
368 000
61 333
04/12/2013
14/01/2014
41
SL
Pors Rand
8 460 000
1 410 000
05/11/2013
11/12/2013
36
Direct seeding of spores onto strings

Monitoring of biological & biochemical data Monthly monitoring from March to June Measurement of :
–Productivity ( g FW per m of rope)
–Density of plants (number per m of rope)
–Morphological characteristics of the 12 largest plants (total length, length of stipe, width, weight, weight of stipe)
–Dry matter
–Sampling for biochemical analysis of the biomass
Blade Width
Peteiro et Freire, 2012
Total Length

Monitoring of environmental data Underwater Light Intensity Nutrients Underwater Temperature
0
50
100
150
200
250
0:00
2:00
4:00
6:00
8:00
10:00
12:00
14:00
16:00
18:00
20:00
22:00
PAR (μE/m²/s)
Time
Nov
Dec
Jan
Feb
March
Apr
May
Jun
9
10
11
12
13
14
0:00
2:00
4:00
6:00
8:00
10:00
12:00
14:00
16:00
18:00
20:00
22:00
°C
Time
Nov
Dec
Jan
feb
March
Apr
May
Jun
0
5
10
15
20
Jan
Feb
March
Apr
May
Jun
July
μmol/L
month
NO3 + NH4 + NO2
2012
2013
2014
0
0,1
0,2
0,3
0,4
Jan
Feb
March
Apr
May
Jun
July
μmol/L
month
PO4
2012
2013
2014

Results: density of plants SL: no difference between seeding densities AE: difference between seeding densities decreases over time. At the end, there is no difference anymore between the two densities
0
200
400
600
800
1000
1200
1400
1600
1800
March
April
May
June
Number of plants per meter
SL density 1 (8.5 M spores/m) SL density 2 (1.4 M spores/m)
AE density 1 (0.6 M spores/m) AE density 2 (0.4 M spores/m)
540 plants/m
268 plants/m

Results: productivity For both species: no difference between seeding densities Higher productivity achieved with SL Density used to seed AE might have been too low
0
5000
10000
15000
20000
25000
30000
35000
March
April
May
June
Yield (g fresh weigh per meter)
20.3 kg/m
9.9 kg/m

Results: morphological characteristics of plants
0
5
10
15
20
25
30
March
April
May
June
Frond Widht (cm) With this low seeding density, AE had higher width than usual  possible interest for downstream processing

Results: morphological characteristics of plants
SL density 1 (8.5 M spores/m)
SL density 2 (1.4 M spores/m)
AE density 1 (0.6 M spores/m)
AE density 2 (0.4 M spores/m)
30 cm
Zone épiphytée
60 cm
Zone épiphytée
FF, 2013
0
50
100
150
200
250
300
March April May June
Total Lenght (cm)
In the last months,
seaweeds get
epiphyted. It’s
especially the case for
AE in 2014
It’s recommended to
harvest before that
time to prevent the
loss of biomass and
quality. A good time
to harvest at our site
is April-May.

Results: biochemical composition
0
10
20
30
40
50
60
70
Fin avril
Fin mai
Fin juin
% DW
Glucose
Fucose
Ac. Glucur.
Galactose
Ac. Gulur.
Ac. Mannur.
Mannose
Mannitol
Acide glutamique
ProtéineSeasonal variation of biochemical composition of Saccharina
April
May
June Time of harvest can be decided depending on biochemical composition

Results to come Crop management: comparison of two techniques
A) One harvest per year, in Spring
B) Two harvests per year (1st in Spring, 2nd in Autum after regrowth of the blade)
1st harvest, above the meristem
2nd harvest, full plant
One harvest, full plant

Results to come Crop management: comparison of two techniques
Crop management
Species
Yield at 1st harvest
Yield at 2nd harvest
Total yield
A
Saccharina
140 kg
140 kg
B
Saccharina
150 kg
To come
To come

Perspectives within the EnAlgae project New trial is planned in 2014-2015
–At 50 m-unit, keeping a distance of 2 m between the lines
–At 100 m-unit, increasing the space between the line to 4 m 4 species
–Alaria esculenta
–Saccharina latissima
–Laminaria digitata
–Laminaria ochroleuca Seeding technique: comparison of two techniques
–Direct seeding of spores on strings (which are then coiled around the rope)
–Direct seeding of spores on ropes (which are transfered at sea right after seeding) - No maintenance of plantlets at sea so it’s a cheapest option
Growing demand on the French market

Further perspectives
Production model that is
–More profitable than only seaweeds. Combination of low (seaweeds) and high-value (salmon) products
–More sustainable than only fish. Bioremediation of animal wastes by seaweeds Future research to be studied at CEVA
–N balance within an IMTA site
–Other environmental concerns
–Potential increase in yield of seaweeds
10 tons
20 tons
50 to 100 tons
Objectives: IMTA: seaweeds + salmon + mussels

Thank you jennifer.champenois@ceva.fr

Session 2 14h25 champenois_ceva

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Session 2 14h25 champenois_ceva