- Email: [email protected]
Commercial land-based farming of European lobster (Homarus gammarus L.) in recirculating aquaculture system (RAS) using a single cage approach
Accepted Manuscript Title: Commercial land-based farming of European lobster (Homarus gammarus L.) in Recirculating Aquaculture System (RAS) using a single cage approach Authors: Asbjørn Drengstig, Asbjørn Bergheim PII: DOI: Reference:
S0144-8609(12)00091-X doi:10.1016/j.aquaeng.2012.11.007 AQUE 1667
To appear in:
Aquacultural Engineering
Received date: Accepted date:
28-9-2012 19-11-2012
Please cite this article as: Drengstig, A., Bergheim, A., Commercial land-based farming of European lobster (Homarus gammarus L.) in Recirculating Aquaculture System (RAS) using a single cage approach, Aquacultural Engineering (2010), doi:10.1016/j.aquaeng.2012.11.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Highlights (for review)
Highlights
Ac
ce pt
ed
M
an
us
cr
ip t
1. Successful production of plate-sized European lobster 2. Respiration and excretion rates of European lobster 3. Water quality in RAS producing European lobster
Page 1 of 22
*Manuscript
1 2
Commercial land-based farming of European lobster (Homarus gammarus L.) in Recirculating Aquaculture System (RAS) using a single cage approach
3 4 5 6 7 8 9 10 11 12 13
ABSTRACT In the past, farming of the European lobster in land-based systems has turned out to be
14
difficult. The ideal system for rearing lobsters individually should be relatively
15
inexpensive to construct and operate, simple to maintain, based on automatic feeding
16
and self-cleaning of tank and cages, maintain ideal water quality conditions, use space
17
in three dimensions, enable high densities, conserve water at high temperatures, ensure
18
good survival and permit easy access to the livestock for inspection and feeding.
19
Several attempts have been made to mass-produce these cannibalistic crustaceans under
20
controlled environments. However, none of the many previous attempts have proved to
21
be successful in incorporating all of these features into a single design. Thus, the
22
development of land-based lobster farming has been severely hampered by lack of
23
suitable technology and production methods. The major constraints have been the need
24
for individual rearing cages to avoid cannibalism, need of heated water, lack of high
25
quality dry food, high labour costs, inadequate technological solutions and high
26
investment costs.
Asbjørn Drengstig1*, Asbjørn Bergheim2 1
d
M
an
us
cr
ip t
Norwegian Lobster Farm AS, Stavanger, Norway Phone: +47 90196731; Fax: +47 51325901; [email protected] 2 IRIS – International Research Institute of Stavanger, Stavanger, Norway *Corresponding author
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
27
Today, Norwegian Lobster Farm operates the world’s first land-based RAS farm
28
producing plate sized lobsters. The company also operates its own brood-stock
29
department and a hatchery for production of IV-stage juveniles. The system contains a
30
patented single cage technology with moving bed biofilters where the recirculation
31
system is designed to fit the water management. Automated solutions for accurate
32
feeding, robots supporting mass-rearing of the IV-stage juveniles and image processing
33
programs for daily monitoring of each single individual have been developed and
34
successfully tested.
35 36
1.
Introduction
37 38
Today, European lobster (Homarus gammarus L.) is considered to be the most
1
Page 2 of 22
exclusive seafood product in the world. At present there is a scarce supply of wild
40
caught lobster into the international markets, with quantities varying between 2,000 –
41
2,500 metric tons (MT) per annum (Agnalt, 2008). In Norway the annual landings have
42
declined from 1,000 – 1,300 MT in the early 20th century to 30 – 50 MT from 1980s and
43
onwards. This has led to elevated market prices due to an increasing gap between
44
supply and demand. Hence, European lobster is a promising candidate for closed-cycle
45
aquaculture.
ip t
39
The attention on full grow-out culture peaked in the 1970’s, when government
47
funded research programs on intensive culture of American lobster were conducted in
48
USA and Canada (e.g. Coffelt and Wikman-Coffelt, 1985). As a result of this research
49
and earlier studies, lobster biology is reasonably well understood (Factor, 1995), seed
50
stock can be produced on demand, and systems and strategies are in place for rearing
51
lobster from larvae to market size (van Olst et al., 1980; Aiken and Waddy, 1995;
52
Nicosia and Lavalli, 1999). Several private companies in America started lobster
53
production, but none of these projects proved to be commercially viable (Nicosia and
54
Lavalli, 1999). A large increase in landings of wild lobsters and an abrupt termination of
55
governmental research programs, before rearing technology and formulated lobster
56
feeds were sufficiently developed, contributed to this scenario (Aiken and Waddy,
57
1995). Besides, the necessary computer and automation technology was too poorly
58
developed by 1995 to achieve a sufficient automation level at a reasonable production
59
cost. However, after the millennium there have been some significant breakthroughs in
60
the development of automation and land-based aquaculture technology (Drengstig and
61
Bergheim, 2010b). Especially in the field of recirculation technology, major progress
62
has made land-based aquaculture using heated water more economical realistic.
d
M
an
us
cr
46
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
63
Compared to other lobster species, the Homarus species are considered very hardy
64
with a simple and abbreviated larval period. They feed readily on natural and artificial
65
feeds (Drengstig et al., 2009), are resistant to disease and exhibit a very rapid and
66
accelerated growth in warmed water (van Olst et al., 1980; Kristiansen et al., 2004).
67
Thus, temperature is the primary controller of growth and optimum water temperature
68
has been found to be 20oC (e.g. Aiken and Waddy, 1995). Larval period in 20oC water
69
is around 12 days (Waddy, 1988; Drengstig et al., 2009) compared to 35 days at 15oC
70
(van Olst et al. 1980). Furthermore, H. gammarus can reach 250-300g (total length 210
71
mm; carapace length 75mm) in 24-30 months as long as constant 20oC water is
72
provided (Wickins and Beard, 1991; Kristiansen et al., 2004). The much higher growth 2
Page 3 of 22
73
rate at 20ºC is primarily a result of the eliminated winter growth inhibition allowing for
74
year-round growth and moulting. Because of large growth variation and high losses due to cannibalism and injuries
76
when kept communally, the cultured lobsters have to be kept in individual containers.
77
Thus, the ideal system for rearing lobsters individually should be relatively inexpensive
78
to construct and operate, simple to maintain, based on automatic feeding and self-
79
cleaning of tank and cages, maintain ideal water quality conditions, use space in three
80
dimensions, enable high densities, conserve water at high temperatures, ensure good
81
survival and permit easy access to the livestock for inspection and feeding (Aiken and
82
Waddy, 1995). Aiken and Waddy (1995) reported that no successful attempts had been
83
made which incorporated all of these features into a single design. Several different
84
methods have been developed for culturing lobsters individually. All of them attempt to
85
provide a separate compartment for each lobster, a constant supply of oxygen saturated
86
seawater to each individual, a method of providing food and removing solids and
87
dissolved wastes, and in general create an environment that will promote rapid, uniform
88
growth and high survival (van Olst et al., 1980; Grimsen et al. 1987). Bottlenecks for
89
commercial culture of lobsters have also been lack of high quality dry feed and
90
technology that can solve the problems related to rearing in individual containers in an
91
effective and profitable way (Drengstig and Bergheim, 2010b).
d
M
an
us
cr
ip t
75
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
92
Successful industrialization of land-based RAS farming has been warranted by
93
overcoming the many technical challenges related to adopting the highly cannibalistic
94
European lobster to high-tech profitable production technologies while still providing
95
optimum rearing conditions. A major R&D project was conducted on the island Kvitsøy
96
in SW Norway by Norwegian Lobster Farm Ltd. during 2000 – 2007. As a result, the
97
company is today the only producer of European lobster in the world. The production
98
utilizes a profitable land-based technology based on re-circulation of seawater and a
99
world-wide patented single cage technology. The R&D program included testing of 6
100
different technical solutions, developing a formulated diet fulfilling nutritional
101
requirements, developing various automated solutions (feeding robot, harvesting robot,
102
selection robot, remote desktop solutions, and image processing program), developing
103
biological protocols, and conducting culinary tests and market studies. As a result,
104
Norwegian Lobster Farm has managed to close the production cycle from egg to plate-
105
size solely based on a formulated diet, demonstrating commercial harvests and market
106
success both in terms of product quality and high farm gate prices. This paper presents 3
Page 4 of 22
107
the system design for the technology developed by Norwegian Lobster Farm and the
108
how the system performed under commercial conditions. The biological data have been
109
collected from a number of individual tests over the last 10 years.
110 111 112 113
2.
114
tank with an annual production capacity of 2 MT plate-sized lobsters (Figure 1 A). The
115
farm was equipped with sea water pumps, mechanical water filtration units, UV filters,
116
recirculation systems with biofilters, titanium heat exchangers, heaters, header tanks,
117
rearing tanks, larval incubators and accessories. Moreover, the buildings were insulated
118
to prevent heat loss. The total water volume of the hatchery was 30 m3 and the on-
119
growing tank contains about 150 m3. Back-up water was taken from a depth of 52 meter
120
below sea level.
us
cr
ip t
The construction consisted of a hatchery, a brood-stock section and an on-growing
an
121
System design
Three recirculation loops supplied 300 L/min of filtered (mesh size: 30 μm) and aerated seawater of 18 – 20ºC. To each loop, 15 L/min of filtered and UV treated
123
seawater was supplied the pump sump. The main units for water treatment were biofilter
124
(aeration/flushing), screening filter and header tank for water chemistry stabilisation.
125
The fluidized bed bio-filters were heavily aerated by air ejectors driven by the
126
recirculation pumps. The size of the biofilters was 0.5 m3 filled with AnoxKaldnesTM
127
biofilter media from KrügerKaldnes Ltd. up to 60% of the total volume of the biofilter.
128
The filter media had an area-volume ratio of 500 m2/m3. UV-treated seawater was added
129
corresponding to approximately one complete renewal of seawater in each loop every
130
third day. The water exchange rate was temporarily been higher than this, especially in
131
the early stages of testing out the RAS technology.
132
d
M
122
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
133
The hatchery had an average production capacity of 350,000 IV stage juveniles annually
134
using 24 upstream Kreisl incubators (40 L). The density during the pelagic stage (I-IV
135
stage) was approximately 2,500 juveniles per incubator. A selection robot was used to
136
determine when the larvae reached IV-stage. In this process, an image of each larvae in
137
the incubator was captured, analyzed and its features were extracted and finally
138
classified. The result of the final classification gave one of two possibilities; either the
139
juvenile had reached IV-stage or not. The capacity was approximately 20 juveniles per
140
minute. Juveniles between I-III stages were automatically transported back to their
4
Page 5 of 22
141
siblings in the incubator, while IV-stage juveniles were transported to a new robot in
142
charge of distributing one lobster into one cage for on-growing.
143 In the on-growing facility, the single cages (Figure 1 B) rotated similar to conventional
145
conveyer belts, and the lobsters were fed when the cages were in an up-right vertical
146
position. The cameras were fixed under the feeding robots, enabling the system to
147
monitor each single individual every day by taking pictures inside the cages before
148
feeding. Image processing programs then determined whether the lobsters were dead or
149
alive, and if moulting had occurred. The image processing program also extrapolated
150
the expected time to harvest by calculating moulting frequency. After feeding, the cages
151
rotated in right hand direction, and new cages came into vertical up-right position.
152
Lobsters inhabiting the cages on the way down started eating their daily meals. When
153
the cages came in vertical down-wards position, uneaten feed and fecal waste fell out of
154
the cages. A wiper with suction rotated vertically on the bottom, efficiently cleaning the
155
tank floor. Self-cleaning of cages was facilitated by inlet current flow being placed
156
within each single-cage unit, while outlet current flow was positioned between the units.
157
Thus, new water was supplied every single cage in addition to providing a slightly
158
overhead pressure pushing the waste out of the cages facing down towards the bottom.
d
M
an
us
cr
ip t
144
159
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
160
A principal sketch of the patented technology is presented in Figure 1 B and Figure 1 C
161
shows the technology in operation.
162 163 164 165 166 167 168 169 170
Figure 1 A
Figure 1 B
Figure 1 C
171
The stocking densities varied according to individual size, with maximum biomass of
172
25 kg/m3 for 6 cm lobster, 35 kg/m3 for 12 cm and approximately 45 kg/m3 for portion
173
sized lobsters, respectively.
174
5
Page 6 of 22
175 176 177 178 179
3.
180
length (TL) were measured during the initial trials at Kvitsøy. However, calculations
181
showed a consistent ratio between CL and TL with a correlation of 0.97 and, thus, only
182
CL was measured in the present study (Kristiansen et al., 2004). The time needed to
183
produce a 300g lobster (approximately 75 mm CL) is dependent on growth rate. In the
184
RAS setup at Norwegian Lobster Farm, portion sized lobsters are produced from
185
hatching to 300g within 800 to 900 days or approximately 17,000 day-degrees at
186
favorable conditions (Drengstig et. al 2009). In Figure 2 linear growth lines have been
187
extrapolated based on obtained growth results Kvitsøy (Kristiansen et al. 2004). The
188
growth of the lobsters produced in this RAS system equals the best growth rates
189
published from other studies (e.g. Wickins and Beard, 1991; Waddy, 1995).
System performance
3.1. Growth and feed utilisation
an
us
cr
ip t
In order to determine growth rates of lobsters, both carapace length (CL) and total
As already demonstrated in several individual trials, it is not unrealistic that plate-
191
sized lobsters can be mass-produced from IV stage to 300g in less than 24 months under
192
intensive production levels (Kristiansen et al., 2004; Drengstig et al., 2009). A
193
prerequisite to obtain such production time is however using an optimum diet and
194
feeding regime, and keeping a stable environment in the system. Moreover, by using the
195
new formulated lobster feed (Table 1), all individuals maintained a natural black color.
196
On the other hand, lobsters fed traditional marine fish feed available on the market
197
turned pale blue to white after 2-3 moults. Three different astaxanthin levels were tested
198
(50, 100 and 200 mg/kg dry weight), but no variation in pigmentation was observed
199
between the three levels (Drengstig et al. 2003). The average feed conversion ratio
200
(FCR) was approximately 1.5 under commercial scaled production, whereas FCR were
201
1.2 -1.3 under small scale controlled trials.
d
M
190
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
202
In addition, selection of family groups with fast growth under intensive farming
203
conditions could further reduce the production time. Several studies have been
204
performed at Kvitsøy in order to promote year-round hatching and reveal correlations
205
between the quality of the female lobster and the egg quality in terms of growth and
206
survival rate (Agnalt, 2008; Drengstig et al., 2011).
207 208 209 210 211
Figure 2
6
Page 7 of 22
212
Table 1
213 214 215
3.2.
216
obtain good welfare and growth, and reduce stress and risk of disease outbreaks.
217
Especially in closed recirculation systems, where there is little or no exchange of water,
218
a build-up of toxic metabolites and reduction in oxygen concentrations may happen very
219
rapidly (Timmons and Losordo, 1994). However, in land-based profitable lobster
220
farming, re-circulation of water is necessary to reduce heating costs. Thus, in any
221
occasion, it is important to understand what the optimal as well as limiting culture
222
conditions are for lobsters.
Water quality
cr
ip t
A system that supplies water of good quality is an essential factor if we want to
Oxygen supersaturated water has on the other hand been shown to cause serious
224
damage as gas bubbles can develop in the hemolymph and restrict blood flow (Aiken
225
and Waddy, 1995). Furthermore, while lobster may tolerate wide fluctuations in
226
salinity, optimal conditions ranges between 28 – 35 ‰ (van Olst et al., 1980; Richards,
227
1981; D’Abramo and Conklin, 1985). Whilst Beard et al. (1985), Beard and McGregor,
228
(2004), and Jacklin and Combes (2007) were unable to provide recommended limits for
229
nitrite and nitrate, ammonia concentration is most likely the most limiting water quality
230
parameter in recirculation systems for seawater. Although the optimal TAN
231
concentration given by van Olst et al. (1980) is slightly higher than that recommended
232
by D’Abramo and Conklin (1985) of less than 1.5mg/l, there is no doubt that Homarus
233
sp. are more tolerant than most finfish. Estrella (2002) indicated that short-term
234
acceptable levels of nitrite and nitrate might be as high as 5 mg/L and 100 mg/L,
235
respectively. According to Wickins and Lee (2002), the desirable levels of water quality
236
for clawed lobsters are temperature of 18 – 22 ºC, salinity of 28 – 35 ‰, above 6.4 mg
237
oxygen/L, pH of 7.8 – 8.2 and less than 14 μg N/L as un-ionized ammonia. Thus, it
238
seems like European lobster can, for short periods, tolerate considerably lower oxygen
239
and higher ammonia concentrations than indicated as desirable levels.
d
M
an
us
223
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
240
Available literature of metabolic rate in European lobster is sparse but Hamelo
241
(2006) performed some studies at Kvitsøy and measured strongly fluctuating oxygen
242
consumption in lobster of different size at 19ºC:
243 244
Small/fry
7 – 10 g:
0.8 – 6.3 mg O2/kg x min
245
Medium-size
43 - 54 g:
0.5 – 3.5
7
“
Page 8 of 22
246
Large
0.7 – 2.1
148 - 208 g:
“
247 The large individual variability in oxygen consumption at various sizes also
249
demonstrates rapid adaptability to new conditions. Typical stress influenced respiration
250
rate seems to be approximately twice the standard rate. The standard rate of European
251
lobster within the size interval 230 – 600 g was found to be 0.73 mg O2/kg x min at 20
252
°C (Whiteley et al., 1990), i.e. about half of the lowest rate found for lobster of 208 g
253
farmed at Kvitsøy.
ip t
248
The oxygen consumption ranges were large, 1:8 to 1:3 within the same size groups,
255
and the fluctuations were due to diurnal rhythm and peaked at feeding (Hamelo, 2006).
256
The measured CO2-production was on average 1.5 – 2 times the corresponding O2-
257
consumption.
us
cr
254
A smaller follow-up study was conducted at the International Research Institute of
259
Stavanger (IRIS) in 2010 (Figure 3). Some of the animals were obviously temporarily
260
stressed, and peak rates were always measured during the first monitoring. In addition,
261
several of the adults, i.e. the individuals of 93.9 g, 122 g and the largest one of 208 g,
262
seemed to suffer from stress in the respirometer, probably due to the small size of the
263
chamber. Figure 3
M
d
264 265 266 267
an
258
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Excretion rates were also measured during the respirometer study performed by IRIS
268
in 2010. The ammonia analyses indicate, as expected, a higher specific excretion rate in
269
terms of mg TAN/kg x min in fry compared to in larger animals:
270 271
Small/fry
0.5 – 1.8 g:
0.35
272
Medium sized
20 – 44 g:
0.07 – 0.1
“
273
Large
94 – 208 g:
0.04 – 0.09
“
mg TAN/kg x min
274 275
However, replicate sampling of the same size groups demonstrated considerable
276
fluctuation from one test situation to another. Increased excretion rate in the largest
277
animals (122 - 208 g) was positively correlated with increased oxygen consumption in
278
the same individuals. Beard et al. (1985) estimated excretion rates in adults (H.
279
gammarus L. of 300 g) of 0.10 – 0.37 mg TAN/kg x min or up to 3 – 4 times the rates
280
found in the present test (size: 208 g). 8
Page 9 of 22
281
At Kvitsøy, the biofilter is efficiently removing total ammonia (TAN) at average rates
282
of 50 – 70% of the before – after biofilter concentration. Concentration of un-ionized
283
ammonia (NH3) as per cent of total ammonia nitrogen (TAN) was calculated according
284
to the following equation:
285
ip t
% NH3 = 100 / (1 + antilog (pKa – pH))
286 287
where the dissociation constant, pKa, ranges from 9.09 to 9.90 dependent on
289
temperature and salinity (Alabaster & Lloyd 1982).
us
cr
288
290
Lobster feed is high in protein and the ammonia excretion rates in the animals are
292
correspondingly high with average rates of 0.1 – 0.5 g TAN/kg x day reported for adult
293
lobster. Due to the high protein content of the feed and the reported low tolerance to
294
ammonia (Wickens and Lee, 2002), the efficiency of the biofilter is vital in RAS for
295
lobsters (e.g. Crear and Forteath, 2002). Table 2
M
d
296 297 298 299
an
291
At low loading level in the grow-out pilot, all measured parameters were within or
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
300
slightly outside the desirable range for lobster (Table 2). The concentration of unionized
301
ammonia (NH3) of 32 µg/L was lower compared to sampling before and after the actual
302
date. Besides, the embedded biofilters seemed to work rather well, stable and problem
303
free at a loading level of 0.1 kg/m3 per 24 hours (Drengstig and Bergheim, 2010a).
304
Ongoing extended water sampling of the present system with higher biomass and
305
correspondingly increased loading level will provide more basic criteria for optimizing
306
the management of RAS for commercial production of European lobster.
307 308 309 310
4.
Conclusion Currently there is still a lack of knowledge on respiration and excretion rates of
311
lobster at all stages, and documentation of optimum rearing conditions in RAS. Based
312
on the economic importance of these issues, priority should be given to detecting critical
313
water quality values for dimensioning of technical equipment in order to sustain a
314
healthy environment for the biomass. Moreover, it is important for successful
9
Page 10 of 22
315
commercialization to improve growth performance, survival and feed conversion ratio
316
(FCR) in RAS in order to increase the turn-over in the biomass. Feed development and
317
genetic breeding is of course essential factors for improved growth rates in land-based
318
lobster aquaculture. References
cr
ip t
Agnalt, A.-L., 2008. Stock enhancement of European lobster (Homarus gammarus) in Norway; Comparisons of reproduction, growth and movement between wild and cultured lobster. Dr. scient. thesis, Department of Biology, University of Bergen, Norway.
us
Alabaster, J. S., Lloyd, R., 1982. Water Quality Criteria for Freshwater Fish. FAO, Butterwords, London. 2nd Ed. 361 p.
an
Aiken, D. E., Waddy, S. L., 1995. Aquaculture. pp. 153-175. In: Factor, J. R. (Ed.), Biology of the lobster Homarus americanus. Academic Press, Inc.
M
Beard, T. W., McGregor, D., 2004. Storage and care of live lobster. Laboratory leaflet number 66 (revised). Cefas. UK. Beard, T. W., Richards, P. R., Wickins J. F., 1985. The techniques and practicability of year-round production of lobsters, Homarus gammarus (L.), in laboratory recirculation systems. Fisheries Research Technical Report, No. 79, Lowestoft, UK. ISSN 0308 – 5589. 22 p.
d
319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361
Crear, B. J., Forteath, G. N. R., 2002. Feeding rate has the largest effect on the ammonia excretion rate of the southern rock lobster, Jasus edwardslii, and the western rock lobster, Panulirus cygnus. Aquacultural Engineering 26, 239 – 250.
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Coffelt, R. J., Wikman-Coffelt J., 1985. Lobsters: One million One Pounders per Year. Aquacultural Engineering 4, 51 – 58. D’Abramo, L. R., Conklin, D. E., 1985. Lobster aquaculture. In: Huner, J., Brown, E.E. (Eds.), Crustacean and mollusc aquaculture in the USA. AVI Publ. Co., Westport, Conn., USA, pp. 159 – 201. Drengstig, A., T. S. Kristiansen, A. Bergheim, T. Drengstig & L. Aardal (2003). It does matter if they are black or white! Quantification of the minimum required level of astaxanthine to ensure natural pigmentation in the European lobster. pp 168 – 169. Extended abstract and Poster presentation. EAS special publication No. 33. August 2003. Trondheim, Norway. 408 pp. Drengstig, A., Drengstig, T., Agnalt, A.-L., Jørstad, K., Farestveit, E., 2009. Utvikling av metoder for stabil produksjon av hummeryngel med gode vekstegenskaper. 42 p. [In Norwegian] (http://www.rup.no/vision/vision7.aspx?hierarchyid=763&type=3)
10
Page 11 of 22
Drengstig, A., Bergheim, A., 2010a. Single cage technology for on-growing of lobster in RAS. Abstract and oral presentation, Progress in Marine Recirculating Aquaculture Systems – World Aquaculture Society, San Diego, California, USA, 1 – 5 March 2010. Drengstig, A., Bergheim, A., 2010b. A pilot RAS for commercial production of European lobster. Aquacultural Engineering Society Proceedings VII, pp. 178-186. AES Fifth Issues Forum, Roanoke, Virginia, USA, 16 – 20 August 2010.
cr
ip t
Drengstig, A., Agnalt, A.-L., Jørstad, K., 2011. Genetic mapping to improve growth performance, survival and feed conversion ratio (FCR) for on-growing of European lobster in Recirculating Aquaculture Systems (RAS). Proceeding 9th International Conference and Workshop on Lobster Biology and Management, Bergen, Norway, 19 – 23 June 2011.
us
Estrella, B. T., 2002. Techniques for live storage and shipping of American lobster. Technical Report TR-8, 18. Division of Marine Fisheries, Massachusetts.
an
Factor, J. R., 1995. Biology of the lobster Homarus americanus, Academic Press, Inc., New York. 528 p.
M
Grimsen, S., Jaques, R. N., Erenst, V., Balchen, J. G., 1987. Aspects of automation in a lobster farming plant. Modelling, identification and control, 8 (1), 61 – 68. Hamelo, J. S., 2006. Investigation of respiration rates of European lobster (Homarus gammarus) in land-based, lobster farming system. Master thesis, Univ. of Stavanger, Norway. 86 p.
d
362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
Jacklin, M., Combes, J., 2007. The good Practice Guide to Handling and Storing Live Crustacea. http://www.seafish.org/media/Publications/CrustaceaGPG_0505.pdf
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Kristiansen, T. S., Drengstig, A., Bergheim, A., Drengstig, T., Svensen, R., Kollsgård, I., Nøstvoll, E., Farestveit, E., Aardal, L., 2004. Development of intensive farming methods for the European lobster (Homarus gammarus L.) in recirculated seawater. Results from experiments conducted at Kvitsøy Lobster Hatchery from 2000 to 2004. Fisken og Havet, 6 – 2004, Institute of Marine Research, Bergen, 52 p. ISSN 0071 – 5638. (http://www.imr.no/__data/page/3839/Nr.6_2004_Methods_for_intensive_farming_of_E uropean_lobster.pdf). Nicosia, F., Lavalli, K.,1999. Homarid lobster hatcheries: Their history and role in research, management, and aquaculture. Marine Fisheries Review 61(2), 1-57. Richards, P. R. 1981. Some aspects of growth and behaviour in the juvenile lobster Homarus gammarus (Linnaeus). PhD Thesis University of Wales, Bangor, Great Britain. 209 p. Timmons, M. B., Losordo, J. G., 1994. Aquaculture water reuse systems: engineering design and management. Elsevier, New York, USA. van Olst, J. C., Carlberg, J. M., Hughes, J. T., 1980. The biology and management of lobsters, pp. 333 -384. In Cobbs, J. S., Phillips, B.F. (Eds.), Aquaculture, Vol. II Academic Press, Inc., New York. 468 p. 11
Page 12 of 22
Waddy, S. L., 1988. Farming the Homarid Lobsters: State of the Art. World Aquaculture,19 (4), 61 – 71. Whiteley, N. M., Al-Wassia, A. H., Taulor, E. W., 1990. The effect of temperature, aerial exposure and disturbance on oxygen consumption in the lobster, Homarus gammarus (L.). Mar. Behav. Physio. 17, 213 – 222.
ip t
Wickins, J.F., Beard, T.W., 1991. Variability in size at moult among individual broods of cultured juvenile lobsters. Aquaculture and Fisheries Management 22, 481 – 489.
M
an
us
cr
Wickins, J. F., Lee, D. O., 2002. Crustacean Farming – Ranching and Culture. Blackwell Science. 446 p.
d
413 414 415 416 417 418 419 420 421 422 423 424 425 426 427
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
12
Page 13 of 22
*Manuscript
Figure and Table captions:
ip t
Fig. 1. RAS facilities at Norwegian Lobster Farm (NLF), Kvitsøy. A) Flow diagram and design of the hatchery, broodstock and grow-out sections with water treatment units B) Principle sketch of the single cage technology C) Fully automated production unit and tank system including, A) single cages, B) feeding robot, C) cameras and image processing solutions, D) control units and E) machine room in centre below deck.
us
cr
Fig. 2. Four estimated growth rates of European lobster from size stage IV until plate-size (75 mm CL). Squared and circular marks indicate measured growth at NLF.
an
Fig. 3. Mean oxygen consumption of European lobster (individual size: 0.06 – 208 g) at 19.5 – 20.3 °C (Report IRIS, unpublished). Unit: mg O2/kg x min.
M
Table 1 Chemical composition and nutritional content of the feed.
ce pt
ed
Table 2 Water quality at four sampling points at low loading level in the grow-out unit, NLF, November 2004.
Ac
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Page 14 of 22
d
M
Figure 1 A
Ac ce pt e
1 2
an
us
cr
ip t
Figure(s)
Page 15 of 22
an
us
cr
ip t
Figure(s)
Ac ce pt e
d
M
1
Page 16 of 22
Figure(s)
1
cr
ip t
B) Feeding robot
C) Cameras
us
A) Single cage farming units
an
D) Control units
d
Figure 1 C
Ac ce pt e
2 3 4 5
M
E) Machine room below deck
Page 17 of 22
Figure(s)
0.10 mm/day
70
0.09 mm/day 0.08 mm/day
60
0.07 mm/day goal Kvitsøy small
40
Kvitsøy large
ip t
CL(mm)
50
30
cr
20
us
10 0 90
180 270 360 450 540 630 720 810 900 990 1080
an
0
d
Figure 2
Ac ce pt e
1
M
Days from Stage IV
Page 18 of 22
d
M
Figure 3
Ac ce pt e
1 2 3
an
us
cr
ip t
Figure(s)
Page 19 of 22
Table(s)
ip t
M
an
us
cr
Nutrient content % of wet weight Protein 54.7 Lipid 15.6 Carbohydrates 13.6 Ash 9.5 Moisture 6.8 Crude energy (MJ/kg) 21.6 Astaxanthin level was 50, 100 and 200 mg/kg dry weight.
d
3 4 5
Table 1
Ac ce pt e
1 2
1
Page 20 of 22
ip t cr Salinity ‰ 8.30 33.7 8.15 33.6
6.4 (89) 6.4 (89)
S-DM, mg/L <5
TOC, mg/L 2.2
TAN, µg/L 645
5.3 6.4
3.2 -
29 -
NH3-N*, µg/L 32 <5 -
NO3-N, µg/L 1,880
Flow L/h 90 6,000
1,860 -
Ac c
ep te
d
Make-up water Outlet lobster tank Outlet biofilter 18.4 8.32 33.5 Outlet drumfilter 18.4 8.32 33.6 *: Calculated (Alabaster and Lloyd, 1982)
DO, mg/L (%) 8.3 (92) 6.2 (82)
us
pH
an
Temp. °C 10.0 18.2
M
Table 2 Sampling point
2
Page 21 of 22
Salinity ‰ 8.30 33.7 8.15 33.6
6.4 (89) 6.4 (89)
S-DM, mg/L <5
TOC, mg/L 2.2
TAN, µg/L 645
5.3 6.4
3.2 -
29 -
NH3-N*, µg/L 32 <5 -
NO3-N, µg/L 1,880
Flow L/h 90 6,000
1,860 -
Ac c
ep te
d
Make-up water Outlet lobster tank Outlet biofilter 18.4 8.32 33.5 Outlet drumfilter 18.4 8.32 33.6 *: Calculated (Alabaster and Lloyd, 1982)
DO, mg/L (%) 8.3 (92) 6.2 (82)
us
pH
an
Temp. °C 10.0 18.2
M
Table 2 Sampling point
cr
ip t
Table(s)
1
Page 22 of 22
S0144-8609(12)00091-X doi:10.1016/j.aquaeng.2012.11.007 AQUE 1667
To appear in:
Aquacultural Engineering
Received date: Accepted date:
28-9-2012 19-11-2012
Please cite this article as: Drengstig, A., Bergheim, A., Commercial land-based farming of European lobster (Homarus gammarus L.) in Recirculating Aquaculture System (RAS) using a single cage approach, Aquacultural Engineering (2010), doi:10.1016/j.aquaeng.2012.11.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Highlights (for review)
Highlights
Ac
ce pt
ed
M
an
us
cr
ip t
1. Successful production of plate-sized European lobster 2. Respiration and excretion rates of European lobster 3. Water quality in RAS producing European lobster
Page 1 of 22
*Manuscript
1 2
Commercial land-based farming of European lobster (Homarus gammarus L.) in Recirculating Aquaculture System (RAS) using a single cage approach
3 4 5 6 7 8 9 10 11 12 13
ABSTRACT In the past, farming of the European lobster in land-based systems has turned out to be
14
difficult. The ideal system for rearing lobsters individually should be relatively
15
inexpensive to construct and operate, simple to maintain, based on automatic feeding
16
and self-cleaning of tank and cages, maintain ideal water quality conditions, use space
17
in three dimensions, enable high densities, conserve water at high temperatures, ensure
18
good survival and permit easy access to the livestock for inspection and feeding.
19
Several attempts have been made to mass-produce these cannibalistic crustaceans under
20
controlled environments. However, none of the many previous attempts have proved to
21
be successful in incorporating all of these features into a single design. Thus, the
22
development of land-based lobster farming has been severely hampered by lack of
23
suitable technology and production methods. The major constraints have been the need
24
for individual rearing cages to avoid cannibalism, need of heated water, lack of high
25
quality dry food, high labour costs, inadequate technological solutions and high
26
investment costs.
Asbjørn Drengstig1*, Asbjørn Bergheim2 1
d
M
an
us
cr
ip t
Norwegian Lobster Farm AS, Stavanger, Norway Phone: +47 90196731; Fax: +47 51325901; [email protected] 2 IRIS – International Research Institute of Stavanger, Stavanger, Norway *Corresponding author
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
27
Today, Norwegian Lobster Farm operates the world’s first land-based RAS farm
28
producing plate sized lobsters. The company also operates its own brood-stock
29
department and a hatchery for production of IV-stage juveniles. The system contains a
30
patented single cage technology with moving bed biofilters where the recirculation
31
system is designed to fit the water management. Automated solutions for accurate
32
feeding, robots supporting mass-rearing of the IV-stage juveniles and image processing
33
programs for daily monitoring of each single individual have been developed and
34
successfully tested.
35 36
1.
Introduction
37 38
Today, European lobster (Homarus gammarus L.) is considered to be the most
1
Page 2 of 22
exclusive seafood product in the world. At present there is a scarce supply of wild
40
caught lobster into the international markets, with quantities varying between 2,000 –
41
2,500 metric tons (MT) per annum (Agnalt, 2008). In Norway the annual landings have
42
declined from 1,000 – 1,300 MT in the early 20th century to 30 – 50 MT from 1980s and
43
onwards. This has led to elevated market prices due to an increasing gap between
44
supply and demand. Hence, European lobster is a promising candidate for closed-cycle
45
aquaculture.
ip t
39
The attention on full grow-out culture peaked in the 1970’s, when government
47
funded research programs on intensive culture of American lobster were conducted in
48
USA and Canada (e.g. Coffelt and Wikman-Coffelt, 1985). As a result of this research
49
and earlier studies, lobster biology is reasonably well understood (Factor, 1995), seed
50
stock can be produced on demand, and systems and strategies are in place for rearing
51
lobster from larvae to market size (van Olst et al., 1980; Aiken and Waddy, 1995;
52
Nicosia and Lavalli, 1999). Several private companies in America started lobster
53
production, but none of these projects proved to be commercially viable (Nicosia and
54
Lavalli, 1999). A large increase in landings of wild lobsters and an abrupt termination of
55
governmental research programs, before rearing technology and formulated lobster
56
feeds were sufficiently developed, contributed to this scenario (Aiken and Waddy,
57
1995). Besides, the necessary computer and automation technology was too poorly
58
developed by 1995 to achieve a sufficient automation level at a reasonable production
59
cost. However, after the millennium there have been some significant breakthroughs in
60
the development of automation and land-based aquaculture technology (Drengstig and
61
Bergheim, 2010b). Especially in the field of recirculation technology, major progress
62
has made land-based aquaculture using heated water more economical realistic.
d
M
an
us
cr
46
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
63
Compared to other lobster species, the Homarus species are considered very hardy
64
with a simple and abbreviated larval period. They feed readily on natural and artificial
65
feeds (Drengstig et al., 2009), are resistant to disease and exhibit a very rapid and
66
accelerated growth in warmed water (van Olst et al., 1980; Kristiansen et al., 2004).
67
Thus, temperature is the primary controller of growth and optimum water temperature
68
has been found to be 20oC (e.g. Aiken and Waddy, 1995). Larval period in 20oC water
69
is around 12 days (Waddy, 1988; Drengstig et al., 2009) compared to 35 days at 15oC
70
(van Olst et al. 1980). Furthermore, H. gammarus can reach 250-300g (total length 210
71
mm; carapace length 75mm) in 24-30 months as long as constant 20oC water is
72
provided (Wickins and Beard, 1991; Kristiansen et al., 2004). The much higher growth 2
Page 3 of 22
73
rate at 20ºC is primarily a result of the eliminated winter growth inhibition allowing for
74
year-round growth and moulting. Because of large growth variation and high losses due to cannibalism and injuries
76
when kept communally, the cultured lobsters have to be kept in individual containers.
77
Thus, the ideal system for rearing lobsters individually should be relatively inexpensive
78
to construct and operate, simple to maintain, based on automatic feeding and self-
79
cleaning of tank and cages, maintain ideal water quality conditions, use space in three
80
dimensions, enable high densities, conserve water at high temperatures, ensure good
81
survival and permit easy access to the livestock for inspection and feeding (Aiken and
82
Waddy, 1995). Aiken and Waddy (1995) reported that no successful attempts had been
83
made which incorporated all of these features into a single design. Several different
84
methods have been developed for culturing lobsters individually. All of them attempt to
85
provide a separate compartment for each lobster, a constant supply of oxygen saturated
86
seawater to each individual, a method of providing food and removing solids and
87
dissolved wastes, and in general create an environment that will promote rapid, uniform
88
growth and high survival (van Olst et al., 1980; Grimsen et al. 1987). Bottlenecks for
89
commercial culture of lobsters have also been lack of high quality dry feed and
90
technology that can solve the problems related to rearing in individual containers in an
91
effective and profitable way (Drengstig and Bergheim, 2010b).
d
M
an
us
cr
ip t
75
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
92
Successful industrialization of land-based RAS farming has been warranted by
93
overcoming the many technical challenges related to adopting the highly cannibalistic
94
European lobster to high-tech profitable production technologies while still providing
95
optimum rearing conditions. A major R&D project was conducted on the island Kvitsøy
96
in SW Norway by Norwegian Lobster Farm Ltd. during 2000 – 2007. As a result, the
97
company is today the only producer of European lobster in the world. The production
98
utilizes a profitable land-based technology based on re-circulation of seawater and a
99
world-wide patented single cage technology. The R&D program included testing of 6
100
different technical solutions, developing a formulated diet fulfilling nutritional
101
requirements, developing various automated solutions (feeding robot, harvesting robot,
102
selection robot, remote desktop solutions, and image processing program), developing
103
biological protocols, and conducting culinary tests and market studies. As a result,
104
Norwegian Lobster Farm has managed to close the production cycle from egg to plate-
105
size solely based on a formulated diet, demonstrating commercial harvests and market
106
success both in terms of product quality and high farm gate prices. This paper presents 3
Page 4 of 22
107
the system design for the technology developed by Norwegian Lobster Farm and the
108
how the system performed under commercial conditions. The biological data have been
109
collected from a number of individual tests over the last 10 years.
110 111 112 113
2.
114
tank with an annual production capacity of 2 MT plate-sized lobsters (Figure 1 A). The
115
farm was equipped with sea water pumps, mechanical water filtration units, UV filters,
116
recirculation systems with biofilters, titanium heat exchangers, heaters, header tanks,
117
rearing tanks, larval incubators and accessories. Moreover, the buildings were insulated
118
to prevent heat loss. The total water volume of the hatchery was 30 m3 and the on-
119
growing tank contains about 150 m3. Back-up water was taken from a depth of 52 meter
120
below sea level.
us
cr
ip t
The construction consisted of a hatchery, a brood-stock section and an on-growing
an
121
System design
Three recirculation loops supplied 300 L/min of filtered (mesh size: 30 μm) and aerated seawater of 18 – 20ºC. To each loop, 15 L/min of filtered and UV treated
123
seawater was supplied the pump sump. The main units for water treatment were biofilter
124
(aeration/flushing), screening filter and header tank for water chemistry stabilisation.
125
The fluidized bed bio-filters were heavily aerated by air ejectors driven by the
126
recirculation pumps. The size of the biofilters was 0.5 m3 filled with AnoxKaldnesTM
127
biofilter media from KrügerKaldnes Ltd. up to 60% of the total volume of the biofilter.
128
The filter media had an area-volume ratio of 500 m2/m3. UV-treated seawater was added
129
corresponding to approximately one complete renewal of seawater in each loop every
130
third day. The water exchange rate was temporarily been higher than this, especially in
131
the early stages of testing out the RAS technology.
132
d
M
122
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
133
The hatchery had an average production capacity of 350,000 IV stage juveniles annually
134
using 24 upstream Kreisl incubators (40 L). The density during the pelagic stage (I-IV
135
stage) was approximately 2,500 juveniles per incubator. A selection robot was used to
136
determine when the larvae reached IV-stage. In this process, an image of each larvae in
137
the incubator was captured, analyzed and its features were extracted and finally
138
classified. The result of the final classification gave one of two possibilities; either the
139
juvenile had reached IV-stage or not. The capacity was approximately 20 juveniles per
140
minute. Juveniles between I-III stages were automatically transported back to their
4
Page 5 of 22
141
siblings in the incubator, while IV-stage juveniles were transported to a new robot in
142
charge of distributing one lobster into one cage for on-growing.
143 In the on-growing facility, the single cages (Figure 1 B) rotated similar to conventional
145
conveyer belts, and the lobsters were fed when the cages were in an up-right vertical
146
position. The cameras were fixed under the feeding robots, enabling the system to
147
monitor each single individual every day by taking pictures inside the cages before
148
feeding. Image processing programs then determined whether the lobsters were dead or
149
alive, and if moulting had occurred. The image processing program also extrapolated
150
the expected time to harvest by calculating moulting frequency. After feeding, the cages
151
rotated in right hand direction, and new cages came into vertical up-right position.
152
Lobsters inhabiting the cages on the way down started eating their daily meals. When
153
the cages came in vertical down-wards position, uneaten feed and fecal waste fell out of
154
the cages. A wiper with suction rotated vertically on the bottom, efficiently cleaning the
155
tank floor. Self-cleaning of cages was facilitated by inlet current flow being placed
156
within each single-cage unit, while outlet current flow was positioned between the units.
157
Thus, new water was supplied every single cage in addition to providing a slightly
158
overhead pressure pushing the waste out of the cages facing down towards the bottom.
d
M
an
us
cr
ip t
144
159
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
160
A principal sketch of the patented technology is presented in Figure 1 B and Figure 1 C
161
shows the technology in operation.
162 163 164 165 166 167 168 169 170
Figure 1 A
Figure 1 B
Figure 1 C
171
The stocking densities varied according to individual size, with maximum biomass of
172
25 kg/m3 for 6 cm lobster, 35 kg/m3 for 12 cm and approximately 45 kg/m3 for portion
173
sized lobsters, respectively.
174
5
Page 6 of 22
175 176 177 178 179
3.
180
length (TL) were measured during the initial trials at Kvitsøy. However, calculations
181
showed a consistent ratio between CL and TL with a correlation of 0.97 and, thus, only
182
CL was measured in the present study (Kristiansen et al., 2004). The time needed to
183
produce a 300g lobster (approximately 75 mm CL) is dependent on growth rate. In the
184
RAS setup at Norwegian Lobster Farm, portion sized lobsters are produced from
185
hatching to 300g within 800 to 900 days or approximately 17,000 day-degrees at
186
favorable conditions (Drengstig et. al 2009). In Figure 2 linear growth lines have been
187
extrapolated based on obtained growth results Kvitsøy (Kristiansen et al. 2004). The
188
growth of the lobsters produced in this RAS system equals the best growth rates
189
published from other studies (e.g. Wickins and Beard, 1991; Waddy, 1995).
System performance
3.1. Growth and feed utilisation
an
us
cr
ip t
In order to determine growth rates of lobsters, both carapace length (CL) and total
As already demonstrated in several individual trials, it is not unrealistic that plate-
191
sized lobsters can be mass-produced from IV stage to 300g in less than 24 months under
192
intensive production levels (Kristiansen et al., 2004; Drengstig et al., 2009). A
193
prerequisite to obtain such production time is however using an optimum diet and
194
feeding regime, and keeping a stable environment in the system. Moreover, by using the
195
new formulated lobster feed (Table 1), all individuals maintained a natural black color.
196
On the other hand, lobsters fed traditional marine fish feed available on the market
197
turned pale blue to white after 2-3 moults. Three different astaxanthin levels were tested
198
(50, 100 and 200 mg/kg dry weight), but no variation in pigmentation was observed
199
between the three levels (Drengstig et al. 2003). The average feed conversion ratio
200
(FCR) was approximately 1.5 under commercial scaled production, whereas FCR were
201
1.2 -1.3 under small scale controlled trials.
d
M
190
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
202
In addition, selection of family groups with fast growth under intensive farming
203
conditions could further reduce the production time. Several studies have been
204
performed at Kvitsøy in order to promote year-round hatching and reveal correlations
205
between the quality of the female lobster and the egg quality in terms of growth and
206
survival rate (Agnalt, 2008; Drengstig et al., 2011).
207 208 209 210 211
Figure 2
6
Page 7 of 22
212
Table 1
213 214 215
3.2.
216
obtain good welfare and growth, and reduce stress and risk of disease outbreaks.
217
Especially in closed recirculation systems, where there is little or no exchange of water,
218
a build-up of toxic metabolites and reduction in oxygen concentrations may happen very
219
rapidly (Timmons and Losordo, 1994). However, in land-based profitable lobster
220
farming, re-circulation of water is necessary to reduce heating costs. Thus, in any
221
occasion, it is important to understand what the optimal as well as limiting culture
222
conditions are for lobsters.
Water quality
cr
ip t
A system that supplies water of good quality is an essential factor if we want to
Oxygen supersaturated water has on the other hand been shown to cause serious
224
damage as gas bubbles can develop in the hemolymph and restrict blood flow (Aiken
225
and Waddy, 1995). Furthermore, while lobster may tolerate wide fluctuations in
226
salinity, optimal conditions ranges between 28 – 35 ‰ (van Olst et al., 1980; Richards,
227
1981; D’Abramo and Conklin, 1985). Whilst Beard et al. (1985), Beard and McGregor,
228
(2004), and Jacklin and Combes (2007) were unable to provide recommended limits for
229
nitrite and nitrate, ammonia concentration is most likely the most limiting water quality
230
parameter in recirculation systems for seawater. Although the optimal TAN
231
concentration given by van Olst et al. (1980) is slightly higher than that recommended
232
by D’Abramo and Conklin (1985) of less than 1.5mg/l, there is no doubt that Homarus
233
sp. are more tolerant than most finfish. Estrella (2002) indicated that short-term
234
acceptable levels of nitrite and nitrate might be as high as 5 mg/L and 100 mg/L,
235
respectively. According to Wickins and Lee (2002), the desirable levels of water quality
236
for clawed lobsters are temperature of 18 – 22 ºC, salinity of 28 – 35 ‰, above 6.4 mg
237
oxygen/L, pH of 7.8 – 8.2 and less than 14 μg N/L as un-ionized ammonia. Thus, it
238
seems like European lobster can, for short periods, tolerate considerably lower oxygen
239
and higher ammonia concentrations than indicated as desirable levels.
d
M
an
us
223
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
240
Available literature of metabolic rate in European lobster is sparse but Hamelo
241
(2006) performed some studies at Kvitsøy and measured strongly fluctuating oxygen
242
consumption in lobster of different size at 19ºC:
243 244
Small/fry
7 – 10 g:
0.8 – 6.3 mg O2/kg x min
245
Medium-size
43 - 54 g:
0.5 – 3.5
7
“
Page 8 of 22
246
Large
0.7 – 2.1
148 - 208 g:
“
247 The large individual variability in oxygen consumption at various sizes also
249
demonstrates rapid adaptability to new conditions. Typical stress influenced respiration
250
rate seems to be approximately twice the standard rate. The standard rate of European
251
lobster within the size interval 230 – 600 g was found to be 0.73 mg O2/kg x min at 20
252
°C (Whiteley et al., 1990), i.e. about half of the lowest rate found for lobster of 208 g
253
farmed at Kvitsøy.
ip t
248
The oxygen consumption ranges were large, 1:8 to 1:3 within the same size groups,
255
and the fluctuations were due to diurnal rhythm and peaked at feeding (Hamelo, 2006).
256
The measured CO2-production was on average 1.5 – 2 times the corresponding O2-
257
consumption.
us
cr
254
A smaller follow-up study was conducted at the International Research Institute of
259
Stavanger (IRIS) in 2010 (Figure 3). Some of the animals were obviously temporarily
260
stressed, and peak rates were always measured during the first monitoring. In addition,
261
several of the adults, i.e. the individuals of 93.9 g, 122 g and the largest one of 208 g,
262
seemed to suffer from stress in the respirometer, probably due to the small size of the
263
chamber. Figure 3
M
d
264 265 266 267
an
258
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Excretion rates were also measured during the respirometer study performed by IRIS
268
in 2010. The ammonia analyses indicate, as expected, a higher specific excretion rate in
269
terms of mg TAN/kg x min in fry compared to in larger animals:
270 271
Small/fry
0.5 – 1.8 g:
0.35
272
Medium sized
20 – 44 g:
0.07 – 0.1
“
273
Large
94 – 208 g:
0.04 – 0.09
“
mg TAN/kg x min
274 275
However, replicate sampling of the same size groups demonstrated considerable
276
fluctuation from one test situation to another. Increased excretion rate in the largest
277
animals (122 - 208 g) was positively correlated with increased oxygen consumption in
278
the same individuals. Beard et al. (1985) estimated excretion rates in adults (H.
279
gammarus L. of 300 g) of 0.10 – 0.37 mg TAN/kg x min or up to 3 – 4 times the rates
280
found in the present test (size: 208 g). 8
Page 9 of 22
281
At Kvitsøy, the biofilter is efficiently removing total ammonia (TAN) at average rates
282
of 50 – 70% of the before – after biofilter concentration. Concentration of un-ionized
283
ammonia (NH3) as per cent of total ammonia nitrogen (TAN) was calculated according
284
to the following equation:
285
ip t
% NH3 = 100 / (1 + antilog (pKa – pH))
286 287
where the dissociation constant, pKa, ranges from 9.09 to 9.90 dependent on
289
temperature and salinity (Alabaster & Lloyd 1982).
us
cr
288
290
Lobster feed is high in protein and the ammonia excretion rates in the animals are
292
correspondingly high with average rates of 0.1 – 0.5 g TAN/kg x day reported for adult
293
lobster. Due to the high protein content of the feed and the reported low tolerance to
294
ammonia (Wickens and Lee, 2002), the efficiency of the biofilter is vital in RAS for
295
lobsters (e.g. Crear and Forteath, 2002). Table 2
M
d
296 297 298 299
an
291
At low loading level in the grow-out pilot, all measured parameters were within or
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
300
slightly outside the desirable range for lobster (Table 2). The concentration of unionized
301
ammonia (NH3) of 32 µg/L was lower compared to sampling before and after the actual
302
date. Besides, the embedded biofilters seemed to work rather well, stable and problem
303
free at a loading level of 0.1 kg/m3 per 24 hours (Drengstig and Bergheim, 2010a).
304
Ongoing extended water sampling of the present system with higher biomass and
305
correspondingly increased loading level will provide more basic criteria for optimizing
306
the management of RAS for commercial production of European lobster.
307 308 309 310
4.
Conclusion Currently there is still a lack of knowledge on respiration and excretion rates of
311
lobster at all stages, and documentation of optimum rearing conditions in RAS. Based
312
on the economic importance of these issues, priority should be given to detecting critical
313
water quality values for dimensioning of technical equipment in order to sustain a
314
healthy environment for the biomass. Moreover, it is important for successful
9
Page 10 of 22
315
commercialization to improve growth performance, survival and feed conversion ratio
316
(FCR) in RAS in order to increase the turn-over in the biomass. Feed development and
317
genetic breeding is of course essential factors for improved growth rates in land-based
318
lobster aquaculture. References
cr
ip t
Agnalt, A.-L., 2008. Stock enhancement of European lobster (Homarus gammarus) in Norway; Comparisons of reproduction, growth and movement between wild and cultured lobster. Dr. scient. thesis, Department of Biology, University of Bergen, Norway.
us
Alabaster, J. S., Lloyd, R., 1982. Water Quality Criteria for Freshwater Fish. FAO, Butterwords, London. 2nd Ed. 361 p.
an
Aiken, D. E., Waddy, S. L., 1995. Aquaculture. pp. 153-175. In: Factor, J. R. (Ed.), Biology of the lobster Homarus americanus. Academic Press, Inc.
M
Beard, T. W., McGregor, D., 2004. Storage and care of live lobster. Laboratory leaflet number 66 (revised). Cefas. UK. Beard, T. W., Richards, P. R., Wickins J. F., 1985. The techniques and practicability of year-round production of lobsters, Homarus gammarus (L.), in laboratory recirculation systems. Fisheries Research Technical Report, No. 79, Lowestoft, UK. ISSN 0308 – 5589. 22 p.
d
319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361
Crear, B. J., Forteath, G. N. R., 2002. Feeding rate has the largest effect on the ammonia excretion rate of the southern rock lobster, Jasus edwardslii, and the western rock lobster, Panulirus cygnus. Aquacultural Engineering 26, 239 – 250.
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Coffelt, R. J., Wikman-Coffelt J., 1985. Lobsters: One million One Pounders per Year. Aquacultural Engineering 4, 51 – 58. D’Abramo, L. R., Conklin, D. E., 1985. Lobster aquaculture. In: Huner, J., Brown, E.E. (Eds.), Crustacean and mollusc aquaculture in the USA. AVI Publ. Co., Westport, Conn., USA, pp. 159 – 201. Drengstig, A., T. S. Kristiansen, A. Bergheim, T. Drengstig & L. Aardal (2003). It does matter if they are black or white! Quantification of the minimum required level of astaxanthine to ensure natural pigmentation in the European lobster. pp 168 – 169. Extended abstract and Poster presentation. EAS special publication No. 33. August 2003. Trondheim, Norway. 408 pp. Drengstig, A., Drengstig, T., Agnalt, A.-L., Jørstad, K., Farestveit, E., 2009. Utvikling av metoder for stabil produksjon av hummeryngel med gode vekstegenskaper. 42 p. [In Norwegian] (http://www.rup.no/vision/vision7.aspx?hierarchyid=763&type=3)
10
Page 11 of 22
Drengstig, A., Bergheim, A., 2010a. Single cage technology for on-growing of lobster in RAS. Abstract and oral presentation, Progress in Marine Recirculating Aquaculture Systems – World Aquaculture Society, San Diego, California, USA, 1 – 5 March 2010. Drengstig, A., Bergheim, A., 2010b. A pilot RAS for commercial production of European lobster. Aquacultural Engineering Society Proceedings VII, pp. 178-186. AES Fifth Issues Forum, Roanoke, Virginia, USA, 16 – 20 August 2010.
cr
ip t
Drengstig, A., Agnalt, A.-L., Jørstad, K., 2011. Genetic mapping to improve growth performance, survival and feed conversion ratio (FCR) for on-growing of European lobster in Recirculating Aquaculture Systems (RAS). Proceeding 9th International Conference and Workshop on Lobster Biology and Management, Bergen, Norway, 19 – 23 June 2011.
us
Estrella, B. T., 2002. Techniques for live storage and shipping of American lobster. Technical Report TR-8, 18. Division of Marine Fisheries, Massachusetts.
an
Factor, J. R., 1995. Biology of the lobster Homarus americanus, Academic Press, Inc., New York. 528 p.
M
Grimsen, S., Jaques, R. N., Erenst, V., Balchen, J. G., 1987. Aspects of automation in a lobster farming plant. Modelling, identification and control, 8 (1), 61 – 68. Hamelo, J. S., 2006. Investigation of respiration rates of European lobster (Homarus gammarus) in land-based, lobster farming system. Master thesis, Univ. of Stavanger, Norway. 86 p.
d
362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
Jacklin, M., Combes, J., 2007. The good Practice Guide to Handling and Storing Live Crustacea. http://www.seafish.org/media/Publications/CrustaceaGPG_0505.pdf
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Kristiansen, T. S., Drengstig, A., Bergheim, A., Drengstig, T., Svensen, R., Kollsgård, I., Nøstvoll, E., Farestveit, E., Aardal, L., 2004. Development of intensive farming methods for the European lobster (Homarus gammarus L.) in recirculated seawater. Results from experiments conducted at Kvitsøy Lobster Hatchery from 2000 to 2004. Fisken og Havet, 6 – 2004, Institute of Marine Research, Bergen, 52 p. ISSN 0071 – 5638. (http://www.imr.no/__data/page/3839/Nr.6_2004_Methods_for_intensive_farming_of_E uropean_lobster.pdf). Nicosia, F., Lavalli, K.,1999. Homarid lobster hatcheries: Their history and role in research, management, and aquaculture. Marine Fisheries Review 61(2), 1-57. Richards, P. R. 1981. Some aspects of growth and behaviour in the juvenile lobster Homarus gammarus (Linnaeus). PhD Thesis University of Wales, Bangor, Great Britain. 209 p. Timmons, M. B., Losordo, J. G., 1994. Aquaculture water reuse systems: engineering design and management. Elsevier, New York, USA. van Olst, J. C., Carlberg, J. M., Hughes, J. T., 1980. The biology and management of lobsters, pp. 333 -384. In Cobbs, J. S., Phillips, B.F. (Eds.), Aquaculture, Vol. II Academic Press, Inc., New York. 468 p. 11
Page 12 of 22
Waddy, S. L., 1988. Farming the Homarid Lobsters: State of the Art. World Aquaculture,19 (4), 61 – 71. Whiteley, N. M., Al-Wassia, A. H., Taulor, E. W., 1990. The effect of temperature, aerial exposure and disturbance on oxygen consumption in the lobster, Homarus gammarus (L.). Mar. Behav. Physio. 17, 213 – 222.
ip t
Wickins, J.F., Beard, T.W., 1991. Variability in size at moult among individual broods of cultured juvenile lobsters. Aquaculture and Fisheries Management 22, 481 – 489.
M
an
us
cr
Wickins, J. F., Lee, D. O., 2002. Crustacean Farming – Ranching and Culture. Blackwell Science. 446 p.
d
413 414 415 416 417 418 419 420 421 422 423 424 425 426 427
Ac ce pt e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
12
Page 13 of 22
*Manuscript
Figure and Table captions:
ip t
Fig. 1. RAS facilities at Norwegian Lobster Farm (NLF), Kvitsøy. A) Flow diagram and design of the hatchery, broodstock and grow-out sections with water treatment units B) Principle sketch of the single cage technology C) Fully automated production unit and tank system including, A) single cages, B) feeding robot, C) cameras and image processing solutions, D) control units and E) machine room in centre below deck.
us
cr
Fig. 2. Four estimated growth rates of European lobster from size stage IV until plate-size (75 mm CL). Squared and circular marks indicate measured growth at NLF.
an
Fig. 3. Mean oxygen consumption of European lobster (individual size: 0.06 – 208 g) at 19.5 – 20.3 °C (Report IRIS, unpublished). Unit: mg O2/kg x min.
M
Table 1 Chemical composition and nutritional content of the feed.
ce pt
ed
Table 2 Water quality at four sampling points at low loading level in the grow-out unit, NLF, November 2004.
Ac
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Page 14 of 22
d
M
Figure 1 A
Ac ce pt e
1 2
an
us
cr
ip t
Figure(s)
Page 15 of 22
an
us
cr
ip t
Figure(s)
Ac ce pt e
d
M
1
Page 16 of 22
Figure(s)
1
cr
ip t
B) Feeding robot
C) Cameras
us
A) Single cage farming units
an
D) Control units
d
Figure 1 C
Ac ce pt e
2 3 4 5
M
E) Machine room below deck
Page 17 of 22
Figure(s)
0.10 mm/day
70
0.09 mm/day 0.08 mm/day
60
0.07 mm/day goal Kvitsøy small
40
Kvitsøy large
ip t
CL(mm)
50
30
cr
20
us
10 0 90
180 270 360 450 540 630 720 810 900 990 1080
an
0
d
Figure 2
Ac ce pt e
1
M
Days from Stage IV
Page 18 of 22
d
M
Figure 3
Ac ce pt e
1 2 3
an
us
cr
ip t
Figure(s)
Page 19 of 22
Table(s)
ip t
M
an
us
cr
Nutrient content % of wet weight Protein 54.7 Lipid 15.6 Carbohydrates 13.6 Ash 9.5 Moisture 6.8 Crude energy (MJ/kg) 21.6 Astaxanthin level was 50, 100 and 200 mg/kg dry weight.
d
3 4 5
Table 1
Ac ce pt e
1 2
1
Page 20 of 22
ip t cr Salinity ‰ 8.30 33.7 8.15 33.6
6.4 (89) 6.4 (89)
S-DM, mg/L <5
TOC, mg/L 2.2
TAN, µg/L 645
5.3 6.4
3.2 -
29 -
NH3-N*, µg/L 32 <5 -
NO3-N, µg/L 1,880
Flow L/h 90 6,000
1,860 -
Ac c
ep te
d
Make-up water Outlet lobster tank Outlet biofilter 18.4 8.32 33.5 Outlet drumfilter 18.4 8.32 33.6 *: Calculated (Alabaster and Lloyd, 1982)
DO, mg/L (%) 8.3 (92) 6.2 (82)
us
pH
an
Temp. °C 10.0 18.2
M
Table 2 Sampling point
2
Page 21 of 22
Salinity ‰ 8.30 33.7 8.15 33.6
6.4 (89) 6.4 (89)
S-DM, mg/L <5
TOC, mg/L 2.2
TAN, µg/L 645
5.3 6.4
3.2 -
29 -
NH3-N*, µg/L 32 <5 -
NO3-N, µg/L 1,880
Flow L/h 90 6,000
1,860 -
Ac c
ep te
d
Make-up water Outlet lobster tank Outlet biofilter 18.4 8.32 33.5 Outlet drumfilter 18.4 8.32 33.6 *: Calculated (Alabaster and Lloyd, 1982)
DO, mg/L (%) 8.3 (92) 6.2 (82)
us
pH
an
Temp. °C 10.0 18.2
M
Table 2 Sampling point
cr
ip t
Table(s)
1
Page 22 of 22