Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Kelp preparations for enhancing the growth of seafood and algae
Description
The present invention relates to the use of a solid or liquid kelp
preparation, preferably
of a liquid kelp preparation, especially of Kelpak (from Compo, Germany) for
promot-
ing the growth of seafood, in particular of crustaceans and especially of
shrimps and
prawns, and to a method for promoting the growth of seafood, which method
comprises
treating the seafood's habitat with a solid or liquid kelp preparation
preferably with a
liquid kelp preparation, especially with Kelpak . Moreover, the invention
relates to the
use of a solid or liquid kelp preparation preferably of a liquid kelp
preparation, espe-
cially of Kelpak , for quantitatively and/or qualitatively enhancing the
growth of algae
and to a method for quantitatively and/or qualitatively enhancing the growth
of algae,
which method comprises treating the algae and/or their habitat with a solid or
liquid
kelp preparation preferably with a liquid kelp preparation, especially with
Kelpak .
The worldwide increasing demand for seafood and especially for shrimps and
prawns
cannot be satisfied by natural populations. Thus, industrial-scale breeding
has become
the main seafood source. In general, intensively and semi-intensively managed
aqua-
culture farms rely on artificial shrimp feeds (often based on cereals or
soybeans), either
exclusively or as a supplement to the organisms that naturally occur in a
pond. Artificial
feeds generally are used in the form of specially formulated, granulated
pellets that
disintegrate quickly. Up to 70% of such pellets are wasted, as they decay
before the
shrimps have eaten them. Waste from the artificial food pellets and excrements
of the
shrimps can however lead to the eutrophication of the ponds and can lead to an
in-
creased disease rate. In case that artificial feeds are used only as a
supplement to the
organisms that naturally occur in a pond, a food chain is established in the
ponds,
based on the growth of phytoplankton. Frequently, fertilizers and mineral
conditioners
are used to boost the growth of the phytoplankton to accelerate the growth of
the
shrimps. This fertilization, especially in case it is not carried out on a
demand basis,
can however also lead to the eutrophication of the ponds and also to an
increased dis-
ease rate.
It was an object of the present invention to provide a method for promoting
the growth
of seafood (in particular of crustaceans and especially of shrimps and
prawns), which
avoids or at least reduces the negative effects of the prior art growth
promoting meth-
ods. It was also an object of the present invention to provide a method for
promoting
the growth of seafood by quantitatively and/or qualitatively enhancing the
growth of
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algae which serve as food for seafood (in particular for crustaceans and
especially for
shrimps and prawns),
The object is achieved by the use of a solid or liquid kelp preparation.
Thus, in a first aspect, the present invention relates to the use of a solid
or liquid kelp
preparation for promoting the growth of seafood, in particular of crustaceans
and espe-
cially of shrimps and prawns. The invention also relates to a method for
promoting the
growth of seafood (in particular of crustaceans and especially of shrimps and
prawns),
which method comprises treating the seafood's habitat with a solid or liquid
kelp prepa-
ration.
As already pointed out, the seafood is preferably selected from crustaceans
and more
preferably from shrimps and prawns. Shrimps are swimming, decapod crustaceans
classified in the suborder Caridea, found widely around the world in both
fresh and salt
water. Prawns are also decapods, belonging however to the suborder Dendrobran-
chiata. They are similar in appearance to shrimp, but can be distinguished by
the gill
structure which is branching in prawns, but is lamellar in shrimp. While in
biological
terms shrimps and prawns belong to different suborders of Decapoda, they are
very
similar in appearance. In commercial farming and fisheries, the terms shrimp
and
prawn are often used interchangeably. However, recent aquaculture literature
increas-
ingly uses the term "prawn" only for the freshwater forms of palaemonids and
"shrimp"
for the marine penaeids. In the terms of the present invention, no strict
distinction is
made.
Preferably, the shrimps and prawns are selected from those species typically
used in
aquaculture. Most aquacultured shrimps/ prawns are of the family Penaeidae.
Exam-
ples are Penaeus vannamei (Pacific white shrimp), Penaeus monodon (giant tiger
prawn), P. stylirostris (Western blue shrimp), P. chinensis (Chinese white
shrimp, also
known as the fleshy prawn), P. japonicus (Kuruma shrimp), P. indicus (Indian
white
shrimp), and P. merguiensis (Banana shrimp).
Kelp are large seaweeds belonging to the brown algae (class Phaeophyceae) and
are
classified as the order Laminariales. There are about 300 different genera.
Some spe-
cies can be very long and form kelp forests.
Suitable kelp species to be used according to the present invention are for
example
Nereocystis luetkeana, Giant kelp (Macrocystis pyrifera), Kombu (Laminaria
japonica or
Saccharina japonica), Laminaria digitata, Laminaria hyperborea, Laminaria
ochroleuca,
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Laminaria saccharina, Laminaria agardhii, Laminaria angustata, Laminaria
bongardina,
Laminaria cuneifolia, Laminaria dentigera, Laminaria digitata, Laminaria
ephemera,
Laminaria farlowii, Laminaria groenlandica, Laminaria longicruris, Laminaria
nigripes,
Laminaria ontermedia, Laminaria pallida, Laminaria platymeris, Laminaria
setchellii,
Laminaria sinclairii, Laminaria solidungula, Laminaria stenophylla, Alaria
marginata,
Costaria costata, Durvillea antarctica, Durvillea willana, Durvillaea
potatorum, Ecklonia
brevipes, Ecklonia maxima, Ecklonia radiata, Eisena arborea, Egregia
menziesii,
Hedophyllum sessile, Macrocystis angustifolia, Pleurophycus gardneri or
Pterygophora
californica. Among these, preference is given to Ecklonia maxima.
Thus, preferably a liquid or solid preparation of Ecklonia maxima (also called
sea bam-
boo) is used.
The kelp preparation to be used according to the invention is preferably
liquid. More
preferably, the kelp preparation to be used according to the invention is a
liquid prepa-
ration of Ecklonia maxima. The liquid preparation is preferably a kelp
extract, especially
an extract of Ecklonia maxima.
The kelp preparation used according to the invention preferably comprises
phytohor-
mones, in particular growth-promoting hormones. The phytohormones preferably
com-
prise auxins, cytokinins and/or gibberellins. More preferably, they comprise
auxins and
optionally also cytokinins and/or gibberellins. Even more preferably, they
comprise aux-
ins, cytokinins, and optionally also gibberellins. Preferably, the auxin
content overbal-
ances the cytokinin content (on a weight basis), preferably by a rate of at
least 2, e.g.
by a rate of 2 to 2000, preferably by a rate of 2 to 1000 and more preferably
by a rate
of 2 to 500, more preferably by a rate of at least 10, e.g. by a rate of 10 to
2000, pref-
erably by a rate of 10 to 1000 and more preferably by a rate of 10 to 500
(i.e. the
weight ratio of auxins to cytokinins in the preparation is preferably at least
2:1, e.g. 2:1
to 2000:1, preferably 2:1 to 1000:1 and more preferably 2:1 to 500:1, and is
more pref-
erably at least 10:1, e.g. 10:1 to 2000:1, preferably 10:1 to 1000:1 and more
preferably
10:1 to 500:1).
Moreover, the kelp preparation used according to the invention preferably also
contains
amino acids, vitamins and/or mineral compounds. The amino acids preferably
comprise
glycine, alanine, valine, leucine, isoleucine, serine, threonine, tyrosine,
lysine, aspar-
agic acid and/or proline. The vitamins preferably comprise vitamin A, vitamins
of the B
group, vitamin C and/or vitamin E. The mineral compounds preferably comprise
follow-
ing elements: K, N, P, Mg, S, Ca, Fe, Mn, Cu, Zn and/or Mo. Without wishing to
be
bound by theory, it is believed that said phytohormones and possibly also said
amino
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acids, vitamins and/or mineral compounds are responsible for the positive
effect
achieved by the use and method according to the invention, namely the promoted
growth of the seafood and/or the quantitatively and/or qualitatively enhanced
growth of
algae.
The kelp preparation used according to the invention is of such a composition
that,
once in contact with water, it releases instantaneously, by degrees or
deferredly com-
ponents of the composition which promote the growth of the seafood and/or
quantita-
tively and/or qualitatively enhance the growth of algae, such as said
phytohormones
and also amino acids, vitamins and mineral compounds.
The kelp preparation can be prepared by any known methods for extracting
active
compounds, such as said phytohormones, amino acids, vitamins and/or mineral
com-
pounds, from algae and plants. For instance, the harvested kelp or a part
thereof, usu-
ally after a purification step for removing salt water and impurities, may be
extracted.
Extraction is preferably carried out under such conditions that the kelp's
cells burst.
Extraction may take place by using pressure or by using steam extraction,
alcohol ex-
traction, osmosis, ultrasound or other known methods. Pressure methods which
lead to
cell disruption are preferred. Suitable pressure methods include the use of
mills, such
as bead mills or ball mills, or homogenizers, such as rotor-stator
homogenizers or high-
pressure homogenizers. Preferably, extraction is carried out by using the
"burst-cell-
method" (also called "cold cell-burst process"), a method using high pressure
at low
temperatures.
The resulting extract may be used as such or may be further purified, e.g. by
filtration.
Specifically, the kelp preparation used according to the invention is Kelpak ,
a sea-
weed extract commercially available from Compo, Germany. This algae extract
pre-
pared from Ecklonia maxima contains, inter alia, auxins, cytokinins, amino
acids, vita-
mins and mineral compounds. Its composition is said to be as follows:
- nitrogen: ca. 3.6 g/I
- phosphor: ca. 17 g/I
- potassium: ca. 7.2 g/I
- auxins: ca. 11 mg/I
- cytokinins: ca. 0.031 mg/I
- amino acids: ca. 2.478 mg/I
- carbohydrates: ca. 16.9 g/I
- proteins: ca. 3 g/I
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- vitamins: ca. 21.7 g/l.
Kelpak is said to be produced by first removing salt water and impurities
from the
freshly harvested kelp Ecklonia maxima and then subjecting its fronds and
stipes to the
5 "burst-cell-method" (also called "cold cell-burst process"), a method using
high pres-
sure at low temperatures (see D.V. Robertson-Andersson et al., J. Appl.
Phycol. 2006,
18, 315-321; W.A. Stirk et al., J. Appl. Phycol. 2004, 16, 31-39; W.A. Stirk
et al., J.
Appl. Phycol. 1996, 8, 503-508; W.A. Stirk et al., S. Afr. J. Bot, 2004, 70,
145-151; F.N.
Verkleij, Biol. Ag. Hort. 1992, 8, 309-324). Only the pure filtered cell sap
is then used
for Kelpak .
In general, the habitat of the seafood, e.g. the pond where it is growing or
living, is
treated with the kelp preparation, e.g. by adding the preparation to the water
in the
pond. The preparation may be added as such or diluted (ordinarily with water)
or may
be mixed with feeds used as an additional nutrient for the seafood growing in
the pond.
The kelp preparation is added to the habitat of the seafood in such a quantity
that the
amount of phytohormones added via the kelp preparation is preferably in a
range of
from 1 mg to 50 mg, more preferably from 3 mg to 20 mg and in particular from
3 mg to
15 mg per hectare of the habitat. If Kelpak is used, this is added in an
amount of
preferably 100 ml to 2 I, more preferably from 200 ml to 1.5 I and
specifically from 0.5 I
to 1 I of the commercial formulation per hectare.
The addition is preferably carried out 1 to 20 times, more preferably 3 to 15
times and
specifically 5 to 12 times during the life cycle of the seafood nourishing on
the algae to
be treated.
It is believed that the growth promotion of the seafood may be partly due to
an en-
hanced growth of algae growing in the ponds where the seafood lives, which in
turn is
caused by the treatment of the ponds with the kelp preparation. Thus, the
invention
also relates to the use of a solid or liquid kelp preparation for
quantitatively and/or
qualitatively enhancing the growth of algae.
As regards suitable and preferred kelp preparations, reference is made to what
has
been said above.
"Quantitatively enhancing the growth" means that the dry biomass of the algae
is en-
hanced, as compared to algae not treated with the kelp preparation or not
growing in a
medium which is/has been treated with the kelp preparation. The biomass
increase is
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either due to a numeric increase (i.e. the number of algae in a specific
volume of the
medium in which they grow/live is increased) or by an increase in weight (i.e.
the dry
biomass of the single organisms increases) or a combination of the two
aspects. More
frequently, the biomass increase via a numeric increase (i.e. the number of
algae in a
specific volume of the medium in which they grow/live is increased)
predominates.
"Qualitatively enhancing the growth" means that the algae have a higher
quality with
respect to their nutritional value and/or their content in vitamins, minerals
and/or other
nutritional factors and thus are healthier and/or more nutritive for the
seafood for which
they serve as food, as compared to algae not treated with the kelp preparation
or not
growing in a medium which is/has been treated with the kelp preparation.
"Healthier"
means that the seafood nourishing on thusly treated algae show a decreased
disease
level and/or a decreased mortality. Additionally or alternatively,
"qualitatively enhancing
the growth" also means that the algae treated with the kelp preparation and/or
growing
in a medium which is/has been treated with the kelp preparation have a
prolongated
lifetime.
Algae are a large and diverse group of simple, typically autotrophic
organisms, ranging
from unicellular to multicellular forms. In water, algae form the
phytoplankton and a big
part of the phytobenthos. The largest and most complex benthic marine forms
are
called seaweeds. Algae are photosynthetic, like plants, and "simple" because
they lack
various structures that characterize land plants, such as phyllids and
rhizoids in non-
vascular plants, or leaves, roots, and other organs that are found in
tracheophytes. For
that reason they are currently excluded from being considered plants. Many are
photoautotrophic, although some groups contain members that are mixotrophic,
deriv-
ing energy both from photosynthesis and uptake of organic carbon either by
osmotrophy, myzotrophy, or phagotrophy. Some unicellular species rely entirely
on
external energy sources and have limited or no photosynthetic apparatus.
Despite the
fact that modern sources restrict the term "algae" to eukaryotic organisms, in
the pre-
sent invention, the prokaryotic Cyanobacteria (commonly referred to as blue-
green
algae), which were traditionally included as "algae" in older textbooks, are
also encom-
passed by this term.
The algae the growth of which is to be enhanced according to the present
invention are
aquatic, preferably marine, and represent a food source for seafood, in
particular for
crustaceans and especially for shrimps and prawns. Examples of suitable algae
groups
are haptophyta, cryptista, dinozoa, chlorarachinphyta, bacillariophyta
(diatoms), phae-
ophyta (brown algae), rhodophyta (red algae), chlorophyta (green algae),
picobiliphyta
and cyanobacteria (blue-green algae). Preferably, the algae the growth of
which is to
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be enhanced according to the present invention are selected from
bacillariophyta (dia-
toms) and cyanobacteria (blue-green algae).
In a further aspect, the present invention relates to a method for
quantitatively and/or
qualitatively enhancing the growth of algae, which method comprises treating
the algae
and/or their habitat with a solid or liquid kelp preparation.
As regards the terms "quantitatively and/or qualitatively enhancing the growth
of algae"
as well as suitable and preferred algae and kelp, reference is made to what
has been
said above.
In general, the habitat of the algae, e.g. the pond where they are growing or
living, is
treated with the kelp preparation, e.g. by adding the preparation to the water
in the
pond. The preparation may be added as such or diluted (ordinarily with water)
or may
be mixed with feeds used as an additional nutrient for the seafood growing in
the pond.
The kelp preparation is added to the habitat of the algae in such an amount
that the
amount of phytohormones added via the kelp preparation is preferably in a
range of
from 1 mg to 50 mg, more preferably from 3 mg to 20 mg and in particular from
3 mg to
15 mg per hectare of the habitat. If Kelpak is used, this is added in an
amount of
preferably 100 ml to 2 I, more preferably from 200 ml to 1.5 I and
specifically from 0.5 I
to 1 I of the commercial formulation per hectare.
The addition is preferably carried out 1 to 20 times, more preferably 3 to 15
times and
specifically 5 to 12 times during the life cycle of the seafood nourishing on
the algae to
be treated.
The use and the method according to the invention lead to a quantitatively
and/or quali-
tatively enhanced growth of algae, as represented by an enhanced dry biomass
and/or
a higher quality of the algae, e.g. a higher nutritional value and/or a higher
content in
vitamins, minerals and other nutritional factors.
The quantitatively and/or qualitatively enhanced growth of algae can in turn
lead to a
promoted growth of seafood, in particular of crustaceans and especially of
shrimps and
prawns nourishing on these algae. However, the enhanced growth of algae does
not
seem to be the only reason for the promoted growth of seafood.
The promoted growth of seafood is reflected in a diminished mortality of the
seafood
larvae, in a faster weight increase and/or in a lower disease level. The
faster weight
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increase in turn means that less supplementary artificial feeds are necessary
for ob-
taining seafood with the same or a comparable weight. This in turn implies a
reduced
pollution with decaying, wasted artificial feeds of the habitat, e.g. the
pond, where the
seafood is grown. If the amount of supplementary feeds is not reduced, this is
never-
theless advantageous for the seafood farmer as he can harvest the seafood
earlier and
thus has the possibility of having more life cycles of the seafood per year.
The invention is now further illustrated by the following non-limiting
examples.
Examples
1. Effect of Kelpak treatment on the growth of shrimps
Between January and June 2008, seawater shrimp ponds containing diatoms and
blue-
green algae were treated with Kelpak , Fitobloom (a fertilizer on a
microalgae basis)
and Cal P-24.
The respective treatments were carried out on the days and in the quantities
compiled
in Table 2:
Table 2
Date Kelpak [I/ha] Fitobloom CAL P-24
[sacks/ha] [sacks/ha]
Jan. 5, 2008 1 11 -
Jan. 21, 2008 0.5 0.51 -
Feb. 4, 2008 0.5 0.51 -
Feb. 12, 2008 5
Feb. 16, 2008 1 11 -
Mar. 3, 2008 - - 5
Mar. 7, 2008 0.5 0.52 -
Mar. 23, 2008 0.5 0.53 -
Apr. 8, 2008 1 13 -
Apr. 24, 2008 0.5 0.53 -
May 9, 2008 0.5 0.53 -
May 25, 2008 0.5 0.53 -
1 Fitobloom 7-1
2 Fitobloom 4-1
3 Fitobloom 2-1
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In parallel, the same number of ponds containing a comparable initial number
of dia-
toms and blue-green algae was treated analogously, but without the use of
Kelpak.
While the shrimps growing in the ponds treated with Kelpak had reached
maturity (=
at least 25 g per shrimp) in 149 days (actually, after 149 days, the shrimps
had a mean
weight of 27.3 g), the shrimps growing in the ponds without Kelpak treatment
had
reached maturity only after 170 days (with a mean weight of 25.9 g). The
survival rate
was 40% in the Kelpak -treated ponds and 39% in the ponds without Kelpak
treat-
ment. The ponds treated with Kelpak yielded 24,052 pounds of shrimps, as
compared
to 22,191 pounds of shrimps of the ponds without Kelpak treatment. The
shrimps in
ponds treated with Kelpak had consumed 16,700 pounds of artificial food, as
com-
pared to 22,191 pounds consumed in the ponds without Kelpak treatment.
