RU2765245C1 - Marine farm for growing far eastern trepang - Google Patents

Abstract

FIELD: seafood industry.

SUBSTANCE: marine farm includes a frame with positive buoyancy, on which mesh fabric is removably placed. The frame is formed by interconnected modular elements made of plastic, along its inner perimeter there are elements for removable fastening of the mesh fabric and collectors for collecting juveniles. The mesh fabric consists of two layers, and the cell size of the outer layer of the mesh fabric is 30 mm, and the inner layer is 75 or 100 microns.

EFFECT: invention provides for the cultivation of trepangs from spawning to settled juvenile trepangs and increasing the strength of the frame with the possibility of changing its size, shape and configuration.

1 cl, 4 dwg, 9 tbl

Description

Marine pool for growing Far Eastern trepang

The invention relates to the fishing industry and can be used for growing Far Eastern trepang under semi-controlled conditions.

It is known to use a bottom aviary made of net fabric, ropes, anchors and overlays for semi-controlled maintenance of Far Eastern trepang spawners (see RF patent No. 2728407, IPC A01K 61/00, publication date 07/29/2020).

The disadvantages of this technical solution are:

- conditions for placing the enclosure - at depths of up to 20 m in areas of the seabed with soft soils, a flat surface, with weak bottom currents;

- during the spawning period, the Far Eastern trepang must be removed and then placed back in the enclosure;

- increased labor intensity of operation and maintenance, because placement and extraction of the Far Eastern trepang is carried out by diving.

As the closest analogue, a marine pool for growing Far Eastern trepang was adopted, containing a frame with positive buoyancy, on which a mesh fabric is removable (see Ilyushchenko V.V. 2020. Suspended method of growing Far Eastern trepang (Apostichopus japonicus) in Troitsa Bay (Posyet Bay, Sea of Japan) in the summer-autumn period of 2019. Mat. V international scientific and technical conference "Comprehensive research in the fishery industry", pp. 11-13).

The disadvantages of the closest analogue are the execution of the frame from wooden boards, which, due to the anisotropic properties of wood, do not quite effectively withstand dynamic loads, especially during storms, and require careful processing from aggressive

the impact of the external environment, as well as the need to use additional pontoons to ensure positive buoyancy.

The task to be solved by the present invention is the development of an easy-to-use marine basin in which Far Eastern trepang can be grown from spawning to settled juveniles.

The technical result, which is achieved when solving the problem, is expressed as follows:

- increased survival rate of the Far Eastern trepang;

- increasing the strength of the frame;

- the ability to change the size, shape and configuration of the frame.

The problem is solved by the fact that the sea pool for growing Far Eastern trepang, containing a frame with positive buoyancy, on which the mesh fabric is removable, is characterized in that the frame is formed by interconnected modular elements made of plastic, along its inner perimeter there are elements for removable fastening of the mesh mesh and collectors for collecting fry, in addition, the mesh fabric consists of two layers, and the mesh size of the outer layer of the mesh fabric is 30 mm, and the inner layer is 75 or 100 microns.

A comparative analysis of the set of essential features of the proposed technical solution and the set of essential features of the prototype and analogues indicates its compliance with the criterion of "novelty".

In this case, the distinctive features of the claims solve the following functional tasks.

The sign "frame is formed by interconnected modular elements" leads to the following factors:

- the ability to change the size, shape and configuration of the frame;

- increasing the overall strength of the frame, since the dynamic load is not concentrated at a specific point, but is distributed between the modular elements;

- easy and convenient operation and the possibility of removing / replacing / repairing individual modular elements;

- simplification of the design as a whole, because no additional pontoons are needed to ensure positive buoyancy of the frame.

The characteristic "modular elements [made] of plastic" describes the material of the modular elements, which is characterized by low weight and resistance to aggressive environmental influences.

In the case when the modular elements are made hollow and closed, it is possible to control the buoyancy of the frame by filling or vice versa pumping out gas/liquids from the cavities of these elements.

The sign “along the inner perimeter [frame] there are elements for removable fastening of the mesh fabric and collectors for collecting juveniles” allows you to stretch floating cables with collectors in the plane of the frame in various directions.

The signs “the mesh cloth consists of two layers, and the cell size of the outer layer of the mesh cloth is 30 mm, and the inner layer is 75 or 100 microns” provide an increase in the survival rate of the Far Eastern trepang.

In FIG. 1 shows a top view of the sea basin with collectors installed in it to collect juveniles.

In FIG. 2 graphically shows the duration of the stages of development of the Far Eastern trepang larvae in marine basins.

In FIG. 3 shows juveniles of the Far Eastern trepang aged 1.5 months from the moment of settling.

In FIG. 4 shows juveniles of the Far Eastern trepang aged 2 months from the moment of settling.

The drawing shows modular frame elements 1, mesh fabric 2, elements for removable fastening 3, collectors 4 for collecting juveniles, halyards 5, floating cables 6.

Modular elements 1 are made of plastic and interconnected, forming a frame with positive buoyancy, along the inner perimeter of which there are elements 3, which can be coaxial loops of modular elements 1 or rods installed in the through holes of these loops.

Mesh fabric 2 consists of two layers, and the mesh size of the outer layer of the mesh fabric is larger than that of the inner layer. The cell size was determined experimentally; either of the two options can be used, but a cell size of 100 μm is preferable, because such a mesh fabric has a greater throughput of water masses and does not let the eggs of the Far Eastern trepang pass through at the first stages of cultivation.

Mesh fabric 2, as well as floating cables 6 with collectors 4 for collecting juveniles, are detachably attached to elements 3.

The assembled pool is installed at a distance of 200-250 m from the shore at a depth of about 10 m, stability is ensured with the help of pickle weights (not shown in the drawings).

Cultivation of Far Eastern trepang is carried out according to standard technology using standard equipment in several stages.

1. Capture/acquisition and placement in the sea basin of Far Eastern trepang spawners - the number is determined experimentally depending on the required stocking density of fertilized eggs.

The stage of development of the gonads in spawners is determined by the histological method, and the mode of stimulation of gametogenesis and the start of spawning are calculated based on the sum of degree days obtained by spawners in nature.

2. Spawning of spawners of the Far Eastern trepang - occurs mainly in summer, at a water temperature of 18-23 ° C, the duration for one individual is 1-3 days, for the entire population - no more than 2 months; fertilization is external and occurs immediately after the release of the reproductive products.

3. Seizure of Far Eastern trepang spawners from the sea basin - after fertilized eggs are found in water samples from the sea basin.

4. Beginning of feeding - when the larvae enter the stage of "early auricularia", they begin to bring food into the sea pools in the form of a suspension with red yeast Rhodotorula spp 2 times a day in the morning and evening.

If the feeding regime was followed, the degree of stomach filling (at least 2-5 cells per field of view) and the presence of a characteristic golden-brown color of the stomachs were monitored in plankton samples of larvae.

5. Installation of collectors for collecting juveniles - carried out with the appearance in the samples of the first specimens of larvae at the "dolliolaria" stage.

Collectors 4 for collecting juveniles are collected on a halyard 5 in a garland of 10-12 pieces, which is fixed on a floating cable 6, a substrate is laid in each of the collectors 4, after which the floating cable 6 is detachably attached at the ends to the elements 3.

6. Settling of juveniles of the Far Eastern trepang on the substrate in collectors 4 and on the inner surface of the inner layer of the mesh fabric 2.

7. Further cultivation of juveniles of the Far Eastern trepang to a viable stage.

8. Viable juveniles (weighing more than 0.3 g) are removed from the collectors and the netting.

Then the process is repeated.

Tests of the declared sea basins were carried out in 2020 directly in the sea waters of Troitsa Bay, Kitovy Bay, in the fish breeding area RVU No. 6-Khs (m).

At the same time, the temperature and salinity of the water were regularly monitored, as well as the selection of specimens of the Far Eastern trepang for analysis.

The cultivation of the Far Eastern trepang was carried out in 12 sea basins, the frames of which are connected into a common structure, the characteristics are given in table 1.

Table 1

Characteristics of marine pools

Number of sea basins, pcs. Dimensions of 1 pool Mesh layer Cell size The number of pools in which this mesh fabric is used, pcs. 12 Length: 5 m
Width: 5 m
Height: 3 m Interior 75 µm 5 100 µm 7 External 12

The productivity of marine basins was calculated based on the possible stocking density of juveniles according to the standard given in Table 2.

table 2

Standards for keeping juveniles of the Far Eastern trepang

Indicator unit of measurement Quantity stocking density of juveniles ind./collector (0.3 m ² ) 150-170 ind./m ² 500-700 ind./t of water 20000-25000

The results of calculating the average productivity of sea basins are shown in Table 3.

Table 3

Performance of sea basins

Average planting density according to the standard, ind./t Maximum planting density, ind./t Total volume of 12 pools, t Performance Average, million copies Maximum, million copies 20000-25000 50000 600 12-15 thirty

At the first stage, the number of Far Eastern trepang spawners involved in spawning was experimentally determined to obtain the required stocking density of fertilized eggs.

As a result, it was found that in order to obtain a stocking density of 3-5 cells/ml in a sea basin with a volume of 50 tons, 30-40 mature individuals of the Far Eastern trepang with an average weight of 170 g were required, which were seized from depths of 10-12 m at a water temperature at the bottom of 10 -12°C.

Since the difference in temperature during planting in the sea basins was 3-4°C, additional adaptation of the producers of the Far Eastern trepang to the conditions of the sea basins was not required.

At the second stage, spawning of Far Eastern trepang spawners was not stimulated in marine basins. As a result, after the spawners were placed within the sea basins, the release of gametes began on average after 30 min.

Spawning in the marine basins was carried out according to the schedule shown in Table 4.

Table 4

Spawning schedule for Far Eastern trepang spawners

in sea basins

Date of spawning pool number 07/06/2020 one 2 07/09/2020 3 4 07/10/2020 10 07/13/2020 9 12 07/15/2020 5 6 7 eight eleven

After 1-2 hours, when collecting samples in the field of view of the microscope, fertilized eggs were observed at the stage of division of two blastomeres.

At the fourth stage, the amount of the applied suspension with the red yeast Rhodotorula spp was determined at the rate of 10,000 cells/ml at a stocking density of larvae of 1 ind./ml.

At the fifth stage, as a substrate, anfeltia thalom weighing 0.2 kg, pre-washed from sludge, was used.

The amount of substrate required to increase the juvenile settling area was also determined based on the possible number of settled juveniles and their capacity in the sea basin, details are given in Table 5.

Table 5

Calculation of the amount of substrate for juvenile trepang

Name Material Quantity per pool, pcs. Total quantity, pcs. Collector for collecting juveniles PVC mesh plates with a mesh of less than 1 mm 864 10368 A garland of collectors with a substrate Fal, 12 collectors, loads 9 108 floating cable Rope, floats, 9 garlands of collectors eight 96

During the period of observation of survival at the larval stages in the conditions of marine basins, the data shown in Table 6 were obtained.

Table 6

Average stocking density of Far Eastern trepang larvae from 07/06/2020 to 07/27/2020

Development stage Average stocking density/ml #1 #2 No. 3 #4 #5 #6 #7 #8 #9 #10 #11 #12 Blastula 3.4 1.7 4 0.8 1.8 3 1.7 2.3 0.4 one 4.7 6.2 gastrula 1.7 1.2 4 0.8 2.5 1.2 one 0.9 0.4 one 4.8 one Dipleurula 2.3 1.4 1.1 7 4.4 4.1 3.4 2.7 0.3 0.3 one 1.5 Early-late auricularia 5.2 3.6 2.9 2.9 2.9 3.7 2.3 2.2 1.2 3.5 4.9 3.3 Dolliolaria 5.6 5.3 2.4 2.3 1.3 3.3 1.4 1.5 0.4 2.7 5 4.1 Pentactula 4.1 2.1 1.9 1.8 0.8 2.5 0.7 1.4 0.3 2.3 4.8 4.5

During the observation of the concentration of larvae at different stages of development in the conditions of marine basins, it was experimentally established that at the stages of early ontogenesis, larvae concentrated in the upper layers of water.

With the transition to the stage of development "middle auricularia", the bulk of the larvae were in the middle layers of water, at a depth of 1-2 m.

With the transition of larvae to the “dolliolarian” stage, the main accumulations were noted in the bottom layers of the reticulate web. At the same time, the number of larvae in the samples taken on the same day varied dramatically. Most likely, this is due to the nature of water exchange within the marine basins, the throughput and fouling of the mesh fabric, the presence of currents and waves.

Primary data on plankton samples of Far Eastern sea cucumber larvae are presented in Table 7.

Table 7

Duration of stage development, stocking density of larvae

and medium sizes

Stage Duration
development stage, days Average stocking density of larvae, ind./ml Average size, microns Blastula one 2.5 one hundred gastrula 2 1.7 158x208 Dipleurula one 2.4 225x350 Early-
late auricularia sixteen 3.2 450x663 Doliolaria one 2.9 265x400 Pentactula 2 2.2 237x530

In the first days after settling, the fry of the Far Eastern trepang are less than 1 mm in size, only white dots are visible through a magnifying glass on the collectors for collecting juveniles. During this period, the juveniles still lack pigmentation of the skin. Under the binocular (magnification 12.5x4), the plates of Selenk, five oral tentacles and one ambulacral leg are clearly visible. With an increase in body length, the number of oral tentacles and ambulacral legs also increases. Pigmentation of the skin begins in some individuals of juveniles with a body size of more than 2-4 mm.

After the appearance of the first specimens of settled juveniles and then, as they grew, the feeding regimen and the amount of feed introduced were adjusted in accordance with the data in Table 8.

Table 8

Feeding regimen and calculation of the amount of feed

for young trepang on the pool with a volume of 50 tons

Juvenile size diet
(name of food) Concentration, g Feeding mode, times / day less than 0.1 cm - 0.5 cm starter feed 10-20 2 yeast Rhodotorula spp. 10-30 strained Sargassum pallidum 50-70 0.5 cm - 1 cm yeast Rhodotorula spp. thirty 2 starter feed 30-50 Sargassum pallidum powder 10-30 compound feed (second fraction) 10-50 more than 1 cm compound feed (second fraction) 50-100 2 compound feed (third fraction) 50-100 Sargassum pallidum powder 30-50 activated sludge 40-60 crushed kelp 5-10

Analyzing the data of plankton samples of larvae, it was found that the total number of settled juveniles in the conditions of marine basins was 8.4 million specimens.

With the advent of juveniles with an average weight of 0.05 g, the total number of individuals reared in marine basins was calculated.

According to the results of the inventory dated September 2, 2020, the number of cultured fry was 1473761, i.e. 20% of the total number of settled specimens.

Upon reaching the grown juveniles with an average weight of 0.5 g, from October 15, 2020 to October 16, 2020, viable individuals of the Far Eastern trepang were planted at the working plot of RVU No. 6Xs(m), for pasture rearing to marketable sizes.

The number of released aquaculture objects amounted to 180,638 units. weighing 90.3 kg.

Data on the survival of individuals from the moment of fertilization of eggs to the viable stage are given in Table 9.

Table 9

Survival rate of the Far Eastern trepang

during the transition to different stages of development

Development stage Survival, % Quantity, pcs. Blastula one hundred 80°975 875 gastrula 97.5 78°951 478 Dipleurula 92.1 72°716 335 Auricularia 94.65 68°829 493 Dolliolaria 75.29 51 824 560 Pentactula 50 25°912 280 Settled juveniles 32.5 8°421 491 Juveniles (0.05 g) 17.5 1°473 761 Viable fry (0.5 g) 12.2 180 638

Claims (1)

Marine pool for growing Far Eastern trepang, containing a frame with positive buoyancy, on which a mesh fabric is removable, characterized in that the frame is formed by interconnected modular plastic elements, along its inner perimeter there are elements for removable fastening of the mesh fabric and collectors for collecting juveniles in addition, the mesh fabric consists of two layers, and the mesh size of the outer layer of the mesh fabric is 30 mm, and the inner layer is 75 or 100 microns.

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