JP2012090639A - Proliferation bank for spiny lobster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new proliferation bank for spiny lobsters, which enables post-larva and fry of the lobster to safely cling to the bottom and to settle and grow, and to provide a new installation method by which the proliferation of the spiny lobsters is promoted by using the proliferation bank.SOLUTION: The proliferation bank for the spiny lobsters is mounted with a body part on a base part having a surface wider than the bottom face of the body part. The body part has one or more sidewalls respectively having, on the surfaces, plurality of recessed parts having different sizes expressed by diameters and depths so as to allow the post-larva and the fry of the lobster to change the living habitat according to the growth thereof. Preferably, the whole or a part of the recessed parts are bored so as to be orthogonal to the surface of the side wall, and the recessed parts in eight-stepped sizes provided in table 1 are randomly arranged so that the number of the recessed parts having smaller sizes is larger in all of the eight-stepped recessed parts at every side wall. The proliferation bank is preferably installed throughout the year in a seaweed colony shallower than the water depth of 20 m or the sea bottom at the surrounding thereof.

Description

  The present invention relates to a growth reef for lobster and its installation method. More specifically, the present invention relates to an artificial reef for lobster that can be safely grown and grown by post-rava and juvenile shrimp, and an installation method for promoting the growth of lobster using the artificial reef.

  There are many conventional lobster breeding reefs, such as stone throwing reefs with a stack of natural stones installed and block-like ones with slit-like gaps, and those combining artificial seaweed with these are also devised. . However, later research shows that post-rava and small fry shrimp are not clogged between stones and stones, but are clogged in small cylinder-like depressions, and fried shrimp that are clogged with seaweeds compared to depressions. It turns out that there are few. Therefore, development of an effective breeding reef for lobster is expected.

  Spiny lobster grows in the order of phyllosoma larvae, post-rava (also called Puerurus), juvenile shrimp, and parent shrimp. Of these, post-rava and later live on the sea floor, just like their shrimp. Postlarva drifts in the sea as plankton in the first half, but descends to the bottom in the second half. It has been misunderstood for many years as to where this post-rava landed first (ie where it hides during the day). In other words, it has been speculated that when a prickly pear is harvested, post-rava and juvenile shrimp are rarely mixed, so that it would be hidden in a small seaweed like a prickly pear. Therefore, as described above, fish reefs with artificial seaweed were devised. However, it has been clarified that there are few post-rava and juvenile shrimp that use seaweed as a hiding place, and there are overwhelmingly many hiding in the recesses on the surface of the reef nearby. In addition, the function of the artificial seaweed as a fry shrimp feeding ground has not been confirmed, and artificial seaweed made of nylon etc. must be replaced frequently, which is difficult to maintain and may cause marine debris problems is there.

  In order to secure and grow lobster resources, it is especially important to be able to settle a lot of post-rava, which is the first stage to return to the coast from offshore after spawning. Conventional lobster breeding reefs were devised in an era when knowledge about post-rava bottoming and habitat was insufficient, and of course it was not possible to fully reflect the effective environmental conditions for post-rava. .

  As a result of numerous diving investigations and various test studies, the present inventors have elucidated for the first time that a post-raba is hidden in a hole and seaweed around the hole is used as a feeding ground. In other words, parent shrimp, as is well known, prefers a slightly more open place than a hole, such as a rock gap or a ledge, but post-rava or fry shrimp prefer a hole that fits the body. And, like the hermit crab, the inventor has the habit of moving to a larger hole (a larger hole that fits in the body) from the time of the post-raba every time it peels off and grows into a large shrimp. These studies revealed this.

  Post-rava landing begins when it floats and swims, comes offshore, detects seaweed growing on the reef, and clings to it. The post-rava clinging to the seaweed will then search for holes scattered around the seaweed and move into it to protect against foreign enemies and ensure safety. Even after growing into juvenile shrimp, every molting finds a larger hole and moves to it, avoiding the danger of being attacked by external enemies, and at night climbing on seaweeds near the hole and feeding Tomorrow. Thus, the existence of seaweeds that serve as both landing and feeding grounds and holes of appropriate size according to the growth stage are necessary as conditions for the lobster growth ground.

  By providing these two environmental conditions (holes and seaweeds) in a close enough place so that post-rava and fry shrimp do not require time to find them, a large amount of post-rava and fry shrimp can be collected. It is thought that it will be possible to increase the survival rate.

JP 59-146529 A Japanese Patent Laid-Open No. 2-72814 JP-A-3-277221 JP-A-4-316436 Japanese Patent Laid-Open No. 5-219857 JP-A-6-14673 Japanese Patent Application Laid-Open No. 7-177834 JP-A-9-28230 JP 2001-314134 A JP 2002-125508 A JP 2004-173668 A Japanese Utility Model Publication No. 62-57670 Japanese Utility Model Publication No. 2-36966 Japanese Utility Model Publication No. 2-100459 Japanese Utility Model Publication No. 2-113958 Japanese Utility Model Publication No. 7-7413

  There are a number of patent documents on artificial reefs of lobster. However, in these documents, there is no recognition of the recognition that it is important to settle a large amount of post-rava for the growth of lobster and the invention relating to the artificial reef suitable for landing the post-raba.

  In view of the above situation, the present inventors provide the environment required for post-rava and juvenile shrimp in an ideal state and simplified state than the natural environment, thereby making the post-rava and juvenile shrimp bottomed. As a result of various investigations and researches, the present invention has been completed with the aim of promoting habitat and realizing an increase in lobster resources.

  It is an object of the present invention to provide a new lobster breeding reef that allows post-rava and juvenile shrimp to settle safely and grow, and to provide a new installation method for promoting the growth of lobster using the breeding reef. And

In order to solve the above-mentioned problems, the invention described in claims 1 and 2 is a size expressed by a diameter and a depth on the surface so that post-raba or juvenile shrimp can be changed according to its growth. This is a lobster breeding reef in which a main body portion having one or more side walls each having a plurality of different concave portions is placed on a base portion having a surface wider than the bottom surface of the main body portion.

Further, the inventions described in claims 2 and 3 also have a size expressed by the diameter and depth of the eight levels defined in Table 1 on the side wall surface of the main body according to the growth stage of the post-rava and juvenile shrimp. 3. The lobster breeding reef according to claim 1, wherein the recesses are randomly arranged so that all of the 8 steps of recesses per side wall increase in number as the size of the recess becomes smaller.

  The breeding reef for spiny lobster according to the present invention has a side wall surface in a dim environment favored by post-rava and juvenile shrimp, and a plurality of post-raba and juvenile shrimp that can fit the body according to their growth In addition to having a recess (hole), the seaweed as a feeding area grows near the recess to satisfy both the hiding place and the feeding area. Can grow. In other words, the lobster breeding reef according to the present invention sufficiently satisfies the important points of lobster growth by providing an accurate growth environment for the lobster at the weakest time and increasing the survival rate of post-rava and juvenile shrimp. Can promote the growth of lobster.

  According to the method for installing the lobster breeding reef according to the present invention, post-rava and juvenile shrimp can be sown for a long period of time, so that many juvenile shrimp stay on the seabed or survive. In other words, by installing the lobster breeding reef according to the present invention in or around the algae field throughout the year, the density of the shrimp and the number of inhabitants of the algae field can be increased, so that the sea bottom can be utilized more effectively.

  The lobster breeding reef according to the present invention artificially gives growth environment conditions required for post-rava and juvenile shrimp more than the natural world, and provides an environment that exceeds the average level of the natural world. By increasing the survival rate of shrimp, it can be expected to increase the lobster stock, and can greatly contribute to the lobster fishery.

It is explanatory drawing of an example of the shape of the whole lobster breeding reef and the shape of a side wall and a recessed part which concern on this invention. It is explanatory drawing which shows the structure and shape of the growth reef for lobsters of Example 1. FIG. It is explanatory drawing which shows the state after installing the growth reef for lobsters of Example 1 in the seabed. It is a graph which shows the relationship of the size of the concave part which they used as a hiding place and the former of post-rava and shrimp. It is a graph which shows the relationship between the instep of shrimp and the number of 1st tactile nodes. It is a graph which shows the diameter (left figure) and depth (right figure) of the utilization recessed part seen according to the molting age.

  In FIG. 2, 1 is the whole lobster breeding reef, 2 is a main body, and 3 is a base.

  FIG. 1 is an explanatory diagram of an example of a type other than FIGS. 2 and 3 in the lobster breeding reef according to the present invention. In FIG. 1, the upper diagram shows the shape of the side wall of the main body of the breeding reef, and the lower diagram shows the overall shape of the breeding reef. FIG. 2 is an explanatory view showing the structure and shape of the lobster breeding reef of Example 1 of the present invention, and FIG. 3 is a view after the lobster breeding reef of Example 1 of the present invention is installed on the seabed. It is explanatory drawing which shows the state of.

The lobster breeding reef according to the present invention comprises a main body and a base as shown in FIGS. First, the structure of the main body will be explained. The main body is a block-shaped material made of concrete or the like, as in a normal lobster breeding reef, and has a side wall extending upwardly in an overhang shape. It is necessary to have one or more surfaces. In addition, it is necessary that the surface of the side wall has a plurality of recesses (holes) of different sizes expressed by a diameter and a depth so that the post-rava and the shrimp can change according to their growth. . Further, it is preferable that all or a part of the concave portion is formed so as to be orthogonal to the surface of the side wall (that is, in a direction perpendicular to the surface of the side wall). Furthermore, the main body portion needs to be placed on a base portion having a surface wider than the bottom surface of the main body portion so that seaweed grows in the vicinity thereof. In addition, although the shape of the surface of a side wall is preferable planar shape or substantially planar shape, it is not necessarily limited to these.

  In the lobster breeding reef according to the present invention, one or more of the side walls of the main body portion "extends upwardly in an overhanging manner" means that the upper edge is the lower edge of one or all of the side walls. It is to form so as to protrude forward. In addition, it is preferable that the inclination | tilt angle of a side wall shall be about 40 degree | times or more with respect to the surface of a base | substrate part. In other words, the phrase “the side wall of the main body portion extends in an overhang shape” means that the side wall is formed so that the area of the top surface (ceiling) is larger than the bottom surface of the main body portion. For example, the shapes of the three breeding reef main body portions shown as “overall shapes” in the lower part of FIG. 1 are all included in the category of “side walls extending upwardly in an overhanging manner” in the present invention. . Moreover, the shape of the side wall may be a flat plate shape, a reverse staircase shape, a curved surface shape, or the like, as illustrated in each of the upper drawings in FIG.

  In the present invention, the reason why the side wall of the main body portion is formed so as to “extend upwardly in an overhang shape” is that the side wall is formed in an overhang shape so that the side wall is in a dim environment preferred by post-rubbers and shrimp. It is to do. Therefore, if the side wall of the main body is formed so as to extend in an overhang shape upward, post-rubber and shrimp are likely to gather on the side wall.

  Further, in the present invention, the reason why the whole or part of the recess (hole) on the side wall of the main body portion is drilled so as to be orthogonal to the surface of the overhanging side wall is that the recess is inclined by drilling the recess. This is because the opening is directed downward, the inside of the recess is inclined, and the risk of the inside being buried with sand mud is reduced. That is, if the concave portion is formed in the above structure, the risk of the concave portion being buried and wasted is reduced, and the function of the concave portion can be maintained for a longer period. Examples of drilling the recesses perpendicular to the surface of the side wall are shown in the upper five views of FIG.

  On the other hand, in the breeding reef for lobster according to the present invention, the base portion has a surface wider than the bottom surface of the main body portion, and the main body portion needs to be placed on the surface. That is, the base has a sufficiently wide surface, and when it is installed on the seabed, it is necessary to make it easy to grow seaweed that can serve as a feeding ground for fried shrimp. In addition, although the main surface plays a main role in ensuring the strength near the corner with the side wall surface, seaweed grows here and can serve as a feeding place for fried shrimp. Moreover, although it is preferable that the surface of a base | substrate part is planar shape or substantially planar shape, as long as a seaweed can grow, it is not necessarily limited to it. Furthermore, since the seaweed is easily damaged near the seabed by the influence of sand drift, the base portion preferably has a thickness (height) of 30 cm or more.

In the lobster breeding reef according to the present invention, the surface of the side wall of the main body has a plurality of recesses of different sizes expressed by diameter and depth for the post-rava and juvenile shrimp to change according to their growth. I wear it. In addition, it is preferable to arrange | position a recessed part at random so that a recessed part with a small size may increase in number about one surface of a side wall. More preferably, the recesses on the side walls are randomly drilled so that the number of all the eight-step sizes for each side wall is increased as the recesses are smaller in size, based on the eight-step sizes shown in Table 1. Moreover, although a recessed part should just be an elongate shape, it is preferable that it is a substantially cylindrical shape.

  In the growth reef for lobster, the hole (recess) is an indispensable place for the lobster to protect themselves from external enemies. For nocturnal lobsters, where and how to spend the day, they are eaten and survive, and light and dark are divided. In the case of an improperly sized hole, for example, if the diameter is too large, it is likely to be attacked by creatures that move around and look for food, such as fish and giant clams. That is, if the gap between the body and the hole is wide, the enemy can easily enter from there. Therefore, post-rava and fry shrimp have a high probability of surviving by hiding themselves in a hole of a size that fits the body, and by taking out two large antennas from the entrance, thereby detecting and driving off external enemies. is doing. In the natural sea, this “perfect hole” is not abundant. Therefore, you can see large holes that are easily attacked by foreign enemies, and lobsters that are lurking in the gaps under the stones instead of the holes, but it is considered that the probability of survival of the shrimps is low. Therefore, in order to multiply lobsters, it is important to increase the probability that post-rava and fry shrimp survive by giving a lot of holes that match the body of the post-rava and fry shrimp and are difficult for foreign enemies to enter.

  Naturally, there are few rocks with many such holes in the first place, and the shrimp gradually spread around the surroundings as they shed from the post-rava one after another. The longer the distance traveled, the higher the risk of being attacked by external enemies, and the more dead. If there are larger holes and feeding grounds near the place where the first post-rubber was caught, the movement distance can be shortened, so the survival rate can be expected to be high.

  It is difficult to raise larvae, and it is difficult to mass-produce artificial lobsters. Therefore, in order to multiply lobsters, it is important to keep the seeds of lobsters that nature sowed, that is, the post-rava, from flowing out and to provide an environment for growth.

Next, the preferable installation method of the lobster breeding reef which concerns on this invention is demonstrated.
The lobster breeding reef according to the present invention is installed in the seaweed community (algae field) facing the open sea, where the juvenile shrimp originally lives, or on the seabed in the vicinity. By installing in this way, it is relatively easy to grow seaweed on the surface of the base part and the top surface of the main body part. The installation water depth is preferably shallower than about 20 m. Moreover, in order to avoid that a main-body part breaks, moves or falls, it is preferable to install in the deep water zone which is hard to receive the influence of the wave at the time of a typhoon. However, if it is installed in a toasted area, for example, the sustaining factor of the toasted burning is lack of light due to turbidity, and unless the problem can be solved by the height of the breeding reef, a high effect cannot be expected. Once installed, as a rule, it should be used throughout the year and not moved. However, this does not apply if seaweed does not grow after installation.

Hereinafter, the process of creating Table 1 and the creation method will be described.
The present inventors conducted a diving survey off Chiba, Shizuoka, Mie, Tokushima, Nagasaki, and Kagoshima prefectures, which are the main sea areas where lobsters are distributed, and post lava and fry shrimp are actually hidden. After finding the location, the size expressed by the diameter and depth of the recess (hole) and the size of the post-rava and fry shrimp were measured, and data was collected to create FIG. FIG. 4 is a graph showing the relationship between the lengths of post-rava and fry shrimp and the size of the recesses they used as a hiding place. The present inventors performed statistical processing using the data shown in FIG. 4, and determined the sizes of the eight-level recesses that are considered to be optimal for post-rava and fry prawns. Table 1 was created. In other words, Table 1 shows the sizes of the recesses that can be applied from a post-rubber with a length of about 7 mm to a shrimp with a length of about 30 mm. Table 1 shows, for example, that the recesses in Step 1 have a diameter of 8 mm or more and less than 12 mm and a depth of 22 mm or more and less than 35 mm, and the recesses in Step 2 have a diameter of 12 mm or more and less than 15 mm and a depth of 35 mm or more. It shows that it is less than 40 mm.
In addition, the straight line in FIG. 4 shows a range in which most of the obtained data is included, and the upper is divided into a plurality of blocks at intervals of 2 mm in accordance with the growth of juvenile shrimp. The maximum value and the minimum value are statistically processed and indicated by a straight line.
As a result, it was found that the maximum value Dmax, the minimum value Dmin, the maximum value Lmax of the depth, and the minimum value Lmin of the diameter are expressed by the following equations when the instep length x [mm] is used.
The maximum value of the instep length x is 30.0 mm, and the minimum value is 6.4 mm.
Dmax = 1.70 · x + 12.89
Dmin = 1.15 · x-3.50
Lmax = 4.07 · x + 28.87
Lmin = 2.73 · x-3.70
As is clear from FIG. 4, most of the data exists within the range surrounded by these straight lines, and if a recess having a size within these ranges is formed, there is a high possibility that juvenile shrimps will hide and live. It can be said.

  On the side wall surface of the main body of the lobster breeding reef according to the present invention, the number of recesses is determined for each side wall on the basis of the numerical values in Table 1, and one side wall has all the 8-level size recesses as smaller recesses. What is necessary is just to arrange | position at random so that the number may increase.

  As a result of examining the present inventors in addition to the known information, the present inventors have found that there is a specific relationship between the lobster armor and the number of first tactile nodes, This is summarized in FIG. That is, FIG. 5 is a graph showing the relationship between the shrimp instep and the number of first tactile nodes. In FIG. 5, the symbol type represents each molting instruction (how many moltings have occurred). From this relationship, the molting age of juvenile shrimp in FIG. 4 was estimated, and the diameter and depth values of the recesses used for each molting age were tabulated and statistically processed.

  When the graph of FIG. 5 is plotted for each molting age obtained previously, FIG. 6 is obtained. FIG. 6 is a graph showing the diameter (left figure) and depth (right figure) of the recesses used according to the molting age. That is, FIG. 6 is an aggregation of FIG. 4 for each boundary value of FIG. FIG. 6 reveals the range of the selected size of the recess depending on the growth stage.

Based on the relationship of FIG. 6, out of the concave size for each molting age, in principle, the upper and lower 99% confidence intervals of the average value were defined as the concave size range suitable for each age. However, for example, when the concave size range between adjacent ages overlaps like the upper limit value of the 5th order and the lower limit value of the 6th order, each intermediate value is calculated as a boundary value. Conversely, if the range is far apart and not overlapping, such as the upper limit value of the 6th order and the lower limit value of the 7th order, it is judged that the sample is biased and a certain range is applied to ensure certainty. In order to do so, the intermediate values are also used as boundary values. Table 1 summarizes the size ranges of the recesses thus obtained.

Hereinafter, the structure of the lobster breeding reef according to the present invention will be described in more detail by way of examples.
FIG. 2 is an explanatory view showing the structure and shape of the lobster breeding reef according to the present embodiment. FIG. 3 is an explanatory diagram showing a state after the breeding reef of FIG. 2 is installed on the seabed. In FIG. 2, reference numeral 1 denotes a lobster breeding reef that includes a main body portion 2 and a base portion 3 and is installed on the seabed with the main body portion 2 placed on the base portion 3.

  In FIG. 2, the main body 2 is made of a concrete block material, has a height of 1 m, and has a substantially flat top surface (ceiling) 21. The top surface 21 has a substantially square shape of about 1 m × 1 m, and the bottom surface 22 has a substantially rectangular shape of about 0.5 m × 1.5 m. Both wall surfaces 23, 23 in the longitudinal direction of the main body 2 extend upward from the bottom surface 22 in an overhang shape. In other words, the long wall surfaces 23 and 23 are narrowly narrowed from the position about 0.2 m below the top surface 21, respectively. The wall surfaces 24 and 24 in the short direction descend substantially vertically toward the base 3. That is, in the lobster breeding reef 1 of the present embodiment, only the long wall surfaces 23 and 23 are formed in an overhang shape.

  In FIG. 2, the base portion 3 is made of the same concrete block material as that of the main body portion 2 and has a substantially long plate shape with a height of about 0.3 m and a length of 1.5 m × width of 1.2 m. The main body 2 is placed in the center. The main body 2 and the base 3 may be integrally formed.

As shown in FIG. 2, the side wall 23 and the side wall 23 of the main body 2 have eight levels of recesses (holes) of different sizes expressed by the diameter and depth of one surface, and the number of the recesses increases from a small recess. However, the positions are arranged at random. The eight-level recess is created based on Table 1.

  In addition, it is preferable that all or a part of the concave portion of the same side wall 24 as the side wall 23 is drilled so as to be orthogonal to the side wall 23 and the surface of the side wall 24. By drilling in this way, the concave portion opens obliquely downward, so that the concave portion is inclined and sand or the like is not easily accumulated therein.

Next, a method for installing the lobster breeding reef 1 on the seabed will be described.
A seaweed bed that is shallower than 20 m and faces the open sea is selected as much as possible, and the lobster breeding reef 1 of this embodiment is installed in the center of the seaweed bed. Once installed, it should be installed throughout the year and not moved. However, when seaweed does not settle after installation, it is preferable to move to another place.

  After a while after installation, as shown in FIG. 3, a lot of seaweed grows on the top surface 21 of the main body 2 and the surface 31 of the base 3 of the lobster breeding reef 1. It is a perfect feeding place for shrimp and shrimp. Therefore, post lava and shrimp come together and reach the side walls 23 and 24 of the main body 2 to find the recess that fits your body, enter the recess, and get caught. Post-rava and fry shrimp lurk in the recesses during the day, and when the surroundings darken, they come out of the recesses and treat small animals that live on and around the seaweeds. As a result, there is no need for long-distance movement to catch seaweed, and as a result, the risk of being attacked by external enemies is reduced and the survival rate is extremely high.

  Post-rava and shrimp are one size larger each time they molt, but the body part 2 of the breeding reef 1 according to the present embodiment has eight stages of different sizes on the wall surface that has a concave recess. Since the dents are arranged randomly, the peeled post-rava and fry shrimp can easily find the dent that matches their body from the dents on the same wall, and can immediately replace them . In other words, once the main breeding reef 1 is caught, the distance from the concave portion to the concave portion is very short, so that the risk of being attacked by an external enemy during the movement is remarkably reduced, and the survival rate can be maintained high.

  As described above in detail, the lobster breeding reef according to the present invention has both feeding grounds and hideouts necessary for growth of lobsters in a short distance. In addition to promoting, the distance to move between the hiding place and the feeding place and the moving distance from the hiding place (concave) to the hiding place can be short, and the seaweed that naturally grows on the surface of the main body and the base part is also a hiding place. By covering a certain recess, the risk of being attacked by external enemies is significantly reduced. As a result, the survival rate of post-rava and juvenile shrimp is greatly improved, and the growth of lobster can be promoted. Thus, the present invention is extremely useful for securing lobster resources, and is an epoch-making invention.

Claims (3)

A main body having one or more side walls each having a plurality of recesses of different sizes expressed by a diameter (D) and a depth (L) for the post-rava or fry shrimp to change according to its growth on the surface. , A diameter (D) and a depth (L) are expressed by the following formulas in the breeding reef for lobster, which is placed on a base having a surface wider than the bottom surface of the main body. growth reefs for lobster to be.
1.15 · x-3.50 ≦ D ≦ 1.70 · x + 12.89
2.37 · x-3.70 ≦ L ≦ 4.07 × x + 28.87
Here, 6.4 ≦ x (the length of fry shrimp) ≦ 30.0, and the units of x, D, and L are [mm]. The lobster breeding reef according to claim 1, wherein the number of the concave portions is smaller. On the surface of the side wall of the main body portion, there are provided eight recesses with a diameter and a depth defined as follows depending on the growth stage of post-rava and juvenile shrimp. Item 3. A growth reef for lobster according to item 1 or 2.
One stage diameter 8-12mm, depth 22-35mm
2-stage diameter 12-15mm, depth 35-40mm
3-stage diameter 15-17mm, depth 40-47mm
4 stages of diameter 17-21mm, depth 47-55mm
5 stages of diameter 21-24mm, depth 55-64mm
6-stage diameter 24-29mm, depth 64-78mm
7-stage diameter 29-36mm, depth 78-94mm
8-stage diameter 36-46mm, depth 94-131mm
(Each dimension range does not include the upper limit)