JPH045406B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention is a method for killing young shellfish, etc. from a surface that has become attached to a surface and has become in a state where no seaweed can grow over time (rocky shore burn). At the very least, it is easy to move the board so that it can be restored to a new surface over time.
Furthermore, the present invention relates to an artificial reef that is designed to increase stability and enhance the fish-attracting effect of the reef.

<Conventional technology and its problems> In general, fishing grounds (pronounced ``Giyojiyo''. ``Giyoba'')
It is different from. same as below. ) means that there are a large number of aquatic organisms living in a certain water area, or they stay there for a while, or new groups appear one after another even after passing through, and there are a large number of them during a certain period of time. It refers to a body of water where fishing can be done using appropriate methods, and where the cost and effort are sufficient to compensate for the amount of catch. All fish and other aquatic organisms live in their own suitable environments, so they naturally flock together, but their range is quite wide, and in order to form a particularly dense community and create a good fishing ground, they must hunt for food and There are two motives for spawning. Animals search for food, so if there is a large amount of food in a given body of water, many flocks will flock to it, and this phenomenon occurs as follows. That is, seawater,
Various elements are dissolved as compounds in both land and water, but floating microscopic algae (phytoplankton) tend to lack nitrogen, phosphorus, and silicic acid to breed, and they thrive in areas where these elements are abundant. It happens. This component is called nutrient salt, and is an important factor that influences the reproduction of phytoplankton. Dead animals and plants sink to the ocean floor, decomposing and producing large amounts of nutrients. However, plants use sunlight to assimilate carbon, so they can only reproduce on the surface of the ocean where sunlight can penetrate, and the nutrients in the deep ocean floor cannot be used as they are. Therefore, the best way for phytoplankton to thrive and make good use of nutrients on the seabed is in shallow areas, or in places where vertical mixing of water occurs and nutrients from the seafloor can rise to the surface. Such places include inner bays, shallow coastal areas, continental shelves, islands, reefs and rapids, and tidal boundaries where cold and warm currents meet, where ocean currents blow up from below or create whirlpools that disturb the water. is responsible for supplying nutrients to the surface layer. When phytoplankton breeds well in such places, zooplankton that feed on them breed, and fish and other species that feed on these plankton gather, creating good fishing grounds. This is also the reason why fishing grounds can be predicted to some extent based on topography and ocean current conditions. Fish and other species then flock to the spawning grounds, and along the way, the spawning grounds become good fishing grounds. This phenomenon occurs when large schools of salmon and trout swim up to rivers to spawn, and when herring flock to shallow coastal areas where algae grow and spawn.

Therefore, in order to increase the yield of seafood and seaweed, some artificial activities are added to fishing grounds to improve fishing grounds. Its aim is the same as that of proliferation, but it is an expression with a broader concept than that. In other words, breeding is a concept that focuses only on the target organisms, while fishing ground improvement is based on the idea that in order to increase the catch, it is important to first improve the environment to make it a better place for fish and shellfish to live. ing.
Therefore, there are a wide variety of means and methods for improving fishing grounds, depending on the purpose, ranging from small-scale methods that can be carried out using only human labor to large-scale methods that use modern construction machinery. In the old days, methods of cutting mountain rocks and dumping them into the ocean floor in large numbers of 40 to 50 cm cubes and stacking them in a two-dimensional or three-dimensional structure, or sinking abandoned ships were also used. However, recently, instead of natural rock, concrete workpieces molded into various shapes depending on the purpose are increasingly being used. However, the reality is that the growth of aquatic plants on this concrete artificial fish reef is highest in the first year of use, and that growth gradually decreases over time. This is commonly referred to as ``shore burn,'' but in order to increase the settlement efficiency, the surface of the artificial reef must be cleaned every year, and in particular, the shellfish that have adhered to the surface must be removed. However, this is an extremely difficult task, and it is almost impossible to easily lift the artificial reef above the sea, which means that the work must be done underwater, and this trend is even more serious. be. Furthermore, even if we expected the highest efficiency in the first year, it would be economically unfeasible to damage it from the second year onwards, so we decided to leave the concrete artificial fish reef as it is, and only treat its surface with some kind of treatment. In other words, it is only necessary to make it replaceable depending on the method.

Therefore, the inventor of the present invention previously proposed that the surface of a concrete artificial reef b formed into a desired shape with water holes a as shown in FIGS. Developed a surface covering device for artificial fish reefs in which a cap body c formed of a material is removably fixed, and only the cap body c is replaced, thereby creating a new surface for aquatic plants to grow on. However, according to this, the cap body c on the artificial reef b had to be replaced every year, which turned out to be no easy task considering that this work was to be done underwater. Therefore, in order to solve the above-mentioned problem, the present inventor separately created a hole a as shown in FIGS. 6 and 7.
If a plurality of plate bodies d having a desired shape with holes are movably stacked closely together in the horizontal or vertical direction, and the surface of the stacked plate bodies d becomes ``sea-burned'',
By moving this to a nearby area and repeating this process one after another, making sure to bring another board into close contact with the ``rock-burned'' surface, the shellfish attached to the ``rock-burning'' part will die over time. In this case, when each plate d was moved as described above, it was necessary to stack them correctly. However, considering that the work is carried out underwater, it is difficult to say that correct positioning can always be achieved.

In addition, as shown in Japanese Utility Model Application Publication No. 59-163371, one side edge of a plurality of plates is rotatably connected with a ring or the like, and they are stacked closely together, making it look like turning the pages of a book. There is a device that allows the plate to rotate, but according to this, it is certainly ``Isoyake''.
Even if it is possible to respond to this problem, it does not have the effect of attracting fish as a fish reef.

Past experiments have also revealed that fishes have color preferences. For example, there is the following experiment conducted by Nobuyuki Kawamoto (see ``Fish Physiology'' by Nobuyuki Kawamoto, published by Ishizaki Shoten in 1957). In other words, in a device that distributes various colored lights, he considers the color of light that fish attracts the most to be the color that fish prefer, divides a circular aquarium into eight fan-shaped rooms, and fills these eight rooms with white and It is divided into 8 colors using red, orange, violet, green, blue, indigo, and purple filters, and each room is equipped with a 60W light bulb, and the intensity of the light is adjusted with blackout paper, so that the water surface in each room is 50 Lux. The fish were released into the tank and the number of times they entered each colored room was measured. The fish used were mainly juvenile marine fish such as stonefish, filefish, Japanese Spanish mackerel, tiger puffer fish, Japanese barracuda, eel, mullet, medina, and killifish with a body length of 2 to 15 cm. The results showed that most fish tended to enter the blue and green rooms, and only the noctilucent eel entered the red and purple rooms.The conclusion was that these experimental fish, excluding the eel, tended to enter the blue and green rooms. It has been found that there is a tendency to prefer

<Means for Solving the Problems> Therefore, in order to solve the above-mentioned problems, the artificial fish reef according to the present invention has a plurality of plates colored in fish-friendly colors and having a desired shape and having a rough surface. One side edge is rotatably connected with a ring or the like so that they are closely stacked, and a hole is drilled in the plate that communicates with the plate in the stacked state as described above, so that it looks like The plates are rotated like turning the pages of a book, and after each rotation, each rotated plate is stacked closely together, and by providing an escape area for fish, it can be used as a fish reef. It is designed to increase the effect of attracting fish.

<Example> Next, an example of an artificial fish reef according to the present invention will be described based on the drawings. Reference numeral 1 denotes a plate having holes 2 and a rough surface. The shape of can be either quadrilateral or triangular, and the shape is not a problem. Further, although the plate 1 is planned to be molded from concrete, it may also be made from metal. And this plate 1 is
A plurality of these are stacked closely together so that they can be moved. To stack them, vertically, as shown in the figure.
That is, it may be in the vertical direction or in the horizontal direction. In short, when stacking them, they just need to be in close contact with each other. Further, the hole 2 is
The holes 2 are drilled so that they communicate with each other when the plates are stacked as described above, and this communicating hole 2 forms a space that serves as an escape location for fish. That is, by making the holes 2 communicate as described above, even if the individual plates 1 are thin, the holes 2 as a whole become a deep space. Reference numeral 3 denotes a ring in which one side edge of each plate 1 is rotatably connected in a stacked state, and by connecting the plates 1 with this ring 3, the plate 1 becomes like a book. It will be formed. Reference numeral 4 denotes a locking portion provided on a part of the plate 1 on the opposite side of the ring 3.

<Operation> However, in the first stage, all the plates 1 are stacked one on top of the other. Then, aquatic plants are allowed to grow on the surface of the stacked plates 1. And since this settlement rate is very efficient even in the first year,
One year after use, one of the plates 1 is rotated through the ring 3 as if turning over the pages of a book. At this stage, the book appears to be open, a new surface emerges, and new aquatic plants grow on this surface. It is a good idea to collect these flourishing aquatic plants. By repeating this, it becomes possible to expect the settlement rate in the first year of each year, and by rotating the plate 1, the surface that has already been ``rock-scorched'' is transferred to the ``shore-scorched'' surface of the other plate 1. ” By adhering to the surface,
The roots or young shellfish of aquatic plants die over time. Further, in order to rotate the plate 1, a wire may be connected to the locking portion 4 from above the ship to be towed. Also, plate 1
By planting seeds in the water, aquatic plants will actively develop. This allows phytoplankton to propagate, and since the plate 1 is painted in a color that favors fish, fish are attracted to the reef and come closer to the reef.

Zooplankton that feed on phytoplankton also proliferate, and eventually the area becomes a water area inhabited by fish and shellfish, that is, a fishing ground. In this way, in order for aquatic plants to grow epiphytically, it is possible to expect even greater effects by molding the plate 1 with concrete and making the surface rough or foaming, and also to prevent the epiphytic plants from growing on the plate 1. Since there are also kelp, seaweed, etc., other effects such as the proliferation of these will also occur.

<Effects of the Invention> As described above, according to the artificial reef according to the present invention, one side edge of a plurality of plates of a desired shape, which are colored in fish-friendly colors and have roughened surfaces, is rotated with a ring or the like. In addition to movably connecting and stacking them closely,
Since holes are drilled in the plates that communicate with each other when they are stacked as described above,
A state in which the plates are rotated as if turning the pages of a book, and after the rotation, each rotated plate is properly stacked tightly together, and seaweed does not grow over time due to the attachment of young shellfish, etc. From the surface that has become (shore-scorched),
In addition to the effect of killing the young shellfish etc. and restoring it to a new surface over time,
By providing an escape area for fish, the effect of attracting fish as a fish reef can be increased, and it is also possible to transform the area into a rocky reef area by submerging it in a place that is traditionally sandy. will also have a great effect.

[Brief explanation of drawings]

The drawings show an embodiment of the artificial reef according to the present invention, in which Fig. 1 is a perspective view, Fig. 2 is a side view, and Fig. 3 and subsequent figures show conventional examples. Fig. 4 is a perspective view of the cap body, Fig. 5 is a perspective view of the cap body covering the artificial reef, Fig. 6 is a perspective view showing a conventional example using a plate body, Fig. 7 6 is a perspective view showing another example of FIG. 6. FIG. 1... Plate, 2... Hole, 3... Ring, 4...
Locking part.

Claims (1)

[Scope of Claims] 1. One side edges of a plurality of plates of a desired shape, which are colored in fish-friendly colors and have roughened surfaces, are connected rotatably with a ring or the like, and stacked closely together,
An artificial reef characterized in that a hole is bored in the plate body so that the plate body communicates with the plate body when the plates are stacked as described above. 2. The artificial reef according to claim 1, in which the plate body is made of concrete. 3 Claim 1 in which the plate is made of foam
Artificial reef as described in paragraph 2 or paragraph 2.