JPH0267205A - Controlling agent against red tide plankton - Google Patents

Abstract

PURPOSE:To obtain the subject controlling agent, containing a carboxylic acid having a 5-24C alkyl group with conjugated double bond, ester or metal salt thereof as an active ingredient, excellent in quick-acting properties against red tide planktons and capable of reducing or eliminating damage thereof. CONSTITUTION:A controlling agent against red tide planktons containing tall oil consisting essentially of eleostearic acid (9,11,13-octadecatrienoic acid), tall oil fatty acid, pomegranate seed oil containing prunic acid, fatty acid thereof, garden balsam seed oil containing parinaric acid, carboxylic acid having a 5-24C alkyl group with conjugated double bond, such as fatty acid thereof, ester or metal salt thereof as an active ingredient. Great damage by red tide planktons in general fishing ground or culture fishing grounds can be reduced or eliminated by using the above-mentioned controlling agent to provided fishing grounds having stable high profit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a red tide plankton control agent for reducing or eliminating damage caused by red tide plankton.

[Conventional technology]

In recent years, the diversification of red tide conditions due to eutrophication in bays and coastal areas, as well as the occurrence of hypoxic conditions, have resulted in reduced feeding, poor growth, or death of farmed fish, which has had a significant impact on the fisheries industry. There is.

In order to solve this problem, it is necessary to control the red tide plankton that causes the problem, but the control agents used for this purpose are: - A powerful control agent that quickly causes the red tide plankton to expel plasma and kills it. - The cost of its use is low; - It does not have a negative impact on marine life other than red tide plankton.
■It is strongly desired that the compound be a biodegradable compound.

Conventionally known red tide plankton control agents include surfactants such as polyoxyethylene laurylamine and polyoxyethylene sorbitan monolaurate.
In addition, in "Marine Natural Products Chemistry" edited by Isao Kitayo, Kagaku Special Issue 1), Volume 1, page 69 (Kagaku Doujin, 1987), 6. 9.
12. It has been disclosed that highly unsaturated fatty acids such as 15-octadecatetraenoic acid, arachidonic acid, eicosapentaenoic acid, γ-lilunic acid, and linoleic acid and their derivatives are effective in controlling red tide plankton.

[Problem to be solved by the invention]

However, none of the above-mentioned known pest control agents can be said to satisfy all of the required properties (1) to (3) above.In particular, the above-mentioned surfactants are inferior in pest control properties, which is the property (2), and cannot meet the intended purpose. In order to achieve this, it is necessary to use a fairly large amount, and in this case, there is a negative effect on marine organisms other than red tide plankton, which is the characteristic of (2), such as increased toxicity to fish.

In addition, some of the above-mentioned highly unsaturated fatty acids and their derivatives have relatively good control properties against red tide plankton, but it still takes a long time to exert effective control, that is, they are not fast-acting. In most cases, it is difficult to achieve the intended purpose unless the amount used is large, taking into account diffusion loss due to tidal currents, etc. Therefore, the same adverse effects as in the case of surfactants cannot be avoided, and this is the cause. It has not yet been put into practical use.

In view of the above-mentioned circumstances, the present invention has been developed to highly satisfy the above-mentioned required properties ① to ②, to have excellent fast-acting properties for controlling red tide plankton, and to reduce or eliminate damage caused by the above-mentioned plankton with a smaller amount of use. The aim is to provide a highly practical pest control agent that can

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the present inventors found that all of the above-mentioned known highly unsaturated fatty acids are unsaturated acids whose double bonds are non-conjugated; We learned that using unsaturated fatty acids with multiple double bonds or their derivatives instead of acids can give very good results in controlling red tide plankton.
The present invention has now been completed.

That is, the present invention provides carbon atoms with a conjugated double bond of 5 to 5 carbon atoms.
This relates to a red tide plankton control agent containing a carboxylic acid having 24 alkyl groups (hereinafter referred to as conjugated unsaturated fatty acid), its ester, or its metal salt as an active ingredient [Structure/effect of the invention] Used in the present invention As mentioned above, the conjugated unsaturated fatty acids have an alkyl group having 5 to 24 carbon atoms with a conjugated double bond, and if the number of carbon atoms in the alkyl group is outside the above range, it is preferable for the control of red tide plankton. This conjugated unsaturated fatty acid, which is difficult to obtain results, may be one type or a mixture of two or more types, and it is also possible to use this conjugated unsaturated fatty acid as the main component, which has saturated fatty acids and non-conjugated double bonds. It may also be a mixed fatty acid in which unsaturated fatty acids are mixed.

In the present invention, in addition to such conjugated unsaturated fatty acids, derivatives thereof such as methanol and ethanol are used.
Various esters may be used, such as esters with alcohols, partial or full esters with polyhydric alcohols such as ethylene glycol, glycerin, and sorbitol (total esters with glycerin include fats and oils such as vegetable oils), Furthermore, various metal salts including alkali metal salts such as sodium salts and potassium salts of the above-mentioned conjugated unsaturated fatty acids can also be used.

Typical examples of such conjugated unsaturated fatty acids, their esters, or their metal salts include tung oil, which is a natural product and whose main component is eleostearic acid (9,1), 13-octadecatrienoic acid). Pomegranate seed oil containing tung oil fatty acid and its hydrolyzate, tung oil fatty acid derivatives such as alkali metal salts of tung oil fatty acid, lower alcohol esters of tung oil fatty acid, and bunicic acid (9,1), 13-octadecatrienoic acid). and its fatty acids and its derivatives, parinaric acid (9,1), 13,15-octadecatetraenoic acid) and its fatty acids and its derivatives, lycanic acid (4-keto-9, Examples include oiticica oil, its fatty acids and derivatives thereof, which contain decadienoic acid (2,4-decadienoic acid), and stillinja oil, its fatty acids, and its derivatives, which contain decadienoic acid (2,4-decadienoic acid).

In addition, as a synthetic product, 2 is synthesized from acrolein.
, 4-pentadienoic acid, 2,4-hexadienoic acid obtained by condensation of crotonaldehyde and malonic acid, and derivatives thereof.

In the present invention, such a conjugated unsaturated fatty acid or a derivative thereof has significantly superior ability to control red tide plankton compared to the known highly unsaturated fatty acid having a non-conjugated double bond or a derivative thereof, and It has been found that it satisfies the required properties (■ to ■) above, and exhibits particularly excellent pesticidal properties even when used in small amounts, thereby avoiding adverse effects on marine organisms other than red tide plankton, such as toxicity to fish. .

The reason for such excellent control properties is not necessarily clear at present, but in the above-mentioned conjugated unsaturated fatty acids or their derivatives, these compounds change the cell membrane of red tide plankton and also cause intracellular damage. This is thought to be due to the fact that it invades and is difficult to be excreted out of the cell, causing plasma extrusion due to swelling of the protoplasm, resulting in rapid death.

In the present invention, in order to apply a control agent containing the above-mentioned conjugated unsaturated fatty acid or its derivative as an active ingredient to the sea surface where red tide plankton occurs, for example, this control agent may be sprayed alone or in the form of an aqueous solution. If the agent is slightly lipophilic, it may be sprayed in combination with an appropriate surfactant, or it may be dissolved in a lower alcohol such as ethanol and sprayed.

The application amount is 100 to 20,000 kg per 1 kd of sea surface, taking into account diffusion due to wave motion and adsorption loss to garbage.
In consideration of environmental pollution and effects on cultured fish, it is particularly preferable to use a small amount of about 100 to 5,000 kg. Furthermore, if the purpose is only to inhibit the growth of red tide plankton, less than 100 kg may be applied.

〔Effect of the invention〕

As described above, by using the pesticidal agent of the present invention, major damage caused by red tide plankton in general fishing grounds and aquaculture fishing grounds can be reduced or eliminated, making it possible to create stable and highly profitable fishing grounds.

〔Example〕

Next, examples of the present invention will be described in more detail.

Example 1 Using 12 wells manufactured by Co5 ter, the following composition was added: Distilled water 1.000 mJN a C
I124.5 g MgSOs ・7H1O4,9g MgC1,・6HgO4,1g KCII 0.75
gCaC1g 1.1)
After injecting 2 mJ each of a physiological experiment medium consisting of gp H-7.9 to 8.0, the following composition was added: Seawater 100 ml N a N
Os 12 m gNatHP
On' 12Hz 0 0.5mgEDTA-F
e 26 μg EDTA-Mn
33 /j gV, B1)
0.1 μg Thiamine-HCj!
lO#gBiotine O,1
Red tide plankton (■ et
erosigma akasiwo) was sown so that the number of red tide plankton was approximately 104/wall.

Next, an aqueous solution containing the red tide plankton control agent of the present invention shown in Table 1 and a surfactant (sorbitan monooleate) was added to this medium, and a physiological experiment test was conducted at 25°C. The final concentration of the red tide plankton control agent in the medium was sflPml, and that of the surfactant was 0.01 ppn+.

In Table 1, the fatty acid compositions of tung oil, tung oil fatty acid, ethyl tung oil fatty acid, and tung oil fatty acid sodium salt are palmitic acid and stearic acid: 5% by weight, oleic acid: 6% by weight, linoleic acid: 6% by weight, Eleostearic acid: 8
It is 3% by weight. In addition, the fatty acid composition of Oiticica oil is
Palmitic acid and stearic acid: 1)%, oleic acid: 6
%, licanic acid: 83%.

Through such a physiological experiment test, changes in red tide plankton were observed using a microscope at predetermined time intervals after the addition of the control agent. The results are shown in Table 1 below, along with the results when only the surfactant was added as a blank test.

Comparative Example 1 The same physiological experimental test as in Example 1 was conducted, except that the red tide plankton control agent shown in Table 1 below was used, and the results are also listed in Table 1. In addition, the fatty acid composition of fish oil, fish oil fatty acid, fish oil fatty acid ethyl fish oil fatty acid, and fish oil fatty acid sodium salt in the control agent used here was as follows: myristic acid, palmitic acid, and stearic acid: 35%, eicosapentaene ta: 15%, and docosahexaenoic acid. :8
%, other years saturated fatty acids: 42%.

As is clear from Table 1 above, the control agent of Comparative Example 1 using unconjugated highly unsaturated fatty acids or derivatives thereof has inferior control properties against red tide plankton, whereas the control agent of Example 1 uses conjugated unsaturated fatty acids or derivatives thereof. It has been found that pest control agents using fatty acids or derivatives thereof can exhibit very good pest control properties with excellent rapid action.

Example 2 The concentration of ethyl tung oil fatty acid, which is the red tide plankton control agent used in Example 1, was 10pp for cocoons and 5pp for cocoons.
pm + lppm + 0.5ppm, 0
．． lppm, 0.05 ppm and 0.01
A physiological experimental test was conducted in the same manner as in Example 1, except that the concentration was changed to ppm. The results were as shown in Table 2 below.

From Table 2 above, it is clear that the larger the amount of ethyl tung oil fatty acid used, the more effective it is, but even a small amount of about 0.1 ppm is effective in quickly controlling red tide plankton.

Claims (1)

[Claims] (1) A red tide plankton control agent containing a carboxylic acid having a conjugated double bond and an alkyl group having 5 to 24 carbon atoms, an ester thereof, or a metal salt thereof as an active ingredient.