Patent Application
20200068898
The present invention is generally directed to chlorophyll water treatments effective for killing or preventing the spread of invasive mussel species.
Dreissenid mussels, also known as Zebra Mussels & Quagga Mussels, are one of the most biological invasive species in North American waters. Zebra mussels are notorious for their biofouling capabilities by colonizing water supply pipes of hydroelectric and nuclear power plants, public water supply plants, and industrial facilities. They colonize pipes constricting flow, therefore reducing the intake in heat exchangers, condensers, fire-fighting equipment, and air conditioning and cooling systems. Navigational and recreational boating can be affected by increased drag due to attached mussels. Small mussels can get into engine cooling systems causing overheating and damage. Navigational buoys have been sunk under the weight of attached zebra mussels. Fishing gear can be fouled if left in the water for long periods. Deterioration of dock pilings has increased when they are encrusted with zebra mussels. Continued attachment of zebra mussels can cause corrosion of steel and concrete affecting its structural integrity.
Containment of invasive mussels can be difficult and cost prohibitive, particularly when the volume of water to be treated is large. For example, a paper company plant located on Lake Michigan spent $1.4 million for removal of zebra mussels from 400 cubic yards near plant equipment. Some current methods of controlling invasive mussels include chemical, bromine, quaternary and poluquaternary ammonium compounds, aromatic hydrocarbons, copper (heavy metal), endothall, zequanox, coatings, UV light, filtration, mechanical, and operational.
What is needed is an improved, low-cost method of treating and controlling the spread of invasive mussel species.
In one embodiment of the present invention, there is provided a method of controlling the spread of an invasive mussel species. The method comprises introducing a nonnative source of chlorophyll to a body of water comprising the invasive mussel species. The nonnative source of chlorophyll is introduced at an amount sufficient to provide a concentration of chlorophyll in the body of water of at least about 10 μg/L.
In another embodiment, there is provided a system for controlling the spread of an invasive mussel species. The system comprises a dosing station. The dosing station is configured to introduce a sufficient amount of a nonnative source of chlorophyll to a body of water comprising the invasive mussel species so as to provide a chlorophyll concentration in the body of water of at least about 10 μg/L.
The present invention is generally directed to methods and systems for killing, preventing, or inhibiting the growth and spread of invasive Dreissenid mussel species, such as Zebra mussels (Dreissena polymorpha) and Quagga mussels (Dreissena rostriformis bugensis), by treating bodies of water comprising the mussels with a nonnative source of chlorophyll. Chlorophyll is a group of green pigments present in cyanobacteria and in the chloroplasts of plants and algae that absorb light for photosynthesis. There are five types of chlorophyll: chlorophyll a, which is present in all photosynthetic organisms except bacteria; chlorophyll b, in plants and green algae; and chlorophylls c, d and e, in some algae. As used herein, the term “nonnative” refers to a source of chlorophyll that is not indigenous or naturally present in the body of water being treated. This can include aquatic and nonaquatic plants and/or other organisms (indigenous or otherwise) that have been artificially modified or processed so as to be in a non-natural form before being introduced to the body of water. For example, leaves, stems, and/or other plant parts may be harvested from aquatic and/or nonaquatic plants and artificially processed to form the nonnative source of chlorophyll. In certain embodiments, the nonnative source of chlorophyll comprises a material selected from the group consisting of cyanobacteria, alfalfa, soy beans, wheat grass, wheat straw, barley grass, mulberry, chlorella, sea weed, fresh water moss, animalia feces, and mixtures thereof. In particularly preferred embodiments, the nonnative source of chlorophyll comprises a material collected from the body of water to be treated. In certain embodiments, the nonnative source of chlorophyll is provided in a form selected from the group consisting of vapor, liquid, paste, powder, pellets, cubes, blocks (both immediate or time release), animalia food, and combinations thereof. In particularly preferred embodiments, the source of chlorophyll is in liquid faun.
Flavoring and other additives may also be mixed with the nonnative source of chlorophyll, for example to encourage drinking by birds and other animalias or to impart preferred consistency and texture. In certain embodiments, the method further comprising introducing a flavoring along with the nonnative source of chlorophyll. The flavoring may be natural or synthetic. The flavoring can be introduced together with or separately from the nonnative source of chlorophyll and may similarly be provided in the form of vapor, liquid, paste, powder, pellets, cubes, blocks, and combinations thereof. In certain preferred embodiments, the flavoring comprises a natural flavoring (such as blended fish or fish meal) that has been mixed with the nonnative source of chlorophyll to be introduced to the body of water. When flavoring is used, the invasive mussels can be killed at a faster rate. Without being bound by any theory, it is believed that the flavoring increases activity and intake of nutrients, including chlorophyll, by the mussels, which leads to increased blockage and suffocation by the filter feeding invasive mussels. Additionally, the nonnative source of chlorophyll may be mixed with natural or synthetic binders, such as cellulose, lignin, and/or other polymer binders.
Methods of controlling the invasive mussel species comprise introducing the nonnative source of chlorophyll to a body of water comprising the invasive mussel species. The body of water may be an open or closed water system and may be internal or external environment. The body of water may include, but is not limited to, lakes, reservoirs, ponds, streams, rivers, processing facilities, and aquariums. As used herein, the “body of water” may refer to the entirety of the water contained within the system or only a localized portion of the water within the system, for example a localized portion of the water in the surrounding water proximate to the invasive mussel species. The body of water may also comprise one or more structures submerged in the body of water including, but not limited to, piping, pumps, inlets, outlets, ballast, piers, boats, and other structures both manmade and nature made. The body of water may also comprise natural and non-natural structures including, but not limited to, wood, cement, hard surfaces, mud, and remains of other mussels. Invasive mussel species often aggregate and grow on one or more of the above-noted structures in the body of water, and thus the nonnative source of chlorophyll is preferably introduced to the body of water at a location proximate to such structures.
The nonnative source of chlorophyll may be introduced to the body of water by a variety of methods including, for example, pouring, spreading, or spraying the nonnative source of chlorophyll onto the surface of the body of water, or injecting the nonnative source of chlorophyll into the body of water below the surface. In other embodiments, for example when the nonnative source of chlorophyll is provided as an animal food, the nonnative source of chlorophyll may be introduced to the body of water by feeding the nonnative source of chlorophyll to an animalia and allowing the animalia to defecate at a location proximate to the invasive mussel species.
The amount of nonnative chlorophyll introduced to the body of water can depend on a number of factors. In certain embodiments, the nonnative chlorophyll is introduced to the body of water so as to provide a chlorophyll concentration in the body of water at a concentration of at least about 10 μg/L. In certain embodiments, the nonnative chlorophyll is introduced to the body of water so as to provide a chlorophyll concentration in the body of water at a concentration of about 10 μg/L to about 900 μg/L, preferably about 15 μg/L to about 50 μg/L. Additionally, the chlorophyll concentration and duration of the treatments can be selected so as to provide effective short-term or long-term kill. In certain preferred embodiments, the nonnative chlorophyll is introduced to the body of water so as to provide an average chlorophyll concentration in the body of water over the duration of treatment of about 15 μg/L to about 25 μg/L for about 3 to about 4 days. In certain preferred embodiments, the nonnative chlorophyll is introduced to the body of water so as to provide an average chlorophyll concentration in the body of water over the duration of treatment of about 20 μg/L to about 40 μg/L for about 1 to about 2 days. In certain preferred embodiments, the nonnative chlorophyll is introduced to the body of water so as to provide an average chlorophyll concentration in the body of water over the duration of treatment of at least about 40 μg/L for less than about 24 hours. Saturated concentrations of chlorophyll may also be used, depending on factors such as the presence of aquatic life and urgency of remedy. For example, the nonnative source of chlorophyll may be introduced so as to provide upper hypereutrophic levels of chlorophyll when aquatic life is not of concern. Additionally, in highly infested bodies of water (i.e., with a large number of zebra mussels within an area), greater concentrations of chlorophyll may be needed to achieve sufficient kill. Therefore, in certain embodiments, the nonnative chlorophyll is introduced to the body of water so as to provide a chlorophyll concentration in the body of water at a concentration of at least about 100 μg/L, or preferably at least about 200 μg/L.
The efficacy of the treatment methods can be dependent on several variances including, but not limited to, water temperature, salinity, toxins, oxygen level, age of mussels, current flow, turbidity, and pH. For example, older mussels can be killed at lower chlorophyll doses. The turbidity and pH of the water can impact both the efficacy of controlling invasive mussels as well as the survival of desirable aquatic life. In certain embodiments, the turbidity of the body of water is maintained at about 5 to about 500 ppm. In certain embodiments, and pH of the water is maintained at about 7 to about 8.
As noted above, the nonnative source of chlorophyll can comprise a material collected from the body of water to be treated. Therefore, in certain embodiments, the methods further comprise collecting an aquatic plant and/or algae material from the body of water and artificially processing the material before introducing the material into the body of water as the nonnative source of chlorophyll. For example, in certain such embodiments, the collected aquatic plant and/or algae is ground or blended into particulates. This artificial processing advantageously allows for increased exposure of the chlorophyll content within the plant or algae when re-introduced into the body of water. The artificial processing may further comprising mixing the material with flavorings or other additives, as discussed above, before re-introducing the material to the body of water.
In certain embodiments, the method further comprises monitoring the chlorophyll concentration of the body of water. The monitoring can be performed with a permanent monitor (e.g., installed at a permanent location in the body of water) or by intermittent manual readings. Monitoring the chlorophyll concentration at the body of water can be used to determine the amount and intervals of treatments with the nonnative source of chlorophyll to maintain a predetermined chlorophyll concentration to effect kill or prevention of the invasive mussel species.
Embodiments of the present invention are also directed to systems for controlling the growth and spread of invasive mussel species. The systems generally comprise a dosing station configured to introduce the nonnative source of chlorophyll (and any additional components described above) to the body of water. In certain embodiments, the system further comprises a chlorophyll concentration monitor residing in the body of water and configured to measure the concentration of chlorophyll at a location in the body of water. The dosing station can comprise a reservoir for storing the nonnative source of chlorophyll and an outlet for introducing the nonnative source of chlorophyll to the body of water. The outlet can be configured to introduce the nonnative source of chlorophyll, for example, by pouring, spreading, or spraying the nonnative source of chlorophyll onto the surface of the body of water, or injecting the nonnative source of chlorophyll into the body of water below the surface. The outlet may also be configured to provide an animalia feed comprising the nonnative source of chlorophyll to or around the body of water for consumption by animalias such as fish and waterfowl. The monitor may be any of a variety of chlorophyll concentration monitors known in the art. The system may further comprise a controller in communication with both the monitor and dosing station. In use, the controller instructs the dosing station to introduce an amount of the nonnative source of chlorophyll to the body of water so as to maintain the chlorophyll concentration in the body of water at a predetermined level as measured by the monitor. The dosing stations can be located anywhere that mussel kill or prevention is desired. In particular embodiments, the dosing station is located at one or more fresh water inlets. This allows chlorophyll concentrations to maintain necessary high levels where lower levels of chlorophyll are generally present.
The particular form of the nonnative source of chlorophyll can be selected based on certain advantages for certain applications. For example, artificially modified or processed aquatic plants (e.g., grass or leaf plants) and/or algae may be advantageous so as to not inadvertently introduce other potentially invasive organisms to the body of water. Additionally, a plant leaf source compressed into a formation releases at a slower rate than powder or liquid forms, and thus such a source may be advantageous for slow-release applications. Spirulina and chlorella have a stronger affinity for osmosis into water than grasses or leaf substances with, and leaf substances seem to be eaten by fish more readily. Thus, in particular embodiments, the nonnative source of chlorophyll comprises spirulina and/or chlorella. In certain embodiments, the nonnative source of chlorophyll excludes grass and/or leaf plants. Chlorella has a higher concentration of chlorophyll than spirulina, which can be advantageous for closed areas, such as piping and equipment. Additionally, spirulina is larger in size than chlorella. Therefore, in certain embodiments, the nonnative source of chlorophyll comprises a mixture of chlorella (for smaller mussels) and spirulina (for larger particles and larger mussels). This mixture may also comprise a leaf source (such as alfalfa) that aquatic life readily consumes. Such a mixture can provide a multi-faceted approach to controlling the spread of invasive mussels. Mixtures of spirulina and alfalfa pellets were particularly advantageous for treatments in areas with aquatic life, as fish, snails, and insects can survive in high chlorophyll levels (30 μg/L-35 μg/L) when such mixtures are used.
In certain embodiments, the nonnative source of chlorophyll does not comprise heavy metals, such as copper, commonly used in prior art treatment methods. Heavy metals can be precursors to several neurological conditions and concentrations can increase over time in bodies of water treated with prior art methods. Therefore, in certain embodiments, the methods and systems advantageously do not comprise introducing a heavy metal to the body of water. Additionally, the use of pesticides has known and possibly unknown health risks to humans. Therefore, in certain embodiments, the methods and systems advantageously do not comprise introducing a pesticide to the body of water.
Additional advantages of the various embodiments of the invention will be apparent to those skilled in the art upon review of the disclosure herein and the working examples below. It will be appreciated that the various embodiments described herein are not necessarily mutually exclusive unless otherwise indicated herein. For example, a feature described or depicted in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the present invention encompasses a variety of combinations and/or integrations of the specific embodiments described herein.
As used herein, the phrase “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing or excluding components A, B, and/or C, the composition can contain or exclude A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.
The present description also uses numerical ranges to quantify certain parameters relating to various embodiments of the invention. It should be understood that when numerical ranges are provided, such ranges are to be construed as providing literal support for claim limitations that only recite the lower value of the range as well as claim limitations that only recite the upper value of the range. For example, a disclosed numerical range of about 10 to about 100 provides literal support for a claim reciting “greater than or equal to about 10” (with no upper bounds) and a claim reciting “less than or equal to about 100” (with no lower bounds).
The following examples set forth various specific treatment methods for killing zebra mussel colonies collected from an infested lake. It is to be understood, however, that these examples are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention.
Items and brands used for testing that were bought were: Chlorella, NOW Foods, Alfalfa Powder, NOW Foods, Certified Organic Wheat Grass, NOW Foods, Organic Spirulina Powder, Sunny Green Products, Barley Grass Bulk Powder, Nature's Way Brands, LLC, Wheat Grass Tablets, Sunny Green Products, Fresh Alfalfa Hay, Fresh Soy Bean Plants and Wheat Straw.
During the tests below, readings of chlorophyll concentration were taken 30 to 60 minutes after adding substances to either lake water or distilled water, unless indicated otherwise.
Locating a small body of water with an infestation of Zebra Mussels, a rock was collected having a colony thereon and placed in an aquarium with fish. After a couple days, the water had become extremely clear, which was different than when 10 gallons of water was originally retrieved from the body of water where the zebra mussels were retrieved. The mussels were fed a chlorophyll-based food, spirulina, by adding a heaping table spoon into the 10-gallon fish tank. The amount of spirulina was enough to turn the water dark/bright green. A few days later, the mussels were open (indicating death). At 7 days, the tank was a smell of worsening debris. The fish had died, likely due to the sudden change in the living environment. The water was drained, and the sample drenched in high concentration of bleach until the shells were bleached out.
Additional colonies of zebra mussels were collected and fed several other plant-based products comprising chlorophyll. Chlorophyll sources tested included: wheat grass, alfalfa powder, barley grass, chlorella, dried soy bean leaves, dried alfalfa leaves, and Spirulina. All zebra mussels died similar to Example I above. It was determined that the chlorophyll of the plant-based products was killing the zebra mussels.
Chlorophyll levels were measured at locations in bodies of water that were known to be completely infested, partially infested, and not infested (thought to be non-infested because no boating activity allowed). Fluorescence readings taken to estimate chlorophyll levels were as follows:
Further lab testing was performed to measure the effect of chlorophyll concentration on killing zebra mussel colonies. A Fluorosense Meter from Turner Designs was used to determine the actual readings that had been used previously by measuring both grain weight and μg/L presence of chlorophyll. Material used to calibrate was also obtained, Fluorosense Chlorophyll Standard Solution, provided by Turner Designs, P/N 2860-220. Equipment included: 1-50-gallon aquarium, 1-10-gallon aquarium, 40×-600× microscope, 3.5×-90× microscope, hydrometer, test tubes, numerous air and water pumps, precision (grain) and bulk pounds' scales, food blenders, ECO Testr Turbidity Meter, HM Digital pH Meter, Turner Designs Flurosense—Chlorophyll Meter, Microscope Camera, 22 1-gallon fish bowls, 15 5-gallon buckets, 2 65-gallon barrels and numerous miscellaneous equipment.
Several tests were performed by measuring weights of products to determine death prior to receiving equipment to evaluate the estimated chlorophyll levels in μg/L, giving the bases to follow up on using the meter readings. The chlorophyll concentrations and turbidity resulting from 12 grain (weight) of various products added to 2 liters of distilled water are provided in Table 1 below.
Various sources of chlorophyll were tested at various concentration ranges by placing live colonies of zebra mussels in 1-gallon containers filled with either lake water (having average chlorophyll concentration of 1 to 3 μg/L) or distilled water. The source of chlorophyll was then added to the container and dissolved. The time required to kill the zebra mussel colonies was determined by tapping the open mussels and observing the response. The results are provided in Tables 2-9, below.
Chlorella
Chlorella
Chlorella
Chlorella
Chlorella
Chlorella
Chlorella
It should be considered that fish are able to tolerate higher levels of chlorophyll if introduced through a time period, instead of a sudden influx to reach the chlorophyll level for zebra mussel death. Additionally, it was observed in the study above that leaf plants seem to have a greater impact on controlling mussels than grasses. Leaf plants are considered a benefit to aquatic life because leave plants are most often considered better food sources for fish.
Some prior art has suggested that zebra mussels may be killed by ducks and geese, for example by ingesting the mussels. Visual observation was performed along lake shores where water fowl moved their habitat around the lake because of grass and clover. The zebra mussels were dead in the areas of travel, but not in the immediate vicinity of the waterfowl. Notably, the shells of the zebra mussels were still intact and attached. This would suggest that the mussels were not eaten by the waterfowl. Additionally, the zebra mussel deaths did not appear due to foot traffic of the waterfowl because the depth of water exceeded the capability of foot contact. Further observation noticed a green tint to the defecation left on the shore. Based on these observations, waterfowl defecation was tested for chlorophyll levels and use for killing zebra mussel colonies.
Fresh waterfowl defecation was collected and placed in distilled water to discover readings of chlorophyll above 199 μg/L. Placing zebra mussels in this water resulted in death within less than 24 hours. See Table 10 below.
Following the results above, additional waterfowl defecation was collected. The dried defecation was dissolved until a 40 μg/L estimated chlorophyll concentration was obtained. At that time, a rock with a colony of zebra mussels was placed in the body of water, along with a bubble stone for an oxygen source. Within 20 hours, the zebra mussel population was dead. See Table 11.
Notably, spiral snails collected while collecting zebra mussels had no response to the higher chlorophyll levels. Passing CO2 gases through an air stone into the chlorophyll concentrations did not have any effect on the chlorophyll readings.
A quart container of a mixture of alfalfa pellets, alfalfa powder, spirulina powder and sugar was placed in a lake near shore line. Weather conditions were windy with water craft waves hitting the shore line. Later in the day (approximately 2 hours), rain fell. The test was still considered successful, as the zebra mussels in the immediate area were found to be unresponsive 7 hours later and still unresponsive 30 hours later. This suggests that high saturation for short periods of time can be effective for killing zebra mussels.
Additional lab testing was performed with water extracted from a lake. Water extracted from the lake with chlorophyll concentrations averages of 20 μg/L to 25 μg/L resulted in death in less than 48 hours, although the chlorophyll concentration level had to be rejuvenated as the chlorophyll levels dropped during the period. Readings taken over the 48-hour period were:
25 μg/L (lake water);
9 μg/L (24 hours);
20 μg/L, (reading after low levels of chlorophyll was replaced); and
7 μg/L (at the end of 48 hours).
This resulted in death in less than 48 hours after introduction. Based on this, it is believed the chlorophyll concentration can determine an estimated time for death, for example: 15-25 μg/L for 3 to 4 days of exposure; 20-40 μg/L 1 to 2 days of exposure; and above 40 μg/L for less than 24 hours.
Initial observations in Example VII were run using lake water, but there was some concern with variations in results. Tests were run with both lake water and distilled water to confirm consistency and also to confirm that the combination of material in the lake water was not creating an unknown chemical reaction that could be killing the ZMs. Therefore, a similar study was performed in distilled water and a comparison found that distilled water provided the same results.
Blended fresh soy bean leaves were added to distilled water at an estimated concentration of 150 μg/L & 10 ppm turbidity. A colony of zebra mussels were added attached to a rock. After 24 hours, there was response from partially opened zebra mussels. Time to kill was approximately 36 hours. See Table 12.
Evaluated mixtures of alfalfa powder of 20 grain per gallon and 20 grain and 4 grain sugar. Later in the day, the alfalfa/powder mixture resulted in zebra mussels open slightly but responsive to touch, while alfalfa powder only resulted in zebra mussels not open upon observation. See Table 13.
Additional testing was performed, as described along with the results in Table 14, below.
Controlled specimens of zebra mussels were placed in both lake water and distilled water with recirculation pumps. The group with lake water was replenished with lake water as evaporation occurred. Distilled water was replenished with distilled water as needed. Zebra mussels lasted approximately 4 weeks in the distilled water, while zebra mussels lived for 6 to 8 weeks in the lake water environment. It is believed that starvation occurred with the distilled water, while the replenishing of lake water provided some nutrients.
Additional testing was performed to study the effects on water and mussel kill of various treatments.
Kill testing was performed using 20 grain of various treatments in 2000 ml of distilled water. Table 15 shows the treatment type, the high/low chlorophyll concentration over 48 hours of testing (variation due to due to break down of material and cell rupture when hydrated), and the zebra mussel time to death (in hours).
Testing was performed to determine water conditions using 20 grain of various treatments in 2000 ml of distilled water. Table 16 shows the treatment type, the high/low chlorophyll concentration over 48 hours of testing (variation due to due to break down of material and cell rupture when hydrated), turbidity, and pH.
Kill testing was performed using differing grain weights of various treatments in 2000 ml of distilled water. Table 17 shows the treatment type, the high/low chlorophyll concentration over 48 hours of testing (variation depended on stirred or settled), chlorophyll flotation, pH, and the zebra mussel time to death (in hours). See Table 17.
Testing was performed to determine the radiation benefit of chlorophyll being present in a body of water. As shown in Table 18, below, chlorophyll treatments increased the temperature of the water when exposed to sunlight. Higher levels of chlorophyll would not only absorb more energy in the winter, but also it provides more oxygen to the environment.
During the above testing described in Examples I-XIII, additional observations were noted and are summarized below:
Fresh water moss was collected from a lake infested with zebra mussels, and the moss was surrounding, floating above, and touching the zebra mussel colonies. The fresh water moss was collected and processed in a blender, similar to what was done with leaves in the examples above. Three treatment samples were prepared, with one flavored with anchovy. The three samples were added to separate bodies of water at approximately 7:00 pm. This resulted in chlorophyll readings greater than an estimated 199 μg/L at 8:00 pm. By 5:00 am the following morning, there were no responses by the open zebra mussels. Additionally, the chlorophyll level readings were 199 μg/L, 144 μg/L and 113 μg/L; it seemed that the number of Zebra Mussels within each container determine the final chlorophyll levels. Notably, spiral snails collected survived testing.
