Algae Control

Harvesting

Explosive Algal Bloom - March 2006

Having more than sufficient nutrientsAny food, chemical element or compound an organism requires to live, grow, or reproduce. to hand, the bloomA rapid growth of microscopic algae or cyanobacteria in water often resulting in a coloured scum on the surface. in March, 2006, was unrestrained,. That the algal bloom in March, 2006, occurred at all, speaks against the effectiveness of the only mechanism currently in use for its “control”. Mechanical harvesting is effective for improving the situation, but it cannot eliminate the threat to the ecosystema community of organisms, including humans, interacting with one another and the environment in which they live. posed by the algae. Areas of the Bay once freely covered with eelgrassA marine plant with long ribbon-like leaves. [Zostera marina.], or, a submerged aquatic plant with narrow, grass-like leaves. [Genus Valisneria.] and nyad are now bare of aquatic plants, smothered by algae or harvested along with it.

Events also have served to pollute the spring out flows into Crystal River / Kings Bay with consequent increases to the potency of the nutrient cocktail. Catastrophes have happened too, not only naturally, according to weather and fire over the centuries, but also from chemical applications to bring invasive or nuisance aquatic plant speciesA taxonomic category subordinate to a genus (or subgenus) and superior to a subspecies or variety, composed of individuals possessing common characters distinguishing them from other categories of individuals of the same taxonomic level. In taxonomic nomenclature, species are designated by the genus name followed by a Latin or Latinized adjective or noun. under control. Herbicides such as 2, 4D, sulphuric acid, diquat, copper sulphate were applied to “control” water hyacinth, milfoil, elodea, water lettuce and hydrilla, with the result that copper residuesWhat is left over or remains; the part of a molecule that remains after portion of its constituents are removed. Residues of some contaminants may remain after now exist in sediments (Leslie, 1992). Nakanishi et. al., in 2004, reported that heavy metal contamination (including copper) contributed to cyanobacteria Bacteria that have the ability to photosynthesize. growth, such as Lyngbya sp. which is highly resistantThe ability of an individual or community to resist being changed by potentially disruptive events. to herbicides (Hawlesby, 1977). These herbicide practices stopped when the USFWS reported copper traces found in stomachs of dead manatee.

Chemical Applications as Algae Control

Algicides and herbicides have long been known which can target and eliminate particular species of algae and SAV. The dangers of attempting this are several. Widespread application of chemical compounds induces ecologic shock as the dying vegetation and algae deplete supplies of dissolved oxygenMeasures the amount of gaseous oxygen dissolved in an aqueous solution. Oxygen gets into water by diffusion from the surrounding air, by aeration (rapid movement), and as a waste product of photosynthesis. needed by other SAV, fish and wildlife feedstock. Some algicides which attack cyanobacteria Bacteria that have the ability to photosynthesize. , can kill off hydrilla, an invasive nuisance, but also a manatee feedstock which in many places has displaced the traditional eelgrassA marine plant with long ribbon-like leaves. [Zostera marina.], or, a submerged aquatic plant with narrow, grass-like leaves. [Genus Valisneria.] feedstock. Many other SAV foods for the manatee could also succumb to algicide treatments. Accidental releases of chemicals in course of application harm humans and the ecosystema community of organisms, including humans, interacting with one another and the environment in which they live. . As mentioned above, harmful residuesWhat is left over or remains; the part of a molecule that remains after portion of its constituents are removed. Residues of some contaminants may remain after accumulate in and pollute sediments, and harm wildlife which feed upon vegetation to which the chemical compounds have been applied.

The robust structure of Lyngbya sp., presents a significant control difficulty to chemical applications. Even the most powerful chemical compounds need an additive to enable them to adhere long enough to filaments for the poison to penetrate the protective sheath. Moreover, the physical break up of mats is necessary to facilitate effective chemical cover of the filaments, promoting spreading as waters move with currents and tide.

Other techniques attempt to place the chemical compounds in benthic mats, using lances, or granules which sink to the bottom. However well such techniques may work in enclosed water bodies it is open to question whether they would be at all effective in constantly moving waters. Notwithstanding the effects of dispersion and dilution in these circumstances, additional significant manpower costs of application and follow up treatments are incurred.

Hydrogen Peroxide as the active agent produced in decay of barley straw floated on water is known to be an effective inhibitor of algal formation, but does not deal with floating algae mats nor penetrate depth to be effective.

The following is taken from an article by Dana Oleskiewicz, OSU Extension Agent, Watershed Management, published with Bibliography in the Buckeye Basins Network:

The use of chemicals is often the chosen method of algae and weed control. These compounds have been on the market for decades and are believed to be safe based on short-term studies. The long-term implication of copper in our waterways is less understood.

Scientific research conducted on these algaecides consists of short-term effects, dissipation of the chemical from the water, and the toxicity to specific animal species. According to these studies, the chemicals appear safe to water systems and have been approved for use at the recommended dosages. When applied correctly, they are not acutely or chronically toxic to non-target aquatic species.

There are studies; however, indicating that there are negative effects involved in the use of chemicals to control algae and aquatic weeds. Specifically, these chemicals can be toxic to zooplankton or fish food, adversely affect the important microbial system in the sediment and water column, and cause a shift to a monoculture or undesirable species. They can impact the sexual reproduction of organisms and can interfere with the metabolism or cause chromosomal mutation in non-target aquatic organisms.

Copper resistant strains of algae have appeared, which is analogous to the overuse of antibiotics in humans causing resistance to medicine. In addition, there are very few long-term studies on the impact to water systems from prolonged chemical exposure. Research is limited on the combined effect to the ecosystem with few studies being done within waterways rather than in laboratory-controlled environments.

One long-term, full ecosystem study involved fifty-eight (58) years of copper sulfate applications that produced the short-term (for days) desired result of controlling algae in Fairmont Lake, Minnesota. However, it also caused oxygen depletions, increase in nutrient cycling, occasional fish kills, copper accumulation in the sediments, increased tolerance by some algae to copper sulfate, a shift to blue-green algae (mats) dominance instead of the more desirable green algae, rough fish replaced game fish, disappearance of aquatic weeds which will promote algae growth, and a decrease in macroinvertebrates indicating a less "healthy" ecosystem. Researchers concluded that the quick fix to the algae problem was at a cost of long-term degradation to the lake.

The algaecides and herbicides on the market today are a "quick fix" that addresses, in the short-term, poor water quality as a symptom, but does not eliminate the problem. Although widely used for many years, in the long run, these products may be more harmful to a system than helpful. The system becomes dependent on the chemical in that it needs to be applied over and over again each season without really taking care of the problem at its source. It may also promote a shift in species to more nuisance aquatic life causing less desirable conditions than before the system was treated. Methods of management other than copper can be explored that could reduce the adverse effects of prolonged chemical use and provide a more long-term solution.

Biological Agents

Similarly, biological agents have been isolatedA population that is separated from other populations of the species (as on an island). to attack particular species. One such cyanaophage LPP-1 has been around for almost fifty years, (called LPP-1 as it is known to lyse Lyngbya, Plectolema and Phormidium). The dangers of using such agents include the unpredictable promotion of resistantThe ability of an individual or community to resist being changed by potentially disruptive events. host mutants in the field. Bacterial agents are known to lose cyanobacteria in several different ways but suffer individual defects as effective remedies. Myxococci has been suggested as a suitable bacterial biological control agent of bloom forming phytoplanktonSmall photosynthetic organisms, mostly algae and bacteria, found inhabiting aquatic ecosystems. Also see plankton and zooplankton. , because of its ability to adapt to physical conditions, to search and trap, to multiply, to consume preyOrganism that is consumed by a predator. , to survive prey shortages, to adapt as a host may change and can attack a range of prey.

Effective strains of antagonists and protozoa Heterotrophic eukaryotic unicellular organisms that belong to the kingdom protista. have also been identified. Such microbial treatments are commercially available, but suffer the same dispersion features as chemical compounds which magnify expense over time as residuesWhat is left over or remains; the part of a molecule that remains after portion of its constituents are removed. Residues of some contaminants may remain after live on to reproduce again. This latter, highlights a countervailing feature of Crystal River/ Kings Bay as its tidally influenced waters flow continually from aquifer into the Gulf exacerbating effects of dispersion.

Resonance Induced Oxygenation

Resonator equipment is available which is claimed to increase dissolved oxygenMeasures the amount of gaseous oxygen dissolved in an aqueous solution. Oxygen gets into water by diffusion from the surrounding air, by aeration (rapid movement), and as a waste product of photosynthesis. levels in a water body and to stimulate microbial activity to the degree that phosphorous is reduced to non detectable levels (which may not be less than background levels) – a necessary nutrient for algal photosynthesisIs the chemical process where plants and some bacteria can capture and organically fix the energy of the sun. This chemical reaction can be described by the following simple equation:
6CO₂ + 6H₂O + light energy >>> C₆H₁₂O ₆ + 6O₂
The main product of photosynthesis is a carbohydrate, such as the sugar glucose, and oxygen which is released to the atmosphere. All of the sugar produced in the photosynthetic cells of plants and other organisms is derived from the initial chemical combining of carbon dioxide and water with sunlight. This chemical reaction is catalyzed by chlorophyll acting in concert with other pigment, lipid, sugars, protein, and nucleic acid molecules. Sugars created in photosynthesis can be later converted by the plant to starch for storage, or it can be combined with other sugar molecules to form specialized carbohydrates such as cellulose, or it can be combined with other nutrients such as nitrogen, phosphorus, and sulfur, to build complex molecules such as proteins and nucleic acids. Also see chemosynthesis. It is said that photosynthesis gives rise to three quarters of the world supply of oxygen that we breathe. . Increased dissolved oxygen levels may also stimulate algal, fish and crustacean predators Consumer organism who feeds on prey. The process of consumption involves the killing of the prey. to deplete algae stocks in a water body.

Ultrasound

Within the area of its emissions, ultrasound also lyses at the microscopicToo small for human eyesight without employing a microscope level, howsoever waters may move under the influence of tide or spring flows. Algal areas under treatment can be corralled to contain wind driven surface mats within the emission area. Powered by sunshine, once initial purchase costs have been met, units can be used with few recurrent costs and moved from place to place as further areas are to be treated.

Known ultrasound designs have been proved in field applications and the laboratory as effective against many types of algae infesting local waters, such as : Anabaena, Microcystis, Spirogyra, Cladophora, Ceratium, Trachelomonas for example. Several thousand such units are successfully in use throughout the world. There is now urgent need to prove them effective against Lyngbya sp., so that either necessary alterations to the electronics can be made to make emission spectra more effective in use against that algal species, or, if required, safer to use in the vicinity of endangered or threatenedSpecies that have declined significantly in total number and may be on the verge of extinction in certain areas. wildlife speciesA taxonomic category subordinate to a genus (or subgenus) and superior to a subspecies or variety, composed of individuals possessing common characters distinguishing them from other categories of individuals of the same taxonomic level. In taxonomic nomenclature, species are designated by the genus name followed by a Latin or Latinized adjective or noun. .

The scientific literature reporting the effects rapid pressure variations have on both cellular and bacterial alga give reason to believe that ultrasound emissions would be very effective and an economic solution for the control of these types of algae. In cellular alga the effect of the ultrasound emissions is to disrupt the cellA cell is the smallest self-functioning unit found in living organisms. Each cell is enclosed by an outer membrane or wall and contains genetic material (DNA) and other parts to carry out its life functions. Some organisms such as bacteria consist of only one cell, but most of the organisms found on the Earth are made up of many cells. structure between plasmalemmaPlasmalemma, is a semipermeable lipid bilayer common to all living cells. It contains a variety of biological molecules, primarily proteins and lipids, which are involved in a vast array of cellular processes. and the containing membrane so that nutrientsAny food, chemical element or compound an organism requires to live, grow, or reproduce. cannot be absorbed causing starvation and cell death. In bacterial alga, such as Lyngbya cyanobacteria Bacteria that have the ability to photosynthesize. , the effect of the ultrasound emissions is to collapse the gas vesicles so that mats lose buoyancy and sink to the bottom. Though cyanobacteria Bacteria that have the ability to photosynthesize. continue to attempt to produce new gas vesicles while sunk, continued exposure to ultrasound inhibits growth of new vesicles sufficient for buoyancy, and prevents the ability of algae to ingest nutrients from the water column and seek sunlight for photosynthesisIs the chemical process where plants and some bacteria can capture and organically fix the energy of the sun. This chemical reaction can be described by the following simple equation:
6CO₂ + 6H₂O + light energy >>> C₆H₁₂O ₆ + 6O₂
The main product of photosynthesis is a carbohydrate, such as the sugar glucose, and oxygen which is released to the atmosphere. All of the sugar produced in the photosynthetic cells of plants and other organisms is derived from the initial chemical combining of carbon dioxide and water with sunlight. This chemical reaction is catalyzed by chlorophyll acting in concert with other pigment, lipid, sugars, protein, and nucleic acid molecules. Sugars created in photosynthesis can be later converted by the plant to starch for storage, or it can be combined with other sugar molecules to form specialized carbohydrates such as cellulose, or it can be combined with other nutrients such as nitrogen, phosphorus, and sulfur, to build complex molecules such as proteins and nucleic acids. Also see chemosynthesis. It is said that photosynthesis gives rise to three quarters of the world supply of oxygen that we breathe. . Further proof of how the demise occurs is the subject of experimentation microscopic analysis

Ultrasound is safe with all plant life forms. Water fleas (Daphnia) are safe with ultrasound. A recently received report from southern England, describes how ultrasound units, of the type ready to be applied in our local waters, have contributed to comprehensive water quality restoration and the control of algae – of speciesA taxonomic category subordinate to a genus (or subgenus) and superior to a subspecies or variety, composed of individuals possessing common characters distinguishing them from other categories of individuals of the same taxonomic level. In taxonomic nomenclature, species are designated by the genus name followed by a Latin or Latinized adjective or noun. we have locally - in important inland fisheries, involving Tench, Crucean Carp, Roach/Rudd and Perch fish species.

Of all the algae control methods reviewed in the scientific literature, ultrasound has been shown to be most effective with the necessary attributes to address the “sleeping giant”. Laboratory and field tests have shown it to be effective both on the cellular and non cellular cyanobacteria Bacteria that have the ability to photosynthesize. that we have locally, but it has not been tried with Lyngbya. Tests with Lyngbya benthic mats must be done in the local environmentall of the external factors that may act on an organism, either plant or animal, or on a natural community. For example: gravity, air, wind, sunlight, moisture, temperature, soil, and other organisms are some of the environmental factors that may affect the life processes of an organism. where they actually occur. To employ any control technology before being assured of the outcome against Lyngbya, could cut back other algal species only to leave the Lyngbya without a competitor and have it run rampant.

Consent has been given for ultrasound to be used where dolphins roam. Manatee acoustic harassment is unlikely, under definitions of the Endangered Species Act, 1973, and, “The underwater audiogram of the West Indian manatee (Trichechus manatus)” Gerstein, et al. 1999. A consent to proceed from USFWS has been offered in the context of a scientific research permit application.