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Blue-Green Algae ID

September 28, 2021 by brittany.chesser

As expected, August was a month with elevated temperatures and little rain in most areas of the state. This led to an influx of questions on the identification, control, and testing of blue-green algae directed to the Aquatic Diagnostics Laboratory (ADL).

The common name “blue-green algae” is a little misleading for cyanobacteria species since they are in fact, photosynthetic bacteria that can have many different growth forms. Some cyanobacteria species considered to be similar to true planktonic algae species and are mixed evenly throughout the water column, not giving off any visual cues. Other, more visible cyanobacteria species can be found floating around the shoreline in various growth forms, largely characterized as “spilled paint”, globules, or mat forming. Furthermore, noticeable cyanobacteria blooms are not always “blue-green”. They can appear green, yellow, brown, red, purple, etc. due to protein complexes that produce various pigmentations in their cells.

See below for several examples.

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  • 20210512_105202
  • 218647445_370762167947731_6958259058562341736_n
  • Deforest1 (2)
  • 229133133_549984956043086_6065376032658284744_n
  • image0
  • gerngross7
  • 46767
  • kline 123
  • BGA back tank
  • Blue-green 2

Cyanobacteria should not be confused with golden alga (Prymnesium parvum) or Euglena (Euglena spp.).

Golden alga are pigmented to give off a golden appearance, and are commonly found in waters with high salinity or rich in minerals during cooler months.  While golden alga blooms do produce toxins and pose a threat to aquatic organisms, there is no known direct threat to humans, wildlife, livestock, or pets. Whereas, Euglena can be found in any water body and even soil. Euglena are unique in the fact that they can change color rapidly depending on sunlight, going from green to a rusty red within minutes. A good indication that a pond is experiencing an Euglena infestation versus a cyanobacteria bloom is the water changing color within a 24 hour period, becoming more red with more sunlight.

  • Karl-2
    Euglena early morning.
  • Karl-3
    Euglena in afternoon.

Sometimes to the untrained eye, a cyanobacteria bloom may also be confused with what is actually an infestation some of the world’s smallest flowering plants, watermeal (Woffia spp.).  Like some cyanobacteria species, they are bright green and can be found heavily concentrated along the edges and in downwind areas of a pond. However, upon closer inspection, watermeal will have a seed-like appearance with a gritty texture.

  • Large pond – 2
  • DeGomez J pond4
  • Small pond – 2
  • Watermeal _Womble

These common misidentification mistakes may seem irrelevant but each of these groupings have unique survival strategies which plays a huge role in management.

There are no reporting or monitoring programs for cyanobacteria at the state or federal level in private waters. If you believe that you are experiencing a fish kill related to cyanobacteria issues, you should contact the Texas A&M AgriLife Aquaculture Extension Specialist, Dr. Todd Sink . The ADL can test for cyanotoxins in water but testing is expensive and does not always lead to definitive answers. See “Texas A&M AgriLife Aquaculture Specialist Addresses Algae-related Dog Deaths” for more information on testing.  The ADL does not test fish tissue. Cyanobacteria issues involving wildlife or livestock can be directed to the Diagnostic Toxicologist at Texas A&M Veterinary Medical Diagnostic Lab, Dr. Catherine Barr, and Texas A&M AgriLife Extension Specialist, Dr. Thomas Hairgrove. To a confirm that cyanotoxins are the cause of death for livestock or wildlife, a necropsy is recommended over a water sample. More information on the management of cyanobacteria, can be directed to the Texas A&M AgriLife Aquatic Vegetation Management Program Specialist, Brittany Chesser.

References & Resources:

AgriLife Today

AquaPlant

EPA: Cyanobacterial Blooms

SRAC: Algal Toxins in Pond Aquaculture

TPWD: Harmful Algal Blooms

Filed Under: Blog

Photos for Aquatic Vegetation Identification

June 11, 2021 by brittany.chesser

When it comes to managing aquatic vegetation, the first critical step in selecting an effective control method is identification. Individual treatments do not work across all, or even most, aquatic vegetation species. Selecting treatments before proper identification can result in an ineffective treatment and a waste of money, time, and labor.

Thanks to current technology, specifically the widespread use of cell phones with high quality cameras, pond owners can forgo collecting a plant specimen and sending it in the mail. This is good news as plant material and Texas heat do not mix well. Mailing usually leaves the recipient with a smelly, decomposing plant, which can make identification hard. Instead, photos of the unidentified plant can be taken and sent directly using a phone, computer or tablet.

The main caveat of plant material being physically absent during identification is the requirement of high quality photos. Some plants, especially those with large, showy flowers, can be identified from a far, however as you can see from the photos below, this is not usually the case and closer inspection is required.

So, what classifies as high quality? Photos should be taken to highlight key characteristics like flowers, leaf arrangements, and nodes (stem area from which a leaf or leaves, branch or branches originate). The unidentified plant should be taken out the water, placed against a contrasting background (preferably white), with stems and leaves spread out. The photo should then be taken up close (preferably within 1 foot, or until the plant fills the frame), with the plant material in focus, and eliminating any shadows. Including scale items, like a hand, coins, or other readily available items, will also help for size comparison. See below for examples.

Additional information like pond use and overall goals, along photos of the plant material relative to the water column (emergent vegetation) and coverage area (all vegetation types), will help provide more guidance when coming up with a management plan.

For more information on aquatic vegetation identification, please visit AquaPlant or contact the Aquatic Vegetation Management Program Specialist, Brittany Chesser (Brittany.chesser@tamu.edu).

Filed Under: Blog

Planktonic Algae Die-off

December 2, 2020 by brittany.chesser

Planktonic algae, otherwise known as phytoplankton, are microscopic, single celled, free floating algae that can exist wherever the sun penetrates. Planktonic algae thrive under sunny conditions at water temperatures greater than 60°F, and contributes to water’s greenish tint. Typically, planktonic algae are considered desirable as they shade the pond bottom which suppresses the establishment of rooted aquatic plants, are the foundation of a pond’s food chain by providing food for zooplankton and larval fishes, and provides 80% of the oxygen in the water.

However, an overabundance of planktonic algae, called “Blooms” – particularly their eventual death – can lead oxygen depletions, and eventually fish kills. Planktonic algae can die-off naturally and rapidly due to cloudy days and cold snaps during rain events or colder months. After the algae cells die, they begin to lose their chlorophyll and green coloration. This is why a tell-tale sign of a die-off is a change in water color, in streaks or entirely, from green to brick-red, brown, or black, and can give off a foul odor. Ultimately, these dead cells will settle to the pond’s bottom, giving the pond a clearer appearance. These dying cells are not only a nuisance aesthetically; beneficial bacteria require oxygen to break down these cells. This lowers the amount of oxygen available to fish and other aquatic organisms.

Samples that are sent in to the Aquatics Diagnostic Laboratory after a planktonic algae die-off, may contain these dead, discolored cells, which are confirmed through microscopic examination. Additionally, samples can have high total ammonia nitrogen (TAN) concentrations through the algae decomposition process. During warmer months or in high pH ponds, high TAN is a serious issue that may lead to a fish kill due to unionized ammonia (UIA) levels. UIA is toxic to fish and concentrations are dependent on TAN, temperature, and pH. Therefore, when the water temperature is cool and pH is low, high TAN levels will result in low UIA and pose little risk to fish.

Negative effects of a planktonic algae die-off can be minimized by stopping all fish feeding until spring when the water temperatures are 60°F or higher. Feeding during winter months (<60°F), when fish are eating less, can contribute to excess ammonia in the pond from protein in uneaten feed and excess protein in feces. An aerator can also be added to increase overall dissolved oxygen and reduce the chances of a potential fish kill. Regardless, stress put on fish due to decreased water quality conditions can lead to secondary diseases.

If you are concerned your planktonic algae bloom density is problematic, a secchi disk can be used to measure water clarity, which can help indicate planktonic algae levels. For more pictures and information on planktonic algae, please read Managing and Controlling Algae in Pond and visit AquaPlant.tamu.edu.

Filed Under: Blog

Swimming with “Strep”

October 17, 2020 by brittany.chesser

Streptococcosis, also known as strep, is the term for diseases caused by a genus of bacteria, Streptococcus. These bacteria are known to be very aggressive in fish causing large die-offs of over 50% mortality within a few days, hindering production and causing massive economic loss.

Aside from rapid and increasing mortality, fish suffering from strep can exhibit a long list of potential symptoms but hemorrhaging, “pop-eye”, and swimming or behaving abnormally, such as spinning, are commonly observed. Erratic behavior can be one of the first tell-tale signs, due to infection of the brain and nervous system, but not all infected fish are symptomatic.


Like most other diseases the key to prevention is minimizing stress, which can be achieved by avoiding crowded stocking conditions and poor water quality. These conditions should particularly be avoided during summer months when water temperatures are at their highest. Commonly stocked fishes like largemouth bass, bluegill, striped bass, golden shiner, channel catfish, and tilapia are found to be susceptible to strep infections.

To prevent further spread, reduce overall mortality, and minimize economic loss, fish should be isolated from other populations immediately if strep is suspected. If a strep confirmation is made rapidly and fish are readily accepting feed, an antibiotic may be prescribed. Sometimes strep can become a reoccurring issue and vaccinations are needed, although not always available or effective.

Fish suspected to have a strep infection can be sent to The Texas AgriLife Extension Service Aquatic Diagnostic Laboratory for a gram positive streptococci selective media isolation to confirm diagnosis.

For more pictures and information on strep, please read Streptococcal Infections in Fish.

Filed Under: Blog

How Do We Compare?

April 24, 2020 by brittany.chesser

 

  • anchorworm
    A hybrid striped bass with an Lernaea (anchor worm, copepod crustacean) parasite attached to the eye that has blinded it.
  • black gill syndrome
    Black gill syndrome caused by the ciliate Hyalophysa sp. found in wild shrimp sent in by commercial trawlers. Only the second case found in Texas and the first cases since pre-2000.
  • Columnaris
    Channel catfish with columnaris bacterial infection.
  • Trematodes
    Largemouth bass liver infested with trematodes (darker spots).

Since starting the Aquatic Diagnostic Laboratory (ADL) blog series, many County Extension offices have shared our information each month to provide pond owners with necessary information. This month seemed like a better time than ever to go over the ADL’s background and how we might stack up against other laboratories.

In 2015, the ADL was founded by the Aquaculture Extension Specialist and ADL Director, Dr. Todd Sink, to fill the need for an in-state fish disease diagnostics laboratory following the closure of the Texas Veterinary Medical Diagnostic Laboratory’s fish pathology program in the 1990s and the creation of USDA veterinary feed directive in 2017. Both of these changes hindered producers’ ability to obtain a timely diagnosis and treatment recommendations, along with a heftier price tag. Compared to out of state laboratories, the ADL was designed to work with local vets and perform at-cost analysis, diagnostics, and non-biased recommendations for producers and recreational pond owners of Texas.

The ADL offers parasite screening, identification, and treatment services and fish pathology services including bacterial pathogen isolation, identification, and recommendation of FDA-approved treatments. The ADL offers a broad spectrum of water quality and waterborne toxin analyses, and water quality analyses has become much more of a focus since Brittany Chesser joined the ADL as the Lead Diagnostic Scientist in early 2019.

The ADL recognizes that rapid diagnostics and recommendations provide Texas stakeholders with the best possible management options when faced with disease or contamination in their ponds. A positive confirmation of a bacterial pathogen can be accomplished just 3 days from the time a sick fish is found, reducing the total amount of infected fish and total loss producers or pond owners could face.

One question we are often asked are how do our water quality analyses differ from those of the TAMU Soils, Water, and Forage Testing Laboratory (SWFTL). The answer is simple, the ADL water analyses are completely geared to determining the suitability of water to support fish and develop a fishery. Therefore, our analyses differ in the chemical parameters that are measure by the SWFTL, include tests that are extremely important for fish that are not included in a basic SWFTL water analyses, and each report comes with advice on the suitability of the water to support a fishery and any amendments that should be done to the water to support a fishery. The ADL also offers a wide range of waterborne toxin and environmental contamination testing that can aid in determine the cause of fish kills or contamination issues. If a water sample is not specifically for determining the suitability of water to support a fishery or to determine the cause of a fish kill or suspected environmental contamination, then it should continue to go to the SWFTL. The ADL also does not do any soil testing for clay content or suitability of soil for pond construction, so all soil samples should go to the SWFTL.

Although the lab was not publicly advertised until 2018, over the past 5 years, the ADL has delivered on its primary mission through assisting over 250 stakeholders of Texas, saving approximately 1,870,000 fish valued at $5.61 million. Even though each year the lab continues to have increased cases, many pond owners statewide do not know of the lab or how the lab may differ from other labs. We hope this helps clear things up!

 

 

 

Filed Under: Blog

Pond Fertilization

March 24, 2020 by brittany.chesser

It’s that time of year when water temperatures are reaching 60-65° F, and pond owners are hearing now is the optimal time for pond fertilization. Fertilizing a pond is different than fertilizing a field and requires using a fertilizer that is high in phosphorus rather than nitrogen. When done correctly, pond fertilization can provide many benefits including enhancing the overall food chain by providing food for phytoplankton which in turn allows the pond to produce more pounds of fish. Additionally, fertilization can reduce the presence of submerged aquatic vegetation by decreasing water clarity and limiting the amount of light that reaches the pond bottom.

In terms of water chemistry, alkalinity, hardness, and calcium are recommended to be tested prior to fertilizing to ensure an efficient fertilization program. A pond with very low alkalinity or hardness (< 20 mg/L) will require the addition of agriculture lime before beginning the fertilization process. The amount of fertilizer required for a pond will be dependent on its hardness and calcium concentrations. Ponds with low, moderate, and high concentrations of hardness will require low, moderate and high rates of fertilizer, respectively.

Not all ponds need to be fertilized. In fact, fertilization is discouraged for ponds with existing populations of aquatic vegetation or water clarity of less than 18” of visibility. But, if you are considering fertilizing your pond this spring start by having your water chemistry checked first. Send your water sample to The Texas AgriLife Extension Service Aquatic Diagnostic Laboratory.

For more information on fertilizing ponds, please read Fertilization of Fish Ponds.

Filed Under: Blog

Back to Basics

March 3, 2020 by brittany.chesser

As temperatures begin to warm up, pond owners may begin to look forward to stocking their ponds. One of the most common questions we get from new and experienced pond owners is “What tests should I get to determine if this pond will support a fishery?”. Usually when this question is asked, there are no obvious indicators to point pond owners in the right direction, which can lead to endless internet searches, leaving their heads spinning with a long list of tests and their associated costs.

Pond

The most common analysis we perform and always recommend first is the base water chemistry analysis. This analysis covers 8 water quality parameters, including pH, hardness, alkalinity, total salinity, total ammonia nitrogen, un-ionized ammonia, nitrite, and chlorides, that are fundamental in supporting fish populations and only requires 16-20 ounces of water for testing. Once we run all 8 tests, current concentrations are compared to acceptable and optimal ranges in a thorough report, along with suggested amendments.

In many instances, these parameters can be overlooked and may not be feasible for pond owners to do themselves, but should still be evaluated before stocking. Levels outside acceptable ranges can impact a fishery significantly; for example, decreased pH levels can increase stress on fish, leaving them more susceptible to disease which will impede on fish growth and larval survival.

Besides determining if their pond’s water can support a fishery, how do pond owners benefit from a base water test? Knowing concentrations for these parameters can also aide in pond management decisions dealing with aquatic plant management, fertilization applications, parasite or disease management, and pond clearing techniques.

Water chemistry vials

Pond owners who are questioning if their water will support a fishery can send their water samples to The Texas AgriLife Extension Service Aquatic Diagnostic Laboratory for a basic water quality test to determine concentration readings and recommended amendments.

For more information on the importance of water quality and respective amendments, please read Understanding Water Quality Reports for Your Pond.

Filed Under: Blog

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