Salvinia Molesta AKA Giant Salvinia

If you have found my freshwater blogg helpful then check out my "Teaching Aquatic Science: Marine

My first introduction to this destructive invasive plant was at Caddo Lake in Texas.  This plant can have serious impacts on wetland areas and ecosystems.  It can cover lakes in thick dense mats which stops light penetration and depletes oxygen.  Fish will either migrate to more oxgenated water or die.   This can affect the the economy and local tourism.  My favorite place to stay when I visit Caddo is Uncertain, Texas.  Cabins along the lake shore were difficult to reach because the roads were often underwater - this resulted in the name "Uncertain". 



Lake front property with lake view??? (water hyacith)

  This small towns economy is based on tourism.  It is a great place to fish, hunt ducks, canoe, kayak, ride a paddle boat or just relax and enjoy the numerous birds and other wildlife. Cabins can be rented and many backwater tours are provided by knowledgeable tour guides.  The lively hood of the people that provide these services depends on this unique ecosystem.  The lake has already been struggling with other invasive plants such as hydrilla, alligator weed, and water hyacinth.  Local people living on the have banded together to fight the invasion and infestation of these destructive plants. This is their home and they will fight to save the lake.

Ah? What happend to the lake???

However, Salvinia is very destructive and impossible to get rid of once it is established.  The introduction of this invasive started on the Louisiana side of the lake.  Due the last hurricane, the state of Louisana did not have the money to fight this infestation and it took over and spread to the Texas side.

Caddo Lake Fence

Local residents built a fence across the lake to help stop the spread of Salvinia.  It worked for a while but eventially Salvinia spread into Texas.  This plant is so difficult to get rid off because it is small and hides among the water hyacinth, water lily, lotus, alligatorweed and cypress trees. The "eggbeater" hairs on the surface of the leaf may die when sprayed with pesticides but the underpart of the plant survives.  Care must be used when leaving lakes infested with this plant.  

Herbicides are most commonly used to stop invasive infestation.

"egg beater hairs"

It is important that visitors to lake with invasive plants are very careful when leaving the lake.  Be sure to check boat, trailors, props or anything that has been in the water.   Don't carry these plants with you to other lakes.  

SAVE TEXAS LAKES!

DON'T TRANSPORT INVASIVE PLANTS

DON'T TRANSPORT ZEBRA MUSSELS



Invasive Aquatic Plants of Texas

Water Hyacinth at Caddo Lake

Invasive Aquatic Plants

Invasive aquatic plants are a major problem in Texas.  My mom used to say that a weed was an unloved plant.  A weed is really just a plant that grows where you don't want it too.  However, an invasive plant is one that grows where you don't want it to and then it takes over.

Invasive aquatic plants have an number of things in common:

A.  They grow fast and cover large areas

B.   Reproduce from seeds, fragments, buds and shoots

C.  Survive in a variety of temperatures and light

D.  Difficult if not impossible to get rid of once they are established

E.   Most decrease oxygen in the water

F.   Invasive plants take over and the biodiversity of an ecosystem 

      decreases.

G.  Damage the economy of an area and are expensive to manage

H.   Destroy fish and wildlife habitat

 I.   Block navigation

J.   Reduce tourism and property values

K.  Stop fishing, boating and swimming



Texas parks and Wildlife Warning



Prevention

Is is easier to prevent an infestation than it is maintain it.  It is also cheaper.

Most of the invasive aquatic plants were brought into this country where intended for the aquarium trade.  They were pretty and they grow fast. Unfortunatly, what they did not have was predators to help keep them undercontrol.  With out insects, diseases or fish to help keep the plant populations down  they out compete our native Texas vegetation and create very expensive problems for our state, counties and cities.

DO NOT:

A.  put aquarium plants or fish into local lakes, rivers or wetlands
B.   leave a lake without cleaning your boat and trailer for plants or   
       organisms like Zebra Mussels. If you can power wash your boat
       and  railer with hot water and let it dry before moving to another
       lake.
C.   transport invasive aquatic plants from one area to another.





Zebra Mussel Warning Lake Lewisville, Texas

 DO:

Report invasive plants or organisms to your  local Texas, Parks and Wildlife office.  And yes the really, really want to know if you see them!

Aquatic Plants

Tuesday, October 9

Lotus

Aquatic students are now starting the aquatic plant unit. Today we started with a review of botany and looked at how aquatic plants differ from aquatic plants.  Aquatic plants (hydrophyte) are found in wetland areas.  The three criteria for a wetland include water, water loving plants and soil that has been inundated with water so that the soil become anaerobic. 

Wetland plants are important because:

A.  Roots bind soil and help stop erosion
B.  Roots take up nitrates and phosphates.
C.  Water leaving a wetland is cleaner than when it entered the wetland.
D.  Wetland plants provide food, nutrients, and nesting areas for many animals including birds, fish, shellfish, insects, reptiles ....

It is important for students to understand that one must protect the environment if they want to protect the animals living there.  Loss of habitat is one of the major causes of decreased diversity of our wetland animals.




Caddo Lake



My favorite wetland is Caddo Lake.   If you are not familiar with Caddo Lake, it is a Cypress Swamp that sits on the border of Texas and Lousianna.  This is a very unique habitat and is endangered due to the influx of invasive aquatic plants.  The major invasive plants are Hydrilla, Water Hyacinth, and Giant Salvinia.

Hydrilla

Water Hyacinth

Giant Salvinia

As class progresses, students will learn to identify the invasive aquatic plants. Since students and their parents are the ones that fish, ski, and boat on the lake, they are more likely to discover new invasive plants in our local lakes.  This is important because the sooner an invasive is identified the sooner management can occur.

Dichotomous Key AKA Thinking Map

Wednesday, October 3

Today the students had to design a dichotomous key for algae.   They had to work with 14 different types of algae. It was a really good exercise for students and their teacher.   I gave them two different examples and let the students decide how to proceed.  This turned out to be a great review for the test.



Very Organized








Organized



It was interesting to see which example students picked.   What is important is to pick the one that is the most user friendly for them.  This is just another example of what is now called "thinking maps" or "concept maps".  Either way it is just one way to help students organize information.

If you want to engage students  it is just one tool among many.

Here are some examples of my students dichotomous keys:

 

It really was a fun activity once they got the idea and hopefully will improve test scores.

Another fun thing we are doing is watching "Big Mama" crayfish.  Today I got pictures of her egg mass.  Soon we will have lots of little baby crayfish.

The pictures are not great but you can see the black egg mass underneath her tail.  She really loves her little log and it has turned out to be a great place for her to hide while she waits for the babys to arrivel

Mama and log home

This was the best picture showing the egg mass.

Yesterday at the end of the aglae lab one of students brought me an egg mass attached to a stem.  It was a mass of snail eggs.  I put it under the digital microscope and took pictures.  We then put it in a petri dish with pond water and left it over night. This morning I took more pictures and some video of the baby snails moving in the egg.   I plan to keep taking pictures until they hatch.  It is facinating to watch.  

Snail Egg Mass

Baby Snail in Egg

FISH STORIES

Happy Friday, September 27

This week was fun.  I always enjoy algae.  What was really cool was the student found they could take pictures of  organisms under the microscope using their cell phones.  It you hold the camera over the eye piece just right you can snap a picture.

Leech or planaria

Mayfly Larva

Daphnia

The other interesting thing that happened this week was in the goldfish and Tigar Oscar tank.  The baby oscar has been getting bigger.  We looked over during lunch and he had some thing hanging out of his mouth.   All you could see was the tail fin of the goldfish hanging out of the oscar's mouth.  I was able to get a couple of pictures.  The students thought it was really cool.

My mom and dad convict chilids had babies last week.  I tried to get a picture but my blue crayfish decided to hunt them.   Mom and dad went after the crayfish.  The moved all the babies to the back of the tank.  They are very protective of their babies.

Raising fish is very interesting  and there is always something new each
week.

Last Friday students turned in their they wetland picture books.  They were really cute.  I picked a variety of animals that live in the wetlands: mammals, birds, fish, reptiles, macroinvertebrates and others.  What I like about this type of booklet is I learn things I did not know.

Algae Assessment

Monday, October 1

Today students are working on an algae assessment.  I developed my own water quality assessment by drawing a field of view and then a data collection chart on the back. Students use colored pencils to count the algae then total the amount.  Once they have the total they can determine if the water is high, moderate or low pollution.  I have six different versions and as students turn them in I check to see if each version had the same count.  If not, I have them get together and figure out who is right. Peer tutoring is great.

These are my picture keys for the algae assessment.  It really helps that we have already done the math formula before they do this assessment. Working in groups helps because the help each other.

Algae and Water Quality

Monday, September 24

This week we are focusing on algae and macroinvertebrates.  Algae is a cheap, easy and quick way to assess the quality of a lotic (standing) water source.  These algae can cause blooms that are a problem for water treatment plants and also for classroom aquariums. 

Diatom

Oscillatoria

Volvox

I usually collect samples from slow creeks or small ponds. Anywhere there is a lot of algae along the shoreline.  Once collected I bring the water source back to class and place it in shallow white trays so that the organisms are easy to see.  It helps to have both a microscope and a dissecting school on each lab stations.  The microscope helps identify algae and small organisms that live in the algae.  The dissecting scope makes it easier to observe large macroinvertebrates and beetles that live in the water.





I enjoy this lab because most students have never looked at pond water before and they are surprised by all the things one can find in the water  and the algae. This week I am going to have them try and take pictures of the organisms by placing the camera of their phone over the eyepiece of the microscope.  I have had some luck with it in past years.  I will also try and collect images using my digital microscope.