Salvinia molesta: An Assessment of the Effects and Methods of Eradication

<p><em>Salvinia molesta </em>is an invasive aquatic fern. It is now the second worse aquatic invader in the world. Since the 1930s, it has invaded most tropical and some temperate countries. <em>S. molesta </em>plants grow vegetatively and can increase in size rapidly. <em>S. molesta</em> can form thick mats of up to 1-meter-thick. There are a number of ways these thick mats negatively affect the environment: 1) reduce light to benthic organisms, 2) reduce oxygen in the water column for other organisms, 3) accumulate as organic matter at the bottom of the water column, 4) decrease nutrients for other organisms, and 5) change water flow. <em>S. molesta</em> not only degrade and alter ecosystems, infestations also increase public health concerns. Dense <em>S. molesta</em> mats are ideal breeding grounds for mosquitoes and other insects that carry vector-borne diseases. Countries are negatively affected economically because <em>S. molesta</em> hinder use of waterways. Recreational activities, tourism, fishing, and transportation are all impeded due to <em>S. molesta</em> infestations. Methods of control are: 1) physical control, 2) chemical control, and 3) biological control. A combination of two or more methods work best for complete eradication. Biological control is the method of choice in tropical areas. Australia was the first to implement biological control via <em>Cyrtobagous salviniae</em>. <em>C. Salviniae</em> have devastative effects on<em> S. molesta</em> plants because both adults and larvae feed on plant parts. Althought <em>C. savliniae</em> are very effective, they have some constraints: 1) temperature, 2) nutrients, and 3) <em>S. molesata</em> infestation growing stage. <em>S. molesta</em> can withstand lower temperatures than <em>C. salviniae</em>, so in temperate regions, <em>C. salviniae</em> are ineffective. These regions are where other methods of control, such as chemical control, are more effective. <em>C. salviniae</em> also require adequate nitrogen concentration for proper development. <em>S. molesta</em> infestations also need to be in the primary or secondary growing stage for <em>C. salviniae</em> to survive. Tungog Lake in Sabah, Malaysia is heavily infested with S<em>. molesta</em> plants that are in the tertiary growing stage. Mats must first be thinned out via chemical control or mechanical removal. <em>C. salviniae</em> then should be introduced to the lake. Other recommendations for control overall of <em>S. molesta</em> are: 1) more studies in temperate regions should be conducted at specific infestation sites, 2) increase public education to reduce use of <em>S. molesta</em> as an ornamental, and 3) ban cultivation sites and sales.</p> <h1> </h1>

Name thesis:degree_name

Master of Science in Environmental Management (MSEM)

Level thesis:degree_level

Project/Capstone - Global access

Discipline thesis:degree_discipline

Environmental Management

Year dc:date.available

2016

Author dc:creator

• Lal, Arti

Contributors dc:contributor

• Deneb Karentz

• Invasive plants
• invasive species
• invasive aquatic plants
• Salvinia molesta
• kariba weed
• giant salvinia
• Biodiversity
• Biology
• Botany
• Ecology and Evolutionary Biology
• Horticulture
• Life Sciences
• Other Plant Sciences
• Plant Biology
• Plant Sciences
• Terrestrial and Aquatic Ecology
• Weed Science

Repository record dc:identifier

https://repository.usfca.edu/capstone/572

OAI identifier oai:identifier

oai:repository.usfca.edu:capstone-1596