You are here

The next "killer" algae? Assessing and mitigating invasion risk for aquarium strains of the marine macroalgal genus Chaetomorpha

Download pdf | Full Screen View

Date Issued:
2012
Abstract/Description:
Biological invasions threaten the ecological integrity of natural ecosystems. Anthropogenic introductions of non-native species can displace native flora and fauna, altering community compositions and disrupting ecosystem services. One often-overlooked vector for such introductions is the release of aquarium organisms into aquatic ecosystems. Following detrimental aquarium-release invasions by the (")killer alga(") Caulerpa taxifolia, aquarium hobbyists and professions began promoting the use of other genera of macroalgae as (")safe(") alternatives. The most popular of these marine aquarium macroalgae, the genus Chaetomorpha, is analyzed here for invasion risk. Mitigation strategies are also evaluated. I found that the propensity for reproduction by vegetative fragmentation displayed by aquarium strains of Chaetomorpha poses a significant invasion threat(-)fragments of aquarium Chaetomorpha are able to survive from sizes as small as 0.5 mm in length, or one intact, live cell. Fragments of this size and larger are generated in large quantities in online and retail purchases of Chaetomorpha, and introduction of these fragments would likely result in viable individuals for establishment in a variety of geographic and seasonal environmental conditions. Mitigation of invasion risk was assessed in two ways(-)rapid response to a potential introduction by chemical eradication and prevention through safe hobbyist disposal. I tested the effectiveness of five chemicals used as algicides and found that acetic acid was highly effective at limiting survival and growth of aquarium Chaetomorpha. Chlorine bleach, copper sulfate and rock salt were effective at limiting growth but were inconsistent or ineffective in reducing survival of algal fragments. The algicide Sonar limited neither survival nor growth. If aquarium strains of Chaetomorpha are released, chemical eradication presents a viable management strategy, particularly through the use of acetic acid. A more cost-effective strategy, however, would be preventing introductions; thus safe alternatives to release were determined for hobbyist disposal of unwanted or excess aquarium Chaetomorpha. Here I present the minimum exposure durations necessary to induce full mortality of aquarium Chaetomorpha through boiling, microwaving, freezing, desiccation and exposure to freshwater. Hobbyist disposal by any of these methods would constitute safe alternatives to introduction of the alga into natural environments. Such preventative measures will inform outreach campaigns in order to limit the potential for aquarium-release introduction.
Title: The next "killer" algae? Assessing and mitigating invasion risk for aquarium strains of the marine macroalgal genus Chaetomorpha.
34 views
13 downloads
Name(s): Odom, Rachel, Author
Walters, Linda, Committee Chair
Hinkle, Charles, Committee Member
Hanisak, M. Dennis, Committee Member
, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2012
Publisher: University of Central Florida
Language(s): English
Abstract/Description: Biological invasions threaten the ecological integrity of natural ecosystems. Anthropogenic introductions of non-native species can displace native flora and fauna, altering community compositions and disrupting ecosystem services. One often-overlooked vector for such introductions is the release of aquarium organisms into aquatic ecosystems. Following detrimental aquarium-release invasions by the (")killer alga(") Caulerpa taxifolia, aquarium hobbyists and professions began promoting the use of other genera of macroalgae as (")safe(") alternatives. The most popular of these marine aquarium macroalgae, the genus Chaetomorpha, is analyzed here for invasion risk. Mitigation strategies are also evaluated. I found that the propensity for reproduction by vegetative fragmentation displayed by aquarium strains of Chaetomorpha poses a significant invasion threat(-)fragments of aquarium Chaetomorpha are able to survive from sizes as small as 0.5 mm in length, or one intact, live cell. Fragments of this size and larger are generated in large quantities in online and retail purchases of Chaetomorpha, and introduction of these fragments would likely result in viable individuals for establishment in a variety of geographic and seasonal environmental conditions. Mitigation of invasion risk was assessed in two ways(-)rapid response to a potential introduction by chemical eradication and prevention through safe hobbyist disposal. I tested the effectiveness of five chemicals used as algicides and found that acetic acid was highly effective at limiting survival and growth of aquarium Chaetomorpha. Chlorine bleach, copper sulfate and rock salt were effective at limiting growth but were inconsistent or ineffective in reducing survival of algal fragments. The algicide Sonar limited neither survival nor growth. If aquarium strains of Chaetomorpha are released, chemical eradication presents a viable management strategy, particularly through the use of acetic acid. A more cost-effective strategy, however, would be preventing introductions; thus safe alternatives to release were determined for hobbyist disposal of unwanted or excess aquarium Chaetomorpha. Here I present the minimum exposure durations necessary to induce full mortality of aquarium Chaetomorpha through boiling, microwaving, freezing, desiccation and exposure to freshwater. Hobbyist disposal by any of these methods would constitute safe alternatives to introduction of the alga into natural environments. Such preventative measures will inform outreach campaigns in order to limit the potential for aquarium-release introduction.
Identifier: CFE0004624 (IID), ucf:49918 (fedora)
Note(s): 2012-08-01
M.S.
Sciences, Biology
Masters
This record was generated from author submitted information.
Subject(s): Caulerpa taxifolia -- Chaetomorpha -- Aquarium dumping -- Aquarium release -- Macroalgae -- Vegetative fragmentation -- Invasive species
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0004624
Restrictions on Access: campus 2014-02-15
Host Institution: UCF

In Collections