Multidimensional approach to invasive species prevention.

Area of Science:

• Marine biology
• Environmental science
• Ecology

Background:

• Nonindigenous species (NIS) spread globally, facilitated by commercial shipping, leading to biotic homogenization and extinctions.
• Ballast water exchange (BWE) regulations mitigate NIS spread in freshwater ports but offer moderate protection for marine environments.
• Emerging ballast water treatment (BWT) systems face reliability concerns in freshwater or turbid conditions, prompting exploration of combined strategies.

Purpose of the Study:

• To compare the biological efficacy of "BWE plus BWT" against "BWT alone" for reducing aquatic NIS transport.
• To evaluate the combined approach's effectiveness in protecting freshwater ports from biological invasions.

Main Methods:

• Experimental testing at a ballast water treatment facility.
• Comparative analysis of "BWE plus BWT" versus "BWT alone" efficacy.
• Assessment of organism group abundance reduction.

Main Results:

• BWT alone significantly reduced most tested organism groups.
• The "BWE plus BWT" strategy significantly reduced all tested organism groups.
• Combined "BWE plus BWT" resulted in significantly lower abundances of most groups compared to BWT alone.

Conclusions:

• Combining BWE with BWT enhances the reduction of aquatic organisms in ballast water.
• This integrated approach offers greater protection against freshwater NIS invasion.
• The findings support the combined strategy for policy makers and environmental managers to reduce invasion risks.