Project period: 7 1 24-9 30 26PROJECT title: investigating the role of plant complexity in facilitating species introductions via the hitchhiking pathwayto date, the unintended transport of exotic…

This Cooperative Agreement award from the U.S. Geological Survey (USGS) under the USGS Research and Data Collection program (CFDA 15.808) will fund a $150,000 research project at the University of South Alabama (USA) from July 1, 2024 to September 30, 2026. The project aims to investigate the role of plant complexity in facilitating species introductions via the "hitchhiking" pathway, where exotic species are unintentionally transported alongside imported aquatic plants, algae, and their packaging. Key project activities include:

1. Conducting a synthesis review to identify gaps in knowledge related to factors influencing the unintended importation of non-native aquatic species, such as plant/algae species, structural complexity, packaging, country of origin, and vendor.

2. Carrying out a lab-based, empirical investigation to assess imported aquatic plants, algae, and their packaging for the presence of hitchhiking organisms.

The project will deliver a list of hitchhikers on common aquatic plants and algae, along with an assessment of the factors most likely to serve as sources of such unintended introductions. This information is expected to assist in the prevention of invasive species introductions nationwide. The University of South Alabama will collaborate with the Dauphin Island Sea Lab on a subaward portion of the project focused on field sampling and data analysis.

Project period: 7 1 24-9 30 26PROJECT title: investigating the role of plant complexity in facilitating species introductions via the hitchhiking pathwayto date, the unintended transport of exotic species alongside imported aquatic plants, algae, and their packaging (hitchhiking) represents an underappreciated invasion pathway. The high structural complexity of many common aquarium and ornamental aquatic macrophytes may play a role in hitchhiking, reducing encounter rates with fauna which may reside within interstitial spaces of the plant and thus go undetected. This potentially problematic pathway was highlighted in the recent marimo moss ball (aegagropila linnaei) contamination incident carrying live hitchhiker zebra mussels (dreissena polymorpha) and a multitude of other exotic taxa in the spring of 2021. Given that introductions of exotic aquatic species contribute to millions of dollars of damage and management costs for the U.S., the identification of potential aquatic plants, algae, and packaging with a high potential of serving as a vector for unintended hitchhikers will aid in managing this group of organisms in trade. Here, will evaluate currently imported aquatic plants and algae for hitchhiking taxa and determine plant metrics (e.g., plant algae species and their structural complexity, packaging, country of origin, vendor, etc.) influencing the unintended importation of non-native species. Propose to accomplish this by: 1) conducting synthesis review efforts of existing information to highlight gaps in knowledge as IT relates to the aforementioned factors of interest, and 2) conducting a lab-based, empirical investigation of plants, algae, and their packaging for hitchhiking organisms. The products of this effort include a list of hitchhikers on the common aquatic plants and algae, along with an assessment of plants, regions, packaging materials, shipping, handling, and other factors that will most likely serve as a source of hitchhikers. This project will provide vital information that will assist in the prevention of invasive species introduction on a nation-wide scale, thus supporting the goals of the united states geological survey.