Document Type

Thesis - Open Access

Award Date

2023

Degree Name

Master of Science (MS)

First Advisor

Alison Coulter

Abstract

Freshwater systems are susceptible to numerous anthropogenic pathways of invasive species introductions and subsequent establishment. Once establishment occurs, invasive species not only impact biodiversity, ecosystem function, and human health, but also cost the global economy billions of dollars every year. Recreational fishing is one of the most prevalent pathways for invasive species introductions in freshwater systems due to increased propagule pressure from boating and angling activity. Within recreational fishing, the live bait trade represents a secondary pathway whereby anglers illegally release baitfish (and water) that may contain invasive species. Preventative actions, including regulations, education, and inspections have been implemented to deter introductions of invasive species but are variable across jurisdictions. For my second chapter, I assessed the risk of the live bait trade as a pathway for Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis (collectively referred to as bigheaded carp), in five states of the Missouri River Basin. Water provided by bait retailers with purchased baitfish was filtered to determine the presence of bigheaded carp with environmental DNA (eDNA) analysis. Bigheaded carp eDNA was present beyond their current range, non-advertised species were present within purchased baitfish, educational signage was limited, and distance from a bait retailer to observed wild bigheaded carp individuals was an important predictor for a bait retailer having a positive eDNA detection. Education and surveillance programs should occur near invasion fronts and regional collaboration is needed to evaluate inconsistencies in preventative actions to reduce weak-link scenarios. For my third chapter, I contacted aquatic invasive species experts in each US state to evaluate regional variation in preventative actions for the freshwater live bait trade. The Great Basin placed the most focus on regulations whereas the Great Lakes placed the most focus on education and inspections. The extent of preventative actions is often limited by time, funding, or personnel; however, regional collaboration could overcome these constraints by increasing available resources and information sharing. The live bait trade remains a high-risk pathway for the introduction of invasive species, but there are opportunities to reduce this risk with regional collaboration and integration of preventative actions.

Library of Congress Subject Headings

Introduced freshwater organisms.
Biological invasions.
Fishing baits -- Ecology.
Bighead carp.
Silver carp.

Publisher

South Dakota State University

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Rights Statement

In Copyright