Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Biology

Program Name/Specialization

Integrative Biology

Faculty/School

Faculty of Science

First Advisor

Erin Leonard

Advisor Role

Primary Academic Advisor

Second Advisor

Ève Gilroy

Advisor Role

Environment and Climate Change Canada Research Affiliate Program Advisor

Abstract

Lead (Pb) angling gear is frequently lost in aquatic environments and is increasingly recognized as a concern by regulatory agencies globally. While Canada banned Pb-based gear in National Parks in the 1990s, the European Chemicals Agency is now proposing broader restrictions. Despite assumptions that Pb fishing gear can transform into dissolved Pb2+ in water, this has yet to be directly measured and assessed. The toxicity of lead salts, such as lead nitrate, has been extensively studied over the past several decades; however, it remains uncertain whether lead fishing gear poses a similar level of toxicity. Freshwater snails like Planorbella pilsbryi, sensitive indicators and key components of aquatic food webs, are ideal for assessing contaminant impacts due to their short generation times. Additionally, multigenerational exposure to contaminants is seldom considered in toxicity assessments, and the mechanisms underlying toxicity from lead fishing gear remain poorly understood. Metabolomic and lipidomic analyses provide insight into the biochemical pathways that may be disrupted in adult snails exposed to lead fishing gear. This study aimed to determine the environmental impact of lead fishing gear through the following objectives: (i) assess the multigenerational toxicity of lead fishing gear to P. pilsbryi, and compare to the toxicity of lead nitrate; (ii) identify mechanisms of lead toxicity through metabolomic and lipidomic analysis; (iii) assess the effect of temperature on the toxicity of lead fishing gear to P. pilsbryi embryos. P. pilsbryi embryos were 2x more sensitive to lead fishing gear than equivalent concentrations of lead nitrate, and the second generation of embryos following parental exposure to lead were 2x more sensitive to lead than those that came from unexposed parents. Elevated sensitivity from fishing gear compared to lead nitrate likely stems from the presence of additional metals such as cadmium, copper, and zinc leaching from the gear. Metabolomic and lipidomic analyses revealed disruptions in amino acid metabolism (e.g., tyrosine, proline, arginine, cysteine) and in pathways related to metal ion, amine, and organic acid transport. This study offers foundational insight into the risks associated with lead fishing gear and generates data that can inform potential future regulations on its use globally.

Convocation Year

2025

Convocation Season

Fall

Download

Available for download on Wednesday, February 24, 2027

Share

COinS