Golden Mussel in the California Delta – Likely Timeline

First Detection in North America

• Date: October 17, 2024
• Location: Rough and Ready Island near the Port of Stockton, San Joaquin County, California
• Significance: First confirmed detection of golden mussels (Limnoperna fortunei) in North America

Source: California Department of Fish & Wildlife → wildlife.ca.gov/golden-mussel

Additional Locations Found Since

• Turner Cut
• O’Neill Forebay (Merced County)
• Contra Costa Canal

These finds confirm the golden mussels are spreading within the Sacramento-San Joaquin Delta system.

Source: Contra Costa Water District → ccwater.com

Likely Source of Introduction

• Ballast water from international shipping (likely from Asia or South America)
• Carried as microscopic larvae in ship water tanks
• Discharged into the Port of Stockton shipping channel

How Long Have They Likely Been Here?

Based on colony size and spread:

• Likely introduced: Between 2019 – 2022
• Official discovery: October 2024

This 2 to 5 year window before discovery matches the invasion patterns seen in South America.

Source: Water Education Foundation → watereducation.org

Likely Timeline: Golden Mussels in the California Delta

Discovered: October 2024 → Port of Stockton, Rough and Ready Island

How Long Before Discovery Were They Likely There?

Golden mussels (Limnoperna fortunei) are tiny when young — and larvae (veligers) are microscopic — so early infestations are almost impossible to detect until:

• Adults grow large enough to be seen
• They form dense colonies
• They begin clogging pipes or showing up on infrastructure

Based on Other Invasions (South America & Asia):

California Delta Estimate:

If first found in October 2024 → Realistically:

Golden mussels were probably introduced between:

2019 to 2022

Most Likely Scenario:

• Entered via ballast water from international shipping (likely Asia or South America origin)
• Settled in deep-water structures near Stockton
• First small colonies developed ~2020-2022
• Spread slowly until adult colonies were visible & sampled in 2024

Important Notes:

• Freshwater invasives like this usually go unnoticed for years unless targeted monitoring occurs.
• The California Delta is massive with endless hard surfaces (rip rap, docks, pilings, pipes) perfect for golden mussels.
• Detection in 2024 means there are likely multiple established colonies already in connected waterways.

Bottom Line:

Golden mussels probably arrived in the California Delta between 2019-2022… long before anyone saw them.

Early detection = Already too late for eradication.

Discover the ultimate resource for bass fishing enthusiasts with Bass Angler Magazine! Packed with expert tips, the latest cutting-edge techniques, and in-depth articles, our magazine is your go-to guide for mastering the art of bass fishing. Whether you’re a seasoned pro or just getting started, Bass Angler Magazine delivers the insights and inspiration you need to reel in the big ones. Subscribe today and elevate your angling game!

.aioseo-author-bio-compact{display:flex;gap:40px;padding:12px;text-align:left;border:1px solid #000;border-radius:5px;color:#111;background-color:#FFF}.aioseo-author-bio-compact-left{flex:0 0 120px}.aioseo-author-bio-compact-right{flex:1 1 auto}.aioseo-author-bio-compact-left .aioseo-author-bio-compact-image{width:120px;height:120px;border-radius:5px}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-header{display:flex;align-items:center}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-header .author-name{font-size:22px;font-weight:600}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-header .author-job-title{margin-left:12px;padding-left:12px;font-size:18px;border-left:1px solid gray}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-main{margin:12px 0;font-size:18px}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-main>p:last-of-type{display:inline}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-main .author-bio-link{display:inline-flex}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-main .author-bio-link a{display:flex;align-items:center}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-main .author-bio-link a svg{fill:#000}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-footer .author-expertises{display:flex;flex-wrap:wrap;gap:10px}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-footer .author-expertises .author-expertise{padding:4px 8px;font-size:14px;border-radius:4px;background-color:#DCDDE1;color:inherit}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-footer .author-socials{margin-top:12px;display:flex;gap:6px}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-footer .author-socials .aioseo-social-icon-tumblrUrl{margin-left:-2px}.aioseo-author-bio-compact-site-editor-disclaimer{color:#000;margin-bottom:12px;font-style:italic}@media screen and (max-width:430px){.aioseo-author-bio-compact{flex-direction:column;gap:20px}.aioseo-author-bio-compact-left .aioseo-author-bio-compact-image{display:block;margin:0 auto;width:160px;height:160px}.aioseo-author-bio-compact-right{text-align:center}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-header{justify-content:center}.aioseo-author-bio-compact-right .aioseo-author-bio-compact-footer .author-socials{justify-content:center}}

Mark Lassagne

Source: https://bassanglermag.com/golden-mussel-in-the-california-delta-likely-timeline/?utm_source=rss&utm_medium=rss&utm_campaign=golden-mussel-in-the-california-delta-likely-timeline

$post[‘post_content’] .= ‘Source‘;