Wildlife Survey & Photo Service

Mussel Surveys

Plankton Tows




Visual Surveys

Mussel colonization plates used to detect and/or monitor for Eurasian Mussels.

Surveys for Eurasian Mussels

To date, we have NOT found Zebra, Quagga, or Golden mussels in Lake Berryessa, Putah Creek, Putah South Canal or anywere in the Solano Project. All surveys have been negative.


We use the best scientific survey protocols established and review those protocols on a regular basis.



A 500 micro plankton tow net used to collect plankton from Lake Berryessa as part of the Protect Lake Berryessa Project

Plankton Tows

In some areas, Quagga Mussels spawn all year. Each healthy female can produce XXX eggsxxxxx. The microscopic larval mussels (see pictures on Microscopic Tab) can move slowly through the water column.


Finding mussel veligers (larvae) is frequently the way mussels are detected in a waterbody. We use EPA-approved 500 micro tow nets to filter 1000-2000 Liters of lake water. Note that is 2-3 times the recommended amount for filtration. Plankton samples from the tow are preserved and examined using special microscopes for the presence of Mussel veligers.

Plankton sample used to survey for Eurasian Mussel veligers (larve)

Plankton sample collected below Monticello Dam

Plankton sample collected from Lake Berryessa

Plankton sample showing a large Daphnia and a common diatom (algae) Asteronella.

Mussel veliger showing structures that allow it to move.
Quagga mussel veligers from voucher sample

Microscopic Exam using Cross-Polarized Microscope

Shows Zebra Mussel veliger (left) in a cross-polarized microscope and Quagga Mussel veligers (right) under a phase-contrast microscope.

Device used in Lake Berryessa to survey for adult Eurasian Mussels. To our knowledge, there are NO Eurasian Mussels in Lake Berryessa.

Adult Colonization Devices

After about six weeks mussel larvae "settle" (attach) to most underwater surfaces. To promote early detection of a mussel infestation, we deploy mussel colonization devices at various levels beneath Lake Berryessa marina docks. The devices are made of materials that mussels prefer for attachment. in reality, they will settle on most materials except copper.

Lake Berryessa - Markley Cove Marina launch ramp. A site we survey for Eurasian Mussels on a regular basis

Visual Surveys

Visual surveys are quick and simple surveys where we look for adult mussels that might be attached to boat hulls, hydrolifts, cables, docks and other existing structures. We never touch or enter any watercraft.



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