lake conroe zebra mussels action plan

Zebra MusselsInitial Information Gathering /

Action Plan for Lake Conroe PreparednessJuly 21, 2010

On April 3, 2009, the first adult zebra mussel in Texas waters was confirmed living in Lake Texoma. Invasive zebra mussels were also found in a stream that feeds into Lake Lavon. Experts fear they could eventually spread throughout the Red and Trinity River systems as well as much of Texas.Texas Invasives.org

Background

The zebra mussel (Dreissena polymorpha) and quagga mussel (Dreissena rostriformis

bugensis),collectively referred to as Dreissenids are among the most devastating aquatic nuisance species to invade North American fresh watersWestern Regional Panel (WRP) for the Aquatic Nuisance Species Task Force (ANSTF)

Why Do We Care?

Are the only freshwater mussels that attach to surfaces Can colonize the insides of pipelines and restrict the flow of

water Can damage boat hulls, plug water systems used in boat

motors Can result in costly mitigation expenses Can cause declines in populations of fish, birds and native

mussel species

Dreissenids

View of exposed zebra mussels at a Kansas reservoir after a lake drawdown.(Photo: Jason Goeckler, KS Department of Wildlife & Parks)

January 28, 2010 TPW Commission Meeting◦ Brian Van Zee discusses Zebra Mussels

Transcript http://www.tpwd.state.tx.us/business/feedback/meetings/2010/0128/transcripts/public_hearing/index.phtml

Audio http://www.tpwd.state.tx.us/business/feedback/meetings/2010/0128/agenda/

TPW Has Addressed the Issue

Zebra Mussels in Texas: Assessment of relative risks to fishery resources, recommendations for action, and expectations for the futureTPWD – Inland Fisheries Division, Heart of the Hills Fisheries Science

Center

http://texasinvasives.org/resources/publications/TPWD_ZebraMussels_in_Texas.pdf

Resulting TPWD Documentation

July 19, 2010 Palms Marina Owner reported Zebra Mussels on a Dry-Docked, NOT-SEAWORTHY vessel that arrived from Lake Texoma

July 21, 2010 SJRA inspected and quarantined the vessel

What About Lake Conroe?

Susceptibility

Dreissenid mussel densities throughout the West could vary widely depending on water chemistry, food availability, and breeding population

Chemistry◦ Calcium◦ Temperature◦ PH◦ Other

Western Regional Panel on Aquatic Nuisance Species

North American zebra mussel populations require 10 mg Ca2+/l to initiate shell growth and 25mg Ca2+/l to maintain shell growth.

Large populations of zebra mussels are not expected where calcium levels are less than 25 mg/l (Hincks and Mackie).

Cohen and Weinstein (2001) found little evidence that zebra mussels can become established at ambient calcium concentrations below about 20mg/l.

It should be noted that calcium may be elevated near concrete structures (Cohen and Weinstein 2001).

Susceptibility Based on Water Chemistry – “CALCIUM”

Dreissenids can tolerate a wide range of water temperatures from roughly 32F to 86F (Ohio Sea Grant 1997).

Spawning will not generally occur at temperatures below about 12C (Claudi and Mackie 1994).

There is evidence, however, that quagga mussels in deep waters of the Great Lakes are capable of spawning at temperatures near 5C (Roe and MacIsaac 1997) and 9C (Claxton and Mackie 1998)

Susceptibility Based on Water Chemistry – “TEMPERATURE”

Larval development is inhibited at pH of 7.4 Optimal larval survival occurs at a pH of 8.4 Higher rates of adult survival occur at a pH

of 7.0-7.5 Optimal adult growth occurs at pH 7.4-8.0

(Benson and Raikow 2007)

Susceptibility Based on Water Chemistry – “PH”

Environmental SummaryVARIABLES HIGH MODERATE LOW VERY LOW

Dissolved Oxygen (ppm)

8 – 10 6 – 8 4 – 6 <4

Water Temperature (C/F)

18/64 – 25/77

16/61 – 18/6425/77 – 28/82

9/48 – 25/7728/82 –30/86

<8/46>30/86

Total Hardness (mg CaCO3/l)

90 – >125 45 – 90 25 – 45 <25

Calcium (ppm) 25 – 125 20 – 25 9 – 20 <9

pH 7.5 – 8.7 7.2 – 7.58.7 – 9.0

6.5 – 7.2 <6.5>9.0

Salinity (ppt) 0 – 1 1 – 4 4 – 10 10 – 35

Conductivity (m Siemens)

83 – >110 37 – 82 22 – 36 >22

Turbidity (secchi disk cm)

40 – 200 20 – 40 10 – 20200 – 250

<10>250

Water Velocity (m/sec)

0.1 – 1.0 .09 – 0.11.0 – 1.25

.075 - .091.25 – 1.5

<.075>1.5

From European & North American Sources C.O’Neill, NY Sea Grant, Mar 96

Spawn 1-2 times/season Spawn from 54° to 80° F Become stressed at 86o F, die within a few

weeks. Die within 5 hours at 90o F. Grow @ 3mm/mo w/ @ 1 cm per year. Filter 1 liter of water per day.

Everett Laney, US Army Corp of Engineers, Tulsa

Historical Biology

They like warm water!

Some spawning in water over 89o F for 2-3 months.

Surviving in water over 90o F for several weeks.

Can grow 1.19-1.25mm/week = 1cm in @ 2 months.

Everett Laney, US Army Corp of Engineers, Tulsa

Biological Reality

Adopt TPWD “Recommendations for Action” as Initial SJRA Action Plan◦ Direct control efforts toward Prevention

Public Awareness (partner w/ LCA and others) Monitoring Law Enforcement

◦ Evaluate potential control or containment measures

Inform L.C. Event Sponsors of the dangers and precautions that must be taken prior to launching◦ Aquapalooza◦ TTBC

What’s Next for SJRA?

Public Awareness Campaign◦ Partner w/ TPWD in:

Community Outreach Efforts Posters Fliers Other

Portland Sampling Efforts Law Enforcement Efforts

What’s Next Cont…

Research◦ Potential Control or Containment Measures◦ Investigate Potential Surface-Water Intake

Structure & Spillway- Gate Modifications Coatings? Other

◦ N.T.M.W.D. Project (Alan Plummer & Associates)

What’s Next Cont...

100th. Meridian Initiative◦ http://www.100thmeridian.org/

Aquatic Nuisance Species Task Force◦ http://www.anstaskforce.gov/default.php

Western Regional Panel on Aquatic Nuisance Species (Have Developed A Detailed Action Plan)◦ http://www.fws.gov/answest/aboutus.htm

TEXASINVASIVES.ORG N.T.M.W.D. Contact – Mike Rickman 972-442-5405 Army Corp Expert - Everett Laney, Tulsa Office 918-669-7411 Alan Plummer & Associates Contact – Chuck Tracey, Ft. Worth

office

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