HYDRILLA IN THE DELAWARE & RARITAN CANAL

HEATHER DESKO SENIOR WATERSHED PROTECTION SPECIALIST

NEW JERSEY WATER SUPPLY AUTHORITY

NEW JERSEY WATER MONITORING COUNCIL

24 MAY 2017

HYDRILLA VERTICILLATA

• TWO BIO-TYPES: MONOECIOUS & DIOECIOUS

• NATIVE TO ASIA

• MEANS OF INTRODUCTION: AQUARIUM PLANT

• RECENT INVADER TO MID-ATLANTIC (1980S)

• REPRODUCES BY FRAGMENTATION, TUBERS, &

TURIONS

• TUBERS CAN REMAIN VIABLE 6+ YEARS

• CAN REACH LENGTHS OF UP TO 25 FEET

• CAN GROW UP TO 1 INCH PER DAY!

HYDRILLA – “THE PERFECT WEED”

• ADAPTS TO VARIETY OF CONDITIONS

• WATER DEPTHS – INCHES TO 20+ FT

• LAKES/PONDS & RIVERS

• SALINTY 0-9PPT (POSSIBLY UP TO 13PPT)

• TURBIDITY/WATER CLARITY

• LOW LIGHT TOLERANCE

• EVEN UP TO 10 WEEKS IN TOTAL DARKNESS!

• IMPACTS:

• NATIVE SAV & OTHER BIOTA

• WATER CHEMISTRY

• WATER FLOW

• RECREATION

D&R Canal at Scudders Falls September 2016

Univ. of Michigan

Sea Grant

USDA

HYDRILLA & CYANOBACTERIA

• TOXIC CYANOBACTERIA AETOKTHONOS HYDRILLICOLA

(EAGLE KILLER – GROWS ON HYDRILLA)

• GROWS ON HYDRILLA STEMS ONLY

• UNIVERSITY OF GEORGIA (S. WILDE) RESEARCHERS

DISCOVERED AND STUDY THIS

• NJWSA SENT SAMPLES FROM THE CANAL IN EARLY

SEPTEMBER 2016:

• A. HYDRILLICOLA WAS NOT FOUND

For more information: https://www.warnell.uga.edu/research/dr-susan-wilde-avm-research

Serrated edges visible w/ naked

eye

Whorls of 3-8 (typically 5) leaves

Hydrilla Features

LOOKALIKE: COMMON WATERWEED

• ELODEA CANADENSIS

• SLOW-MOVING/STILL WATER, DEPTHS OF 10

FEET

• LEAVES IN WHORLS OF 3 AROUND THE STEM

• EDGES APPEAR SMOOTH, VERY FINE

SERRATIONS REQUIRE MAGNIFICATION TO VIEW

• VERY BRITTLE

• STEMS ARE BRANCHED, AND GROW IN MASSES

ALONG THE BOTTOM

NATIVE

Delaware River at Bulls

Island

Hydrilla & Eelgrass Photo by: Chris Doyle,

SOLitude Lake Management

D&R CANAL SAV MAPPING SUMMARY

Date (2016) Sect. Description Miles # Sites Sites w/Hydrilla % Hydrilla Notes 9/15 and

9/23 1 Rte 179 to Titusville Bridge 5.23 165 67 40.6%

1st occurrence of rooted

hydrilla

9/6 and 9/7 2 Titusville Bridge to

Washington's Crossing 1.74 57 49 86.0%

9/7, 9/8, 9/9 3 Washington's Crossing to

Lower Ferry Road 4.50 149 139 93.3%

9/9 and 9/16

4 Lower Ferry Road to Hermitage

Ave. 2.12 69 60 87.0%

9/21 5 Canal Support Structure to

Carnegie Road 1.97 65 22 33.8% All trace sites

9/22 6 Provinceline Road to Alexander

Road 2.75 92 0 0.0%

Floating hydrilla

fragments observed

Rooted Hydrilla occurred at 337 of 597 Sample Stations (56.4%)

SAMPLE HYDRILLA ABUNDANCE AND DISTRIBUTION MAP

• Colored Circles: Rooted

Hydrilla

• Average of Both Banks (2

Tosses)

• Data Collected for All SAV

2016 TUBER MONITORING

Site Name

(Section)

# Cores 2016 Tuber

Density (m2)

2016 Turion

Density (m2)

DR-1 3 462.8 0.0

DR-2 5 85.6 203.3

DR-3 5 288.9 42.8

DR-4 3 320.4 17.8

DR-5 5 10.7 0.0

TUBER MONITORING – 2016 RESULTS

• METHODS OF CONTROL:

• MECHANICAL: CUTTING, HARVESTING, DREDGING

• BIOLOGICAL: TRIPLOID GRASS CARP

• PHYSICAL: BENTHIC MATS

• CHEMICAL: SELECTIVE/BROAD SPECTRUM, SYSTEMIC/CONTACT HERBICIDES

HYDRILLA MANAGEMENT

Photo by: Gene Huntington,

Remote Intelligence

26 options evaluated in the

2017 Canal SAV Management Plan

Available at www.njwsa.org/hydrilla

HERBICIDE: FLURIDONE

Eno River, NC

Photo: Mark Heilman, SePRO

Injection unit

• SLOW ACTING, SYSTEMIC HERBICIDE

• REQUIRES LONG (90-120 DAY) CONTACT TIME

• LOW DOSE (2-4 PPB) REDUCE/ELIMINATE

WATER USE RESTRICTIONS

• AT LOW CONCENTRATIONS, CAN BE VERY

SELECTIVE IN EFFECTS ON OTHER AQUATIC

PLANTS (HYDRILLA HIGHLY SUSCEPTIBLE)

• PERMITS APPROVED

DYE TRACER STUDY

• RHODAMINE DYE INJECTED FOR 48

HOURS

• DYE CONCENTRATIONS MEASURED

REAL-TIME WITH FLUOROMETER

• DYE SIMULATES HERBICIDE TRAVEL TIME

• CONSERVATIVE ESTIMATE OF HERBICIDE

CONCENTRATIONS

4.9

4.8

4.6

4.4

4.2 4.0

3.9

3.9

3.5

3.2

3.1

2.9 3.1

2.9

2.5 2.1

2.1

Maximum Rhodomine Levels Measured

Following 5 ppb dye injection

BENCHTOP SIMULATIONS

• CANAL WATER WITH FLURIDONE

• SIMULATED EACH TREATMENT PLANT PROCESS

• SAMPLES COLLECTED AND ANALYZED FOR

FLURIDONE CONCENTRATION

• CARBON VERY EFFECTIVE AT REMOVING

FLURIDONE

2017-2019 MONITORING EFFORTS

• 2017 – COMPLETE SUBMERGED

AQUATIC PLANT (SAV) SURVEY OF D&R

CANAL (40 MILES)

• 2017-2019 – ANNUAL SAV SURVEY OF

MANAGEMENT ZONE

• 2017-2019 – ANNUAL TUBER SAMPLING

• 2017-2019 – HERBICIDE

CONCENTRATION MONITORING

Photo by: Chris Doyle

SOLitude Lake Management

Delaware & Raritan Canal,

Workhouse Spillway

(to the Delaware River),

Hopewell Township

EDUCATION

• SIGNAGE/KIOSKS

• BOAT PERMIT ATTACHMENTS

• WEBSITE: WWW.NJWSA.ORG/HYDRILLA

• FAQS

• HANDOUTS

• MUNICIPAL OUTREACH

• D&R CANAL COMMISSION MEETINGS (PUBLIC)

• CANAL WATER CUSTOMER MEETINGS

PREVENTING THE SPREAD

• CHECK FOR AND REMOVE PLANTS, MUD AND

AQUATIC LIFE FROM EQUIPMENT

• DRAIN WATER FROM BOATS, LIVE WELLS, BILGE

AND BAIT BUCKETS

• CLEAN* EQUIPMENT WITH HOT

WATER/DETERGENT AND

• DRY TO THE TOUCH FOR SEVERAL DAYS

SPECIAL THANKS:

HEATHER DESKO

SENIOR WATERSHED PROTECTION SPECIALIST

908-730-0270 X231

HDESKO@RARITANBASIN.ORG

CHRIS DOYLE, SOLITUDE LAKE MANAGEMENT

MARK HEILMAN, PH.D., SEPRO

www.njwsa.org/hydrilla