Habitats and Sensitive Wildlife Species of the Ventura River

Watershed

Laura Riege, Sr. Project Ecologist

Ventura River Watershed UMay 13, 2010

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Introduction

• Watershed overview from a wildlife habitat perspective

• Overview of the sensitive wildlife species in the watershed

• Four listed species that are frequently impacted by projects

• Invasive species threatening the watershed

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Overview: Ventura River Watershed

Ventura River Preserve

Ventura River Confluence Reserve

Ilvento Preserve

Ojai Meadows Preserve

Total Watershed area = 223 square miles

Nearly half are in the National Forest

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Vegetation Communities• Wetland Habitats

– Lacustrine– Riverine– Palustrine– Estuarine– MarineRiparian

• Upland Habitats– Grassland– Scrub– Chaparral– Woodland– Sand Dunes

Lacustrine

Marine & Sand Dune

Palustrine & Grassland

Riverine

Scrub and Chaparral

Estuarine

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Land Use and Vegetation Types

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Sensitive Species in the Watershed

• 3 fish• 2 amphibians• 5 reptiles• 29 birds• 2 mammals

Many others are “watch list”

• 7 endangered• 3 threatened• 22 CA species of

special concern• 4 CA fully protected• 4 other protections

(e.g., state or federal forest service)

40 sensitive wildlife species

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Protection Under ESA and CESAFederal Endangered Species Act:

– Federal ESA prohibits the “take” of any threatened or endangered animals and protects their habitat

– Take is defined as “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect or attempt to engage in any such conduct”

– “Harm” is defined as “an act which actually kills or injures wildlife.” Harm includes significant habitat modification or degradation

– Section 7 – Federal Actions– Section 10 – Non-federal Actions

Habitat Conservation Plan (HCP)

California ESA:– Fish and Game Code prohibits "take" of any species that the commission

determines to be an endangered species or a threatened species – Take is defined as "hunt, pursue, catch, capture, or kill, or attempt to hunt,

pursue, catch, capture, or kill" – Fully Protected species may not be taken or possessed at any time

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T&E Species: Estuarine and Sand Dune

• Tidewater goby• California least tern• Western snowy plover• Southern steelhead• California brown

pelican – delisted!CA Fully Protected

species

Photo Courtesy California State Parks

Photo by Steve Howard

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T&E Species: Riverine/Riparian

• Southern Steelhead• California red-legged

frog• Least Bell’s vireo• Bank swallow• Southwestern willow

flycatcher• Western yellow-billed

cuckoo

Photo by Marcel GahbauerPhoto by Nicky Davis

Photo by Kylie Fischer

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T&E Species: Upland

• California Condor• American peregrine

falcon – delisted!CA Fully Protected

species

Photo by Francois Gohier/Auscape Intl.

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Southern Steelhead

• Steelhead are the ocean-going (anadromous) form of rainbow trout

• Juveniles spend 1-3 years in freshwater to rear– Require pool or riffle habitat, optimally less than

20°C/68°F with good dissolved oxygen– May rear in the lagoon/estuary– Smolts require adequate flows to migrate to ocean

• Adults spend 1-2 years in the ocean before returning to the stream to spawn– Usually migrate in storm events with good flows– Require good gravels to lay eggs (spawn) with

clear water and good dissolved oxygen

Federally-listed Endangered/CA Species of Special Concern

Photo by John Southwick

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Steelhead Spawning Habitat

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Steelhead Rearing Habitat

Rearing habitat is

the limiting factor for

steelhead in the Ventura

River

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California Red-legged Frog

• In a wide range of aquatic habitats: creeks, streams, and ponds that have perennial or near-perennial standing water

• Breeds from November through March• Breeding sites: deep pools or backwaters within

streams, ponds, marshes, dune ponds, lagoons, and artificial impoundments

• During the summer adults may move to forested sections of slow streams with undercut banks and exposed root masses

• Frogs also occur in upland habitat; recorded moving over two miles from nonbreeding to breeding sites

Federally-listed Threatened/ CA Species of Special Concern

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Suitable Habitat and Recent Sightings of California Red-legged Frog

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Least Bell’s vireo

• Structurally diverse woodlands in riparian areas– Dense cover within 2 meters of the ground for

nesting – Dense, stratified canopy for foraging– Well-developed overstory (willow, cottonwood,

sycamores) with a dense shrub understory– Nests in shrubs between 5 – 10 years old

• Prey on a variety of insects including beetles, bugs, grasshoppers, caterpillars, and moths

• Breeding season is April 1 through August 31

Federally- and State-listed Endangered

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Least Bell’s Vireo: Suitable Habitat

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Tidewater Goby

• Inhabits coastal brackish water habitats of estuaries and lagoons

• Favors calm conditions when lagoons are cut-off from the ocean by beach sandbars

• Low-salinity conditions and minimal water currents

• Bottom dwellers and are: found at water depths of less than 3 feet

• Requires fresh unconsolidated sand for reproduction

• Life spans are approximately 1 year

Federally-listed Endangered/CA Species of Special Concern

Photo courtesy USFWS

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Invasive Species

Ventura River Streamteam

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Invasive SpeciesAn "invasive species" is

1) non-native (or alien) to the ecosystem 2) whose introduction causes … economic or environmental harm, or

harm to human health

Small subset of exotic, non-native, alien species are invasive– May be native, even endangered, in one place and invasive in

another

U.S. spends ~$120 billion annually on invasive species

Invasives impact approximately half of all federally-listed species;40% of all animal extinctions due in part to invasive species

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Problems caused by invasive species

• Prey on native species– bullfrogs, green sunfish

• Compete with native species – Arundo

• Spread parasites/diseases– West Nile Virus

• Change physical conditions – zebra mussels, crayfish

• Harm to infrastructure and recreation– quagga mussels

Star Thistle

Bullfrog (left) and Red-legged Frog (right)

New Zealand Mudsnail

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Giant Reed Impacts to Riparian/Riverine Habitat

Outcompete native riparian plants– Inadequate habitat for nesting birds– Does not support insects and other prey for foraging

birds and wildlife– Does not provide food for wildlife– Does not provide overhanging cover and instream

cover for fish

Form dense, pure stands – Block fish migration– Increased flood risk– Highly flammable

High water demand reduces instream habitat for fish and amphibians

Giant Reed

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Aquatic Invasive SpeciesNew Zealand MudsnailSize: a grain of sand to 1/8 inch in lengthColor: black or brown• Reproduce clonally to very high

densities• Compete with native invertebrates and

reduce food resources for fish• Small and sticky, spread through

hatcheries and as “hitchhikers” on gear and clothing

Quagga and Zebra MusselsSize: fingernail-sized but can grow up to 2

inchesQuagga: black, cream, or white bandsZebra: alternating dark and light stripes• Damage ecosystems and clog pipes

and other infrastructure• Spread through water transfers and

trailered boats

Color variation in Zebra and Quagga mussels.

New Zealand Mudsnail

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Invasive Species: General Best Practices• Do not transfer water, mud, plants or

seeds from one stream or study area to another– Inspect boats, fishing gear, boots and clothes– Quarantine gear, dry, or freeze– Remove visible snails with a stiff brush and follow

with rinsing• Do not plant invasive species• Never release water or organisms from a

fish tank or water garden• Comply with boat washes, inspections,

Casitas quarantine

Quagga mussels can survive three to five days out of water depending upon temperature and humidity in

summer, longer in the winter - up to 30 days

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Questions?