Lamprey Conservation Guidance for Instream Activities. Bianca Streif. U.S. Fish and Wildlife Service Oregon Fish and Wildlife Office

Transcription

1 Lamprey Conservation Guidance for Instream Activities Bianca Streif U.S. Fish and Wildlife Service Oregon Fish and Wildlife Office Introduction Life history characteristics of lampreys. How to identify of locations of lampreys within streams to avoid impacts. Habitat impacts to lampreys. Recommended actions that address the conservation needs of lampreys. 1

2 ???????? Information is limited on lamprey life history and ecology, and even more limited on reasons for decline and recommended conservation actions. Recommendations presented are based on literature, information from biologists conducting research and implementing projects on lampreys or other aquatic species throughout the west. In addition, information was gathered from various experts using a survey specific to this presentation. lamprey An eel-like primitive fish with a jawless sucking mouth. -The American Heritage Dictionary Lampetra lambere = lick + petra = stone (Stone licker) 2

3 Pacific Northwest Lampreys Pacific lamprey Lampetra tridentata River Lamprey L. ayresi Western Brook Lamprey L. richardsoni Other species in region: Dwarf Pacific Lamprey Miller Lake lamprey L. minima Pacific brook lamprey L. pacifica Klamath River lampreys: L. similis, L. lethophaga, L. folleti Distribution Historically, Pacific lampreys were thought to be distributed wherever salmon and steelhead once occurred. 3

4 Pacific Lamprey Life History Adults live in ocean 2-3 years and feed on host fish Adult migrates to freshwater Adults spawn in gravel nest in stream riffles, then die Eggs hatch into larvae Larvae (ammocoetes) drift downstream to backwater area Sucking disk Teeth pattern used for ID Larvae transform to juveniles (macropthalmia) and migrate to ocean or stay in stream Ammocoetes live in silt/sand substrates as filter feeders for 5-7 years Adult Phase Pacific & river lamprey adults in ocean 1 4 years. Lamprey scars on basking shark M. Mitchell Goose Lake lamprey on tui chub Western brook lamprey are not parasitic and do not feed as adults. R. White 4

5 Spawning Adults enter freshwater Feb. Oct. and spawn the following Feb. - May. Adult Pacific Lamprey Spawning Needs Spawn in low gradient riffles, runs, glides and pool tail outs. Use gravel /cobble substrate (2-4 in.) with low embeddedness. Nest is usually feet deep with ~ ft/sec flow. Passage to spawning areas. Intact stream systems. Ammocoete pheromones? 5

6 Migrating adult lampreys may be directed to their spawning areas by the smell (pheromones) of larval and juvenile lampreys. It is unknown if they have any homing instinct like that of salmon. Habitat alteration effects on adult lampreys: Physical barriers Entrainment Altered flows Altered sediment regimes Loss of riparian habitat Water temperature & quality 6

7 Ammocoetes (larvae) The most important habitat to protect for lamprey... ammos = sand koites = dwellers Multiple age classes reside in fine sediments for 3 7 years. Feed on diatoms, algae, and detritus. Pacific Lamprey Ammocoete Needs Undisturbed low velocity areas with fine substrates such as backwater habitat. Stable channel bottom. Passage to rearing areas. Clean water and natural flows. Habitat complexity / large wood. Healthy riparian corridors. 7

8 Habitat alteration effects on ammocoetes: Altered Flows / de-watering of stream. Contaminants. Altered sediment regimes. Streambed disturbance and/or degradation. Degradation of floodplain and riparian habitats. Elevated water temperature. Physical barriers to rearing areas. Entrainment / Impingement. Macropthalmia (juvenile) Transform July Oct. migrate to ocean late fall and spring. macr = large opthalmia = eye USGS 8

9 Pacific Lamprey Juvenile Needs Unobstructed passage to ocean. Habitat complexity / large wood. Natural flows. Habitat alteration effects on juvenile lampreys: Entrainment / impingement Altered Flows Physical barriers Elevated water temperature Loss of habitat diversity Conditions that favor predators 9

10 Value Tribal Food Cultural / medicinal Commercial Bait Ecological Forage for birds, sturgeon, sea lions Ocean derived nutrients Filter feeders Status Three Pacific Northwest lamprey species were petitioned for listing but found not to be warranted (due to a lack of information) for listing under the ESA: Pacific lamprey Western brook lamprey River lamprey It appears there has been a decline in abundance and distribution of lampreys. 10

11 Determine if lampreys are in the stream before your project begins! Methods Used to find Lampreys: Locating them in a stream before your project begins. Local experts and / or mapping data Video monitoring Adults / Juveniles: Direct observation during spawning Observation of lamprey redds Night-time observations esp. at barriers Nets (hand, dip, drift, fyke) and seines Electro-fishing (slow pulse) Screw traps / pot traps Snorkeling Weirs 11

12 Methods Used to find Lampreys: Locating them in a stream before your project begins. Ammocoetes: Nets and seines Electro-fishing (slow pulse) Not recommended: Screening substrate De-watering Gill-netting the absence of evidence is not evidence of absence Stewart Reid Passage Lampreys move mostly at night with bursts of swimming followed by attaching to a relatively smooth surface. They will wedge into crevices, climb most vertical faces, and seek out lower velocity flows! Lampreys travel deeper in the water column (no air bladder) compared to salmonids, therefore, traditional spill gates may block passage. Use removable spillway weirs during peak movement periods. Lampreys avoid light. Hanging culverts (a couple of inches) are barriers to lampreys. 12

13 Lamprey friendly passage features include: Smooth surfaces. Round corners with no 90 bends in high velocity areas. No grating that precludes attachment. Natural substrate in culvert bottoms or fitted with attachment surfaces. Lamprey friendly passage features include: Flat plates (e.g., steel, aluminum, polycarbonate) to provide attachment points for passage ramps over flashboards or grating. Smaller gaps on screens to reduce impingement or entrainment of ammocoetes on screens or intakes. Rock piled with water overflow to accommodate passage at barriers. 13

14 Flows Avoid de-watering streambeds containing ammocoetes. Ramp down flows slowly so ammocoetes and juveniles can move out. Protect natural surface and subsurface flows. Provide adequate stream flow velocities during peak migration periods. Stream Substrates Spawning substrates probably not as critical as salmonids due to shorter in gravel time. Prevent substrate smothering. Projects that may reduce the complexity of substrate particle size (esp. decrease in sand and silt) below historic levels may have an adverse impact on lamprey populations. 14

15 Habitat Complexity Protect water quality. Preserve slow water habitats used by lampreys. Avoid alteration of low gradient stream reaches because they may impact lamprey rearing capacities. Habitat Complexity Generally lampreys appear to be more abundant in streams with high habitat complexity (leaf litter, woody debris of all sizes, complex pools / riffle habitats, diverse substrate size). Lamprey ammocoetes have an affinity for riparian canopy cover (shade). However, it is unclear if this behavior is in response to thermal preferences or light avoidance. 15

16 Diversions / Screening Approach velocity, screen size, and diversion routes should be considered with lamprey behavior in mind, i.e., they may not follow hydraulic cues like salmonids. Newer irrigation ditch screen bypass systems function for most older (> age 2) ammocoetes and macropthalmia. Younger ammocoetes sometimes move between drum screen seals and into ditches. Design to avoid impingement: small (3/32-inch) screen placed vertically. Mid-water intakes might reduce entrainment: ammocoetes appear to move downstream close to the surface at night. Reduce night diversions to avoid most entrainment. In-Water Work Periods Limit in-stream-work to the higher velocity habitats to reduce the overall numbers of lamprey encountered. Disturbance to one rearing area can result in mortality of hundreds and perhaps several thousand rearing ammocoetes of several age classes. Instream work manipulating the substrates and stream channel is likely to impact rearing lampreys to some degree year-round. 16

17 Primary Considerations in Project Design and Implementation 1. Provide Lamprey Passage 2. Protect Ammocoete Habitat 3. Think Channel Complexity Freshwater Mussels. Old growth forests of aquatic ecosystems 17

18 Special Thanks Abel Brumo OSU Stewart Reid Western Fishes, CA Jason Dunham - USGS Christopher Claire Idaho DFG Mary Moser NOAA Fisheries Larry Ward Elwha Tribe, WA Michael Meeuwig Montana Coop Fish Res. Unit David Clungston COE, Portland Chris Brun Conf. Tribes of the Warm Springs Dennis Dauble PNW National Lab Shawn Chase, Sonoma Co. Water Agency Daniel Domina - PGE Steve Corbett Olympic Nat l Park, WA Tammie Steelman California DFG Doug Baus USFWS, OR Damon Goodman USFWS Arcata CA Petey Brucker Salmon River, CA Leo Grandmontagne Coquille River, OR Erich Yokel Siskiyou Co. CA Lisa Briggs Coos Watershed Assoc. Ann Gray USFWS, OR Paul Cadrett USFWS Stockton, CA Chad Smith City of Portland Dan Van Slyke BLM Christina Luzier USFWS Vancouver Mike Clement Grant PUD Rob Nielsen URS Corporation, WA 18