ELECTRONIC SUPPLEMENTARY MATERIAL

FACTORS INFLUENCING CAPTURE OF INVASIVE SEA LAMPREY IN TRAPS BAITED WITH A SYNTHESIZED PHEROMONE COMPONENT

NICHOLAS S. JOHNSON1*, MICHAEL J. SIEFKES2, C. MICHAEL WAGNER3, GALE BRAVENER4, TODD STEEVES4, MICHAEL TWOHEY5, WEIMING LI3

(1)  USGS, Great Lakes Science Center, Hammond Bay Biological Station, 11188 Ray Road, Millersburg, MI 49759.

(2)  Great Lakes Fishery Commission, 2100 Commonwealth Blvd., Suite 100, Ann Arbor, MI 48105.

(3)  Department of Fisheries and Wildlife, Michigan State University, Room 13 Natural Resources Building, East Lansing, MI 48824

(4)  Fisheries and Oceans Canada, Sea Lamprey Control Centre, 1219 Queen Street East Sault Ste. Marie ON P6A 2E5.

(5)  U.S. Fish and Wildlife Service, Marquette Biological Station, 3090 Wright St., Marquette, MI 49855.

*Corresponding Author: e-mail: , Phone: 989-734-4768, Fax: 989-734-4494

METHODS

Methods to collect predictor variable data for objective 1 (listed in Table 1). Trap – Portable assessment traps are described in detail in Schuldt and Heinrich (1982). Permanent traps are built into the dam face and have water from upstream of the dam flowing through the trap funnel to induce a rheotaxic response in sea lamprey (attractant water). VelocityTrap - Mean water velocity exiting the trap funnel (m/sec; as determined over 30 sec) measured weekly using a flow meter (Marsh-McBirney Flo-Mate 2000). Width, Velocity, Depth –Stream discharge was manually estimated weekly using the velocity area method (McMahon et al. 1996) about 500 m downstream of each trap site. While estimating discharge, stream width was determined and velocity and depth at 10 points along a transect were recorded. Velocity and depth was averaged across the sampling points. Then the average width, velocity, and depth recorded throughout the trapping season each year was used in the model. Dismouth – Log transformed distance from the barrier-integrated traps to the stream mouth as determined by measuring stream length down the middle of the stream channel. Abundance – Log transformed abundance of adult sea lamprey in that stream during that year as estimated by Mullett et al. (2003). Males – Average number of male sea lamprey observed in that stream during that year within 500 m of the barrier-integrated trap as determined by walking upstream from the furthest downstream extent of the survey (500 m downstream of trap) once per week and counting the number of males on spawning nests using a glass panel to obtain a clear image of the stream substrate. Con 3kPZS – Mean 3kPZS concentration measured 500 m below the sea lamprey barrier once per week during the day using methods described in Xi et al. (2011) and Wang et al. (2013).

Methods to collect predictor variable data for objective 2 (listed in Table 2). Bias – Categorical variable where the baited trap was less likely (0), equally likely (0.5), or more likely (1.0) to catch sea lampreys than the adjacent paired trap. Bias was assigned on a given stream if one of the paired traps captured more than 75% of the sea lampreys on average during the three years prior to the study period. ΔDischarge – Discharge (cms) observed that night minus discharge observed the previous night divided by discharge observed the previous night. Discharge was determined as described above for objective 1. ΔTemp – Water temperature (ºC) observed that night at 2200 hours minus water temperature observed the previous night as recorded by HOBO temperature loggers (Onset Corporation, Cape Cod, MA, USA). Distance – Distance (m) between paired traps. Note that paired traps were set on dam faces and therefore the traps were set in an array perpendicular to stream flow. PropRun and Trapdate – see Table 2 for explanation.

Methods to collect predictor variable data for objective 3 (listed in Table 3). ΔDischarge ΔTemp, and Trapdate. See details provided above.

REFERENCES

Gore JA (2006) Discharge measurement and streamflow analysis. In: Hauer FR, Lamberti GA (eds) Methods in Stream Ecology, Revised 2nd edn. Academic Press, San Diego, pp 53-74

McMahon TE, Zale AV, Orth DJ (1996) Aquatic habitat measurements. In: Murphy BR, Willis DW (eds) Fisheries Techniques, 2nd edn. American Fisheries Society, Maryland, pp 83-120

Mullett KM, Heinrich JW, Adams JV, Young RJ, Henson MP, McDonald RB, Fodale MF (2003) Estimating lake-wide abundance of spawning-phase sea lampreys (Petromyzon marinus) in the Great Lakes: extrapolating from sampled streams using regression models. J Great Lakes Res 29(Suppl. 1):240-252.

Schuldt RJ, Heinrich JW (1982) A portable trap for collecting adult sea lampreys. Prog Fish-Cult 44:220-221.

Wang H, Johnson NS, Bernardy J, Hubert T, Li W (2013) Monitoring sea lamprey pheromones and their degradation using rapid stream-side extraction coupled with UPLC-MS/MS. J Sep Sci 36:1512-1520.

Xi X, Johnson N S, Brant CO, Yun S-S, Chambers KL, Jones AD, Li W (2011) Quantification of a male sea lamprey pheromone in tributaries of the Laurentian Great Lakes by liquid chromatography-tandem mass spectrometry. Environ Sci Technol 45: 6437-6443.

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