Target Strength Measurements of Juvenile Blueback Herring from the Mohawk River, New York

Gurshin, Christopher W.D.

doi:10.1080/02755947.2012.678562

Cited by 6 publications

(5 citation statements)

References 25 publications

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“…The direction of the horizontal transducers across the river channel was assumed to generally produce a side-aspect TS distribution when fish swim through the beam during their downstream migration. The TS mode observed by horizontal transducers ranged from ¡50 to ¡44 dB, which was similar in magnitude to Gurshin (2012) and Brooking and Rudstam (2009). The estimates used for the net rate of downstream or upstream movement (averaged 2.4-2.6 body lengths/s) were consistent with the range of swimming speeds reported for Alewives from previous split-beam tracking by Arrhenius et al (2000).…”

Section: Meanssupporting

confidence: 76%

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Importance of Ultrasonic Field Direction for Guiding Juvenile Blueback Herring Past Hydroelectric Turbines

Gurshin¹,

Balge²,

Taylor³

et al. 2014

N American J Fish Manag

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Populations of Blueback Herring Alosa aestivalis, an important anadromous forage fish in the northeastern USA, have declined from historic levels. Measures to reduce mortality from many sources, including entrainment by hydroelectric turbines, are cited by fishery managers to be important to restoring populations. At the Crescent Hydroelectric Project (Crescent) on the Mohawk River, New York, pulsed ultrasound (122–128 kHz) was used to deter adult and juvenile Blueback Herring migrating out to sea from entering the intake channel to the headrace and turbines, where mortality may occur. To increase the deterrence rate, the sound field was extended further upriver to expose juvenile Blueback Herring to an increasing sound gradient as they migrate downriver and allow them more time to avoid the intake channel. When juvenile Blueback Herring were present upstream of Crescent and exposed to an ultrasound field, mean catch per unit effort (CPUE) by pelagic trawling in the main channel downriver of the ultrasound was 94% of the mean CPUE in the upriver trawl region and 250% of the mean CPUE in the intake channel. Repeated mobile echo sounder surveys revealed that the abundance of juvenile Blueback Herring averaged 35 times higher in the downriver main channel region than in the intake channel region. During the peak migration period of September 20 through October 14, 2012, continuous fixed‐location horizontal echo sounding showed the percentage of net downstream passage of juvenile Blueback Herring that bypassed the intake channel significantly increased from 31.1% to 76.5% after redirecting the ultrasonic field upriver. These results demonstrate that pulsed ultrasound, when properly directed, can be used effectively as a fish deterrent system to provide safe downstream passage of juvenile Blueback Herring at hydropower dams. At Crescent, this could increase annual survival by tens of thousands of fish or more. Received October 4, 2013; accepted August 26, 2014

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Section: Meanssupporting

confidence: 76%

“…All fish were released back to the river. The target strength (TS) distribution of the Blueback Herring catch was estimated from the TS-TL relation for Alewife (Warner et al 2002), which is also representative of juvenile Blueback Herring (Gurshin 2012).…”

Section: Trawl Sampling Of Fish Populationsmentioning

confidence: 99%

Importance of Ultrasonic Field Direction for Guiding Juvenile Blueback Herring Past Hydroelectric Turbines

Gurshin¹,

Balge²,

Taylor³

et al. 2014

N American J Fish Manag

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“…Given the low salinity levels at the surface (typically less than 5‰) we can infer that the fish using this habitat must be euryhaline fish such as (but not limited to) river herring, Atlantic Tomcod, or Rainbow Smelt. The TS range (<−42 dB) also suggests that many of the fish targets we detected in the middle estuary throughout the year were young of year fish potentially using this area as a nursery (e.g., Rudstam et al 2003;Gurshin 2012). Diadromous fish using northeastern U.S. estuaries for juvenile rearing has been noted in other systems (Grabe 1996) and is also likely to be important in the Penobscot estuary (e.g., MDMR and MDIFW 2009).…”

mentioning

confidence: 63%

“…Fish track detection settings were: TS threshold = −55 dB, minimum number of single targets in a track = 1, and maximum gap between single targets = 0. We used the −55 dB threshold to filter out weak backscatter to focus on postlarval fish responses only; the target strength of many of the main species inhabiting the estuary (e.g., Saunders et al 2006) have been estimated empirically (e.g., Foote 1987;Rudstam et al 2003;Simmonds and MacLennan 2005;Gurshin 2012).…”

Section: Hydroacoustics and Pelagic Fish Distributionmentioning

confidence: 99%

Using Hydroacoustics to Describe Pelagic Fish Distribution in the Penobscot Estuary, Maine

et al. 2017

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Temperate estuaries are inherently variable and productive ecosystems that provide nursery habitat, migration pathways, and forage areas for diadromous, estuarine, and marine fish. We used multifrequency scientific echo sounders (SIMRAD EK60 split‐beam, 38 and 120 kHz) to describe the distribution of pelagic fish in the Penobscot River estuary, Maine, in 2012 and 2013. Differences in responses between frequencies were used to distinguish fish from other biota. Acoustic area backscatter from echo integration (sA [m2/nautical mile2], a common measure proportional to fish density) and target strength (TS; dB re 1 m2, an acoustic measure of fish size) distributions varied with season and salinity. Overall, the sA and TS distributions were similar in both years, with detectable spatial and temporal patterns. The highest value of sA occurred in July of both years, when dense schools of fish were detected in higher‐salinity areas of the lower estuary. The middle estuary had high sA values in April both years, particularly in the vicinity of the seawater–freshwater interface. The mixing area in the middle estuary stratum appears to be important fish habitat; we found fish in this area throughout the year. Fish of variable TS were using this mixing zone throughout the survey period. In full freshwater, upstream from the salinity mixing area, sA was generally low. The majority (~77%) of discrete fish detected had TS values less than −42 dB. The TS distributions varied seasonally, with the highest TS measurements occurring more frequently in April and May and the lowest ones occurring most frequently in July and August. This study demonstrates the efficacy of using a mobile hydroacoustic survey to assess pelagic fish distribution in a complex estuary and may provide a template for long‐term monitoring in dynamic estuarine ecosystems. Received November 3, 2016; accepted March 15, 2017 Published online June 20, 2017

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“…Moreover, previous studies (Boswell & Wilson, 2008;Frouzova et al, 2005;Gurshin, 2012;Kubecka & Wittingerova, 1998;Lilja et al, 2000;Rudstam et al, 2003) show that the target strengths obtained from lateral orientations are greater than the target strengths obtained from oblique or head-tail orientations. This difference can be explained by the increased exposure of the body surface of the fish when it is at a perpendicular position, exposing its swim bladder (Boswell & Wilson, 2008).…”

Section: Discussionmentioning

confidence: 92%

Hydroacoustic assessment of standing stock of Nile tilapia ( Oreochromis niloticus ) under 120 kHz and 200 kHz split‐beam systems in an aquaculture pond

Liu

Setiazi

2021

Aquaculture Research

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Tilapia production is one of the most diversified fish sectors globally and is expected to continually grow. In Taiwan, Nile tilapia (Oreochromis niloticus) is the second most produced fish species in the aquaculture industry. Traditionally, fishermen would use a net to estimate the volume of the fish species in the, pond but this method offer numerous disadvantages and acoustic methods were proven to be reliable in fisheries resource survey. Thus, this study explored an acoustic method to measure the standing stock and biomass in a Nile tilapia aquaculture pond. A rectangular tank (2.3 × 0.82 × 0.66 m) with a set of echo sounders (frequencies: 120 and 200 kHz) fixed on a steel frame was utilized to approximate the target strengths of Nile tilapia samples (n = 35) in lateral positions. Findings reveal that the estimated target strength using the two beam frequencies did not differ significantly (p > 0.05). A horizontal conversion equation in lateral position was established, which was used for biomass backscattering analysis of Nile tilapia in fish ponds. The results show that 120 kHz frequency can accurately predict Nile tilapia fish biomass in an aquaculture pond. This study has determined a species‐specific equation for the hydroacoustic method to enable a more accurate estimation of fish biomass, such as that of Nile tilapia. Fish biomass estimation will enhance aquaculture management, such as optimizing capital invested and minimizing overfeeding.

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Target Strength Measurements of Juvenile Blueback Herring from the Mohawk River, New York

Cited by 6 publications

References 25 publications

Importance of Ultrasonic Field Direction for Guiding Juvenile Blueback Herring Past Hydroelectric Turbines

Importance of Ultrasonic Field Direction for Guiding Juvenile Blueback Herring Past Hydroelectric Turbines

Using Hydroacoustics to Describe Pelagic Fish Distribution in the Penobscot Estuary, Maine

Hydroacoustic assessment of standing stock of Nile tilapia ( Oreochromis niloticus ) under 120 kHz and 200 kHz split‐beam systems in an aquaculture pond

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