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Zhang H.,Chinese Academy of Fishery Sciences | Wei Q.W.,Chinese Academy of Fishery Sciences | Kyanrd B.E.,BK Riverfish LLC | Du H.,Chinese Academy of Fishery Sciences | And 2 more authors.
Journal of Applied Ichthyology | Year: 2011

This study was performed to determine the spatial structure and bottom characteristics of the only remaining spawning area of Chinese sturgeon (Acipenser sinensis) located just downstream of the Gezhouba Dam. During the period 1996-2003, three methods were employed, including (i) the examination of the stomachs of opportunistic predatory fishes that feed on sturgeon eggs, (ii) tracking the mature sturgeons by ultrasonic tags and (iii) capturing eggs and yolk-sac larvae (ELS) at and near the river bottom by D-shaped bottom drift nets to monitor the spawning activities of A. sinensis. It was found that A. sinensis selected permanent locations to mate. There were two mating locations: an upstream mating area (UMA), in the tailrace of the Dajiang Hydroelectric Station and about 870m far from the Gezhouba Dam (area, 0.1km2), and a downstream mating area (DMA), about 2500m from Gezhouba Dam (area, 0.3km2). The DMA was the chief mating area and was used every year. The incubation area (for dispersal of fertilized eggs to incubate) was range from 870m to 7km from the dam. Generally, the total length of the spawning area was 5-7km length (area 2.0-2.7km2) with the range slightly varied in different spawning activities. A relief map of the riverbed and a bottom hydroacoustic survey of the DMA found a deep depression and rocky substrate. These may be important characteristics of geomorphology for the spawning area of A. sinensis. © 2011 Blackwell Verlag, Berlin.

Wang C.Y.,Huazhong Agricultural University | Wang C.Y.,Chinese Academy of Fishery Sciences | Wei Q.W.,Huazhong Agricultural University | Wei Q.W.,Chinese Academy of Fishery Sciences | And 4 more authors.
Journal of Fish Biology | Year: 2012

From 2006 to 2009, 27 ultrasonic-tagged wild adult Chinese sturgeon Acipenser sinensis [eight males, 19 females; total length (L T) range = 245-368 cm] were captured on the spawning ground just downstream of Gezhouba Dam (GZD) in the Yangtze River. Twenty-six individuals were tracked for 7 to 707 days (mean number of relocations = 859; range = 3-4549). Acipenser sinensis movements were divided into four categories: (1) spawning migration, two tagged A. sinensis (one female and one male) returned to the Yangtze River and migrated from the Yangtze Estuary (river kilometer, rkm, 0) to the spawning ground (1678 rkm) between June and October. Their mean upstream ground speed was 1·41 km h -1 (range = 0·26-2·35 km h -1). The speed of the male was faster than the female; (2) pre-spawning holding, four of five females tagged in November 2008 stayed within 1678·00-1674·15 rkm for c. 1 year before the spawning period; (3) spawning movements, all A. sinensis swam mostly from the tailrace of the GZD (1678 rkm) to the Miaozui (1674·15 rkm) reach and some moved downstream c. 18·21 rkm (range = 3·93-24·64 rkm), but then, returned upstream to the GZD. Most tagged A. sinensis were on the spawning ground on the day when the spawning occurred; (4) post-spawning migration males (n = 6) and females (n = 2) departed the spawning area on a different time schedule, females leaving before males. The mean seaward ground speed of six A. sinensis was 4·87 km h -1 (range = 0·68-7·60 km h -1). There were no significant differences (P > 0·05) in ground speeds among reaches or between sexes within reaches between telemetry receivers. These broad spatiotemporal scale results will help establish an effective protection strategy for the species in the Yangtze River. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Li Y.,Huazhong Agricultural University | Li Y.,Chinese Academy of Fishery Sciences | Kynard B.,BK Riverfish LLC | Wei Q.,Huazhong Agricultural University | And 4 more authors.
Environmental Biology of Fishes | Year: 2013

We conducted laboratory experiments with early life stages of kaluga sturgeon, Huso dauricus, from the middle reach of the Amur River to quantify ontogenetic behavior and compare their behavior with similar laboratory data collected previously on young kaluga from the Amur River. Our hatchling free embryos initiated an intense downstream migration that peaked on day 1, and continued strongly to day 3, decreased strikingly during days 4-6, and ceased on day 7 (8-day migration). Migrants preferred a bright habitat (illuminated and white bottom), open habitat, and swam-up far above the bottom (daily median distance, 3.5 m). On days 21-22, larvae initiated a second downstream migration of similar intensity (four fish passes per 5 min), with a peak at 34-35 days. Juveniles continued a slow intensity migration (one fish pass per 5 min) until day 66, indicating a long-duration migration style by early life stages that would carry them far downstream from a spawning site. Free embryos, larvae and early-juveniles also strongly preferred open habitat, suggesting a similar use of this habitat type by wild individuals of these three life stages. The behavior and migration of our kaluga early life stages were similar to the young kaluga studied previously, but the migration of the two groups was different in major ways. This result suggests there are at least two breeding stocks in the river, each with a slightly different early behavior. If correct, culture programs for stock enhancement must ensure breeding populations are not mixed, which would produce non-adapted early life stages. Genetics studies are needed to identify the kaluga populations in the Amur River. © 2013 Springer Science+Business Media Dordrecht.

Li Y.H.,Huazhong Agricultural University | Li Y.H.,Chinese Academy of Fishery Sciences | Kynard B.,University of Massachusetts Amherst | Kynard B.,BK Riverfish LLC | And 6 more authors.
Journal of Applied Ichthyology | Year: 2013

Summary: The effect of two environmental factors (substrate type and water velocity regime) was studied in the ontogenetic migration intensity of kaluga, Huso dauricus, a protected species in the Amur River. Early-life stages studied were: free embryos = days 0-8; larvae = days 9-49; and juveniles = days 50-66. Effect of treatments on fish migration intensity was observed in circular channels, allowing migration in an endless stream. Daily migration intensity of fish was characterized by counting the number of daily upstream or downstream fish passes past a specific site in the channel observed for 5 min every hour by vision or video camera. The hypothesis that substrate type (bare bottom or sand-small cobble) affects migration intensity was accepted, depending on the life stage. For example, the substrate type had no effect on migration intensity of days 0-6 free embryos. However, the intensity in days 7-8 free embryos and days 9-29 larvae was greater over rock substrate, while intensity in days 46-49 larvae and days 50-66 juveniles was greater when the bottom was bare. Thus, the effect of the substrate on migration varied in intensity according to the life stage, and within the larva life stage, by age. The velocity regime had a positive effect on migration intensity of free embryos, but a high velocity (mean, 29.9 cm{bullet operator}s-1) delayed the resting period of day 8 free embryos and day 9-15 larvae. Free embryos and larvae in low vs fast velocities showed that they may have a drive to migrate a similar distance, and moreover, that a triggering velocity may be needed to initiate or to stop migration. The hypothesis was accepted that the rearing velocity affects migration intensity, e.g. larvae reared in still water and then placed in moving water had a compensatory migration intensity response. For population enhancement stocking of H. dauricus, the results indicate culture practices must insure that: (i) same-population individuals are mated to produce early-life stages with the correct behaviour, (ii) migrating larvae, not juveniles, should be stocked, and (iii) larvae should be released in a river reach with a bottom velocity ≥30 cm{bullet operator}s-1 containing sand and small pebbles. © 2013 Blackwell Verlag GmbH.

Kynard B.,BK Riverfish LLC | Kynard B.,U.S. Geological Survey | Kynard B.,University of Massachusetts Amherst | Pugh D.,University of Massachusetts Amherst | Parker T.,University of Massachusetts Amherst
Journal of Applied Ichthyology | Year: 2011

Research and development of a fish ladder for sturgeons requires understanding ladder hydraulics and sturgeon behaviour in the ladder to insure the ladder is safe and provides effective passage. After years of research and development, we designed and constructed a full-scale prototype side-baffle ladder inside a spiral flume (38.3m long×1m wide×1m high) on a 6% (1:16.5) slope with a 1.92-m rise in elevation (bottom to top) to test use by sturgeons. Twenty-eight triangular side baffles, each extending part way across the flume, alternated from inside wall to outside wall down the ladder creating two major flow habitats: a continuous, sinusoidal flow down the ladder through the vertical openings of side-baffles and an eddy below each side baffle. Ascent and behaviour was observed on 22 cultured Lake Sturgeon=LS (Acipenser fulvescens) repeatedly tested in groups as juveniles (as small as 105.1cm TL, mean) or as adults (mean TL, 118cm) during four periods (fall 2002 and 2003; spring 2003 and 2007). Percent of juveniles entering the ladder that ascended to the top was greater in spring (72.7%) than in fall (40.9-45.5%) and 90.9% of 11 adults, which ascended as juveniles, ascended to the top. Six LS (27.3%) never swam to the top and seven (31.8%) swam to the top in all tests, indicating great variability among individuals for ascent drive. Some LS swam directly to the top in <1min, but most rested in an eddy during ascent. Juveniles swimming through outside wall baffle slots (mean velocity, 1.2ms-1) swam at 1.8-2.2body lengthss-1 and 3.2-3.3tail beatss-1, either at or approaching prolonged swimming speed. The side-baffle ladder was stream-like and provided key factors for a sturgeon ladder: a continuous flow and no full cross-channel walls, abundant eddies for resting, an acceptable water depth, and a water velocity fish could ascend swimming 2bls-1. A side-baffle ladder passes LS and other moderate-swimming fishes. © 2011 Blackwell Verlag, Berlin.

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