fish ladder
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2022 ◽  
Vol 8 ◽  
Author(s):  
Vishnu Kandimalla ◽  
Matt Richard ◽  
Frank Smith ◽  
Jean Quirion ◽  
Luis Torgo ◽  
...  

The Ocean Aware project, led by Innovasea and funded through Canada's Ocean Supercluster, is developing a fish passage observation platform to monitor fish without the use of traditional tags. This will provide an alternative to standard tracking technology, such as acoustic telemetry fish tracking, which are often not appropriate for tracking at-risk fish species protected by legislation. Rather, the observation platform uses a combination of sensors including acoustic devices, visual and active sonar, and optical cameras. This will enable more in-depth scientific research and better support regulatory monitoring of at-risk fish species in fish passages or marine energy sites. Analysis of this data will require a robust and accurate method to automatically detect fish, count fish, and classify them by species in real-time using both sonar and optical cameras. To meet this need, we developed and tested an automated real-time deep learning framework combining state of the art convolutional neural networks and Kalman filters. First, we showed that an adaptation of the widely used YOLO machine learning model can accurately detect and classify eight species of fish from a public high resolution DIDSON imaging sonar dataset captured from the Ocqueoc River in Michigan, USA. Although there has been extensive research in the literature identifying particular fish such as eel vs. non-eel and seal vs. fish, to our knowledge this is the first successful application of deep learning for classifying multiple fish species with high resolution imaging sonar. Second, we integrated the Norfair object tracking framework to track and count fish using a public video dataset captured by optical cameras from the Wells Dam fish ladder on the Columbia River in Washington State, USA. Our results demonstrate that deep learning models can indeed be used to detect, classify species, and track fish using both high resolution imaging sonar and underwater video from a fish ladder. This work is a first step toward developing a fully implemented system which can accurately detect, classify and generate insights about fish in a wide variety of fish passage environments and conditions with data collected from multiple types of sensors.


PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252183
Author(s):  
Mariana O. Côrtes ◽  
Alexandre Peressin ◽  
Alexandre L. Godinho

Determining the number of fish that use a fishway is essential to fisheries management but counting all fish can be impracticable due to labor and cost. We present the daily run-size estimation (DARSE) method, which uses systematic sampling to estimate the number of fish per species that pass through a fishway daily (daily run size, D). The DARSE method makes it possible to determine the minimum fraction of each hour (or hourly samples) of the day necessary to estimate D with known accuracy. We apply DARSE to each of the seven most abundant fish species (other species grouped under ‘Others’) recorded in video images taken during 46 days of one year at the Igarapava Fish Ladder, Brazil. Accuracy in estimating D was influenced by the fraction of the hour sampled and the temporal pattern of fish passage through the fishway. For species with a more uniform temporal pattern of passage, the DARSE method reduced the time spent on sampling by up to 96%, depending on the accuracy used to estimate D. Some of these species required counts of fish that pass in a fraction of an hour for all hours of the day while counts for other species can be done every 2 hours or, more rarely, every 3 hours. For species with a more aggregated temporal pattern of passage, it was possible to estimate D by sampling a fraction of an hour but with reduced accuracy in the estimation of D and little reduction in sampling time.


2021 ◽  
Vol 8 (1) ◽  
pp. 29-34
Author(s):  
Vincenzo Ferri ◽  
Paolo Crescia ◽  
Christiana Soccini ◽  
Alessio Olini ◽  
Stefano Celletti

[The spring presence of two individuals of the Sea lamprey, Petromyzon marinus, in the River Mignone near Tarquinia (Northern Lazio) could highlight a new Italian reproductive site of this rare and endangered species. This exceptional possibility could certainly be favored by the good quality of both the waters of the Mignone, and the environmental context of the record, but would require the urgent equipment of the barrier of Le Mole with a fish ladder in order to allow the sea lamprey’s upstream migration towards the areas of the upper course, even more suitable for their reproduction].   [Article in Italian]


2021 ◽  
Author(s):  
Sheryl Schwert

<p>Atlantic salmon swim upstream from the North sea through Frierfjorden to spawn in the Skien watershed, the third largest in Norway. There are two hydroelectric power plants in the lower reaches of the Skienselva: Klosterfoss and Skotfoss. Salmon caught swimming up the fish ladder at the downstream power plant (Klosterfoss) were tagged, released, and at the downstream power plant tracked from the beginning of the upstream migration to the end of the spawning period in the entire anadromous watershed. Salmon spent unequal amounts of time at the four spawning areas in the main river and a tributary between Klosterfoss and Skotfoss. Salmon spent less time at the larger spawning site, Vadrette, compared to the smaller Fossum and Grøtsund spawning sites. 26% of tagged salmon which swam upstream to the Skotfoss hydroelectric power plant ascended the fish ladder. Further, 16% of all salmon ascended the fish ladder at Skotfoss and continued to upstream spawning sites, indicating that they were homing to sites in the upper watershed. This is much smaller than the what is expected based on the fry populations in the rivers of the Skien watershed, which are augmented by yearly stocking in some of the rivers. Salmon which ascended the Klosterfoss ladder relatively early, swam upstream to Skotfoss more quickly than salmon that arrived relatively late at the Klosterfoss ladder. Short and repeated movements upstream to Skotfoss, and downstream to areas in the Farelva, and back again to Skotfoss were observed in the majority of tagged salmon that approached Skotfoss. The “yo-yo” migration of salmon in the Farelva is for the most part unexplained, but the movement costs the salmon valuable energy before and during the spawning season and may have negative consequences. Overall, these results indicate that salmon find the entrance to the fish ladder and do not remain stuck at the tunnel outlet, but most do not successfully ascend it. This could be the result of poor ladder construction, too low flow from the ladder, low survival of fry from upstream of Skotfoss reducing the number of salmon that are homing to upstream spawning areas, or that not all salmon which approach Skotfoss are homing to areas above the ladder. The possibility exists that salmon which will eventually spawn in areas downstream of the ladder engage in searching behavior near the fish ladder. If efforts to restore the populations in the upper watershed are to continue, issues salmon have with ascending the Skotfoss fish ladder must be addressed first.</p>


Engineering ◽  
2021 ◽  
Vol 13 (04) ◽  
pp. 173-183
Author(s):  
Eric Krebs ◽  
Dylan A. Gravenhof ◽  
Joshua M. A. Caasi ◽  
Robert P. Hanten ◽  
Nathan Huysman ◽  
...  
Keyword(s):  

2021 ◽  
Vol 7 (2) ◽  
pp. 57
Author(s):  
Kristian Angele ◽  
Patrik Andreasson ◽  
Ake Forssen ◽  
David Aldven ◽  
Gustav Hellstrom ◽  
...  
Keyword(s):  

2020 ◽  
Vol 9 (1) ◽  
pp. 18
Author(s):  
Dylan A Gravenhof ◽  
Michael E Barnes ◽  
Robert Hanten

Feral spawning fall Chinook salmon (Oncorhynchus tshawytscha) in Lake Oahe, South Dakota, are captured using a fish ladder and catch raceway at Whitlock Bay Spawning Station. The number of salmon that escaped the catch raceway and descended the fish ladder prior to spawning was unknown. During October 2017, all salmon that ascended the fish ladder at the spawning station were tagged. Tagged males remained in the catch raceway. Tagged females were moved to other secure raceways and used to estimate tag retention. Of the 383 tagged males, 159 (41.5%) were initially designated as escaped from the catch raceway. Tag loss in the females was 3.9%. Thus, the estimated male salmon escapement rate from the catch raceway was 37.6%. Male salmon remained in the catch raceway for one-to-three days before escaping. The escapement rate decreased over the month-long spawn, with nearly 60% of the males going back down the fish ladder in the first week of October, compared to less than 20% escapement by the final week. Such high rates of escapement from the spawning station may be negatively impacting the spawning efficiencies. Possible solutions include re-engineering of the fish ladder or daily removal of the salmon in the catch raceway to other more secure locations at the spawning station.


ZOO-Journal ◽  
2019 ◽  
Vol 5 ◽  
pp. 32-40
Author(s):  
Ganesh Timilsina ◽  
Subash C Bastola ◽  
Sherman Gurung ◽  
Kishor K Pokharel

Present study deals with fish diversity along with management aspects of lakes in Pokhara Valley. It was conducted during September 2009 to February 2010. Monthly fish sampling was done using gill net with the help of experienced fishermen. Altogether 34 species of fishes were recorded in the present study. The population status of important fish species viz., Tor Tor (Hamilton- Buchanan) was found to be endangered, that of Tor putitora (Hamilton-Buchanan), Neolissocheilus hexagonolepis (Mc Clelland), Chagunius chagunio (Hamilton-Buchanan), and Brachydanio rerio (Hamilton-Buchanan) were found to be vulnerable (VU); five species were uncommon (UN) and 24 species were common (C) including common exotic(C*). The lakes were found to be influenced by human activities such as direct disposal of domestic sewage, unscientific agricultural practices, construction of dams without fish ladder or passes, deforestation causing soil erosion etc., which were creating threat to the lentic ecosystem.


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