Individual downstream swimming speed during the natural smolting period among young of Baltic salmon (Salmo salar)

1993 ◽  
Vol 71 (9) ◽  
pp. 1782-1786 ◽  
Author(s):  
Hasse Fängstam
Keyword(s):  
Swimming Speed ◽  
Water Velocity ◽  
Water Current ◽  
Migratory Fish ◽  
Pit Tag ◽  
Passive Integrated Transponder ◽  
Individual Fish ◽  
Hatchery Stock ◽  
The Individual ◽  
Immature Fish

The individual downstream swimming behaviour of two-summer-old salmon from the Ume River hatchery stock was monitored throughout the natural smolting period in May–June. The experiment was performed in an artificial-stream tank (diameter 11 m) equipped with a passive integrated transponder (PIT) tag monitoring system. The swimming speed of individual fish in relation to water velocity and the porportion of time during which an individual fish showed active versus passive displacement were investigated using a total of 224 sexually immature fish and previously mature males, individually PIT tagged. At peak migration fish swam downstream at an average speed of about double the water velocity, indicating active downstream migration. No differences in downstream swimming speed between migratory and nonmigratory fish were observed. However, migratory and nonmigratory fish used considerably different proportions of the total time swimming faster than the water current, 10% for migratory fish but only 0.1% for nonmigratory fish. Migratory smolts covered about 25% of their total downstream displacement by means of active downstream swimming: 3.3 km out of 13.5 km in 24 h. Thus, the study clearly shows that active downstream swimming is an important part of the migratory repertoire of salmon smolts.

Energetic cost of active branchial ventilation in the sharksucker, Echeneis naucrates

1983 ◽  
Vol 103 (1) ◽  
pp. 185-192 ◽  
Author(s):  
J. F. Steffensen ◽  
J. P. Lomholt
Keyword(s):  
Oxygen Consumption ◽  
Water Velocity ◽  
Moving Object ◽  
Water Current ◽  
Energetic Cost ◽  
Gill Ventilation

1. Sharksuckers use active branchial ventilation when swimming or at rest in stationary water. When attached to a moving object or when placed in a water current, they shift to ram gill ventilation as water velocity exceeds a certain threshold. 2. Water velocities required for the transition from active to ram gill ventilation were from 10–50 cm s-1, depending on the size of the fish. 3. Oxygen consumption increased between 3.7 and 5.7% when the fish shifted from ram gill ventilation to active branchial pumping. 4. When water velocity was increased beyond the threshold for ram gill ventilation, no further increase in oxygen consumption was observed. 5. It is concluded that the energetic cost of active ventilation in sharksuckers is lower than has previously been reported for fish in general.

The Angler in the Environment: Social, Economic, Biological, and Ethical Dimensions

2011 ◽  
Keyword(s):  
Animal Welfare ◽  
Animal Rights ◽  
Mental States ◽  
Ethical Challenge ◽  
Recreational Fishing ◽  
Ethical Challenges ◽  
Catch And Release ◽  
Individual Fish ◽  
Recreational Angling ◽  
The Individual

<i>Abstract</i>.—Ever since fishing was called recreational fishing, a cruelty charge has hovered around somewhere in the background. In recent times, however, it has made it to the fore substantiated by anthropomorphic reasoning and fuelled by high-visibility papers claiming that fish can feel pain and suffer. Because some segments of the public perceive the infliction of these mental states to fish as abhorrent and not outweighing the costs imposed on the individual fish by appropriate benefits to the human, recreational fishing is coming under attack on moral grounds. Other challenges have also emerged that do not center on the issue of whether fish are sentient or not. In this paper, we describe five of the most prevalent moral challenges to recreational angling, two of which—animal welfare and wilderness-centered perspectives—can offer a constructive outlook by calling upon improved treatment of individual fish (animal welfare) and generally more sustainable management (wilderness perspective). In contrast, if one subscribes to animal liberation or animal rights philosophies, the outlook for recreational fishing is generally negative: it has to stop. A final challenge is associated with the motivations of anglers. The moral argument there is that the activity is carried out largely for angler pleasure rather than as a means of securing survival. The outlook of this ethical challenge sometimes leans towards only accepting one form of recreational fishing: catching, killing, and eating. Voluntary catch-and-release fishing and practices such as tournament fishing with a strict total catch-and-release policy would then not be ethically permissible. In this paper, we highlight the origin and background of each of the five ethical challenges and explain their implications for recreational fishing.

scholarly journals The Levantine jellyfish Rhopilema nomadica and Rhizostoma pulmo swim faster against the flow than with the flow

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dror Malul ◽  
Tamar Lotan ◽  
Yizhaq Makovsky ◽  
Roi Holzman ◽  
Uri Shavit
Keyword(s):  
Swimming Speed ◽  
Laboratory Testing ◽  
Eastern Mediterranean ◽  
Abundant Species ◽  
Water Velocity ◽  
Pulsation Frequency ◽  
The Past ◽  
Sensory Ability

AbstractJellyfish locomotion and orientation have been studied in the past both in the laboratory, testing mostly small jellyfish, and in the field, where it was impossible to control the seawater currents. Utilizing an outdoor water flume, we tested the locomotion of jellyfish when swimming against and with currents of up to 4.5 cm s−1. We used adult jellyfish from two of the most abundant species in the eastern Mediterranean, Rhopilema nomadica and Rhizostoma pulmo, and measured their pulsation frequency and swimming speed relative to the water. While pulsation frequency was not affected by the water velocity, jellyfish swam faster against the current than with it. This finding suggests that jellyfish possess a sensory ability, whose mechanism is currently unknown, enabling them to gauge the flow and react to it, possibly in order to reduce the risk of stranding.

An Evaluation of the Stereocinematographic Method to Estimate Fish Swimming Speed

1992 ◽  
Vol 49 (3) ◽  
pp. 523-531 ◽  
Author(s):  
Daniel Boisclair
Keyword(s):  
Coordinate System ◽  
Sample Size ◽  
Swimming Speed ◽  
Fish Swimming ◽  
Individual Fish ◽  
Precision And Accuracy ◽  
Over Time

I evaluated the precision and accuracy of the stereocinematographic (SCG) method for estimating fish swimming speed. The SCG method implements the differences in images recorded by two cameras to determine the position of a target in an x, y, z, coordinate system. Movements and speeds were determined using variations in the position of the targets over time. Movements of rulers [Formula: see text] estimated in the laboratory did not differ significantly from measured values. The accuracy of the SCG method in the field was assessed by comparing simultaneous estimates of the speed of the head and of the tail of individual fish observed in in situ enclosures. Differences between these descriptors of fish swimming were always < 2 body lengths (bl)∙s−1 and, on average, did not differ significantly from 0. Swimming speeds [Formula: see text] ranged from 0.6 to 20.7 cm∙s−1 (0.1–3.8 bl∙s−1). Speed variations between two consecutive 1-s intervals ranged from −23.9 cm∙s−1 (deceleration) to 23.6 cm∙s−1 (acceleration). Positioning fish at 1- to 6-s intervals tended to decrease the variance of swimming speed estimates. A sample size of 100–150 speeds per hour was sufficient to accurately describe fish swimming in an in situ enclosure.

Successful use of a passive integrated transponder (PIT) system for below-ground detection of plethodontid salamanders

2012 ◽  
Vol 39 (1) ◽  
pp. 1 ◽  
Author(s):  
Grant M. Connette ◽  
Raymond D. Semlitsch
Keyword(s):  
Spatial Ecology ◽  
Detection Efficiency ◽  
Control Group ◽  
Pit Tag ◽  
Field Methods ◽  
Passive Integrated Transponder ◽  
Pit Tags ◽  
Plethodontid Salamanders ◽  
Below Ground ◽  
Pit Tagging

Context Passive integrated transponder (PIT) technology allows for permanent and unambiguous marking of animals and has recently been adapted for locating tagged individuals in the field with portable detection systems. Aims We seek to assess the effects of PIT tagging on the growth and survival of plethodontid salamanders in the laboratory and to evaluate the effectiveness of this method for subterranean detection of salamanders in the field. Methods In a laboratory experiment, we assigned 36 Plethodon shermani to either a PIT tag or control group and compared survival and growth rates over the course of 9 weeks. For the field study, we implanted six Plethodon metcalfi with PIT tags and conducted surveys so as to determine their below-ground positions with a portable detector. Key results We found no effect of PIT tagging on either growth or survival in the laboratory. In the field, PIT telemetry resulted in an overall detection efficiency of 44%, with nighttime surveys yielding a greater detection efficiency than daytime surveys. This technique provided a significant improvement over traditional hand-capture because detected salamanders were rarely visible on the ground surface. Key conclusions Our study indicates that even these relatively small-bodied salamanders (range: 2.14–5.18 g) are capable of bearing PIT tag implants and confirms the results of previous studies that found no effect of PIT tagging on the health or survival of amphibians. This study further demonstrates that the use of a portable PIT detector can be an effective method for locating below-ground salamanders. Implications Because of the small size and long lifespan of PIT tags, we believe portable PIT detectors can provide researchers with an unprecedented level of detail for studies of the movement behaviour, spatial ecology and management of species that are small or otherwise challenging to detect and monitor with other techniques.

scholarly journals Monitoring the use of road-crossing structures by arboreal marsupials: insights gained from motion-triggered cameras and passive integrated transponder (PIT) tags

2015 ◽  
Vol 42 (3) ◽  
pp. 241 ◽  
Author(s):  
Kylie Soanes ◽  
Peter A. Vesk ◽  
Rodney van der Ree
Keyword(s):  
Individual Identification ◽  
Road Mortality ◽  
Pit Tag ◽  
Identification Methods ◽  
Passive Integrated Transponder ◽  
Crossing Structures ◽  
Animal Populations ◽  
Arboreal Marsupials ◽  
Eastern Australia ◽  
Wildlife Crossing Structures

Context Wildlife crossing structures are installed to mitigate the impacts of roads on animal populations, yet little is known about some aspects of their success. Many studies have monitored the use of structures by wildlife, but studies that also incorporate individual identification methods can offer additional insights into their effectiveness. Aims We monitored the use of wildlife crossing structures by arboreal marsupials along the Hume Freeway in south-eastern Australia to (1) determine the species using these structures and their frequency of crossing, (2) determine the number and demographic characteristics of individuals crossing, and (3) use the rate of crossing by individuals to infer the types of movement that occurred. Methods We used motion-triggered cameras to monitor five canopy bridges and 15 glider pole arrays installed at 13 sites along the Hume Freeway. The five canopy bridges were also monitored with passive integrated transponder (PIT)-tag readers to identify the rate of use by individuals. Key results Five species of arboreal marsupial were detected using canopy bridges and glider poles at 11 sites. Our analysis suggested that increasing the number and the distance between poles in a glider pole array reduced the rate of use by squirrel gliders. The PIT tag and camera footage revealed that the structures were used by adult males, adult females and juveniles, suggesting that all demographic groups are capable of using canopy bridges and glider poles. At two canopy bridges, multiple squirrel gliders and common brushtail possums crossed more than once per night. Conclusions Given that previous studies have shown that the freeway is a barrier to movement, and that many of the species detected crossing are subject to road mortality, we conclude that canopy bridges and glider poles benefit arboreal marsupials by providing safe access to resources that would otherwise be inaccessible. Implications Although the factors influencing crossing rate require further study, our analysis suggests that glider pole arrays with fewer poles placed closer together are likely to be more successful for squirrel gliders. The individual identification methods applied here offer insights that are not possible from measuring the rate of use alone and should be adopted in future monitoring studies.

scholarly journals Otoliths as individual indicators: a reappraisal of the link between fish physiology and otolith characteristics

2016 ◽  
Vol 67 (7) ◽  
pp. 881 ◽  
Author(s):  
Peter Grønkjær
Keyword(s):  
Life History ◽  
Fish Growth ◽  
Chemical Information ◽  
Fish Physiology ◽  
Environmental Signals ◽  
Research Areas ◽  
Individual Fish ◽  
Growth Zones ◽  
The Individual ◽  
New Research

Otoliths are remarkable recorders that store visual and chemical information that can be interpreted with regard to individual fish phenotype trajectory, life history events and environment. However, the information stored in the otoliths must be interpreted with the knowledge that the otolith is an integral part of fish sensory systems. This means that the environmental signals recorded in the otoliths will be regulated by the homeostatic apparatus of the individual fish – its physiology and ultimately its genetic make-up. Although this may complicate interpretation of environmental signals, it also opens up avenues for new research into the physiology and life history of individual fish. This review focuses on research areas where the coupling between otolith characteristics and fish physiology may yield new insights. Most of the research ideas are by no means new, but rather represent largely forgotten or less-explored research areas. Examples of questions that are fundamental, unanswered and with the potential to yield significant new insights are those related to the coupling of otolith and fish growth through metabolism, and the formation of opaque and translucent growth zones in relation to the physiology of the individual. An integration of visual and chemical data with bioenergetic modelling may yield some of the answers.

How Reliable are Growth Back-Calculations Based on Otoliths?

1990 ◽  
Vol 47 (11) ◽  
pp. 2219-2227 ◽  
Author(s):  
Steven E. Campana
Keyword(s):  
Somatic Growth ◽  
Growth Effect ◽  
Fish Otolith ◽  
Stochastic Error ◽  
Individual Fish ◽  
Back Calculation ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Slow Growing

Growth back-calculations from otoliths assume that the relationship between fish and otolith length is linear through time. The final (or observed) individual fish-otolith ratios are then combined to prepare a fish-otolith regression for the population, upon which the subsequent back-calculations are based. However, recent studies have demonstrated that the fish:otolith size ratio varies systematically with somatic growth rate, resulting in relatively large otoliths in slow-growing fish. Such a growth effect will result in a fitted fish-otolith regression which differs significantly from that of the mean of the individual fish-otolith slopes. Fraser–Lee growth back-calculations made from such a regression consistently underestimate previous lengths at age. The bias may explain the apparent ubiquity of Lee's phenomenon. Back-calculation bias was eliminated through use of an algorithm defining individual fish-otolith trajectories and a biologically determined, rather than a statistically estimated, intercept. Adaptations of the biological intercept back-calculations procedure accurately predicted previous lengths in the presence of both stochastic error and time-varying growth rates. When used to reevaluate some published back-calculations, the biological intercept procedure resulted in more accurate values than those previously estimated, and reduced or eliminated the presence of Lee's phenomenon.

scholarly journals Accumulation of trace metals by aquatic macrophytes and their possible use in phytoremediation techniques

2008 ◽  
Vol 56 (1) ◽  
pp. 97-104
Author(s):  
Michaela Hillermannová ◽  
Radovan Kopp ◽  
Ivo Sukop ◽  
Tomáš Vítek
Keyword(s):  
Surface Water ◽  
Trace Metals ◽  
Plant Species ◽  
Aquatic Plants ◽  
Aquatic Macrophytes ◽  
Plant Biomass ◽  
Water Current ◽  
Ecological Group ◽  
Individual Plant ◽  
The Individual

The aim of the performed research was to obtain knowledge on the ability of aquatic plants naturally growing at a site to absorb trace metals contained in bottom sediments and surface water. Furthermore, we compared differences in the accumulation of trace metals by the individual groups of aquatic plants (submerged and emergent) and assessed a possible use of the individual plant species in phytoremediation techniques. Representative samples of water, sediments and aquatic macrophytes were taken from three anthropogenically loaded streams in six monitoring cycles in several collection profiles differing in the distance from a source of contamination. The samples were analysed for the total content of selected trace metals (As, Cd, Pb, Al, Hg, Zn, Fe, Mn, Cr, Ni and Cu). For comparison, one profile at an unloaded site was sampled as well. The obtained results were subjected to multivariate statistical analysis of data. Increased contents of Fe, Al, Mn, Cr and Zn were detected in sediments and plant biomass at loaded sites, namely 2–3× higher than at the comparing site. The contents of metals in surface water samples were altogether below the detection limit of the analytical method. When evaluating the individual plant species, we can state that the lowest contents of metals were detected in shore species (reed canary grass Phalaroides arundinacea, wood club-rush Scirpus silvaticus and red dock Rumex aquaticus); plant species growing in the very water current (water star-wort Callitriche sp. and flote-grass Glyceria fluitans) exhibited mean contents of metals. In species forming mats (Fontinalis antipyretica and Cladophora sp.), these contents were several times higher as compared to the previous species. The results of the performed research show that one of important factors, which influence the accumulation of trace metals in plants, is their ecological group (emergent – submerged) affiliation and the species classification within this group. Based on the evaluated data, we can recommend species of moss and algae that form mats eventually species growing in the very water flow for the future use in phytoremediation techniques.

scholarly journals Behavioral Response of Bats to Passive Integrated Transponder Tag Reader Arrays Placed at Cave Entrances

2014 ◽  
Vol 5 (1) ◽  
pp. 146-150 ◽  
Author(s):  
Eric R. Britzke ◽  
Mark W. Gumbert ◽  
Matthew G. Hohmann
Keyword(s):  
Pit Tag ◽  
Passive Integrated Transponder ◽  
Pit Tags ◽  
Bat Activity ◽  
White Nose Syndrome ◽  
Winter Activity ◽  
Initial Sampling ◽  
Opening Up ◽  
Potential Use ◽  
Insight Into

Abstract An increasingly popular mark–recapture method to study the ecology of bats is the use of passive integrated transponder (PIT) tags. Deployment of PIT reader arrays at entrances to caves and mines can yield insight into bat behavior during swarming, winter activity, and emergence. This application has the potential to address questions about bat activity at cave and mine entrances in response to white-nose syndrome or bat seasonal movements; however, no studies have examined the response of bats to these arrays. We describe bat response to placement of PIT tag reader arrays using camcorders and supplemental infrared illuminators at three cave entrances near Bloomington, Indiana, during spring 2006. A random subset of 5-min periods was viewed and bat behavior was classified. Circling represented &gt;70% of all behavior noted for two caves but only represented approximately 30% of behavior at the third cave. Proportions of observed activity that resulted in contacts or landings were consistently low across the three caves (x̄  =  1.34%; range 0.5–3.0%), with most contacts causing bats to simply change course and fly away. Based on our observations, positioning reader PIT tag reader arrays at cave entrances to passively recapture PIT tags does not limit bat movements. However, video monitoring during initial sampling efforts of future projects should be conducted to verify appropriate placement and configuration of PIT tag reader arrays. This research provides data illustrating the lack of significant impact in using PIT tag reader arrays at cave entrances, thereby opening up the potential use of this technology to address issues of bats ecology that cannot be obtained with other marking techniques.

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