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Upstream Movements (upstream + movement)
Selected AbstractsDetection efficiency of multiplexed Passive Integrated Transponder antennas is influenced by environmental conditions and fish swimming behaviourECOLOGY OF FRESHWATER FISH, Issue 4 2009J. C. Aymes Abstract,,, The efficiency of a Passive Integrated Transponder (PIT)-tag detection system was tested during a 23-day experiment using a permanent digital video to record the passage of fish through multiplexed antennas. Coupling video to the PIT system allowed the detection of error sources and the correction of erroneous data. The efficiency of the detection system and its variation were investigated according to fish swimming speed, direction of movement and individual fish behaviour. Influence of time and environmental conditions on detection results were also checked. The PIT tag system was 96.7% efficient in detecting fish. Upstream movements were better detected (99.8%) than downstream movements (93.7%). Moreover, results showed that efficiency rate was not stable over the experiment; it was reduced on stormy days. Several sources of errors were identified such as sub-optimal orientation of the PIT tag relative to the antenna plane, the influence of fish swimming speed, individual fish behaviour and influence of environmental conditions. [source] Denil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamicsECOLOGY OF FRESHWATER FISH, Issue 4 2001C. M. Bunt Abstract , Two different Denil fishways on the Grand River, Ontario, were used as check-points to evaluate the upstream movement of fishes past a low-head weir and to examine the proportions and inferred swimming performance of non-salmonid warmwater fishes that used each fishway type. Traps installed at fishway exits were used to collect fish during 24-hour sampling periods, over 40,51 days each year, from 1995 to 1997. Passage rates, size selectivity, water temperature, water velocity and turbidity for the periods of maximum passage for each year were examined. General species composition from trap samples shifted from catostomids to cyprinids to ictalurids to percids and centrarchids, with some overlap, as water temperatures increased from 8 °C to 25 °C in the spring and early summer. Water depths, and therefore water velocities in each fishway, were independent of river discharge due to variable accumulations of debris on upstream trash-racks. Relationships between the water velocity and the swimming and position-holding abilities of several species emerged. Turbidity was directly related to river discharge and precipitation events, and many species demonstrated maximum fishway use during periods of increased turbidity. This study 1) provided evidence of strongly directional upstream movements among several species that were previously considered non-migratory and 2) describes physical and hydraulic conditions during fishway use for 29 non-salmonid fish species., [source] Importance of the olfactory sense to migratory sea lampreys Petromyzon marinus seeking riverine spawning habitatJOURNAL OF FISH BIOLOGY, Issue 4 2010L. A. Vrieze This study tested the hypothesis that the sea lamprey Petromyzon marinus, a diadromous species of fish, relies on innately discerned odours, including pheromones, to locate riverine spawning habitat. Migratory, sexually immature P. marinus were captured as they entered streams flowing into the Great Lakes, and their olfactory systems were occluded or not by injecting either innocuous dental impression material or a saline control into their nasopores. Animals were then released back into lakes or streams and their recapture rates in stream traps noted. When released into Lake Huron, P. marinus with intact (functional) olfactory systems were very successful in locating rivers (recapture rates ranged up to 65%), while animals with occluded nasopores were virtually unable to do so and had recapture rates five to 20 times lower than intact animals. With few exceptions, intact fish entered the stream closest to their release point within a few days, irrespective of where they had been originally captured; their ability to locate streams is apparently innate and well developed. In contrast, when released within streams, both intact and occluded P. marinus successfully swam upstream to traps for several days although the ability of the former exceeded that of the latter after this period. Migratory P. marinus rely heavily on olfactory cues, of which a larval pheromone is presumably one, to locate river mouths and to a lesser extent to promote upstream movement within rivers. [source] Evidence of a rheotactic component in the odour search behaviour of freshwater eelsJOURNAL OF FISH BIOLOGY, Issue 3 2003A. G. Carton The detection of food odour by the freshwater eels, Anguilla australis and Anguilla dieffenbachii released a behavioural response to flow that resulted in direct upstream movement toward the odour source. Changes in various orientation parameters were observed as eels neared the source. Eels had substantially lower swimming velocities and considerably more variable heading and course angles close to the odour source (,0·9 m) than further away (>0·9 m). Observed changes in orientation parameters were primarily due to changes in the behaviour of a searcher following odour loss. Cross-stream movements were initiated when the eel moved beyond the lateral margins of the odour plume. The behavioural switch from odour-conditioned rheotaxis to cross-stream casting following odour loss occurred more frequently close to the odour source where the plume was most narrow. Odour-conditioned rheotaxis enables the searcher to move quickly and efficiently toward the odour source without the need to extract directional information from a highly intermittent and complex chemical signal. [source] Effect of habitat fragmentation on spawning migration of brown trout (Salmo trutta L.)ECOLOGY OF FRESHWATER FISH, Issue 3 2006C. Gosset Abstract , Human-induced habitat alteration is one of the main causes of the decline of freshwater fish populations. The watershed of the River Bidasoa (Spain) is an example of heavily fragmented habitat. The local brown trout (Salmo trutta L.) population is disturbed, with evidence of poor recruitment as well as low adult densities in the main stem. Forty male and female adult migratory trout were tagged with external or internal radio transmitters and released. Fixed stations with data loggers and mobile antennae were used with daily surveys to track fish movements during the migration and spawning period (3 months). Migration distances did not exceed 10 km, and half of the fish never entered a tributary in the study area. Fragmentation because of weirs on the main stem apparently prevented fish from reaching their spawning destination. Fish that entered the tributaries were first confronted with an accessibility problem because of low discharge. However, each fish chose one tributary, without making attempts to run up in other tributaries. Once in the tributary, fish were restrained in their upstream movements by dams. The study area appeared to be isolated from the vast upper part of the watershed. Within the study area, upper parts of tributaries also seemed strongly disconnected from the main stem. This study illustrates the negative impact of river fragmentation on S. trutta migration pattern. Population sustainability can be directly affected through the low availability of spawning grounds for migratory fish. Long-term effects of fragmentation may cause reproductive isolation within watersheds, which in the case of trout also means isolated phenotypic population units. [source] Denil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamicsECOLOGY OF FRESHWATER FISH, Issue 4 2001C. M. Bunt Abstract , Two different Denil fishways on the Grand River, Ontario, were used as check-points to evaluate the upstream movement of fishes past a low-head weir and to examine the proportions and inferred swimming performance of non-salmonid warmwater fishes that used each fishway type. Traps installed at fishway exits were used to collect fish during 24-hour sampling periods, over 40,51 days each year, from 1995 to 1997. Passage rates, size selectivity, water temperature, water velocity and turbidity for the periods of maximum passage for each year were examined. General species composition from trap samples shifted from catostomids to cyprinids to ictalurids to percids and centrarchids, with some overlap, as water temperatures increased from 8 °C to 25 °C in the spring and early summer. Water depths, and therefore water velocities in each fishway, were independent of river discharge due to variable accumulations of debris on upstream trash-racks. Relationships between the water velocity and the swimming and position-holding abilities of several species emerged. Turbidity was directly related to river discharge and precipitation events, and many species demonstrated maximum fishway use during periods of increased turbidity. This study 1) provided evidence of strongly directional upstream movements among several species that were previously considered non-migratory and 2) describes physical and hydraulic conditions during fishway use for 29 non-salmonid fish species., [source] Migratory movements of pacu, Piaractus mesopotamicus, in the highly impounded Paraná RiverJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2007M. C. Makrakis Summary A mark-recapture study was conducted in 1997,2005 to investigate movements of stocked pacu, Piaractus mesopotamicus, in the Paraná River Basin of Brazil, Paraguay, and Argentina. Fish raised in cages within the Itaipu Reservoir and in ponds were tagged externally (n = 2976) and released in the Itaipu Reservoir (53.2%) and bays of its major tributaries (46.8%). In total, 367 fish (12.3%) were recaptured. In all, 91% of the pacu moved away from the release site; upstream movements were more extensive than downstream movements. Pacu traveled upstream a maximum of 422 km (average of 41.3 km) at a maximum rate of 26.4 km day,1 (av. 0.8). Downstream movements were limited in terms of number of individuals and distance moved. Fish released during the wet season moved farther than those released during the dry season, and feeding rather than spawning might have been the compelling reason for movement. Although fish passed downstream through dams, none of the marked fish were detected to have moved upstream through the passage facilities. Pacu showed movement patterns not radically different from those of other neotropical migratory species, but their migratory movements may not be as extensive as those of other large migratory species in the basin. [source] Spatial ecology of the white-clawed crayfish in an upland stream and implications for the conservation of this endangered speciesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 5 2008Damian H. Bubb Abstract 1.Populations of white-clawed crayfish (Austropotamobius pallipes) have undergone substantial declines across Europe. Remaining populations tend to be fragmented and in many catchments they are restricted to upland streams. Information is needed concerning their spatial ecology to assist with conservation and rehabilitation of existing fragmented populations, as well as possible reintroductions. 2.A novel method for the long-term tagging of white-clawed crayfish was used to study the spatial ecology of a white-clawed crayfish population fragment in a small, moderate-gradient upland stream. Internal passive integrated transponder (PIT) tags enabled adult crayfish (carapace length >27 mm) to be permanently tagged, each with a unique identification code and resulted in a high number of recaptures. Of 501 crayfish tagged 413 were subsequently relocated at least once. 3.Crayfish did not make extensive movements, the median annual distance moved was 84.8,m,yr,1, equivalent to annual net movement of 0.233,m,day,1, substantially less than reported in previous studies. The lower levels of movement may reflect the study encompassing all seasons, including winter, when crayfish are relatively inactive. 4.Significantly more crayfish moved downstream compared with upstream and distances moved downstream were significantly greater than those in an upstream direction. This may be linked to the relatively high gradient of the stream and a reduced passability of the abundant riffles to upstream movements of crayfish. 5.A small weir acted as a barrier within the stream, preventing upstream movements of crayfish. Even small barriers may limit the movements of white-clawed crayfish and have the potential to limit connectivity within populations and prevent expansion or recolonization. 6.The results presented suggest that fragmented populations of white-clawed crayfish in upland streams are unlikely to expand rapidly and reconnect to other population fragments, even where habitat is suitable. In establishing stream populations care should be taken to ensure that even small barriers to movement are removed unless these are intended to exclude non-native biota, especially crayfish. Copyright © 2007 John Wiley & Sons, Ltd. [source] | |||||||||||||