scholarly journals Utilising the boundary layer to help restore the connectivity of fish habitats and populations

2018 ◽  
Author(s):  
Jabin R. Watson ◽  
Harriet R. Goodrich ◽  
Rebecca L. Cramp ◽  
Matthew A. Gordos ◽  
Craig E. Franklin
Keyword(s):  
Habitat Fragmentation ◽  
Fish Species ◽  
Juvenile Fish ◽  
Fish Passage ◽  
Freshwater Ecosystems ◽  
Water Velocity ◽  
Fish Movement ◽  
Important Species ◽  
Significant Contributor ◽  
Remediation Design

SignificanceHabitat fragmentation is a significant contributor to the worldwide decline of freshwater ecosystem health, the most pervasive cause of which is culverts. Culverts act as a barrier to fish movement, impacting feeding, predator avoidance, spawning, and community structures. Here we show that a common remediation strategy that involves baffles, is detrimental to the successful passage of small bodied and juvenile fish at high velocities. To remedy this widespread problem, we present a novel remediation design that benefits a range of small-bodied species and juvenile fish at the same high velocities, regardless of morphology or ecological niche. The application of this remediation design may be expanded to any smooth surfaced anthropogenic structure, to improve fish passage and restore ecosystem functionality.AbstractCulverts are a major cause of habitat fragmentation in freshwater ecosystems, are a barrier to fish movement, and are regarded as a significant contributor in the decline of freshwater fish populations globally. To try to address this, various culvert remediation designs have been implemented, including the installation of vertical baffles and the provision of naturalistic (rock) substrates. While remediation strategies generally aim to reduce the velocity of water flowing through the structure, there is often resistance to their use because the resultant reduction in culvert discharge can negatively impact upstream flooding while also resulting in debris clogging and increased culvert maintenance costs. In addition, baffles markedly increase water turbulence that may be detrimental to passage by some fish species or size classes. Here we present some novel remediation designs that exploit the reduced water velocity in boundary layers along the culvert wall to enhance fish passage without significantly compromising discharge capacity. These longitudinal designs produce an expanded reduced velocity zone along the culvert margins that generate minimal turbulence. We show that these novel designs are significantly advantageous to the swimming endurance and traversability for six small-bodied Australian fish species. We also provide data on how and why some culvert baffle designs may impede small-bodied fish passage. This data scales with increasing water velocity, encompassing inter-specific differences in swimming capacity. These results have broad implications for fish community structure and the requirement of juvenile cohort of large-bodied commercially important species where baffles have been implemented to facilitate fish passage.

Effects of Water Velocity and Trash Rack Architecture on Juvenile Fish Passage and Interactions: A Simulation

2007 ◽  
Vol 136 (5) ◽  
pp. 1177-1186 ◽  
Author(s):  
Emily Y. Floyd ◽  
Roger Churchwell ◽  
Joseph J. Cech
Keyword(s):  
Juvenile Fish ◽  
Fish Passage ◽  
Water Velocity

Factors affecting juvenile galaxiid fish passage at culverts

2011 ◽  
Vol 62 (1) ◽  
pp. 38 ◽  
Author(s):  
Katharina Doehring ◽  
Roger G. Young ◽  
Angus R. McIntosh
Keyword(s):  
Fork Length ◽  
Fish Passage ◽  
Water Velocity ◽  
Fish Movement ◽  
Migratory Fish ◽  
Factors Affecting ◽  
The World ◽  
Galaxias Maculatus ◽  
Habitat Variables

Alteration of urban streams by culverts is common throughout the world and is known to impede freshwater fish movement. The main objectives were therefore to investigate how different culvert characteristics (e.g. height, length, angle, perched v. non-perched) and habitat variables (e.g. water velocity, riverbed gradient) affect the passage success of juvenile inanga (Galaxias maculatus), a weak-swimming migratory fish. We determined whether passage of juvenile G. maculatus could be improved by installing a ramp at thirteen replicate in situ culverts in Nelson City, New Zealand. As expected, none of the 400 fish tested were able to pass undercut (i.e. perched) culverts before ramp installation (0% passage), compared with the 250 fish (65% passage) that were able to pass non-perched culverts. Significantly more fish (44% passage) reached perched culvert outlets when aided by the ramp. Passage success with the ramp depended on its length and angle, with fewer fish passing longer or steeper ramps. To provide upstream passage for weak-swimming species such as juvenile (fork length < 60 mm) G. maculatus, ramp length and angle should not exceed three metres and 20 degrees, respectively. With passage requirements known and mitigation processes in place, urban fish populations might be able to be sustained.

scholarly journals How barriers shape freshwater fish distributions: a species distribution model approach

2016 ◽  
Author(s):  
Mathias Kuemmerlen ◽  
Stefan Stoll ◽  
Peter Haase
Keyword(s):  
Habitat Fragmentation ◽  
Fish Species ◽  
Species Distribution ◽  
Species Distribution Model ◽  
Freshwater Ecosystems ◽  
Distribution Model ◽  
Catchment Management ◽  
Distribution Models ◽  
Stream Network ◽  
Fish Distributions

Barriers, from dams to culverts, continue to be built globally despite their well-known negative effects on freshwater ecosystems. While large barriers strongly influence distribution through habitat fragmentation, the effects of smaller barriers on the distribution patterns of many fish species remains poorly studied. Obstruction metrics were calculated including different types and magnitudes of barriers considering upstream, downstream or barriers within a 10 km stream network distance. These were then included in species distribution models (SDMs) of 20 fish species and compared to predictions without barriers to understand their effects on fish distributions. Barriers were important for the predictions of many fish species with the metric upstream barriers being the most relevant barrier predictor across the fish community. With the inclusion of barriers, most species saw a reduction in their predicted range and habitat suitability decreased, suggesting habitat fragmentation and indicating a higher extirpation risk. Predictions from this SDM application point out how and where barriers influence fish distributions in the studied catchment. This species-specific and spatially-explicit information is highly valuable for target-oriented river restoration measures, biodiversity conservation efforts and catchment management in general.

scholarly journals Swimming performance traits of twenty-one Australian fish species: a fish passage management tool for use in modified freshwater systems

2019 ◽  
Author(s):  
Jabin R. Watson ◽  
Harriet R. Goodrich ◽  
Rebecca L. Cramp ◽  
Matthew A. Gordos ◽  
Yulian Yan ◽  
...  
Keyword(s):  
Fish Species ◽  
Swimming Speed ◽  
Swimming Performance ◽  
Fish Passage ◽  
Freshwater Ecosystems ◽  
Performance Data ◽  
Management Tool ◽  
Freshwater Systems ◽  
Australian Fish ◽  
The Impact

AbstractFreshwater ecosystems have been severely fragmented by artificial in-stream structures designed to manage water for human use. Significant efforts have been made to reconnect freshwater systems for fish movement, through the design and installation of dedicated fish passage structures (fishways) and by incorporating fish-sensitive design features into conventional infrastructure (e.g. culverts). Key to the success of these structures is making sure that the water velocities within them do not exceed the swimming capacities of the local fish species. Swimming performance data is scarce for Australian fish, which have a reduced swimming capacity when compared to many North American and European species. To help close this knowledge gap and assist fisheries management and civil engineering, we report the swimming performance capacities of twenty-one small-bodied fish and juveniles (< 10 cm) of large bodied species native to Australia as measured by critical swimming speed (Ucrit) and burst swimming speed (Usprint) in a recirculating flume. This data is complemented by endurance swim trials in a 12-meter hydraulic flume channel, and by measures of flume traverse success. Building on the utility of this dataset, we used a panel of morphological, behavioural and ecological traits to first assess their relative contributions to the observed swimming performance data, and second, to determine if they could be used to predict swimming performance capacity – a useful tool to assist in the management of species of conservation concern where access to swimming performance data may be limited. We found that body length combined with depth station (benthic, pelagic or surface) explained most of the interspecific variation in observed swimming performance data, followed by body shape and tail shape. These three traits were the most effective at predicting swimming performance in a model/unknown fish. This data will assist civil engineers and fisheries managers in Australia to mitigate the impact of in-stream structures on local fish populations.

Diversity and abundance of cichlids in Ikere Gorge Reservoir, Iseyin, Oyo State, Nigeria

2021 ◽  
Vol 18 (1) ◽  
pp. 52-56
Author(s):  
S.O. Ajagbe ◽  
R.O. Ajagbe ◽  
O.S. Ariwoola ◽  
F.I. Abdulazeez ◽  
O.O. Oyewole ◽  
...  
Keyword(s):  
Fish Species ◽  
Riparian Forest ◽  
Abundant Species ◽  
Freshwater Ecosystems ◽  
Freshwater Species ◽  
Fishing Villages ◽  
Gorge Reservoir ◽  
Commercially Important ◽  
Sarotherodon Galilaeus ◽  
Fish Species Diversity

Cichlids are highly abundant and commercially important fish in freshwater ecosystems in Nigeria. This study examined the diversity and abundance of cichlids in Ikere Gorge Reservoir. Four fishing villages were randomly selected from 12 fishing villages in Ikere Gorge Reservoir as sampling sites. Cichlids were sampled randomly and examined from fishermen catch in each selected fishing village; were identified with appropriate keys; the weight and abundance of the catches were recorded. The data obtained was subjected to descriptive statistical analysis using SPSS (Version 20.0) software to determine the abundance of fish species. Fish species diversity was carried out by using Palaeontological Statistics (PAST). Eight species of cichlids were sampled in Ikere Gorge but Sarotherodon galilaeus was the most abundant species while the least abundant species was Pelmatolapia mariae. It was observed that, cichlids were  abundant in rainy season than in the dry season. Likewise, cichlids were abundant in Ikere-gorge reservoir but they have low diversity. This may be as a result of unsustainable fishing pressure and deforestation of riparian forest and sedimentation in Ikere-gorge reservoir. Therefore, to maintain sustainable fishing activities and improve cichlids population in Ikeregorge reservoir, unsustainable activities in and around Ikere Gorge reservoir should be put under control. Keywords: Cichlidae; freshwater species; dominant; Sarotherodon galilaeus; Pelmatolapia mariae.

scholarly journals Culverts in paved roads as suitable passages for Neotropical fish species

2012 ◽  
Vol 10 (4) ◽  
pp. 763-770 ◽  
Author(s):  
Sergio Makrakis ◽  
Theodore Castro-Santos ◽  
Maristela Cavicchioli Makrakis ◽  
Ricardo Luiz Wagner ◽  
Maurício Spagnolo Adames
Keyword(s):  
Fish Passage ◽  
Fish Movement ◽  
Upstream Migration ◽  
Migratory Species ◽  
Neotropical Fish ◽  
Potential Barriers ◽  
Medium Risk ◽  
Fall Height ◽  
Additional Monitoring ◽  
Spawning Success

Improperly installed or poorly maintained culverts can pose a serious threat to fish by disrupting their habitat and endangering spawning success. Road culverts that are not designed for fish passage frequently can become obstacles. This can be especially problematic for migratory species, but can lead to fragmentation of resident populations as well. This study evaluated 40 culverts of 29 sites within a 25-km radius from Toledo city, Paraná State, southern Brazil, with respect to their likely effects on movement of the local ichthyofauna. We collected data on the shape and length of culverts, culvert material, waterfall height, water column depth, slope, and estimated flow velocity. Culverts were categorized by level of barrier risk for upstream migration: high, medium, low, and impassable, as well as the type of barrier posed (fall height, depth, length and velocity). Most of culverts analyzed were considered potential barriers to fish movement, with 45% classified as impassible, 45% as high risk, 10% as medium risk, and no culverts as low risk. Brazilian culverts as fishways will require additional monitoring and studies to corroborate the premises proposed in the present study. Road culvert projects that are properly built and maintained will be able to simultaneously improve function of roadways and protect fish populations.

scholarly journals Morphological differentiation among migratory fish species from the Paraná River basin

2012 ◽  
Vol 12 (4) ◽  
pp. 41-49 ◽  
Author(s):  
Lucileine de Assumpção ◽  
Maristela Cavicchioli Makrakis ◽  
Sergio Makrakis ◽  
Pitágoras Augusto Piana ◽  
Patrícia Sarai da Silva ◽  
...  
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Fish Passage ◽  
Paraná River ◽  
Migratory Fish ◽  
Migratory Species ◽  
Caudal Peduncle ◽  
Parana River ◽  
Maximum Body ◽  
Paraná River Basin

This study characterized the morphological differences among migratory fish species from the Paraná River Basin. A total of 177 adult fish of Leporinus elongatus, Leporinus macrocephalus, Prochilodus lineatus, Salminus brasiliensis, Pimelodus maculatus, Pinirampus pirinampu, Pseudoplatystoma corruscans, Pterodoras granulosus, and Rhaphiodon vulpinus were sampled in the Canal da Piracema, a fish passage system at Itaipu Dam, Paraná River. The migratory species were analyzed through 22 morphometric measurements and fineness ratio to identify morphological patterns related to swimming performance. Four species groups were indicated by the Cluster analysis: I) R. vulpinus; II) P. corruscans; III) L. macrocephalus, L. elongatus, P. lineatus, P. maculatus, and S. brasiliensis - measurements of head height and anal fin length formed this group; and IV) P. granulosus and P. pirinampu - measurements of maximum body width and caudal peduncle width contributed to form this group. The morphometric variables that most contributed to the distinction were head length and mouth width for groups I and II. The species R. vulpinus and P. granulosus differed from other species, showing fineness ratios of 9.4 and 3.7, respectively. Leporinus elongatus, L. macrocephalus, P. lineatus, P. maculatus, and S. brasiliensis showed significant differences from other species, with ratios ranging from 4.57 to 5.19, indicating that these species may be better swimmers. Long-distance migratory species using the Piracema Canal to ascend upstream areas differed morphologically, morphological characteristics such as a narrow caudal peduncle and maximum body length, besides to the values of the fineness ratio, were essential to differentiate the migratory species.

scholarly journals Comparing on site human and video counts at Igarapava fish ladder, south eastern Brazil

2006 ◽  
Vol 4 (2) ◽  
pp. 291-294 ◽  
Author(s):  
Mark D. Bowen ◽  
Simone Marques ◽  
Luiz G. M. Silva ◽  
Volney Vono ◽  
Hugo P. Godinho
Keyword(s):  
Fish Species ◽  
Accurate Method ◽  
Fish Passage ◽  
Southeastern Brazil ◽  
Human Observer ◽  
Full Spectrum ◽  
Prochilodus Lineatus ◽  
Number Of Species ◽  
Fish Ladder ◽  
Number Of Individuals

On site human observations and video images were collected and compared at the window of the Igarapava Dam fish ladder (IDFL), rio Grande , Southeastern Brazil, between March 1st and June 30th, 2004. We conducted four experiments with two humans (Observer 1 and Observer 2) observing fish passage in the IDFL window while a Sony 3CCD video camera (Observer 3) recorded fish passage at the same time. Experiments, each one hour in length, were distributed throughout the diel cycle using full spectrum lights. We identified fish species, the number of individuals for each species, and the real time that they passed. Counts from each human observer were compared to the video counts. The fish species most commonly observed in the window were - curimba (Prochilodus lineatus), mandi-amarelo (Pimelodus maculatus), piau-três-pintas (Leporinus friderici) and ferreirinha (Leporinus octofasciatus). The number of species and individuals were indistinguishable for the three observers. But, the number of species and individuals were significantly different among experiments. Thus, the three observers register the same number of species and count the same number of individuals even when these two response variables differ significantly among experiments. Based on these results, we concluded that the video count was an accurate method to assess fish passage at the IDFL.

scholarly journals Juvenile fish in Cystoseira forests: influence of habitat complexity and depth on fish behaviour and assemblage composition

2019 ◽  
Vol 20 (2) ◽  
Author(s):  
AMALIA CUADROS ◽  
JOAN MORANTA ◽  
LUIS CARDONA ◽  
PIERRE THIRIET ◽  
PATRICE FRANCOUR ◽  
...  
Keyword(s):  
Body Length ◽  
Fish Species ◽  
Habitat Complexity ◽  
Fish Assemblages ◽  
Juvenile Fish ◽  
The Body ◽  
Environmental Drivers ◽  
Independent Effect ◽  
Depth Range ◽  
Canopy Volume

The sublittoral forests formed by the fucoid algae Cystoseira spp. are important juvenile habitats for many Mediterranean fish species. However, the spatial variability of juvenile fish assemblages within the forests and the potential environmental drivers, such as depth and habitat complexity, remain poorly understood. We estimated densities, sizes and behaviours of juvenile fish assemblages in subtidal (0-15 meters) Cystoseira brachycarpa var. balearica forests in north Minorca Island (North-western Mediterranean Sea) over two consecutive autumns (2012 and 2013). Depth and forest complexity, here measured as canopy volume, had both a significant and independent effect on the juvenile fish assemblages in terms of species abundance composition and body size. Assemblages found in the shallowest depth range (3-4m) were characterized by greater densities of the ornate wrasse Thalassoma pavo, while those deeper (10-12m) had higher densities of the rainbow wrasse Coris julis, independently of its size composition. Juveniles of both species were more abundant in less complex forests; conversely juveniles of wrasses of the genus Symphodus were more abundant in more complex forests. The smallest sizes of T. pavo occurred in the most complex forests. On the other hand, our results demonstrated that juvenile fish behaviours were unrelated to the complexity of the Cystoseira forests but mainly related to the body length. The effects of body length on behaviour were however species dependent. Cryptic and transitory behaviours were mostly observed in the smallest and largest juveniles of T. pavo and C. julis, respectively, while the behaviour of Symphodus spp. was unrelated to their body length. Our study emphasises the importance of preserving healthy Cystoseira forests and their intrinsic patchy nature, as this habitat, with its mosaic of different complexity degrees and bathymetrical variability, enable the presence of different fish species at various life stages.

Sign in / Sign up

Export Citation Format

Share Document