Fish Habitat Research Articles

Effects of 2D hydrodynamic model resolution on habitat estimates for rearing Coho Salmon in contrasting channel forms

AbstractEstimating the impacts of water allocation decisions on fish populations and habitat availability is an important part of environmental flow assessments, especially in locations where water resources are limited. Two‐dimensional hydrodynamic models (2DHMs) are commonly coupled with biological models to estimate fish habitat quality, area, and capacity across a range of proposed streamflows. Increasingly, resource managers are relying on landscape‐scale model domains with coarse model resolutions to maintain feasible computational loads, but this may affect habitat estimates if the mesh element size of the model exceeds the spatial scale relevant to the organism. We investigated how coarsening the resolution of a 2DHM influences the area and spatial distribution of estimated Coho Salmon (Oncorhynchus kisutch) fry habitats. We used an interpolation scheme that upscaled mesh elements from a high‐resolution (0.25 m2) 2DHM to quantify and visualize the effects of 2DHM resolution on estimates of Coho Salmon fry habitat for two contrasting channel morphologies and across a broad range of streamflows. Estimates of Coho Salmon fry habitat at increasingly coarser resolutions led to 20%–50% reductions in weighted usable habitat area (WUA) across several streamflow scenarios for a complex channel type, but did not impact estimates in a confined, flume‐like channel. Additionally, flow‐to‐habitat area relationships were not congruent at a given streamflow when resolution coarsened. Along with almost 500% more high‐quality habitat area estimated in the complex channel type over the confined, discrepancies in habitat area increased with higher flows in areas defined as optimal for rearing Coho Salmon fry. Considering that complex channel types contain critical habitat for Coho Salmon fry, this study suggests coarse 2DHM resolutions may exclude important wetted edge and off‐channel habitats from environmental flow assessments.

Wood you believe it? Experimental addition of nonnative wood enhances instream habitat for native dryland fishes

AbstractFlow alteration and riparian vegetation encroachment are causing habitat simplification with severe consequences for native fishes. To assess the effectiveness of enhancing simplified habitat in a large dryland river, we experimentally added invasive wood at 19 paired treatment and reference (no wood added) subreaches (50–100 m) within the main channel of the San Juan River. Using a before‐after‐control‐impact design, we sampled fishes and macroinvertebrates, and quantified habitat complexity. After wood addition, total native fish densities were 2.2× higher in treatments compared with references, whereas total nonnative fish densities exhibited no response. Macroinvertebrate densities were 6.8× higher, and habitat complexity increased in treatments. Counts of geomorphic features in treatments increased from 1 to a maximum of 11 following wood addition, while the number of features in references remained unchanged. Wood addition has potential to instigate natural riverine processes, ultimately enhancing native fish habitat by increasing macroinvertebrate densities and habitat complexity in dryland rivers. Water overallocation and increasing aridity will continue to challenge efforts to improve habitat conditions with environmental flows alone, and managers might consider integrating non‐flow alternatives like addition of abundant, invasive wood to reduce habitat simplification.

Consistencies in the dietary and isotopic niche of spotted seatrout, Cynoscion nebulosus, across a salinity gradient within a coastal Louisiana estuary.

Estuaries are essential habitats for recreational and commercial fish that are shaped by both natural and anthropogenic processes. In Louisiana a combination of climate change and planned coastal restoration actions is predicted to increase freshwater introduction to coastal estuaries. As such there is a need to quantify the relationships between estuarine fish ecology and salinity to aid in predicting how species will respond to shifts in salinity. We investigated the relative abundance and dietary niches of adult (24.5 ± 5.4 cm standard length) spotted seatrout Cynoscion nebulosus across varying salinity regimes (oligohaline, mesohaline, and polyhaline) within Barataria Bay, Louisiana, using a combination of net sampling and gut content and stable isotopes analysis. We found that the relative abundance of C. nebulosus was lowest at the oligohaline site, translating to approximately five fewer fish captured for every single psu decrease in a site's average annual salinity. In contrast, we found that diets and, to a lesser extent, isotopic niches had a high degree of overlap across sites with differing salinity regimes. Fish and penaeid shrimp were the most common and important prey taxa recovered from guts at all sites. The small isotopic differences found among sites were likely due to spatial variation in hydrogeochemical baselines, and the observed isotopic overlap provides support for the idea that C. nebulosus move between adjacent salinity regimes and forage throughout Barataria Bay. Our results contribute to a greater understanding of the salinity preference and trophic ecology of C. nebulosus that can aid in predicting their responses to future salinity and habitat changes within Barataria Bay associated with predicted climate change and planned coastal restoration actions.

Characteristics of surface flow field and substrate in the spawning ground of Schizothorax grahami

The Spawning ground is a crucial habitat for fish, and the physical characteristics of the habitat are important for fish life history. In this paper, Large-Scale Particle Image Velocimetry (LSPIV) was used to measure the surface flow field and the substrate (particle size and mineral composition) in the spawning ground of Schizothorax grahami. Based on the literature and consideration of experimental feasibility, two spawning grounds in the source of the Chishui River were selected—Erlongqiangbao (located in the mainstream) and Bamaoba (located in the tributary), two and three cross sections of each river section were analyzed respectively. The results show that Erlongqiangbao first flows in the direction of “southeast-northwest” and then “southwest—northeast” after crossing the bridge; the maximum velocity of the reach is 3.374m/s. The size of the substrate is mainly less than 1mm in the upstream section of Erlongqiangbao, both 25-50mm in the middle and downstream, and the substrate type mainly is quartz and calcite; Gushangtian flows in the direction of “southwest-northeast,” the maximum velocity of the reach is 1.537m/s, the size of the substrate is mainly greater than 50mm in the upstream, and 25-50mm in the middle and downstream, the substrate type mainly is quartz, calcite, and dolomite. The mineral compositions of the two spawning sites were analyzed by principal component analysis. Quartz and anorthose are more than 1 in composite scores, respectively ranked first and second, indicating that they play a dominant role in the mineral composition. This study could provide basic data and ideas for restoring S. grahami spawning ground.

Detection differences between eDNA and mid‐water trawls are driven by fish biomass and habitat preferences

AbstractMarine scientific trawl surveys are commonly used to assess the distribution and population size of fisheries‐related species, yet the method is effort‐intensive and can be environmentally destructive. Sequencing environmental DNA (eDNA) from water samples can reveal the presence of organisms in a community without capturing them; however, we expect the detectability of taxa to differ between eDNA and trawl surveys, and understanding how species traits and population variables contribute to detection differences can help calibrate our expectations from each form of sampling. Here, we coupled eDNA metabarcoding and capture trawl surveys in British Columbia, Canada, to examine species traits that explain recurrent differences in detectability between the two methods, including habitat, body size, and biomass. At the regional scale, 17 of 23 fish species (74%) captured by the trawl were detected by eDNA metabarcoding, and 39 additional species were detected by eDNA sampling only. We found that eDNA metabarcoding disproportionately detected trawl‐caught species with greater local biomass (i.e., greater biomass in the adjacent trawl). Fish detected only in eDNA had a greater range of body lengths and a broader range of habitat preferences outside the trawls' target size and sampling areas. Our results suggest that with our level of sampling, eDNA metabarcoding can adequately recapitulate detection of fish communities detected by trawl surveys, but with a bias toward fish of high population biomass and greater inclusion of fish from outside the trawled area.

Multi‐year monitoring shows higher species richness and diversity of fish assemblages in a Danish seagrass meadow as compared to neighbouring non‐vegetated areas

AbstractSeagrass meadows provide an important nursery and feeding habitat for fish, globally. However, limited data exist on how these vegetated coastal ecosystems affect local fish stocks over longer time periods. By means of beach seine hauling with a bio‐monitoring seine net, we collected fish data in Kronborg Bay (Denmark) over 4 years. The bay contains both vegetated and bare sediment areas in close proximity to Kronborg Castle in Elsinore and is part of the Øresund strait; a dynamic marine environment linking the Baltic Sea with the inner Danish waters (Kattegat). We investigated the biodiversity and fish abundance in a healthy seagrass meadow and compared it with a bare adjacent sediment area. We show that seagrass is important for fish species like the Atlantic cod, the two‐spotted goby, and the broadnosed pipefish. The seagrass meadow harboured more fish species and higher biodiversity, while the number of individuals was higher in the adjacent bare sediment area as a result of high abundances of lesser sand eel. Pilou's evenness and the Shannon‐Wiener index showed 2–4‐fold higher biodiversity in the seagrass meadow. The seagrass meadow harboured about 35% more fish species than the bare adjacent sediment. The Atlantic cod was almost entirely found in the seagrass meadow, while lesser sand eel that showed an overall increase in abundance in both habitats, represented the largest proportion of the total number of fish individuals (up to about 60%) and was mostly found on the bare adjacent sediment. Species abundance was analysed for changes over time, where, for example the European plaice showed an increase in abundance over the 4‐year period of investigation. Seagrass meadows can thus be very important for the Atlantic cod population in the Øresund strait and generally for local fish productivity, abundance and diversity.

A dataset of the ecological security patterns in the peripheral region of Poyang Lake from 2000 to 2020

With the continuous expansion of human activities, the habitats of many species are confronted with serious destruction and threats, leading to increasingly prominent ecological security issues. Therefore, it is crucial to establish an ecological security pattern that takes species habitats into consideration, so as to protect biodiversity and maintain ecological balance. Poyang Lake, as a paradise for wildlife, serves as the habitat and breeding ground for many bird species, fish, and other aquatic organisms. Taking the research scope of the peripheral region of Poyang Lake as an example, we produced the land use data for the years 2000, 2010, and 2020 on the basis of the Google Earth Engine platform and the random forest classification method. By integrating morphological spatial pattern analysis, landscape pattern indices, landscape connectivity indices, circuit theory, and long-term land use data, we developed a long-term ecological security pattern for the peripheral region of Poyang Lake from 2000 to 2020, which takes into accounts habitats for various species including fish and birds. This dataset contains various types of data, including innovative elements. In terms of data quality control and evaluation, strict quality control and evaluation processes were conducted on the data used and the predicted results, ensuring the accuracy and credibility of the data and providing effective data support and references for relevant research. The dataset not only comprises indicator data for constructing an ecological security pattern to protect species habitats but also includes historical and predicted ecological security pattern data for the peripheral region of Poyang Lake. It can provide important scientific data support and serve as references for future research on species protection and ecological security patterns in the peripheral region of the Poyang Lake.

Xenobiotics and pollution of Lake Ladoga

Advances in applied chemistry have led to the emergence of a new group of organic toxicants - xenobiotics, which have found wide application in industry, agriculture and everyday life, and quickly spread through the biosphere, exerting a prolonged effect on living organisms, including humans. Research was carried out in the waters of the Shlisselburg, Volkhov and Svirskaya lips of the littoral zone of the southern part of Lake Ladoga in the period 2020-2023, using generally accepted methods of biological and chemical analytical analysis of fish and their habitat. 1500 specimens were examined. Fish and 3000 larvae. Chemical-analytical studies of samples of water, bottom sediments, atmospheric precipitation and fish for metals were carried out in the laboratory of fishery ecology of the St. Petersburg branch of the Federal State Budgetary Institution "VNIRO" ("GosNIORH" named after L.S. Berg) on an atomic absorption spectrophotometer AA - 7000 (Shimadzu) according to approved methods (PNDF., 2010; M02-2406., 2013 and M02-902-125, 2005), and in the research laboratory of food and natural objects "ANALECT" of the Institute of the Ministry of Health of the Russian Federation, using the method of atomic absorption spectrometry according to approved methods. Hydrochemical and hydrological indicators were determined using an automatic multiparameter probe Aqua TROLL 500. The content of metals in the fish habitat at the surveyed equators, as dangerous toxicants and previously significant for Lake Ladoga, showed their low content and especially such highly toxic ones as lead and cadmium. Minor excesses were noted for copper and manganese, but they could not in themselves be the cause of pathological manifestations of toxicosis in fish and disruption of the process of their natural reproduction.

Importance of complex sponges as habitat and feeding substrata for coral reef fishes

Coral reef fishes are usually assumed to be most strongly associated with reef-building corals. However, sponges can be a significant structural component of coral reef ecosystems and their framework can enhance the local abundance and biodiversity of fish assemblages. Little is known regarding the range of fish species using complex sponges as either shelter or feeding substrata. Here we use a combination of stationary video cameras and focal animal sampling to document fish species positively associated with complex sponges in Kimbe Bay, Papua New Guinea. Stationary cameras identified 45 fish species using the sponges for either shelter, feeding substrata or as sites for ambush predation. A guild of 10 individual fish species from five families (Blenniidae, Chaetodontidae, Gobiidae, Labridae and Pomacentridae) were observed to quantify sponge and other habitat use and compared with habitat availability to determine the level of sponge selectivity. One species, Pleurosicya elongata (the Slender Spongegoby), lived in obligate association with Ianthella basta (Elephant Ear sponge), and there was a positive relationship between sponge size and number of resident fish, however this was not significant for all life stages. Five other fish species appeared to preferentially select sponges as habitat (Amblyglyphidodon aureus, Chaetodon kleinii, Coradion chrysozonus, Escenius prooculis and Pomacentrus nigromanus), while for others, sponge use appeared incidental. When selectivity indices were calculated for specific sponge species it was apparent that some fishes exhibited preferences for particular sponge species or growth forms. These results suggest more fish species may be reliant on sponges than is widely appreciated.

Mangrove ecosystems as fundamental habitats for fish from the Mexican Caribbean: An evaluation between a conserved and restoration zone

Mangrove ecosystems can function as a habitat for many juvenile marine fish species, with provisions of food and refuge. Seemingly, these ecosystems have been extensively reduced due to anthropogenic activity, as is widespread land use and road construction along the coastline. Nonetheless, much needed restoration efforts have increased tremendously over time. This study analyzes fish community, and the manner in which habitats in the mangrove ecosystem are used, comparing two mangrove zones, a conserved zone (healthier state) and one undergoing restoration. Hydrologically, no significant differences were registered (KW p>0.05). Of the 24 species registered, marine species were dominant in the conserved zone and estuarine species dominant in the restoration zone. Juvenile fishes were more abundant in the conserved mangrove zone, with a higher proportion of adults found in the restoration zone. According to Hutcheson’s t test, fish diversity showed significant statistical differences between sites combined with distinct climatic seasons. The Canonical Correspondence Analysis (CCA) indicated a relationship between secondary freshwater species Floridichthys polyommus and Cyprinodon artifrons and greater salinity and temperature, whereas marine species had a higher relationship with well oxygenated sites. A high number of marine fish species in juvenile stage in the conserved area may relate to mangroves functioning as nurseries. This can serve as a useful indicator by managers taking an integral approach to evaluate and monitor present and future mangrove restoration programs and pathways.

FISH APARTMENT AS AN EFFORT TO INCREASE PRODUCTIVITY AND CONSERVATION OF FISH RESOURCES (LITERATURE REVIEW)

The decline in global marine fisheries production has sparked concerns about depletion of fish resources. The innovation developed is the use of fish apartments to increase productivity and conserve fish resources. Fish apartment is useful as fishing media, replacement habitat for damaged coral reefs, nursery ground and feeding ground for fish habitat ecology. Fish apartment can also be an indicator of changes in trophic levels in the food chain in aquatic ecosystems. This research explores the benefits of fish apartment for increasing productivity and conserving fish resources. Descriptive and exploratory research methods were carried out by combining literature and published research results. The benefits of fish apartment as an effort to increase the productivity of fish resources can be seen from the existence of waters that have the potential to become fishing areas which contribute to increasing fish stocks so that catches increase by 80% per year from 2013-2015. The fish apartment can restore damaged aquatic ecosystems because it increases the abundance of 39 types of fish species and improves the fish habitat for the 20 families of coral fish that occupy the fish apartment.

Shallow estuarine reef as nursery habitat for Australasian snapper (Chrysophrys auratus)

ABSTRACT Estuaries are important recruitment sites for many fish species, with structurally-complex habitats such as subtidal seagrass beds on soft sediments particularly valuable due to their provision of food and shelter. Soft sediments dominate most estuaries, but where hard-bottom reefs are present they have the potential to act as nursery habitats for juvenile fish. We document recruitment of juvenile Australasian snapper (Chrysophrys auratus) to a shallow linear sandstone reef in Whangateau Harbour, a small estuary in north-eastern New Zealand. Up to several hundred 0 + juveniles (∼20–70 mm fork length) were present on the reef during early summer to mid-late autumn each year from 2018 to 2021. Numbers were consistently highest at the seaward end of the reef, facing into incoming tidal currents, and lowest in the deeper central part of the reef, where larger, potentially cannibalistic, snapper were common. Juveniles disappeared from the reef fairly abruptly at the end of each season, with departure in at least two of the years appearing to follow a sudden decrease in water temperature rather than being associated with body size or absolute temperature. Although relatively small in area, estuarine reefs may be increasingly important nursery habitats in the future given the widespread loss of subtidal seagrass beds.

Coupling hydrological methods with ‘Flow Health’ to simulate ecological flow in the Weihe River Basin, China

AbstractReducing river flows significantly affects livelihoods, ecology and industrial production. Therefore, allowing for ecological flow requirements has been applied to limiting human water consumption and is incorporated into water allocation planning. However, the unavailability of ecological data greatly limits e‐flow studies and this lack of sufficient ecosystem data is mostly addressed by using hydrological metrics as surrogates of the river ecosystem. This study employed the nine indicators of the ‘Flow Health’ model to assess river hydrological health and explore optimal ecological flow regimes. The modelling estimated the required flow and the extra flood flows of ecosystem conservation under default and custom thresholds. Ecological flows were calculated for five stations of the Weihe River through coupling with three hydrological methodologies. The index of flow deviation indicated that the flow regimes in Weihe River have partially changed from the reference period. Fish and other aquatic habitats have changed by reduced flows, but the health of the floodplain ecosystem has not been seriously affected. The ecological flow modelling results showed that the extra flow required for the ecology restoration in five stations is concentrated from July to September. The optimal ecological flows in dry seasons by coupling three hydrological methods were less than the average current flow, which is reasonable. This coupling provides ideas on how environmental flow assessments are undertaken in similar regions.

Plastic Contamination in Aquatic Ecosystems: A Fisheries Perspective

Plastic contamination poses a dire threat to aquatic ecosystems and fisheries, necessitating a comprehensive exploration of its ecological, economic, and socio-economic dimensions. From the ubiquity of plastics globally to their adverse impacts on fish habitats and the economic viability of fisheries, this analysis delves into the intricate dynamics of plastic pollution. The socio-economic implications for local communities, coupled with the staggering costs of mitigation measures, underscore the urgency of addressing this pervasive issue. The article critically evaluates research quality, emphasising the need for interdisciplinary approaches and robust regulatory frameworks. Mitigation strategies, including sustainable fishing practices and community engagement, are proposed to preserve aquatic ecosystems for future generations. The study also outlines future research directions, emphasising the importance of understanding long-term ecological consequences and addressing spatial and temporal variability in plastic pollution.

Silences of the Dam: The Intimate Geographies of Ethnic Lao Well-Being on the Sesan River

In the locales where hydropower dams in the Mekong River Basin have been constructed, ethnically and economically marginalized groups who depend on rivers and their tributaries for well-being often bear the greatest burdens: loss of fisheries and river-based livelihoods, riverbank gardens, and sacred sites, to name a few. In December 2018, the controversial Lower Sesan 2 Dam in northeastern Cambodia started operations, exacerbating old challenges and creating new ones for the riverine communities along the Sesan and Srepok Rivers. In this article, I employ a feminist political ecology framework to explore the varying ways that personal and community well-being are impacted in two ethnic Lao locales of Sre Kor (Na Kor in Lao language) commune and Phluk village as a result of the Lower Sesan 2 Dam. While the dam has disrupted flows of water and fish habitats and migrations, rendering new ecological circumstances, I argue that infrastructural violence can variably hide intimate geographies of well-being and un-wellness. Only by interrogating the silences of intimate geographies of the body and home in local villages and communal ethnic spaces will such impacts of violence become visible.

Hydraulic analysis for assessing environmental flow selection and ecological model formulation

AbstractEcosystem management depends on transforming qualitative observations (e.g., slow‐moving shallow conditions provide nursery refugia for silvery minnow larvae) into management actions to increase habitat quantity or improve habitat quality. To be effective, decision metrics that are developed for management objectives should be validated with field observations. Model assumptions, precision and parameter importance can be refined by comparing the fidelity of selected parameters computed as habitat quality metrics and the correlation of these metrics to real‐world observations. Validated environmental metrics are more credible for management and can be compatible with ecosystem monitoring and project design processes. In this study, streamflow monitoring data and hydraulic modelling are used to quantify fish habitat extent for 15 years of spring runoff. The spring runoff event coincides with larval maturation to a free‐swimming juvenile phase for the silvery minnow, a critical period in Rio Grande habitat management. Different methods to estimate habitat availability (i.e., hydrology statistics, inundation extents based on hydraulic modelling and areal habitat availability based on different formulations of a habitat suitability index curve) were used to test the efficacy of different metrics relative to species population monitoring. This analysis finds that flow–ecology relationships based on hydraulic modelling or hydrology statistics are both effective and highly correlated to larval production. The investigation shows how seasonal hydrologic characterization and hydraulic discretization have varying levels of correlation with seasonal fish production. This study demonstrates how hydraulic modelling data and hydrologic characterization of riverine environments can be used to validate or develop conceptual ecological models.

Strategic restoration-development mitigates tradeoffs between hydropower and fish habitat fragmentation in the Mekong

Strategic restoration-development mitigates tradeoffs between hydropower and fish habitat fragmentation in the Mekong

The hide-and-seek effect of pulsed-flows in a potamodromous cyprinid fish

The artificial pulsed-flows impact associated with hydropower production on the downstream biological and physical processes has been extensively addressed, showing that it may cause fish drift while changing fish habitat selection toward lower water velocity patches, acting as refuge areas. We aimed to evaluate the attraction efficiency of two flow-refuges differing in their approaching angles, for Luciobarbus bocagei at an indoor experimental flume. We tested two flow-refuge insertion angles (45° and 70°), and two flow events (base 7 L/s and pulsed-flow 60 L/s) for each. To analyze flow-refuge efficiency, we quantified fish individual and group patterns, flow-refuge use, and permanence time, while measuring glucose and lactate responses. The results showed that the individual frequency of use during simulated pulsed-flow was higher, especially on the 45° flow-refuge. The simulated pulsed-flow condition did not disrupt group behavior for both approaching angles. Glucose and lactate analysis did not trigger physiological responses in the tested trials. The 45° flow-refuge was used more often than the 70°. The narrowing of the channel caused by the 45° flow-refuge, and the consequent higher flow homogeneity increased the attractiveness of the flow-refuge. Therefore, the flow-refuge insertion angle should be a decisive criterion in the construction and installation of flow-refuges for cyprinids, and be considered a potential indirect mitigation measure.

Hematological Profile of Bader Fish (Barbonymus altus) in the Brantas River, Blitar Region in Measurement of River Water Quality

Brantas River is habitat to a fish species known as the bader fish (Barbonymus altus). Research aims to evaluate the hematological profile of the bader fish as a means to assess the quality of the Brantas River in the Blitar region. Determining the waste flow from community activities that influences blood quality of bader fish is another goal of this research. To achieve this, various water quality indices were measured in the river and hematological parameters measured in the fish. Data collection was conducted once every week for three weeks during 17 January to 17 March 2022. The measurements aimed to observe any changes in the fish's hematological profile over this period. Two data analysis techniques were employed for the research: Pollution Index (IP) and Canonical Correlation Analysis (CCA). IP measurements reveal that all three stations share a common assessment, classifying them as having light pollution. When analyzing correlation measurements through CCA, it was found that erythrocytes exhibited a robust positive correlation with a pH value of 0.549, while conversely, DO (Dissolved Oxygen) showed a strong negative correlation with leukocytes with value -0.717. In summary, the water conditions in the Brantas region remain conducive for the habitat of bader fish.

Enhancing ecological success in Yangtze River channel construction: A numerical modelling approach

AbstractChannel constructions significantly impact river hydrodynamics, subsequently influencing river ecosystems. To mitigate the negative influence of channel construction and protect fish habitat, it is essential to evaluate fish habitat suitability through the integration of hydrodynamic and habitat models. This study models channel constructions on both the left and right riverbanks to evaluate habitat suitability for Four Major Chinese Carps and the Chinese sturgeon. Initially, flow velocity, water depth and grain size are simulated, followed by an assessment of habitat conditions using the Habitat Suitability Index (HSI) for three distinct construction strategies. Results reveal that constructing channels on the left bank mitigates adverse effects on fish habitat, while constructions on the right bank and both riverbanks lead to habitat degradation. Long‐term effects on riverbed elevation and fish habitat suitability post‐construction were also investigated. Notably, the Four Major Chinese Carps consistently demonstrate greater suitability for the studied river, regardless of flow rate or construction strategies, in comparison to the Chinese sturgeon. These findings underscore diverse responses to channel construction, providing valuable insights for identifying critical habitat areas for endemic fish conservation. This research presents a robust framework for assessing fish ecology in river systems, offering support for conservation decision‐makers.