Estimating Total Fish Abundance and Total Habitat Area in Small Streams Based on Visual Estimation Methods

1988 ◽  
Vol 45 (5) ◽  
pp. 834-844 ◽  
Author(s):  
David G. Hankin ◽  
Gordon H. Reeves
Keyword(s):  
Coho Salmon ◽  
Fish Abundance ◽  
Estimation Methods ◽  
Salmo Gairdneri ◽  
Visual Estimation ◽  
Habitat Types ◽  
Small Streams ◽  
Total Fish ◽  
Habitat Unit ◽  
Made In

We present sampling designs for estimating total areas of habitat types and total fish numbers in small streams. Designs are applied independently within strata constructed on the basis of habitat unit type and stream reach. Visual methods for estimating habitat areas and fish numbers are used to increase sample sizes and thereby reduce errors of estimation. Visual estimates of area are made for all habitat units, and visual estimates of fish numbers are made for systematic samples of units within given habitat types. Use of systematic sampling circumvents the requirement for a preexisting map of habitat unit locations and simplifies selection of units. We adjust for possible proportional bias of visual estimation methods by calibrating visual estimates against more accurate estimates made in subsamples of those units for which visual estimates are made. In a test application of these sampling designs, correlations between visual estimates and more accurate estimates were generally high, r > 0.90. Calculated 95% confidence bounds on errors of estimation were 13 and 16% for total areas of pools and riffles, respectively, and were 17 and 22% for total numbers of 1 + steelhead trout (Salmo gairdneri) and juvenile coho salmon (Oncorhynchus kisutch), respectively. Our methods appear to offer a cost-effective alternative to more traditional methods for estimating fish abundance in small streams. In addition, visual estimation surveys can produce detailed maps of the areas and locations of all stream habitat units.

scholarly journals Integrating Towed Underwater Video and Multibeam Acoustics for Marine Benthic Habitat Mapping and Fish Population Estimation

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 176
Author(s):  
Alexander R. Ilich ◽  
Jennifer L. Brizzolara ◽  
Sarah E. Grasty ◽  
John W. Gray ◽  
Matthew Hommeyer ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Video Data ◽  
Fish Abundance ◽  
Habitat Mapping ◽  
Benthic Habitat ◽  
Underwater Video ◽  
High Definition ◽  
Habitat Types ◽  
Total Fish ◽  
Rocky Habitats

The west Florida shelf (WFS; Gulf of Mexico, USA) is an important area for commercial and recreational fishing, yet much of it remains unmapped and unexplored, hindering effective monitoring of fish stocks. The goals of this study were to map the habitat at an intensively fished area on the WFS known as “The Elbow”, assess the differences in fish communities among different habitat types, and estimate the abundance of each fish taxa within the study area. High-resolution multibeam bathymetric and backscatter data were combined with high-definition (HD) video data collected from a near-bottom towed vehicle to characterize benthic habitat as well as identify and enumerate fishes. Two semi-automated statistical classifiers were implemented for obtaining substrate maps. The supervised classification (random forest) performed significantly better (p = 0.001; α = 0.05) than the unsupervised classification (k-means clustering). Additionally, we found it was important to include predictors at a range of spatial scales. Significant differences were found in the fish community composition among the different habitat types, with both substrate and vertical relief found to be important with rock substrate and higher relief areas generally associated with greater fish density. Our results are consistent with the idea that offshore hard-bottom habitats, particularly those of higher vertical relief, serve as “essential fish habitat”, as these rocky habitats account for just 4% of the study area but 65% of the estimated total fish abundance. However, sand contributes 35% to total fish abundance despite comparably low densities due to its large area, indicating the importance of including these habitats in estimates of abundance as well. This work demonstrates the utility of combining towed underwater video sampling and multibeam echosounder maps for habitat mapping and estimation of fish abundance.

scholarly journals Evaluating Coexistence of Fish Species with Coastal Cutthroat Trout in Low Order Streams of Western Oregon and Washington, USA

Fishes ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Kyle D. Martens ◽  
Jason Dunham
Keyword(s):  
Pacific Northwest ◽  
Species Interactions ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
Single Species ◽  
The Pacific ◽  
Small Streams ◽  
Coastal Cutthroat Trout ◽  
Multiple Species ◽  
Low Order

When multiple species of fish coexist there are a host of potential ways through which they may interact, yet there is often a strong focus on studies of single species without considering these interactions. For example, many studies of forestry–stream interactions in the Pacific Northwest have focused solely on the most prevalent species: Coastal cutthroat trout. To examine the potential for interactions of other fishes with coastal cutthroat trout, we conducted an analysis of 281 sites in low order streams located on Washington’s Olympic Peninsula and along the central Oregon coast. Coastal cutthroat trout and juvenile coho salmon were the most commonly found salmonid species within these streams and exhibited positive associations with each other for both presence and density. Steelhead were negatively associated with the presence of coastal cutthroat trout as well as with coho salmon and sculpins (Cottidae). Coastal cutthroat trout most frequently shared streams with juvenile coho salmon. For densities of these co-occurring species, associations between these two species were relatively weak compared to the strong influences of physical stream conditions (size and gradient), suggesting that physical conditions may have more of an influence on density than species interactions. Collectively, our analysis, along with a review of findings from prior field and laboratory studies, suggests that the net effect of interactions between coastal cutthroat trout and coho salmon do not appear to inhibit their presence or densities in small streams along the Pacific Northwest.

Physiological Response of Juvenile Coho Salmon (Oncorhynchus kisutch) and Rainbow Trout (Salmo gairdneri) to Handling and Crowding Stress in Intensive Fish Culture

1976 ◽  
Vol 33 (12) ◽  
pp. 2699-2702 ◽  
Author(s):  
Gary A. Wedemeyer
Keyword(s):  
Rainbow Trout ◽  
Feeding Behavior ◽  
Coho Salmon ◽  
Physiological Stress ◽  
Oncorhynchus Kisutch ◽  
Fish Distribution ◽  
Salmo Gairdneri ◽  
Crowding Stress ◽  
Normal Feeding ◽  
Intensive Fish Culture

Moving 4–5-in. coho salmon (Oncorhynchus kisutch) held in soft (20 ppm CaCO3) water from the relatively light loading density of 0.5 lb/ft3 to 1, 2, or 4 lb/ft3 (density index, DI = 0.1, 0.2, 0.4, 0.8) caused significant stress as indicated by loss of feeding behavior, but only minimal physiological disturbances, as indicated by lack of hyperglycemia or hypochloremia. However, moving them to 6 or 12 lb/ft3 (DI = 1.2, 2.4) caused significant physiological stress which required at least a week for recovery. Smolting coho salmon were physiologically stressed by population densities of 1 lb/ft3 or more and a subclinical corynebacterial kidney infection was activated. Rainbow trout (Salmo gairdneri) (4–5 in.) were physiologically stressed when moved and held at 1 lb/ft3 or more but retained normal feeding behavior. This indicates that handling and crowding stress will be minimized in softwater areas if densities in fish distribution trucks or in ponds or raceways during disease treatments are held to 0.1–0.5 lb/gal.

scholarly journals A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 2. Spatially and environmentally explicit estimates of egg production

2011 ◽  
Vol 68 (3) ◽  
pp. 528-536 ◽  
Author(s):  
Miguel Bernal ◽  
Yorgos Stratoudakis ◽  
Simon Wood ◽  
Leire Ibaibarriaga ◽  
Luis Valdés ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Environmental Variables ◽  
Egg Production ◽  
Stock Assessment ◽  
Production Model ◽  
Estimation Methods ◽  
Statistical Framework ◽  
Spatio Temporal ◽  
The Relationship ◽  
Made In

Abstract Bernal, M., Stratoudakis, Y., Wood, S., Ibaibarriaga, L., Uriarte, A., Valdés, L., and Borchers, D. 2011. A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 2. Spatially and environmentally explicit estimates of egg production. – ICES Journal of Marine Science, 68: . A spatially and environmentally explicit egg production model is developed to accommodate a number of assumptions about the relationship between egg production and mortality and associated environmental variables. The general model was tested under different assumptions for Atlanto-Iberian sardine. It provides a flexible estimator of egg production, in which a range of assumptions and hypotheses can be tested in a structured manner within a well-defined statistical framework. Application of the model to Atlanto-Iberian sardine increased the precision of the egg production time-series, and allowed improvements to be made in understanding the spatio-temporal variability in egg production, as well as implications for ecology and stock assessment.

scholarly journals Fish fauna of small streams of the Catua-Ipixuna Extractive Reserve, state of Amazonas, Brazil

Check List ◽  
2009 ◽  
Vol 5 (2) ◽  
pp. 154 ◽  
Author(s):  
Renildo Ribeiro de Oliveira ◽  
Marcelo Salles Rocha ◽  
Maeda Batista dos Anjos ◽  
Jansen Zuanon ◽  
Lúcia H. Rapp Py-Daniel
Keyword(s):  
Species Richness ◽  
Fish Species ◽  
Fish Fauna ◽  
Conservation Unit ◽  
Extractive Reserve ◽  
Small Streams ◽  
Total Fish ◽  
Amazonas State ◽  
Solimões River ◽  
Hydrographic Network

This study was conducted in an Amazonas state conservation unit, the Catuá-Ipixuna Extractive Reserve (Catuá-Ipixuna RESEX). The main purpose was to provide an ichthyological survey of its small streams, all them tributaries of the Solimões River. Nine small streams (up to 4 m width and 1 m depth) were sampled in September 2006. A total of 1,525 specimens were captured, belonging to 78 species, 24 families and eight orders. Eight species had higher abundances and represented altogether 61.4 % of all collected specimens (Hemigrammus belotii, Microphilypnus amazonicus, Physopyxis ananas, Apistogramma agassizii, Elachocharax pulcher, Apistogramma cf. cruzi, Gladioglanis conquistador and Copella nigrofasciata). Based on the high number of singletons and doubletons present in our samples, as well as the estimated number of species for those streams (106 spp.), we believe that the total fish species richness present in the Catuá-Ipixuna Extractive Reserve may be considerably higher than indicated by our samples. This seems especially true when considering the dimensions of the Catuá-Ipixuna RESEX and the dense hydrographic network present in the area.

Barriers to accurately measuring patients’ dietary intake in hospitals using the visual estimation method

2016 ◽  
Vol 29 (8) ◽  
pp. 835-845 ◽  
Author(s):  
Yui Kawasaki ◽  
Yui Kojima ◽  
Rie Akamatsu
Keyword(s):  
Dietary Intake ◽  
Estimation Method ◽  
Reliability And Validity ◽  
Estimation Methods ◽  
Clinical Settings ◽  
Visual Estimation ◽  
Content Type ◽  
Clinical Nurses ◽  
Individual Interviews ◽  
Routine Work

Purpose Visual estimation, an easy-to-perform technique, is commonly used in hospitals to assess dietary intake in patients. The authors performed a qualitative study where the authors interviewed nurses and dietitians about their perceptions of barriers to accurately measuring patients’ dietary intake in hospitals using the visual estimation method. The paper aims to discuss these issues. Design/methodology/approach Ten dietitians and ten clinical nurses responded to 30-minute individual interviews in Tokyo, Japan, in September 2014. Each interview was conducted using a common protocol of open-ended questions focusing on the challenges of the visual estimation method and barriers to accurately measuring patients’ dietary intake as part of their routine work. The tape-recorded interviews were transcribed and analyzed based on grounded theory. Findings Five main categories emerged: hospitals, meals, colleagues, raters, and patients. Various individual barriers such as skill, attitude, knowledge, and others that had not been considered in previous studies also emerged. External barriers that were out of the raters’ control, such as shortage of time, human resources, financial ability, and others, emerged from the “hospitals” category. Research limitations/implications Research participants were all females and many of them had less than ten years of experience. Practical implications In addition to standardizing the visual estimation process, medical staff need to overcome various other internal and external barriers to accurate measurements. Originality/value This is the first study to articulate some important barriers that influence reliability and validity when measuring patients’ dietary intake by visual estimation methods in typical clinical settings.

Comparative cleaning behaviour of Pederson's cleaner shrimp (Ancylomenes pedersoni) between geographically close yet ecologically dissimilar coral reef habitats

2020 ◽  
Vol 100 (7) ◽  
pp. 1093-1106
Author(s):  
Joseph J. Romain ◽  
Dan A. Exton ◽  
David J. Smith ◽  
Amelia Rose ◽  
Clayton Vondriska ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Fish Population ◽  
Fish Abundance ◽  
Environmental Drivers ◽  
Variable Nature ◽  
Total Fish ◽  
Abundance And Diversity ◽  
Lutjanus Apodus ◽  
Cleaner Shrimp

AbstractCleaning mutualisms are important interactions on coral reefs. Intraspecific variation in cleaning rate and behaviour occurs geographically and is often attributed to local processes. However, our understanding of fine-scale variation is limited, but would allow us to control for geography and region-specific behavioural patterns. Here, we compare the cleaning activity of Pederson's cleaner shrimp (Ancylomenes pedersoni) on two neighbouring, yet ecologically dissimilar, reef systems in Honduras: Banco Capiro, an offshore bank close to significant land runoff with high coral cover but a depleted fish population, and an oligotrophic fringing reef around the island of Utila, with lower coral cover but high fish abundance and diversity. The proportion of realized to potential fish clientele was <60% at both sites, and the composition of clientele was neither reflective of the demographics of the resident assemblages at each site nor similar between sites. Parrotfishes represented 13–15% of total fish abundance at both sites yet accounted for >50% (Banco Capiro) and 10% (Utila) of all cleans. Conversely, the schoolmaster snapper (Lutjanus apodus) represented ~1% of total fish abundance at both sites yet accounted for 40% (Utila) and 1% (Banco Capiro) of all cleans. After standardizing our cleaning rate data by clientele abundance, we find that clientele at Banco Capiro engage in over four times as many cleaning encounters per hour with A. pedersoni than at Utila. Our study highlights the variable nature of coral reef cleaning interactions and the need to better understand the ecological and environmental drivers of this biogeographic variation.

Determination of the signature of a dynamite source using source scaling, Part 2: Experiment

Geophysics ◽  
1993 ◽  
Vol 58 (8) ◽  
pp. 1183-1194 ◽  
Author(s):  
Anton Ziolkowski ◽  
Karel Bokhorst
Keyword(s):  
Seismic Data ◽  
Scaling Law ◽  
Estimation Methods ◽  
Acceptable Error ◽  
Test Charge ◽  
Source Scaling ◽  
Test Record ◽  
Seismic Data Acquisition ◽  
Made In

In April 1990 we performed an experiment in the Netherlands to test the theory of the determination of the signature of a dynamite source using the scaling law. The theory says that the source signature may be determined from the recorded seismic data using two shots of different charge size at the shotpoint; we used 125 g and 500 g charges. The theory was put at risk with a 250-g test charge at each shotpoint. According to the theory, the test record should be different from the other two and, apart from the noise, should be predictable from them. This experiment was repeated 95 times at approximately 50 m shotpoint intervals, using a 240-channel recording system. The results corroborate the theory within an acceptable error. The second‐derivative of the volume injection function was extracted as the source signature; it varied slightly from shot to shot and was minimum phase. This new method of seismic data acquisition allows the signature of the dynamite source to be obtained from the data, uncontaminated by the earth, and avoids the assumptions that must be made in statistical wavelet estimation methods. If there is good shot‐to‐shot repeatability, the second shot is only needed occasionally for calibration.

Comparative gluconeogenesis in hepatocytes from salmonid fishes

1986 ◽  
Vol 64 (5) ◽  
pp. 1110-1115 ◽  
Author(s):  
Thomas P. Mommsen
Keyword(s):  
Sockeye Salmon ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Coho Salmon ◽  
Glucose Production ◽  
Isolated Hepatocytes ◽  
Substrate Oxidation ◽  
Endogenous Glucose Production ◽  
Salmo Gairdneri ◽  
Salmonid Fishes ◽  
Isolated Mitochondria

Rates of gluconeogenic flux and substrate oxidation are assessed in isolated hepatocytes from three species of salmonid fishes: rainbow trout (Salmo gairdneri), coho salmon (Oncorhynchus kisutch), and sockeye salmon (Oncorhynchus nerka). Coho salmon displays the highest capacity for gluconeogenesis from lactate and alanine, but rates are well below those of eels. Enzyme compartmentation on isolated mitochondria shows that in trout and sockeye, phosphoenolpyruvate carboxykinase is almost entirely localized in the mitochondrion and the cytosol, respectively, while in the coho, 40% of phosphoenolpyruvate carboxykinase activity is associated with the cytosol. Freshly isolated salmonid hepatocytes are in negative glycogen balance. It is established here that at low (<250 μmol glucosyl units/g) glycogen concentrations a linear relationship exists between the rate of endogenous glucose production and the initial glycogen concentration. High rates of endogenous glycogen breakdown necessitate the use of radiotracers for determining gluconeogenic fluxes in fish hepatocytes. Rates of gluconeogenesis calculated from radiolabel experiments are compared with nonlabelled lactate and are determined not to be significantly different from each other. It is concluded that in fish hepatocytes, (i) radiotracer experiments give accurate estimates of gluconeogenesis, (ii) dilution of label at the oxalacetate level is insignificant, and, consequently, (iii) rates of 14CO2 production are a valid measure of true substrate oxidation.

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