scholarly journals Lake morphometry moderates the relationship between water color and fish biomass in small boreal lakes

2018 ◽  
Vol 63 (5) ◽  
pp. 2171-2178 ◽  
Author(s):  
David A. Seekell ◽  
Pär Byström ◽  
Jan Karlsson
Keyword(s):  
Boreal Lakes ◽  
Fish Biomass ◽  
Lake Morphometry ◽  
Water Color ◽  
The Relationship

Natural variation of profundal macroinvertebrate communities in boreal lakes is related to lake morphometry: implications for bioassessment

2009 ◽  
Vol 66 (4) ◽  
pp. 589-601 ◽  
Author(s):  
Jussi Jyväsjärvi ◽  
Kimmo T. Tolonen ◽  
Heikki Hämäläinen
Keyword(s):  
Environmental Factors ◽  
Human Activities ◽  
Natural Variation ◽  
Geographical Location ◽  
Boreal Lakes ◽  
Biological Assessment ◽  
Compositional Variation ◽  
Macroinvertebrate Communities ◽  
Lake Morphometry ◽  
Partial Canonical Correspondence Analysis

Modern biological assessment of aquatic systems is often based on the reference condition approach, which requires characterization of biota in undisturbed conditions. For this approach, it is essential to recognize the origins and degree of natural variation in communities. We used data from 55 minimally disturbed Finnish lake basins to investigate the natural variation of profundal macroinvertebrate community composition in relation to environmental factors. Partial canonical correspondence analysis showed that most (68% combined, 39% uniquely) of the total explained compositional variation (29%) was correlated with environmental variables insensitive to human activities, especially lake morphometry. In contrast, the unique contributions of geographical location and variables influenced by human activities (dissolved oxygen and total phosphorus) were substantially smaller (5.5% and 22%, respectively). All of the explained variation (38%–64%) of three widely used community metrics was also correlated with human-insensitive environmental factors. The results suggest that variation in undisturbed profundal invertebrate communities of reference sites is strongly dependent on variables insensitive to human activities and especially on those related to lake morphometry, suggesting that reference communities for bioassessment of impacted lakes should be rather predictable from these variables.

scholarly journals Growth, temperature, and density relationships of North Sea cod (Gadus morhua)

2008 ◽  
Vol 65 (3) ◽  
pp. 456-470 ◽  
Author(s):  
Anna Rindorf ◽  
Henrik Jensen ◽  
Corinna Schrum
Keyword(s):  
Ambient Temperature ◽  
North Sea ◽  
Growth Temperature ◽  
Gadus Morhua ◽  
Demersal Fish ◽  
Fish Biomass ◽  
Fishing Mortality ◽  
Prey Fish ◽  
Fish Prey ◽  
The Relationship

This study presents an analysis of the relationship between ambient temperature, cod density, fishing mortality, prey fish biomass, and growth of North Sea cod (Gadus morhua) as estimated from survey catches during the period from 1983 to 2006. Growth of young cod was positively related to temperature; however, although temperature increased, distribution of 1-year-olds changed concurrently and no increase in length at age 1 occurred. Growth from age 1 to age 2 decreased as ambient biomass of sandeel and density of cod decreased, whereas growth of cod older than 2 years decreased with increasing density of cod and increased with increasing biomass of demersal fish prey. Though growth of juveniles was strongly positively correlated to ambient temperature, no indication of direct temperature limitation of growth of older North Sea cod was found.

A Test of Lead-210 Dating for the Measurement of Whole Lake Soft Sediment Accumulation

1983 ◽  
Vol 40 (4) ◽  
pp. 506-515 ◽  
Author(s):  
R. Douglas Evans ◽  
Frank H. Rigler
Keyword(s):  
Lake Sediment ◽  
Accumulation Rate ◽  
Sediment Accumulation ◽  
Soft Sediment ◽  
Lake Morphometry ◽  
Southern Ontario ◽  
Lake Bottom ◽  
Lead 210 ◽  
Shield Lakes ◽  
The Relationship

We have tested the hypothesis that variation in accumulation of soft sediments over a lake bottom is related to the lake morphometry, allowing an accurate measurement of whole lake sediment accumulation. In each of two Laurentian Shield lakes in southern Ontario, sediment accumulation was measured at ~20 locations. In both there was a statistically significant linear relationship between soft sediment accumulation and the water depth at the sample locations. The relationship explained 72 and 57% of sediment accumulation variation in Costello and Red Chalk lakes, respectively. Using these relationships, it was possible to calculate the whole lake sediment accumulation rate for each lake. The results indicate that, in general, there is a linear variation in sediment accumulation as a function of depth in small Shield lakes. This study points out the need for a closer examination of sediment movement and accumulation in the shallow regions of lakes.

scholarly journals A Low-Cost Digital Colorimetry Setup to Investigate the Relationship between Water Color and Its Chemical Composition

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6699
Author(s):  
Ruosha Zeng ◽  
Chris M. Mannaerts ◽  
Zhehai Shang
Keyword(s):  
Low Cost ◽  
Digital Camera ◽  
Water Quality Assessment ◽  
Chemical Constituent ◽  
Optically Active ◽  
Colored Dissolved Organic Matter ◽  
Water Color ◽  
Color Indices ◽  
Hue Angle ◽  
The Relationship

Developments in digital image acquisition technologies and citizen science lead to more water color observations and broader public participation in environmental monitoring. However, the implications of the use of these simple water color indices for water quality assessment have not yet been fully evaluated. In this paper, we build a low-cost digital camera colorimetry setup to investigate quantitative relationships between water color indices and concentrations of optically active constituents (OACs). As proxies for colored dissolved organic matter (CDOM) and phytoplankton, humic acid and algae pigments were used to investigate the relationship between water chromaticity and concentration. We found that the concentration fits an ascending relationship with xy chromaticity values and a descending relationship with hue angle. Our investigations permitted us to increase the information content of simple water color observations, by relating them to chemical constituent concentrations in observed waters.

scholarly journals Varve Distribution Reveals Spatiotemporal Hypolimnetic Hypoxia Oscillations During the Past 200 Years in Lake Lehmilampi, Eastern Finland

Quaternary ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 20 ◽  
Author(s):  
Sarianna Salminen ◽  
Saija Saarni ◽  
Mira Tammelin ◽  
Yu Fukumoto ◽  
Timo Saarinen
Keyword(s):  
Climatic Factors ◽  
Sediment Cores ◽  
Boreal Lakes ◽  
Water Volume ◽  
Spatiotemporal Variations ◽  
The Past ◽  
Hypoxic Water ◽  
The Relationship ◽  
Eastern Finland

We investigated 34 sediment cores to reconstruct spatiotemporal variations in hypolimnetic hypoxia for the past 200 years in Lehmilampi, a small lake in Eastern Finland. As hypoxia is essential for varve preservation, spatiotemporal changes in varve distribution were used as an indicator for hypolimnetic hypoxia oscillations. The hypoxic water volume was used as a variable reflecting hypolimnetic hypoxia and determined for each year by estimating the water volume beneath the water depth where shallowest varves were preserved. As a result, seven hypoxia periods, highlighting the variations in hypolimnetic hypoxia, are established. These periods may be influenced by bioturbation, lake infill, and lake level changes. Furthermore, we evaluated the relationship between hypolimnetic hypoxia oscillations and climatic factors. Diatom assemblage changes were also analyzed to estimate whether the hypoxia periods could be related to anthropogenic eutrophication. The diatom analyses suggest relatively stable nutrient conditions for the past 200 years in Lake Lehmilampi. Climate, on the other hand, seems to be an important driver of hypoxia oscillations based on correlation analysis. The role of individual forcing factors and their interaction with hypolimnetic hypoxia would benefit from further investigations. Understanding climatic and anthropogenic forcing behind hypolimnetic hypoxia oscillations is essential when assessing the fate of boreal lakes in a multi-stressor world.

On the Relationship between Regional Geomorphology and Lake Morphometry. A Swedish Example

1984 ◽  
Vol 66 (1/2) ◽  
pp. 103 ◽  
Author(s):  
Lars Håkanson ◽  
Bert Karlsson ◽  
Lars Hakanson
Keyword(s):  
Lake Morphometry ◽  
The Relationship

scholarly journals Feeding rate of freshwater eel Anguilla bicolor bicolor: at the body weight of 1–2 g

2015 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Latifa Fekri ◽  
Ridwan Affandi ◽  
Tatag Budiardi
Keyword(s):  
Body Weight ◽  
Protein Content ◽  
Feeding Rate ◽  
Maximum Growth ◽  
The Body ◽  
Fish Growth ◽  
Fish Biomass ◽  
Feeding Level ◽  
Freshwater Eel ◽  
The Relationship

<p class="BasicParagraph" align="center"><strong>ABSTRACT</strong></p><p class="BasicParagraph" align="center"><strong> </strong></p><p class="Pa3">The aim of the research was to determine feed requirement for the maintenance, optimum, and maximum growth of freshwater eel (<em>Anguilla bicolor bicolor</em>) seed (1–2 g body weight). Feed used in this research was KRA feed with 46% protein content, with different feeding level (FR) at 0%, 5%, 10%, and 15% of fish biomass. The experiment was conducted in 30 days. Parameters measured were survival and <em>s</em>pecific growth (SGR). The results showed that survival of fish in all treatments were 100%, except in fish fed on 15% of biomass (only 96). Fish growth with feeding of 0%, 5%,10%, and 15%, were -1.06%; 0.42%; 0.73%; and 0.19%, respectively. Based on the analysis of the relationship between feeding level and growth, the feed requirement for maintenance, optimum, and maximum growth in 1–2 g freshwater eel seed were 3.3%; 7.0%; and 9.5% of the biomass, respectively.</p><p class="Default"> </p><p>Keywords: eel seed, feed requirement, growth</p><br /><p class="BasicParagraph"> </p><p class="BasicParagraph" align="center"><strong>ABSTRAK</strong></p><p class="BasicParagraph"><strong> </strong></p><p class="Pa3">Penelitian dilakukan dengan tujuan untuk mendapatkan kebutuhan pakan untuk <em>maintenanc</em>e, dan untuk pertumbuhan optimum serta maksimum benih ikan sidat (<em>Anguilla bicolor bicolor</em>) (bobot tubuh 1–2 g). Pakan yang digunakan pada penelitian ini adalah pakan KRA dengan kadar protein 46%, dengan tingkat pemberian pakan 0%, 5%, 10%, dan 15% dari bobot biomassa ikan. Pemeliharaan berlangsung selama 30 hari. Parameter yang diukur meliputi sintasan (STS) dan laju pertumbuhan spesifik (LPS). Hasil penelitian menunjukkan bahwa STS benih ikan sidat selama pemeliharaan, memiliki nilai yang baik (100%) kecuali pada pemberian pakan 15% (hanya 96%). Laju pertumbuhan benih ikan sidat selama pemeliharaan dengan pemberian pakan 0%, 5%, 10%, dan 15% berturut-turut adalah -1,06%; 0,42%; 0,73%; dan 0,19%. Berdasarkan analisis hubungan antara tingkat pemberian pakan dan laju pertumbuhan spesifik, maka kebutuhan pakan <em>maintenance</em>, pertumbuhan optimum dan maksimum benih ikan sidat berukuran 1–2 g berturut-turut adalah 3,3%; 7%; dan 9,5% dari biomassa.</p><p class="Default"> </p><p class="Pa3">Kata kunci: benih ikan sidat, kebutuhan pakan, pertumbuhan</p>

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