scholarly journals Effect of abiotic factors and environmental concentrations on the bioaccumulation of persistent organic and inorganic compounds to freshwater fish and mussels

Author(s):  
Lies Teunen ◽  
Maarten De Jonge ◽  
Govindan Malarvannan ◽  
Adrian Covaci ◽  
Claude Belpaire ◽  
...  
Ecotoxicology ◽  
2021 ◽  
Author(s):  
Joyce Andreia dos Santos ◽  
Gabrielle Rabelo Quadra ◽  
Rafael M. Almeida ◽  
Laís Soranço ◽  
Haroldo Lobo ◽  
...  

1994 ◽  
Vol 51 (12) ◽  
pp. 2856-2865 ◽  
Author(s):  
Pierre Magnan ◽  
Marco A. Rodríguez ◽  
Pierre Legendre ◽  
Sylvain Lacasse

We used multivariate analyses to examine which variables among the environmental and spatial components can best account for dietary variation in a freshwater fish, brook trout, Salvelinus fontinalis. The diet composition of brook trout was quantified in 37 lakes of the Laurentian Shield, Québec, Canada. Among the 25 measured environmental variables, fish species composition, sampling date, macrophyte abundance, and trout body length were the best predictors of diet composition. The total variation in diet composition was partitioned into four components: pure environmental 21.6%, pure spatial 23.2%, shared 19.9%, and unexplained 35.3%. A significant spatial trend in diet composition existed even after accounting for the main effects measured by the environmental variables. The two sets of spatial variables, when combined with the environmental descriptors, extracted different components of the dietary variation. The study allowed us to (1) highlight the role of spatial structure in diet variation of brook trout, (2) determine the relative contribution of both environmental and spatial components, and (3) generate testable hypotheses concerning mechanisms underlying the observed structure. Dependent variables other than diet composition, such as the density of different species at different sampling sites, can be used within the same statistical framework in studies of community ecology.


Author(s):  
O. V. Honcharova ◽  
R. P. Paranjak ◽  
B. V. Gutyj

The purpose of the work was to conduct a scientific and experimental analysis of the study of the functional state of the organism of hydrobionts while growing in recirculation of aquaculture systems using an unconventional method of water treatment, which was used in the formation of feed forage for their feeding. The experimental part of the work was carried out on the basis of the laboratory of aquatic bioresources and aquaculture of the Biotechnology Faculty of the Dnipro State Agrarian and Economic University and the Scientific and Experimental Center “Aquatic Biodiversity and Aquaculture of the Pre Dnieper” of the Dniprovsky State Agrarian and Economic University. The practical part of the work consisted of several stages: the formation of the preparatory period (obtaining the breeding culture of phytoplankton and zooplankton, cultivation on different environments in order to establish an optimal scheme); obtaining of fish planting material and determination of fish objects for experiment; staging of the experiment (conducting research on feeding natural food of different processing of mother-crops). Scientific and experimental studies on the study of the functional state of the organism of hydrobionts when cultivated in the PAC with the use of an unconventional method of processing fodder mixed with their feeding give grounds to note the positive impact on its qualitative and functional characteristics. Investigation of the morpho-functional status of blood of freshwater fish on the background of the use of the proposed method for processing fodder mixed with fertilization in the early stages of ontogeny showed that stimulation of erythropoiesis, activation of protein metabolism in the organism of hydrobionts within the limits of the physiological norm occurs in the experimental group. The combination of several rapid methods (GRU) makes it possible to provide comprehensive research and acquires scientific and practical value, since the study of the physiological state of the object of biotesting against the background of the use of various factors involves the implementation of an entire chain of sequential research.


Author(s):  
Anastasios Bounas ◽  
Giorgos Catsadorakis ◽  
Irene Koutseri ◽  
Harris Nikolaou ◽  
Delphine Nicolas ◽  
...  

Freshwater fish declines are triggered by a suite of anthropogenic threats, including habitat degradation, climate and land use change, biological invasions, pollution and overfishing. Robust monitoring schemes are needed to understand and detect any effects of different factors on freshwater fish abundance and to be able to predict and respond to potential stressors. Here, we used standardized biomass-per-unit-effort (BPUE) data deriving from gillnet sampling over a 34-year period in the two Prespa Lakes and determined species trends using general additive models coupled with structural change models. Furthermore, the influence of seven environmental variables was assessed for each fish species using an analytical approach based on random forests. We showed that the total annual BPUE is increasing in Lake Mikri Prespa whereas it is stable in Megali Prespa and that the relative BPUE of introduced species in the former is increasing through the years. Differences in the lakes' trophic status were reflected in species trend patterns. Random forests showed that air temperature, the introduction of the invasive Lepomis gibbosus, predation and water management played a role in shaping species biomass in Mikri Prespa whereas abiotic factors are the main drivers of biomass changes in Megali Prespa. Our results provide empirical evidence on the importance of long-term monitoring in distinguishing between direct and indirect effects of large-scale stressors on fish abundance as well as insights towards sustaining the integrity of fish communities.


2021 ◽  
Vol 657 ◽  
pp. 123-133
Author(s):  
JR Hancock ◽  
AR Barrows ◽  
TC Roome ◽  
AS Huffmyer ◽  
SB Matsuda ◽  
...  

Reef restoration via direct outplanting of sexually propagated juvenile corals is a key strategy in preserving coral reef ecosystem function in the face of global and local stressors (e.g. ocean warming). To advance our capacity to scale and maximize the efficiency of restoration initiatives, we examined how abiotic conditions (i.e. larval rearing temperature, substrate condition, light intensity, and flow rate) interact to enhance post-settlement survival and growth of sexually propagated juvenile Montipora capitata. Larvae were reared at 3 temperatures (high: 28.9°C, ambient: 27.2°C, low: 24.5°C) for 72 h during larval development, and were subsequently settled on aragonite plugs conditioned in seawater (1 or 10 wk) and raised in different light and flow regimes. These juvenile corals underwent a natural bleaching event in Kāne‘ohe Bay, O‘ahu, Hawai‘i (USA), in summer 2019, allowing us to opportunistically measure bleaching response in addition to survivorship and growth. This study demonstrates how leveraging light and flow can increase the survivorship and growth of juvenile M. capitata. In contrast, larval preconditioning and substrate conditioning had little overall effect on survivorship, growth, or bleaching response. Importantly, there was no optimal combination of abiotic conditions that maximized survival and growth in addition to bleaching tolerances. This study highlights the ability to tailor sexual reproduction for specific restoration goals by addressing knowledge gaps and incorporating practices that could improve resilience in propagated stocks.


Sign in / Sign up

Export Citation Format

Share Document