Effects in fish exposed to particles deriving from construction sites
The purpose of this study is to investigate negative consequences in fish exposed to discharge of waterborne particles originating from construction sites, e.g tunnel construction. Tunneling work utilizes a huge amount of water during drilling and blasting which is normally discharged to the nearest waterbody. This type of water contains high loads of particles, metals from bedrock, and other construction-related contaminants. Particles from blasting and drilling are commonly described as angular and needle-like in shape, not round as naturally eroded particles, and are therefore thought to be more detrimental to biota. To protect the aquatic environment from harm, environmental authorities give discharge permits with threshold values for various contaminants, including particles. However, the threshold levels of particle discharge have large uncertainties as they are based on older research using natural round particles and not particles from construction. Thus, the levels of particles released today may cause more toxicity to biota than we expect.
This study consists of a pilot experiment and main experiments and seeks to gain new and updated knowledge about the effects of particles in Atlantic salmon, a native and commercially important species in Norway, from water discharged produced during construction work with special attention on the effects of particles originating from construction work in different bedrocks.
The fish will be exposed during the pilot for 96h and during the main experiments for 192 h to waterborne particles. Mortality is not an endpoint in the pilot nor the main experiment. In both experiments, early sub-lethal biomarkers will be used, that is, effects expressed on molecular, cellular, and organ/tissue levels rather than on higher biological complexity levels (e.g. death of individuals), and thereby allowing us to use early humane endpoints. Expected effects are mechanical damage to the gills, which may cause inflammation and affect gas exchange and ion regulation. Additionally, elevated levels of enzyme activity and a general increase in stress levels are anticipated.
This study will contribute to new and updated knowledge on particle toxicity from construction, and the output of the experiments will be used to update the current threshold levels of particles in discharge permits to protect aquatic biota.
In total, 99 Atlantic salmon (Salmo salar) will be used, 15 fish in the pilot experiment and 84 fish in the main experiment
Uptake of toxicants in the body, such as particles, and the negative consequences they produce, such as destruction of gills, are processes that are dependent on the uptake in a live animal, how the tissues work together, and behavioral patterns of the animal. Therefore, using organisms, not cell lines, are the most adequate choice for illustrating the negative effects that salmonid fish may experience in nature due to particles. Furthermore, as the physiological effect mechanisms in fish are different from lower trophic organisms, such organisms are not used to obtain information about effects in fish. By doing a pilot experiment, we ensure that we can adjust the number of fish and the exposure levels in the main experiment to avoid unnecessary lives being harmed and ensure the scientific quality of the study.
This study consists of a pilot experiment and main experiments and seeks to gain new and updated knowledge about the effects of particles in Atlantic salmon, a native and commercially important species in Norway, from water discharged produced during construction work with special attention on the effects of particles originating from construction work in different bedrocks.
The fish will be exposed during the pilot for 96h and during the main experiments for 192 h to waterborne particles. Mortality is not an endpoint in the pilot nor the main experiment. In both experiments, early sub-lethal biomarkers will be used, that is, effects expressed on molecular, cellular, and organ/tissue levels rather than on higher biological complexity levels (e.g. death of individuals), and thereby allowing us to use early humane endpoints. Expected effects are mechanical damage to the gills, which may cause inflammation and affect gas exchange and ion regulation. Additionally, elevated levels of enzyme activity and a general increase in stress levels are anticipated.
This study will contribute to new and updated knowledge on particle toxicity from construction, and the output of the experiments will be used to update the current threshold levels of particles in discharge permits to protect aquatic biota.
In total, 99 Atlantic salmon (Salmo salar) will be used, 15 fish in the pilot experiment and 84 fish in the main experiment
Uptake of toxicants in the body, such as particles, and the negative consequences they produce, such as destruction of gills, are processes that are dependent on the uptake in a live animal, how the tissues work together, and behavioral patterns of the animal. Therefore, using organisms, not cell lines, are the most adequate choice for illustrating the negative effects that salmonid fish may experience in nature due to particles. Furthermore, as the physiological effect mechanisms in fish are different from lower trophic organisms, such organisms are not used to obtain information about effects in fish. By doing a pilot experiment, we ensure that we can adjust the number of fish and the exposure levels in the main experiment to avoid unnecessary lives being harmed and ensure the scientific quality of the study.
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The purpose of this study was to investigate the negative consequences when fish are exposed to the discharge of waterborne particles originating from tunnel construction. Expected effects as mechanical damage to the gills, elevated levels of enzyme activity and a general increase in stress levels were observed. Hence, the goals of the project were fulfilled.
Additionally, it was detected that different particles produced different effects in fish despite being similar in concentration, size, shape, and mineralogy. Thus, other attributes of the particles, such as surface charge, particle erosion, ion exchange, could be important factors to investigate when studying toxicity of particles from tunnel construction.
The experiments have provided information about the effects on fish exposed to two types of tunnelling particles. Particles accumulated on the gills in a concentration-based manner, did not result in physical mechanical damage. However, small inflammatory changes were observed, and the effects differed depending on which particle was used. There were also different responses in blood parameters, stress, and enzyme activity effects between the particles. In the future, this can help to navigate which other attributes of particles should be examined to further aid in the understanding of particle toxicity and aid in planning long-term studies as this is needed.
Fifteen fish in the pilot and 84 fish in the main experiment were used. The fish in the pilot experiment, were classified as moderately harmed, which was less than expected. In the two highest concentration levels in the main experiment totally five fish died after 24 and 48 hours. Thus, these levels were terminated immediately. The severity for rest of the fish in the main experiment were moderate.
The researchers assess that they should probably have used more fish in the pilot, since only three fish per concentration level were used.
The researchers wished they had a method for better monitoring of the animals. However, low visibility produced by the particles made it difficult. Therefore, early humane endpoints were difficult to practice. A gillnet to study fish was a good tool to help visualize the fish, but hard to detect abnormal behaviour in the water.
Additionally, it was detected that different particles produced different effects in fish despite being similar in concentration, size, shape, and mineralogy. Thus, other attributes of the particles, such as surface charge, particle erosion, ion exchange, could be important factors to investigate when studying toxicity of particles from tunnel construction.
The experiments have provided information about the effects on fish exposed to two types of tunnelling particles. Particles accumulated on the gills in a concentration-based manner, did not result in physical mechanical damage. However, small inflammatory changes were observed, and the effects differed depending on which particle was used. There were also different responses in blood parameters, stress, and enzyme activity effects between the particles. In the future, this can help to navigate which other attributes of particles should be examined to further aid in the understanding of particle toxicity and aid in planning long-term studies as this is needed.
Fifteen fish in the pilot and 84 fish in the main experiment were used. The fish in the pilot experiment, were classified as moderately harmed, which was less than expected. In the two highest concentration levels in the main experiment totally five fish died after 24 and 48 hours. Thus, these levels were terminated immediately. The severity for rest of the fish in the main experiment were moderate.
The researchers assess that they should probably have used more fish in the pilot, since only three fish per concentration level were used.
The researchers wished they had a method for better monitoring of the animals. However, low visibility produced by the particles made it difficult. Therefore, early humane endpoints were difficult to practice. A gillnet to study fish was a good tool to help visualize the fish, but hard to detect abnormal behaviour in the water.