Does climate change alter the effect of UV radiation on aquatic ecosystems?
Climate change will influence various aspects of how UV-B radiation affects aquatic ecosystems, such as through changes in temperature and sea-level, shifts in the timing and extent of sea-ice cover, changes in the wave climate, ocean circulation and salinity and alterations in the stratification of the water column.
These complex changes are likely to have significant effects on ecosystems, including biological production as well as changes in the global hydrological cycle, vertical mixing and efficiency of carbon dioxide uptake by the ocean (Figure 10c). Such effects will vary over time and between different locations. Changes in temperature and the intensity and frequency of rainfall may alter the input of terrestrially-derived coloured dissolved organic matter (CDOM) to inland and coastal aquatic ecosystems. For example, decreased rainfall and increased temperature cause reductions in CDOM inputs and consequent increases in the depth to which UV radiation penetrates. In addition, the dissolved and suspended material in the water column changes the ratio of UV-A to UV-B to photosynthetically active radiation (PAR) in the penetrating UV radiation. These changing ratios, in turn, have various influences on decomposers, producers and consumers.
Climate change influences the amount of ice and snow cover in polar and sub polar areas. Ice and snow strongly attenuate the penetration of solar radiation into the water column. Any substantial decrease in ice and snow cover will alter the exposure of aquatic ecosystems to solar UV radiation.
Shifts in atmospheric circulation will change wind fields, influencing mixing and the depth of the upper mixed layer of the ocean. Such changes, and increases in temperature, affect the stratification of the surface layer of the ocean and the potential impact of UV-B radiation on near-surface organisms. Changing winds will also influence coastal upwelling systems and the potential for possible influence of these systems on UV radiation Additionally, many physiological responses are dependent on temperature, providing another route whereby climate change may interact with the effects of UV radiation.
Climate change will influence various aspects of how UV-B radiation affects aquatic ecosystems, such as through changes in temperature and sea-level, shifts in the timing and extent of sea-ice cover, changes in the wave climate, ocean circulation and salinity and alterations in the stratification of the water column.
These complex changes are likely to have significant effects on ecosystems, including biological production as well as changes in the global hydrological cycle, vertical mixing and efficiency of carbon dioxide uptake by the ocean (Figure 10c). Such effects will vary over time and between different locations. Changes in temperature and the intensity and frequency of rainfall may alter the input of terrestrially-derived coloured dissolved organic matter (CDOM) to inland and coastal aquatic ecosystems. For example, decreased rainfall and increased temperature cause reductions in CDOM inputs and consequent increases in the depth to which UV radiation penetrates. In addition, the dissolved and suspended material in the water column changes the ratio of UV-A to UV-B to photosynthetically active radiation (PAR) in the penetrating UV radiation. These changing ratios, in turn, have various influences on decomposers, producers and consumers.
Climate change influences the amount of ice and snow cover in polar and sub polar areas. Ice and snow strongly attenuate the penetration of solar radiation into the water column. Any substantial decrease in ice and snow cover will alter the exposure of aquatic ecosystems to solar UV radiation.
Shifts in atmospheric circulation will change wind fields, influencing mixing and the depth of the upper mixed layer of the ocean. Such changes, and increases in temperature, affect the stratification of the surface layer of the ocean and the potential impact of UV-B radiation on near-surface organisms. Changing winds will also influence coastal upwelling systems and the potential for possible influence of these systems on UV radiation Additionally, many physiological responses are dependent on temperature, providing another route whereby climate change may interact with the effects of UV radiation.
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