engleski

Biological endpoints on micro and macro scales responding to climate changes

Regardless of the level at which biological (ecological) system is observed, it is possible to detect parameters of these systems sensitive to different environmental factors - biomarkers. Such measurable changes of system parameters are called biomarkers. Depending on the system level there are molecular, biochemical, cellular, histological, organismal, populational, biocenosical, and ecosystemical biomarkers. Biomarkers of levels below organismal are considered as microbiomarkers while the biomarkers of other, higher levels, are considered as macrobiomarkers. Until now, the attention to biomarkers was given manly in terms of detection of environmental pollution (as a part of early warning systems) and of environmental risk assessment. Our research on few biomarkers has shown that some of them are specifically sensitive to long-term changes of temperature. Namely, with application of a multivariate and modeling approach in research we have proved that the short and long term changes of environmental temperature alter the properties of some biomarkers in at last two different ways. Microscale level. Increase of freshwater temperature leads to the domination of cyanobacteria among phytoplankton. Some species of Cyanobacteria produce toxins that affect other organisms in various ways. Namely, these toxins in fish such as carp (Cyprinus carpio), prussian carp (Carassius auratus gibelio) and brown bullhead (Ameiurus nebulosus) cause significant decrease of ethoxyresorufin-O-deethylase (EROD) activity. As EROD activity is a well-known biomarker of environmental pollution with planar PAH, the presence of Cyanobacteria hinders the correct interpretation of biomonitoring results. While the short-term exposure of fish to cyanotoxins causes reduced expression of EROD biomarker, the long term exposure (which does not necessarily have to be continuous) causes reduced expression but also an induction of this biomarker. Macroscale level. Populations of some insects in continental, sub Mediterranean and Mediterranean climate zones, have more or less uniform annual, e.g. seasonal dynamics, with one or several sudden increase of population size (invasions). Such insects are mosquitoes. Short term increase of temperature during one or several years cause an increase in intensity and in overall size of populations through the years. Long term increase of temperature with positive trend during 15 year period caused an additional changes in population dynamics of this insect in the form of additional numbers of invasions despite the fact that the season is still equally long (because one limiting factor for mosquito populations is photoperiod). According to our results we can suppose that different quality of biomarker expression could be a significant marker of a long term temperature changes e.g. solid indicator of local climate changes.

fish; mosquitoes; climate change; biomarkers; EROD

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