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Copepod carcasses and non‐predatory mortality can occur due to natural senescence, disease, pollution, and physicochemical stress. Our objective is to evaluate and characterize the rates of non‐predatory mortality and the contribution of zooplankton community carcasses, represented by the copepods, in tropical estuarine ecosystems with different degrees of urbanization. During the study, there was a significant difference between environments and copepod carcasses, with Suape Bay (moderately urbanized) being the environment with the highest abundance of adult copepod carcasses (93.3%). The average non‐predatory mortality rate of adult copepods was 0.15 day−1: Santa Cruz Channel (sparsely urbanized) contributed the lowest values, with a mortality rate of 0.01 day−1, and Suape (moderately urbanized) had the highest rate (2.80 day−1). The families Paracalanidae (0.554 day−1) and Oithonidae (0.122 day−1) had the highest values, with an average carcass decomposition of 4.7 days. Among the environments studied, there was little differentiation between carcass percentages and mortality rate, not supporting the hypothesis that the higher rates of mortality among non‐predatory copepods were related to large urban centers. However, there was an almost proportional contribution of carcasses and non‐predatory mortality in all but a few areas, agreeing with the hypothesis that there is spatial variation with respect to carcasses in tropical estuaries. With our work, we show that estuaries can provide the estuarine food web with a significant portion of copepod carcasses, which may vary by family, and that it is not necessarily environments with a higher degree of urbanization that will have higher mortality rates. [ABSTRACT FROM AUTHOR]

Although it has been proven that non-predatory mortality accounts for a large proportion of copepod mortality, there is still a lack of knowledge of the temporal and spatial patterns and influence of environmental variables on non-predatory mortality, especially in tropical areas where reefs are influenced by estuarine plumes. This study evaluated the percentage of carcasses and the non-predatory mortality rates for planktonic nauplii and copepodites in a bay with the presence of reefs under the influence of an estuarine plume, in the Atlantic tropical region. The average percentage of carcasses was less than 13% for both nauplii and copepodites, and was close to the minimum for other marine environments. However, there was a variation according to the different families and life stages of planktonic copepods. Nauplii had the highest mortality rate, with a mean rate of 0.04 ± 0.02 day−1 (maximum, 0.11 day−1), while the copepodites had a mean of 0.03 ± 0.01 day−1 (maximum of 0.06 day−1). Non-predatory mortality was higher in the rainy season, and differed between the nearby studied areas (bay, plume and reefs). Considering the three areas separately, only the estuarine plume showed higher percentages of carcass and non-predatory mortality rates of nauplii and copepodites. The increase in mortality rates for some copepod families was influenced by high salinity and low values of chlorophyll-a, dissolved oxygen and pH. These results demonstrate that the non-predatory mortality of copepods varies in a complex mosaic of interconnected ecosystems, and that the relationships between environmental variables with some groups may indicate susceptibility of different stages and families to death due to specific environmental conditions. • The percentage of carcasses and non-predatory mortality rates of copepods differed between nearby coastal areas in Brazil. • Between 4 and 30% of individuals from both nauplii and copepodites are carcasses. • The mortality rates for copepods had a maximum mean of 0.04 d−1 and higher rates were observed during the rainy season. • The mortality rates of some copepod families were related to high salinity and low values of chlorophyll-a, oxygen and pH. [ABSTRACT FROM AUTHOR]