Mapping lifehistory strategies of macrobenthic communities

In recent decades, biological traits - any morphological, physiological or phenological features defined at the species level- have been widely used to assess how macrozoobenthic life respond to stress and influence ecosystem functioning. In the framework of response and effect traits, response traits - traits that respond in a specific way to environmental factors - can be combined (e.g. age at maturity, longevity, offspring size) to derive specific life-history strategies. These latter inform on species ability to withstand external pressures by sorting vulnerable species (i.e. slow-growing, long-lived) from tolerant to disturbance ones (i.e. fast-growing, short-lived). Despite the growing interest of trait-based approaches in marine ecology, there is still a clear lack of benthic studies considering simultaneously several traits and gathering trait information is time-consuming, unwell documented and scarce for many benthic taxa. Here, we propose to fulfill the gap in macrozoobenthic traits knowledge for the northwestern shelf of the Black Sea. Based on our extensive species and traits datasets, we assess the spatial variability of life-history strategies. In more detail, macrozoobenthic samples were collected during several campaigns, from 2008 to 2017, in a total of 111 sampling sites. Then, we select 15 traits based on those expected to respond to external pressures and we compile a trait matrix for a subset of 96 taxa. From an appropriate clustering of the traits, main life-history strategies are derived and each taxa is defined by a unique functional group (i.e. resistant, resilient and vulnerable groups). For building maps of those functional groups, we use spatial optimal interpolation based on variational analysis. In future research, the confidence in those maps will be improved through the inclusion of neural network tools. Mapping of benthic functional groups may be used as ecological indicators for ecosystem health assessment and may be helpful for conservation policy.