The black scorpionfish, Scorpaena porcus (Scorpaenidae): Could it serve as reliable indicator of Mediterranean coastal communities’ health?

Status of coastal fishery organisms, which are exposed to a wide range of stressors throughout their lives, can be indicative of various pressures. The black scorpionfish, Scorpaena porcus, is ubiquitous in Mediterranean coastal waters where it has ecological and economic importance and thus may qualify as suitable indicator of status of littoral fish assemblages. To test this, we analysed spatial and temporal variability in the abundance, biomass, size and weight of this scorpaenid species. Between 1993 and 2009, investigated population was monitored by experimental trammel net fishing, within the warm period (May to September) and at multiple areas along the eastern Adriatic coast with the aim of testing for the consistency of patterns of change across a large spatial scale (∼600 km). We hypothesized that if S. porcus could serve as a reliable indicator of Mediterranean coastal communities’ health, then reduction in its abundance and biomass and decrease in its size and weight should be observed, as a consequence of the constant fishing pressure. The results revealed that the pattern of variability in NCPUE and BCPUE through time followed an increasing trend at all the areas, except for one where the slope of regression analysis was positive but not significant. On the other hand, length and weight structure fluctuated irregularly from year to year. Non-significant decrease in size of S. porcus was still observed across the studied region. However, we conclude that investigated Adriatic population did not go through profound changes and we briefly explore the possible reasons why this species did not clearly match the concept of indicator organisms.