One of the expected effects of global change is increased variability in the abundance and distribution of living organisms, but information at the appropriate temporal and geographical scales is often lacking to observe these patterns. That is why researcher sometimes are pushed to use alternative methods (with respect to costly and time consuming scientific surveys and experiments) to enhance data collection in the marine environment.

The Journal PLoS ONE has recently published a paper *, selected and evaluated by “Faculty 1000” among the top published articles in biology and medicine, that demonstrates the potential of using Local Ecological Knowledge (LEK) to detect diversity changes among Mediterranean fish at both spatial and temporal scale.

The work was based on interviews – performed with an ad hoc protocol adopted by the CIESM Tropical Signals Programme – with both professional and sportive fishermen on four different areas of the Mediterranean along a latitudinal gradient. Results suggest that 59 fish species belonging to 35 families have experienced abrupt changes in their abundance during the last three decades. Data strongly indicate the northward expansion and increasing abundances of thermophilic species such as Carangidae barracuda’s, while Scombridae and Clupeidae were generally identified as decreasing. Moreover the study identifies the decade between 1990 and beginning of 2000 as a critical period for change in fish biodiversity.

Despite the limited geographic coverage and sampling power of the study (based on 39 interviews at four different Mediterranean localities) this work is an example of the importance of LEK as complementary tool to evaluate biodiversity changes at large geographical scales.

* Azzurro E., Moschella P. and Maynou F., 2011.Tracking signals of change in Mediterranean fish diversity based on Local Ecological Knowledge. Plos ONE, 6(9) e24885, doi:10.1371/journal.pone.0024885. Download