Juvenile pelagic fish assemblages in the coastal waters of Lebanon : diversity, biological characteristics, and landings / by Garabed Hagop Kazanjian.

Abstract

Small pelagic fishes constituted half of the Mediterranean landings and a considerable portion of the Lebanese catches. In this study, the purse seine fishery was analyzed between 2006 and 2007 in two sites along the northern coast of Lebanon. Thirty-six different fish species were collected, out of which seven constituted more than 97percent of the landings. Engraulis encrasicolus, Sardinella aurita and Sardina pilchardus composed 57.7percent, 20.9percent and 5.6percent of the abundance of catches respectively and 31.3percent, 19.2percent, 9.2percent of its biomass. Non-indigenous species comprised 7.2percent of the total abundance and 18.7 percent of the landing biomass. The fishery targeted mainly the new recruits (0+), and the vast majority of the catches were fishes below their size at first maturity. Diversity and species richness were high in the warmer in the months and low in the colder ones. Temperature and salinity were positively correlated with species richness, while the chlorophyll content of seawater was positively associated with diversity. Clear temporal patterns with distinct shifts of dominance within the landings were detected throughout the year for the most common species. Engraulids dominated catches from October to March, while the rest of the year was characterized by clupeids, Boops boops, and Scomber colias. A temporal niche partitioning seems to exist in the easternmost Mediterranean pelagic waters, possibly to minimize competition.