No abstract

Increasing anthropogenic pressure on oneof the most frequented touristic coastal region of Lebanon, Bay of Jounieh, located to the North of Beiruturgesthe assessment of itscoastal marine environmental state. Therefore, the geochemical, physical, chemical and biochemical characteristics of its sedimentsareanalyzed andevaluated. The samples are collected from 3 three transects (North, Middle & South) at 3 consecutive depths 15, 30 and 60 m using the platform of the Lebanese scientific vessel “CANA-CNRS”. The sediments of shallower sampling points, 15 and 30 m, are mainly composed of fine sandand are poor in most of the studied parameters except chlorophyll-a.While those of 60 m are exclusively represented by the fine fractionand contain maximumconcentrations of organic matter (2.97%), calcium carbonates(47.7 %), phosphates (264 μg/g) and pheopigments(7.03 μg/g). The labile fraction through the 3 transects isrepresented by low concentrations of carbohydrates (0.011 -0.06 mg/g), low concentrations of proteins (0.009 -0.051 mg/g) and highlevels of lipids (0.324 -1.036 mg/g).The results show thatthe deep points (60 m) of Jounieh Bay are the most affected by the anthropogenic pressure combined with hydrodynamic factors and geomorphological issues. Theenvironmental conditionof Jounieh’sBay appears to betolerantto the impact of multiformof contaminantsto which itis been exposed since longtime andit isstill able to show a meso-oligotrophic systemwith acceptable nutritive values for the proliferation of benthic organisms.Thisstudy is expected to provide a valuable tool for monitoring and research programs in other marine areas of the Lebanese coast.

For a better evaluation of the ecological status of aquatic ecosystems, especially at the land–sea interface, a multidisciplinary holistic approach is crucial and various indices should be taken into account. The combined use of chemical and biological indices may be an efficient way to determine ecological status in highly dynamic coastal ecosystems. Therefore, the present study analysed grain size composition, organic carbon (OC), major and trace elements and macroinvertebrate communities in surface sediment samples collected from the coastal marine area facing the Ibrahim River. The stations studied were slightly contaminated by trace elements with no effect on biota. Based on the chemical indices and the polychaetes : amphipods ratio, the ecological status of the stations studied was considered good.