The diet of the greater forkbeard
(Brünnich, 1768) of the Algerian coast was studied between December 2013 and June 2015, providing information on its ecology for a better understanding of the ...feeding strategy. A total of 956 individuals, whose total length (TL) varied between 9.7 and 54.5 cm and weight (W) between 2.80 and 1334.11 g, were examined. The index of relative importance (%IRI), combining the three main descriptors of the presence of different ingested prey (%F, %N, %W), was used to characterize the relative importance of different food taxa. Qualitative and quantitative variations in diet were studied according to sex, size and seasons. The average annual digestive vacuity index (%V) was 5.51. It did not vary between seasons (x
= 5.43, x
= 7.82, α = 5%) and size (x
= 2.08, x
= 5.99, α = 5%), but was different between male (%V = 4.94) and female (%V= 12.78). Qualitative analysis of stomach contents reveals a fairly diverse range of predation with 1342 preys counted for a total weight of 462.84 g, which corresponds to an average number (AN) and weight (AW) of 3.03 and 1.04 g, respectively. This species feeds on benthic preys, composed mainly of natantia crustaceans (%IRI = 44.84) and teleost fish (%IRI = 2.61) with intraspecific preys (%IRI = 6.15). This cannibalism was frequent in specimens with a TL that exceeds 20 cm; it was even more frequent in females as well as in winter. Significant differences in feeding habits of
occurred according to sex, fish size and between seasons. The trophic level (TROPH) was high (3.66 < TROPH < 3.97), corresponding to carnivorous character.
The assessment and preservation of the marine environment, particularly coastal ecosystems, has emerged as a global priority. In this study, the rocky bottom quality (CFR) index, which is based on ...macroalgae composition and abundance, was used to assess the ecological quality of coastal waters at six sites along the Algerian coast that represent a wide range of anthropogenic pressures. The sensitivity of the CFR index to the anthropogenic pressure index (MALUSI) was also assessed. Multivariate analyses (DCA, nMDS, cluster, SIMPER, and PCA) were used to assess the variability of macroalgal community structure. The CFR index calculated for this study was compared to the EEI-c and CARLIT indices. The CFR index classified the study sites based on ecological quality: good to high quality in the western sites (Ténès, Kouali1, and Kouali2) and moderate quality in the central sites (Fontaine, Fort de l’eau, and Surcouf). The findings indicate that the CFR and MALUSI indices are highly correlated. The abundance and composition of macroalgal communities are useful indicators of rocky shore quality, as demonstrated by structural analyses of characteristic macroalgae and opportunistic species. The competitive characteristic macroalgae of the Cystoseira sensu lato species were found to be associated with sites of good and high ecological quality. Stress-tolerant characteristic macroalgae (Pachymeniopsis lanceolata, Ellisolandia elongata, and Halopteris scoparia) and opportunistic ruderal species (Ulva rigida, Ulva lactuca, and Ulva linza) were found in sites with moderate ecological quality. The CFR index was compared with the EEI-c and CARLIT indices, and it can be noted that the three indices use different spatial scales, biological levels and species classifications. Therefore, CFR, EEI-c, and CARLIT indices are useful tools for assessing the quality of coastal waters.
The cartography of shallow water macroalgal assemblages allows the assessment of water quality in coastal water bodies through the application of CARLIT. In this study, we have applied CARLIT to ...assess the ecological status of Algerian coastal water bodies for the first time. The surveyed zone is still in a good ecological status since 52% have a good to a high ecological Status. CARLIT index is well correlated with anthropogenic pressures and has proved suitable for the evaluation of the ecological status of coastal waters. Comparison between EQR values and EEI-c shows a similar pattern of change. CARLIT method allowed the collection of accurate information on the distribution and abundance of shallow-water communities. We also provide a cartographic baseline of the coastal assemblages useful for further evaluations on their geographic extension and for the implementation of a monitoring project on water quality in Algerian coast.
•Application of CARLIT method and assessment of the water quality of Algerian coast•First cartography of shallow macroalgal assemblages along the Algerian coastline•Using macrophytes assemblages to assess an ecological status of coastal water•Understanding of the composition structure and functioning of the coastal ecosystem•Comparison of CARLIT index with other ecological indexes
U razdoblju od prosinca 2013. do lipnja 2015. istraživan je sastav ishrane tabinje bjelice Phycis blennoides (Brünnich, 1768) na obali Alžira pružajući informaciju o ekologiji vrste te pridonoseći ...boljem razumijevanju strategije njenog hranjenja. Analizirano je ukupno 956 primjeraka čija je totalna dužina (TL) varirala između 9,7 i 54,5 cm i mase (W) između 2,80 i 1334,11 g. Za obilježavanje relativne važnosti različitih taksona u progutanoj hrani, korišten je indeks relativne važnosti (%IRI) kombinirajući tri glavna deskriptora prisustva različitog progutanog plijena. Kvalitativne i kvantitativne varijacije u ishrani proučavane su prema spolu, veličini i godišnjim dobima. Prosječni godišnji indeks praznine crijeva (% V) je bio 5,51. Nije varirao između sezona (χ²cal = 5,43, χ²th = 7,82, α = 5%) i veličine (χ²cal = 2.08, χ²th = 5,99, α = 5%), ali je bio različit između mužjaka (%V = 4,94) i ženki (%V= 12,78). Kvalitativna analiza sadržaja želudca otkriva prilično raznolik raspon predacije s izbrojana 1342 plijena ukupne mase 462,84 g što odgovara prosječnom broju (AN) i masi (AW) od 3,03 odnosno 1,04 g. Ova vrsta se hrani bentoskim plijenom, uglavnom sastavljenim od rakova plivača (natantia) (% IRI = 44,84) i riba košunjača (% IRI = 2,61) te s intraspecifičnim plijenom (% IRI = 6,15). Ova pojava kanibalizma je česta kod primjeraka s TL koja premašuje 20 cm a još je češća kod ženki u zimskom periodu. Značajne razlike u prehrambenim navikama P. blennoides javljaju se prema spolu, veličini ribe i godišnjim dobima. Trofička razina (TROPH) bila je visoka (3.66 <TROPH <3.97), što odgovara karnivornom karakteru vrste.
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