Characteristics and sources of anthropogenic and biogenic hydrocarbons in sediments from the coast of Qatar

Abstract

Surface sediment samples from the coastal zone of Qatar were collected and analyzed to determine the characteristics, and sources of anthropogenic and biogenic hydrocarbons. The main compounds in these surface sediments included n-alkanes, methyl n-alkanoates, diterpenoids, hopanes, steranes, phthalate esters, polycyclic aromatic hydrocarbons (PAHs) and unresolved complex mixture (UCM). Their total concentrations ranged from 18.7 ± 3.7–81.1 ± 7.5 ng/g (3.7 ± 0.6–10.4 ± 4.8%) for n-alkanes, 8.3 ± 2.3–51 ± 3.4 ng/g (3.0 ± 2.0–5.6 ± 2.0%) for methyl n-alkanoates, 1.8 ± 0.1–10.5 ± 1.0 ng/g (1.0 ± 0.5–0.4 ± 0.1%) for diterpenoids, 0.0–79.3 ± 7.4 ng/g (0.0–7.9 ± 0.6%) for hopanes, 0.0–32.9 ± 7.9 ng/g (0.0–6.5 ± 1.0%) for steranes, 0.7 ± 0.1–36.3 ± 3.4 ng/g (0.1 ± 0.1–1.9 ± 3.4%) for phthalates, 0.30 ± 0.2–7.8 ± 0.7 ng/g (0.02 ± 0.04–0.42 ± 0.72%) for PAHs, and 38 ± 9–609 ± 57 ng/g (38.5 ± 13.4–56.5 ± 13.4%) for UCM. The major sources of these lipids were anthropogenic petroleum residues and plasticizers (80–89%), with lesser amounts from natural higher plants and microbial residues (11–20%). Petroleum residues and plasticizer inputs to the coastal sediments of Qatar likely affect the marine ecosystems and associated species groups as well as shallow coastal nursery and spawning areas.