Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO, Marseille, France.
Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO, Marseille, France.
Mar Pollut Bull. 2023 Sep;194(Pt B):115386. doi: 10.1016/j.marpolbul.2023.115386. Epub 2023 Aug 15.
Aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs, respectively) were analyzed in the dissolved fraction (<0.7 μm) of surface water and in various particulate/planktonic size fractions (0.7-60, 60-200, 200-500 and 500-1000 μm) collected at the deep chlorophyll maximum, along a North-South transect in the Mediterranean Sea in spring 2019 (MERITE-HIPPOCAMPE campaign). Suspended particulate matter, biomass, total chlorophyll a, particulate organic carbon, C and N isotopic ratios, and lipid biomarkers were also determined to help characterizing the size-fractionated plankton and highlight the potential link with the content in AHs and PAHs in these size fractions. ƩAH concentrations ranged 18-489 ng L for water, 3.9-72 μg g dry weight (dw) for the size fraction 0.7-60 μm, and 3.4-55 μg g dw for the fractions 60-200, 200-500 and 500-1000 μm. AH molecular profiles revealed that they were mainly of biogenic origin. ƩPAH concentrations were 0.9-16 ng L for water, and ƩPAH concentrations were 53-220 ng g dw for the fraction 0.7-60 μm and 35-255 ng g dw for the three higher fractions, phenanthrene being the most abundant compound in planktonic compartment. Two processes were evidenced concerning the PAH patterns, the bioreduction, i.e., the decrease in concentrations from the small size fractions (0.7-60 and 60-200 μm) to the higher ones (200-500 μm and 500-1000 μm), and the biodilution, i.e., the decrease in concentrations in plankton at higher suspended matter or biomass, especially for the 0.7-60 and 60-200-μm size fractions. We estimated the biological pump fluxes of ƩPAHs below 100-m depth in the Western Mediterranean Sea at 15 ± 10 ng m day, which is comparable to those previously reported in the South Pacific and Indian Ocean.
在 2019 年春季（MERITE-HIPPOCAMPE 考察期间），沿着地中海的南北向剖面，在深叶绿素最大值处，我们分析了水中的溶解部分（<0.7 μm）以及各种颗粒/浮游生物大小部分（0.7-60、60-200、200-500 和 500-1000 μm）中的脂肪族和多环芳烃（分别为 AH 和 PAHs）。还测定了悬浮颗粒物、生物量、总叶绿素 a、颗粒有机碳、C 和 N 同位素比值以及脂质生物标志物，以帮助描述大小分级浮游生物的特征，并强调与这些大小级分中 AH 和 PAHs 含量的潜在联系。水中的 ƩAH 浓度范围为 18-489 ng L，0.7-60 μm 大小级分中的浓度为 3.9-72 μg g 干重（dw），60-200、200-500 和 500-1000 μm 级分中的浓度为 3.4-55 μg g dw。AH 分子谱表明它们主要来源于生物源。水中的 ƩPAH 浓度为 0.9-16 ng L，0.7-60 μm 大小级分中的 ƩPAH 浓度为 53-220 ng g dw，三个较高级分中的浓度为 35-255 ng g dw，其中菲是浮游生物中最丰富的化合物。有两个过程与 PAH 模式有关，即生物还原，即从小尺寸级分（0.7-60 和 60-200 μm）到较高尺寸级分（200-500 μm 和 500-1000 μm）浓度降低，以及生物稀释，即悬浮物质或生物量较高时，浮游生物中的浓度降低，特别是对于 0.7-60 和 60-200 μm 大小级分。我们估计在西地中海 100 米以下深度的 ƩPAHs 的生物泵通量为 15±10 ng m -1 天 -1，与南太平洋和印度洋之前报道的通量相当。
