Seawater carbonate chemistry and diatom aggregation when exposed to crude oil and chemical dispersant

Roller table experiments with Thalassiosira pseudonana, a small centric diatom, were conducted to produce marine snow aggregates in six treatments: Control (pCO2 = 400 ppm), OA (pCO2 = 750 ppm), water accommodated fraction of oil (WAF), OAWAF, diluted chemically enhanced WAF (DCEWAF), and OADCEWAF. Measurements included intracellular photophysiological responses, oil concentrations and polycyclic aromatic hydrocarbons (PAHs), aggregate morphology, transparent exopolymeric particles (TEP), and extracellular polymeric substances (EPS) to investigate if OA will affect the response to oil spill conditions. The experiments were conducted in the dark to eliminate cell replication and photosynthesis and used both stationary and exponential growth phases.

以假微型海链藻(Thalassiosira pseudonana，一种小型中心硅藻)为实验材料开展辊台实验，设置6组处理以制备海洋雪聚集体：对照组(pCO₂=400 ppm)、海洋酸化(Ocean Acidification, OA)组(pCO₂=750 ppm)、油的水可溶组分(WAF)组、OAWAF组、稀释型化学强化水可溶馏分(DCEWAF)组以及OADCEWAF组。实验测定指标涵盖胞内光生理响应、油类浓度与多环芳烃(PAHs)含量、聚集体形态、透明胞外聚合物颗粒(TEP)以及胞外聚合物(EPS)，旨在探究海洋酸化是否会影响生物对溢油环境的响应。本实验在黑暗条件下开展以排除细胞增殖与光合作用的干扰，并同时采用了稳定生长期与指数生长期的藻细胞。