The interactions of plastic with tar and other petroleum derivatives in the marine environment: A general perspective

A comprehensive review of oil residues in the world oceans: types, characteristics, sources and distribution

The increasing industrialization and extensive utilization of petroleum products, resulting in the emergence of its residues, contribute to the formation of tar. Their accumulation is strongly influenced by environmental factors, including winds, currents, and coastal geomorphology. This review explores the physical characteristics and primary sources of tar residues, with particular focus on tanker operations and oil spill incidents. It further synthesizes the existing literature, focusing on regional tar surveys in the North Atlantic, Pacific and Indian Oceans, the Mediterranean Sea and the Arabian Gulf, aiming to consolidate current knowledge and compare regional tar concentrations. Global assessments of tar concentrations reveal notable spatial variability, with the Mediterranean Sea exhibiting the highest concentration, followed by the Arabian Gulf and the Caribbean Sea. Lower concentrations were recorded in the Pacific's Bering Sea and Gulf of Alaska areas characterized by limited shipping activity. However, non-standardized sampling strategies, inconsistencies in tow techniques, and irregular tar surveys introduce considerable uncertainty in assessing the distribution of tar residues. Significant gaps are identified in quantitative and qualitative assessments and source identification, resulting in systematic documentation of coastal tar concentrations. Despite regulatory advancements including the implementation of MARPOL Annex I, and technological improvements like segregated ballast systems, tar pollution remains a global concern. The review also highlights the urgent need for long-term monitoring, standardized methodologies, and improved risk assessment to inform effective management, particularly in tourism-dependent coastal regions.

Transformations of crude oil into tar: a case study from a plastitar-contaminated site in NE Sicily, Italy (Western Mediterranean)

This study examines the aging of industrial crude oil to simulate the chemical transformations that occur when it is exposed to environmental conditions over time. It was triggered by the finding of plastitar - a mixture of tar and plastic waste - on the coast of Milazzo, Sicily. Research began with a chemical characterization of the tar component of plastitar, followed by aging experiments designed to simulate environmental conditions such as seawater, UV light and sunlight. Fourier transform infrared spectroscopy (FTIR) was used to analyze the chemical changes during the aging process and compare the results with local tar samples. The results showed significant chemical changes in the aged crude oil, including oxidation, degradation of hydrocarbons and the formation of oxygenated compounds. In particular, the FTIR spectra of the aged crude oil closely matched those of the local tar and provided valuable insights that could help address similar coastal pollution issues in other regions.

New Plastitar Record for the Mediterranean Sea: Characterization of Plastics and Tar from the Salento Peninsula (Ionian Sea)

The various forms of anthropogenic pollution are regarded as a serious threat to marine coastal areas. The overproduction and mismanagement of petroleum derivatives, such as tar and plastics, have resulted in a significant correlation between these two pollutants. The aggregation of tar, microplastics (MPs), and natural materials can create plastitar blocks, which are common in coastal areas. These raise concern about the undeniable negative impact on the marine ecosystem and the associated biota, and serve as a recognizable and understandable indication of environmental decline. Here, the composition of the 11 plastitar blocks collected on the Ionian side of the Apulia region (Italy) was characterized both in tar and plastics using nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy, respectively. Of the 250 particles extracted from the tar, 208 were identified as plastics, predominantly Polyethylene. The majority of these were in the form of pellets (90%), with fragments accounting for 5% and films and filaments representing the remaining 5%. This study provides new data that can be used to enhance the understanding of the distribution and baseline information about this novel form of pollution in Italian waters.

Application of marine sponges for biomonitoring active pharmaceutical ingredients (APIs) in coral reefs. Optimization of an SPME and ESI-LC-MS/MS method

Chemical pollution is a threat to coral reefs. To preserve them, it is crucial to monitor novel contaminants and assess the related risks. The occurrence of active pharmaceutical ingredients (APIs) in coral reefs has been poorly investigated until now. Under this light, we tested the use of the marine sponge Cf. Hyrtios as bio-monitors and conducted a pilot study in the Faafu Atoll (Maldives). Analyses were carried out by in vivo solid-phase microextraction (SPME) and liquid chromatography (LC) electrospray ionization (ESI) tandem mass spectrometry (MS/MS). Twelve APIs were selected for method optimization. Limits of quantitation (LOQs) were in the 0.6 and 2.5 ng/g range, accuracy between 86.5 % and 104.7 %, and precision between 3.0 % and 14.9 %. All the sponges located in the inner reefs resulted contaminated with at least one API. Gabapentin and Carbamazepine displayed the highest detection rates, while Ketoprofen had the highest concentration (up to 15.7 ng/g).

The toxic effects of petroleum pollutants to microalgae in marine environment

Marine oil pollution is one of the major global environmental pollution problems. Marine microalgae are the foundation of the marine food chain, providing the main primary productivity of the ocean. They not only maintain the energy flow and material cycle of the entire marine ecosystem, but also play an important role in regulating global climate change. Exploring the impact of petroleum pollutants on marine microalgae is extremely important for studying marine environmental pollution. This review first introduced the sources, compositions, and forms of petroleum pollutants and their migration and transformation processes in the ocean. Then, the toxic effects of petroleum pollutants on marine microalgae were summarized. The growth of marine microalgae showed low-concentration promotion and high-concentration inhibition. The population growth and interspecific relationships of marine microalga was changed and the photosynthesis of marine microalgae was influenced. Finally, potential research directions and suggestions for marine microalgae in the future were proposed.