Bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs) by the

Jun 14, 2018 - (2−4) For example, the Hebei Spirit Oil Spill (HSOS) that occurred 10 km off the ... were used for the preparation of OSAs mixture, t...
0 downloads 0 Views 9MB Size
Subscriber access provided by UNIVERSITY OF TOLEDO LIBRARIES

Ecotoxicology and Human Environmental Health

Bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs) by the Marine Clam, Mactra veneriformis, Chronically Exposed to Oil-suspended Particulate Matter Aggregates Junsung Noh, Hosang Kim, Changkeun Lee, Seo Joon Yoon, Seungoh Chu, Bong-Oh Kwon, Jongseong Ryu, Jae-Jin Kim, Hanbyul Lee, Un Hyuk Yim, John P. Giesy, and Jong Seong Khim Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b06692 • Publication Date (Web): 14 Jun 2018 Downloaded from http://pubs.acs.org on June 15, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 37

1

Environmental Science & Technology



2 3

Bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs) by the Marine

4

Clam, Mactra veneriformis, Chronically Exposed to Oil-suspended Particulate

5

Matter Aggregates

6 7

Junsung Noh,a Hosang Kim,a Changkeun Lee,a Seo Joon Yoon,a Seungoh Chu,a Bong-Oh Kwon,a

8

Jongseong Ryu,b Jae-Jin Kim,c Hanbyul Lee,c Un Hyuk Yim,d John P. Giesy,e,f,g,h and Jong Seong Khima,*

9 10 11 12 13 14 15 16 17 18 19 20

a

School of Earth and Environmental Sciences & Research Institute of Oceanography, Seoul National University, Seoul,

Republic of Korea b

Department of Marine Biotechnology, Anyang University, Ganghwa-gun, Incheon, Republic of Korea

c

Division of Environmental Science & Ecological Engineering, Korea University, Seoul, Republic of Korea

d

Oil and POPs Research Group, Korea Institute of Ocean Science and Technology, Geoje, Republic of Korea

e

Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon,

Saskatchewan, Canada. f

Department of Zoology, and Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA

g

School of Biological Sciences, University of Hong Kong, Hong Kong, SAR, China

h

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University,

Nanjing, People’s Republic of China

21 22

Word counts

23

4712 words (Abstract (197) + Text) + 2 Large Figures and 3 Small Figures (words 2100 equivalent)

24

= Total 6812 words equivalent

25 26

* Corresponding author.

27

Address: School of Earth and Environmental Sciences & Research Institute of Oceanography, Seoul

28

National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.

29

Tel.: +82 2 880 6750; fax: +82 2 872 0311.E-mail address: [email protected] (J.S. Khim). 1

ACS Paragon Plus Environment

Environmental Science & Technology

30

ABSTRACT: Dispersion and biodegradation of petroleum hydrocarbons are significantly enhanced

31

by formation of oil-suspended particulate matter aggregates (OSAs), but little is known about their

32

adverse effects on benthic invertebrates or microbes. In this study, we investigated: (1)

33

bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) by the marine bivalve, Mactra

34

veneriformis and (2) changes in composition and relative abundances of microbes, during 50-d of

35

OSAs feeding experiment. Total concentrations of PAHs increased more rapidly during the first week

36

of exposure, peaked at Day 30, then gradually declined to the end of experiment. While

37

bioaccumulation of PAHs by clams varied among the 20 target compounds, two major groups of

38

PAHs were identified by the cluster analysis. One group including 3-methylphenanthrene, 1,6-

39

dimethylphenanthrene, 1,2,6,9-tetramethylphenanthrene, and benzo[a]anthracene showed a fairly

40

constant rate of accumulation, while the second group including 2-methyldibenzothiophene, 2,4-

41

dimethyldibenzothiophene, 2,4,7-trimethyldibenzothiophene, 3-methylchrysene, 6-ethylchrysene,

42

and 1,3,6-trimethylchrysene exhibited a bell-shaped pattern. Bioaccumulation of PAHs by clams was

43

dependent on changes in abundance of Gammaproteobacteria, indicating active degradations of

44

hydrocarbons by selected species. Six key species included: Porticoccus litoralis, Porticoccus

45

hydrocarbonoclasticus, Cycloclasticus spirillensus, Alcanivorax borkumensis, Alcanivorax dieselolei,

46

and Alkalimarinus sediminis. These results are the first to demonstrate interactions of OSAs and

47

macrofauna/microbe in oil cleanup operations.

48

2

ACS Paragon Plus Environment

Page 2 of 37

Page 3 of 37

49 50

Environmental Science & Technology

INTRODUCTION Spills of oil associated with transportation in marine environments, oilfield drilling, petroleum

51

refining, oil storage and waste management, can have consequences for aquatic ecosystems,

52

particularly to subtidal and intertidal habitats1. Crude oil and oil-derivatives not only contain toxic

53

components, such as polycyclic aromatic hydrocarbons (PAHs), but can also be spread widely and

54

persist and be accumulated into food chains. Detrimental effects of oil spills on marine organisms

55

and their habitats over an extended period can be significant 2,3,4. For example, the Hebei Spirit Oil

56

Spill (HSOS) occurred 10 km off the coast of Taean, Korea in 2007 released approximately 10,800

57

tonnes of crude oil into the sea and eventually damaged entire marine ecosystems5,6. Recovery of the

58

marine environment from this oil spill took >five years to return to baseline conditions of water and

59

sediment quality7. To date, it is still debatable whether recovery of the benthic community in the area

60

is complete.

61

PAHs are omnipresent contaminants in marine environments. In fact, pyrogenic PAHs are

62

commonly found in marine organisms. Petrogenic PAHs, which originate from crude oil, contain a

63

wide range of alkylated derivatives. Thus, it is not surprising that marine organisms exposed to oil

64

spills contain significant concentrations of both PAHs and alkylated PAHs4,8,9. Lower molecular

65

mass (LMM) PAHs, such as naphthalene and its alkylated groups dominate the PAHs of Iranian

66

heavy crude (IHC) oil, followed by the another group of LMM PAHs including dibenzothiophene,

67

phenanthrene, and fluorene, and then by relatively minor components representing higher molecular

68

mass (HMM) PAHs, such as chrysene and other HMM PAHs10. Bioaccumulation and adverse effects

69

of LMM PAHs on marine organisms are well known (see SI-Table S1). HMM PAHs are particularly

70

hazardous because they have greater toxic potencies and are also carcinogenic to humans and

71

wildlife and often degrade quite slowly. 3

ACS Paragon Plus Environment

Environmental Science & Technology

72

PAHs are transformed primarily by microbes, which play an essential role in degrading spilled

73

oils and/or residues. In fact, a number of bacterial taxa can decompose a wide variety of

74

hydrocarbons and those taxa can reproduce rapidly in oiled environments11–15. Thus, microbial

75

communities could be used to effectively and economically bio-remediate environments

76

contaminated by oil16.

77

Suspended particulate matters (SPM) have been recognized as vectors for transport of oil from

78

one environment to another and to affect accumulation by marine organisms. Oil and a variety of

79

SPMs bind together in seawater, to form oil-SPM aggregate (OSA), which is known to affect

80

dispersions of spilled oil and degradation of petroleum hydrocarbons17–20. In addition to being called

81

OSAs, previous studies have referred to these aggregates of oil and SPM as oil-mineral aggregates,

82

or oil-particle aggregates21–25. In areas where SPMs are prevalent, OSAs form naturally21. Due to

83

their lesser viscosities, OSAs are not as adhesive to seashore habitats as is crude oil. This is because

84

oil droplets originating from spills usually become coated with fine, non-sticky organic particles as

85

oil disperses. This type of aggregation enhances biodegradation because aggregates significantly

86

increase oil-water contact areas, which maximizes accessibility of hydrocarbon-degrading bacteria

87

and fungi to oil26,27,28. Furthermore, by being nearly neutrally buoyant, OSAs can be easily dispersed

88

away from the oil-contaminated sites by tides and/or currents29. Although characteristics of OSAs

89

formed under various environmental conditions have been well studied23,30-32, there have been few

90

studies examining bioaccumulation and/or biodegradation of oil in the form of the OSAs, by

91

microbial communities.

92

In the present study, a laboratory mesocosm experiment was used to simulate a shallow,

93

subtidal environment contaminated by chronic exposure to OSAs (Figure 1A). Since this shellfish is

94

commercially important worldwide and the very species prefer to inhabit in muddy tidal flat33 which 4

ACS Paragon Plus Environment

Page 4 of 37

Page 5 of 37

Environmental Science & Technology

95

has greater potential in OSAs formation compared to that in sandy areas, when exposed to the oil

96

contaminated environment, the filter-feeding bivalve, clam Mactra veneriformis was studied.

97

Concentrations of PAHs in exposed animals, microbial communities, and other parameters were

98

monitored for 50 d (Figure 1B) because the spilled oil could last >30 days5,6 and possibly OSAs

99

could be formed and persist for longer periods of time. Specific objectives were to: (1) evaluate

100

bioaccumulation of PAHs into soft tissues of M. veneriformis chronically exposed to OSAs in the

101

water column; (2) examine compound-specific patterns of bioaccumulation in clams targeting parent

102

PAHs and alkylated PAHs; (3) identify specific constituents of microbial communities dominating an

103

OSA-contaminated environment, and (4) assess how bioaccumulation of PAHs into clams influences

104

microbial-mediated biodegradation.

105 106

MATERIALS AND METHODS

107

Preparation of OSAs. OSAs were prepared by previously described methods25, with a slight

108

modification (see details in SI-Table S3). In brief, OSAs were prepared using 1 L (1000 g) of filtered

109

seawater in a glass carboy, with 0.6 g of IHC oil, and 0.2 g of ground and sieved sediment (Φ 6% loss on ignition).

111

This enriched, dried sediment was mixed with seawater, and then IHC was added by use of pre-

112

calibrated pipettes. A reciprocating shaker (set up at 170 rpm) in a temperature-controlled room (18 ±

113

0.5 oC) was used to simulate mixing of the crude oil, sediment, and seawater. After 24 hours, the

114

carboy was allowed to stabilize for about 5 minutes, and then 700 ml of a mixture of OSAs and

115

seawater was extracted using a faucet located at the bottom. The mixture was used for feeding

116

materials of 300 mL and 600 mL, respectively, in OSAlow and OSAhigh treatments (Figure 1).

117 5

ACS Paragon Plus Environment

Environmental Science & Technology

118

Experimental Design. Individuals of the test organism, M. veneriformis (mollusks) were collected

119

in June of 2016, from intertidal mudflat off the west coast of Korea (36.095ºN, 126.613ºE). After

120

collection clams were immediately (within 4 h) transported to laboratory aquariums where they were

121

acclimated to lab conditions for one month. For each OSA feeding experiment (described below), 40

122

clams (3.5 ± 0.5 mm shell length) were placed in experimental aquariums (40 × 40 × 30 cm), which

123

were filled with sandy sediment (3 cm deep) and seawater (40 L). Clams were acclimated in

124

aquariums for 2 d before the beginning of experiments. Seawater was filtered through 0.7-µm glass-

125

fiber filters. Movement of water inside aquariums was maintained by use of a continuous-flow pipe

126

attached to an air pump. During the experiment, salinity was maintained at 34 (± 1.0) psu. To

127

minimize the influence of organic carbon from exogenous sources, a sediment composed of cleaned

128

and dried sandy loam (95% of the population in samples, except dried sediment.

257

In particular, Proteobacteria and Bacteroidetes represented >92% of the microbial populations, while

258

in the source sample (dried sediment) represented 5% of

275

members, were identified in all three temporal sampling times of the experiment, including

276

representatives of Bacteroidetes (unresolved taxa) and Proteobacteria (Alphaproteobacteria and

277

Gammaproteobacteria) (Figure 4B’). The Shannon-Weaver index of the core communities ranged

278

from 2.5 to 3.8, which suggested that the number of species and evenness indicated relatively more 12

ACS Paragon Plus Environment

Page 13 of 37

Environmental Science & Technology

279

diverse bacterial communities in each class compared with that of other classes in phyla.

280

Gammaproteobacteria was the most prevalent class in all samples. It was abundant in the OSA of all

281

feeding tanks and the Shannon-Weaver index of Gammaproteobacteria increased over the

282

experimental period (Figure 4B’).

283

Two of dominant genera (>10%) in initial source sediment were Hydrogenophaga and

284

Panacagrimonas, however, the dominant genera in treatments with OSA indicated changes during

285

experimental periods (Figure 5A). Communities of Proteobacteria bloomed in the beginning of

286

experiment (at Day 1), representing over 85% dominated by anaerobic and halophilic species, then

287

the proportion of Proteobacteria sharply declined until Day 14 (Figure 5B). After Day 14, there was

288

still a large proportion of Proteobacteria which predominated, with relative abundance of ca. 70% to

289

the total. The sum of Proteobacteria and Bacteroidetes were maintained collectively at greater than

290

90% in relative abundance during the experiment.

291

Comparisons of three phylogenetic representations at Day 1, Day 30, and Day 50 showed that

292

specific genera of Gammaproteobacteria were remarkably changed and more abundant in the OSA

293

treatments compared to Control. The corresponding genera include Pseudomonas, Methylophaga,

294

Rheinheimera, Porticoccus, Cyclosticus, Methylophaga, and Alcanivorax (Figure 5A). At species

295

level, nine Gammaproteobacteria taxa were found to be abundant in the OSA treatments, including

296

Porticoccus litoralis, Pseudomonas guineae, Pseudomonas taeanensis, Porticoccus

297

hydrocarbonoclasticus, Cycloclasticus spirillensus, Thioprofundum lithotrophicum, Alcanivorax

298

borkumensis, Alcanivorax dieselolei, and Alkalimarinus sediminis (Figure 5C). In general,

299

Pseudomonas was found to be the predominant genus, particularly peaked during early exposure

300

(until Day 7 or 14) among treatments. However, its relative abundance gradually decreased over the

301

last period of time. Alternatively, the relative abundance of Porticoccus increased consistently, 13

ACS Paragon Plus Environment

Environmental Science & Technology

302

ultimately to become the most prevalent taxa, representing over 20% of the total microbial

303

abundances (Figure 5C). Relative abundances of Porticoccus and Pseudomonas seemed to indicate a

304

competitive interaction, which might be influenced by temporal changes in PAHs concentrations

305

and/or compositions apparently related to the degree of PAHs degradation.

306 307 308

DISCUSSION Relative compositions of PAHs in OSAs were a function of the process used to prepare OSAs.

309

Naphthalene (Nap), 1-methylnaphthalene (C1-Nap), 2-methylnaphthalene (C2-Nap), 1,4,5-

310

trimethylnaphthalene (C3-Nap), 1,2,5,6-tetramethylnaphthalene (C4-Nap), fluorene (Flu), 9-

311

methylfluorene (C1-Flu), 1,7-dimethylfluorene (C2-Flu), 9-n-propylfluorene (C3-Flu), Phe, C1 to

312

C4-Phe in the OSAs of this study, had relative compositions of PAHs as did weathered oil in situ

313

sediments, while relative proportions of other PAHs, including Dbt, C1 to C3-Dbt, Chr, and C1 to

314

C3-Chr resembled that of IHC, supporting lesser weathering at the beginning stage of oil exposure in

315

the environment10 (SI-Figure S5). Characteristics that typically occur after weathering of HMM

316

PAHs were not observed during preparation of OSAs. Shaking was performed to form OSAs, thus,

317

the weathering of Nap, Flu, Phe, and their alky derivatives proceeded as the input of energy and

318

microbial activities were experienced during formation of OSAs.

319

Fecal pellets were produced in tanks in which clams were fed, such as OSAhigh, which in turn

320

confirmed that M. veneriformis fed on OSAs. In order to evaluate bio-assimilation of oil components

321

in OSAs, carbon and nitrogen isotopic ratios in soft tissue of M. veneriformis were measured (see

322

Supporting Information), however, there was no evidence for assimilation of oil-derived materials

323

during the experiments (SI-Figure S6). Results of several previous studies indicated that some

324

marine mollusks possess detoxification enzymes, especially with cytochrome P450 (CYP 450) 14

ACS Paragon Plus Environment

Page 14 of 37

Page 15 of 37

Environmental Science & Technology

325

catalyzed enzymatic reactions such as by benzo[a]pyrene-hydroxylase, ethoxycoumarin O-

326

deethylase, and N,N-dimethylaniline N-demethylase, which can biotransform PAHs44,45,46.

327

Nevertheless, due to high hydrophobicity in stable lipid-rich tissues, bivalves usually have been

328

reported to be a media as retaining xenobiotic contaminants47.

329

In general, the major route of exposure for LMM PAHs is via water, while GMM PAHs

330

generally accumulate via an intake of particulate materials from sediments48,49. In this study, LMM

331

PAHs were more abundant than HMM PAHs in OSAs. The concentration of Nap fluctuated among

332

LMM PAHs, of which accumulation was seemingly controlled by osmotic uptake, such that slight

333

variations in rates of filtration and elimination by M. veneriformis resulted in differences in rates of

334

accumulation. This is because relatively greater hydrophilicity (i.e., the log octanol-water partition

335

coefficient, log Kow) of Nap was less (3.3) than those of other targeted PAHs (SI-Table S4). Among

336

alkylated PAHs during 30 days, bioaccumulation was proportional to log Kow of PAHs, such that

337

PAHs with greater log Kow were more accumulated by clams (SI-Figure S7). The TPAH in Group I

338

gradually increased until the end of 50-d experiment without any inflections, with C2-Phe accounting

339

for >75% of the total concentration of PAHs. In spite of the regular and lasting intake of OSAs, the

340

TPAH in Group II included not only LMM PAHs (C1- to C3-Dbt) but also HMM PAHs such as

341

alkylated chrysene (C1- to C3-Chr) reported to exhibit greater log Kow (refer to SI-Table S4).

342

Therefore, PAHs of Group II did not follow predictions based on log Kow, although substituted,

343

chrysene compounds have been reported to exhibit greater log Kow (Chr = 5.81, C1-Chr = 6.42, C2-

344

Chr = 6.88, C3-Chr = 7.44) (refer to SI-Table S4, references given in table only).

345

Theoretically, by exposing a much greater surface area of oil to microbial communities, the

346

formation of OSAs would increase rates of degradation of oil by associated microbes, however,

347

studies of this process are scarce50. Bioremediation of spilled oil by PAHs-degrading microbial 15

ACS Paragon Plus Environment

Environmental Science & Technology

348

communities could mitigate bioaccumulation of PAHs by benthic organisms. In our OSA-

349

contaminated environment, Proteobacteria (especially Gammaproteobacteria) responded rapidly to

350

greater concentrations of PAHs by increasing both abundance and diversity. This means that they

351

have potential to degrade PAHs that tend to accumulate on surfaces of OSAs. One of the major

352

insights provided by the results of the present study was that changes in microbial community

353

composition over a 50-d period was observed in the various OSA treatments. As a result,

354

bioaccumulation of PAHs by clams was influenced by several factors, including chemical properties

355

and exogenous degradation such as chemical weathering and/or microbial degradation.

356

Several studies, in marine environments, have described species of Gammaproteobacteria as

357

key transformers of PAHs and that they respond immediately to crude oil spills, even within a day or

358

so13,51–54. Results of this study generally confirmed this quick microbial response to OSAs. For

359

instance, a rapid recolonization by microbial communities with some selected species was observed,

360

particularly in the presence of OSAhigh. The associated microbial taxa responding most rapidly to oil-

361

soaked organic-rich suspended particles included mainly the class Gammaproteobacteria

362

Pseudomonas, Porticoccus, Cycloclasticus, Methylophaga, and Alcanivorax spp. Such rapid changes

363

in composition in response to OSAs by microbial communities persisted for almost 2 months (50

364

days in our study). This result suggests that Gammaproteobacteria could be used to control

365

bioaccumulation of PAHs in marine environments.

366

Page 16 of 37

Similarly, increases in abundances of species of Cycloslasticus and Alcanivorax have also been

367

reported in environments contaminated by petroleum hydrocarbons55–61. Pseudomonas has been

368

reported to degrade Nap, Ant, Phe, and Flu in various types of terrestrial soils62–66 and is thought to

369

be involved in co-metabolization of Flu67. Although Thioprofundum was considered to be mesophilic,

370

anaerobic, and sulfur-oxidizing bacterial community occurred in hydrothermal areas68, the decrease 16

ACS Paragon Plus Environment

Page 17 of 37

Environmental Science & Technology

371

of concentrations of Dbt and alkylated Dbt in clams also could be explained by the increase of

372

Thioprofundum, which could have accelerated desulfurization of sulfur heterocycles. P. litoralis and

373

P. hydrocarbonoclasticus have been reported to be specialized hydrocarbon-degrading bacteria living

374

in association with marine phytoplankton69. In this study, by Day 50, at the end of experiment, P.

375

litoralis composed about 21% of the entire bacterial composition in the OSAhigh treatment, which

376

was almost 42-fold greater in relative abundance than in the Control treatment (0.6%). A. sediminis

377

has been only recently isolated from marine sediment70, hence studies of biodegradation by that

378

species are limited. However, A. sediminis was considered one of the hydrocarbon degraders because

379

relatively great abundance was evidenced in the OSA treatments compared to that in the Control.

380

Overall, bioaccumulation of PAHs into soft tissues of M. veneriformis was related to temporal

381

changes of hydrocarbon-degrading bacterial compositions and abundances. Such an association

382

between bioaccumulation and microbial degradation should be taken into account when handling and

383

utilizing the OSAs in remediating oil spills. Of course, there might be differences in the microbial

384

communities that decompose OSA depending on the type and characteristics of crude oil. In

385

particular, what mechanisms are involved in degradation of PAHs by microbes is the limit of this

386

study and further studies are needed.

387

The primary goal of the present study was to address the role of microbial degradation

388

associated with bioaccumulations of PAHs by benthic organisms. The results presented here indicate

389

the importance of Porticoccus spp., which can use PAHs as a source of carbon. Some of the results

390

presented here provide insight into how OSAs are related to bioaccumulation by bivalves and

391

biodegradation by microbes. Based on the results of this study, we can consider ways to promote the

392

formation and degradation of OSA by injecting fine sediment particles and oil-degrading bacterial

393

agents in offshore oil spill accidents. To our knowledge, no other study has focused on 17

ACS Paragon Plus Environment

Environmental Science & Technology

Page 18 of 37

394

bioaccumulation of OSAs in association with microbial communities. Thus, the present study

395

appears to be the first step, in developing protocols for OSAs to remediate oil spills.

396

18

ACS Paragon Plus Environment

Page 19 of 37

Environmental Science & Technology

397

ASSOCIATED CONTENT

398

Supporting Information

399

Additional details of the methods, results, and discussions are given for 1) carbon and

400

nitrogen stable isotopic ratios in soft tissue of M. veneriformis (Supporting Materials and Methods),

401

2) comparison of carbon and nitrogen stable isotopic ratios in clams (Supporting Results), 3) mini-

402

review of bioaccumulation of PAHs in marine organisms (Table S1), 4) baseline information of

403

sediment properties (Table S2), 5) experimental conditions of preparation of the OSAs (Table S3), 6)

404

list of target PAHs compounds measured by GC/MSD (Table S4), 7) GC/MSD conditions for the

405

analyses of PAHs and alkylated PAHs (Table S5), 8) mean concentration of PAHs in soft tissue of

406

clams under OSAs feeding experiment (Table S6), 9) result of Mann-Whitney U-test for comparison

407

of replicates per treatment in total PAHs (Table S7), 10) spearman rank correlation results for

408

concentrations of 20 PAHs in soft tissue of clams (Table S8), 11) result of Kolmogorov-Smirnov

409

normality test for concentrations of PAHs in soft tissue of clams over the period of 50 days in OSAs

410

feeding treatments (Table S9), 12) total PAHs concentration in sediment (Figure S1), 13) PAHs and

411

alkylated PAHs in OSAs (Figure S2), 14) concentrations of 25 PAHs in soft tissue of clams (Figure

412

S3), 15) PAHs compounds in soft tissue of clams by the bioaccumulation of OSAs feeding

413

experiment (Figure S4), 16) relative compositions of PAHs and alkylated PAHs in crude oil,

414

sediments contaminated by Hebei Spirit oil spill, 17) OSA made of IHC (Figure S5), 18) stable

415

isotopic ratios of carbon and nitrogen in clams, OSAs, sediment, and crude oil (Figure S6), and 19)

416

relationship between Log Kow and concentration of PAHs in soft tissue of clams (Figure S7). (PDF)

417 418

19

ACS Paragon Plus Environment

Environmental Science & Technology

Page 20 of 37

419

ACKNOWLEDGMENTS

420

This work was supported by projects entitled “Marine ecosystem-based analysis and decision-

421

making support system development for marine spatial planning (20170325)” and “Integrated

422

management of marine environment and ecosystems around Saemangeum (20140257)” funded by

423

the Ministry of Oceans and Fisheries of Korea (MOF) granted to JSK. JPG was supported by the

424

Canada Research Chair program, the 2012 "High Level Foreign Experts" (#GDT20143200016)

425

program, funded by the State Administration of Foreign Experts Affairs, the P.R. China to Nanjing

426

University, the Einstein Professor Program of the Chinese Academy of Sciences and a Distinguished

427

Visiting Professorship in the School of Biological Sciences of the University of Hong Kong.

428

Finally, we thank Ms. Ji Hyun Kim for the technical assistance for the part of experiments.

20

ACS Paragon Plus Environment

Page 21 of 37

Environmental Science & Technology

429

REFERENCES

430

(1) Marine Board, Ocean Studies Board, and National Research Council. Oil in the sea III: inputs,

431 432

fates, and effects. National Academies Press, 2003. (2) Jewett, S. C.; Dean, T. A.; Woodin, B. R.; Hoberg, M. K.; Stegeman, J. J. Exposure to

433

hydrocarbons 10 years after the Exxon Valdez oil spill: evidence from cytochrome P4501A

434

expression and biliary FACs in nearshore demersal fishes. Mar. Environ. Res. 2002, 54 (1), 21-

435

48.

436

(3) Hong, S.; Khim, J. S.; Ryu, J.; Park, J.; Song, S. J.; Kwon, B.-O.; Choi, K.; Ji, K.; Seo, J.; Lee, S.

437

Two years after the Hebei Spirit oil spill: residual crude-derived hydrocarbons and potential

438

AhR-mediated activities in coastal sediments. Environ. Sci. Technol. 2012, 46 (3), 1406-1414.

439

(4) Sammarco, P. W.; Kolian, S. R.; Warby, R. A.; Bouldin, J. L.; Subra, W. A.; Porter, S. A.

440

Distribution and concentrations of petroleum hydrocarbons associated with the BP/Deepwater

441

Horizon Oil Spill, Gulf of Mexico. Mar. Pollut. Bull. 2013, 73 (1), 129-143.

442

(5) Guard, K. C., KCG 2008 White Paper. 11–1530000–000048–10, 2008, p523.

443

(6) Kim, M.; Yim, U. H.; Hong, S. H.; Jung, J.-H.; Choi, H.-W.; An, J.; Won, J.; Shim, W. J. Hebei

444

Spirit oil spill monitored on site by fluorometric detection of residual oil in coastal waters off

445

Taean, Korea. Mar. Pollut. Bull. 2010, 60 (3), 383-389.

446

(7) Hong, S.; Khim, J. S.; Ryu, J.; Kang, S.-G.; Shim, W. J.; Yim, U. H. Environmental and

447

ecological effects and recoveries after five years of the Hebei Spirit oil spill, Taean, Korea.

448

Ocean. Coast. Manage. 2014, 102, 522-532.

449

(8) Soriano, J.; Viñas, L.; Franco, M.; González, J. J.; Ortiz, L.; Bayona, J.; Albaigés, J. Spatial and

450

temporal trends of petroleum hydrocarbons in wild mussels from the Galician coast (NW Spain)

451

affected by the Prestige oil spill. Sci. Total. Environ. 2006, 370 (1), 80-90. 21

ACS Paragon Plus Environment

Environmental Science & Technology

452

(9) Uno, S.; Koyama, J.; Kokushi, E.; Monteclaro, H.; Santander, S.; Cheikyula, J. O.; Miki, S.;

453

Añasco, N.; Pahila, I. G.; Taberna, H. S. Monitoring of PAHs and alkylated PAHs in aquatic

454

organisms after 1 month from the Solar I oil spill off the coast of Guimaras Island, Philippines.

455

Environ. Monit. Assess. 2010, 165 (1), 501-515.

456

(10)Hong, S.; Lee, S.; Choi, K.; Kim, G. B.; Ha, S. Y.; Kwon, B.-O.; Ryu, J.; Yim, U. H.; Shim, W. J.;

457

Jung, J. Effect-directed analysis and mixture effects of AhR-active PAHs in crude oil and coastal

458

sediments contaminated by the Hebei Spirit oil spill. Environ. Pollut. 2015, 199, 110-118.

459

(11) Hazen, T. C.; Prince, R. C.; Mahmoudi, N., Marine oil biodegradation. Environ. Sci. Technol.

460 461

2016, 50 (5), 2121-2129. (12) Hazen, T. C.; Dubinsky, E. A.; DeSantis, T. Z.; Andersen, G. L.; Piceno, Y. M.; Singh, N.;

462

Jansson, J. K.; Probst, A.; Borglin, S. E.; Fortney, J. L. Deep-sea oil plume enriches indigenous

463

oil-degrading bacteria. Science 2010, 330 (6001), 204-208.

464

(13) Redmond, M. C.; Valentine, D. L., Natural gas and temperature structured a microbial

465

community response to the Deepwater Horizon oil spill. Proc. Nat. Acad. Sci. 2012, 109, (50),

466

20292-20297.

467

(14) Valentine, D. L.; Mezić, I.; Maćešić, S.; Črnjarić-Žic, N.; Ivić, S.; Hogan, P. J.; Fonoberov, V. A.;

468

Loire, S. Dynamic autoinoculation and the microbial ecology of a deep water hydrocarbon

469

irruption. Proc. Nat. Acad. Sci. 2012, 109 (50), 20286-20291.

470

Page 22 of 37

(15) Röling, W. F.; Milner, M. G.; Jones, D. M.; Fratepietro, F.; Swannell, R. P.; Daniel, F.; Head, I.

471

M. Bacterial community dynamics and hydrocarbon degradation during a field-scale evaluation

472

of bioremediation on a mudflat beach contaminated with buried oil. Appl. Environ. Microb. 2004,

473

70 (5), 2603-2613.

474

(16) Duran, R.; Cravo-Laureau, C. Role of environmental factors and microorganisms in determining 22

ACS Paragon Plus Environment

Page 23 of 37

Environmental Science & Technology

475

the fate of polycyclic aromatic hydrocarbons in the marine environment. FEMS Microbiol. Rev.

476

2016, 40 (6), 814-830.

477 478 479 480 481

(17) Muschenheim, D.; Lee, K. Removal of oil from the sea surface through particulate interactions: review and prospectus. Spill Sci. Technol. B. 2002, 8 (1), 9-18. (18) Owens, E. H.; Lee, K. Interaction of oil and mineral fines on shorelines: review and assessment. Mar. Pollut. Bull. 2003, 47 (9), 397-405. (19) Gong, Y.; Zhao, X.; Cai, Z.; O’reilly, S.; Hao, X.; Zhao, D. A review of oil, dispersed oil and

482

sediment interactions in the aquatic environment: influence on the fate, transport and

483

remediation of oil spills. Mar. Pollut. Bull. 2014, 79 (1), 16-33.

484

(20) Boglaienko, D.; Tansel, B. Partitioning of fresh crude oil between floating, dispersed and

485

sediment phases: Effect of exposure order to dispersant and granular materials. J. Environ.

486

Manage. 2016, 175, 40-45.

487

(21) Sun, J.; Khelifa, A.; Zhao, C.; Zhao, D.; Wang, Z. Laboratory investigation of oil–suspended

488

particulate matter aggregation under different mixing conditions. Sci. Total. Environ. 2014, 473,

489

742-749.

490 491 492

(22) Stoffyn-Egli, P.; Lee, K. Formation and characterization of oil–mineral aggregates. Spill Sci. Technol. B. 2002, 8 (1), 31-44. (23) Ajijolaiya, L. O.; Hill, P. S.; Khelifa, A.; Islam, R. M.; Lee, K. Laboratory investigation of the

493

effects of mineral size and concentration on the formation of oil–mineral aggregates. Mar. Pollut.

494

Bull. 2006, 52 (8), 920-927.

495

(24) Sun, J.; Zheng, X. A review of oil-suspended particulate matter aggregation—a natural process

496

of cleansing spilled oil in the aquatic environment. J. Environ. Monitor. 2009, 11 (10), 1801-

497

1809. 23

ACS Paragon Plus Environment

Environmental Science & Technology

498

(25) Gustitus, S. A.; Clement, T. P. Formation, fate and impacts of microscopic and macroscopic oil‐

499

sediment residues in nearshore marine environments–a critical review. Rev. Geophys. 2017, 55

500

(4), 1130-1157.

501 502 503 504 505

(26) Lee, K.; Weise, A. M.; St-Pierre, S. Enhanced oil biodegradation with mineral fine interaction. Spill Sci. Technol. B. 1996, 3 (4), 263-267. (27) Weise, A.; Nalewajko, C.; Lee, K. Oil-mineral fine interactions facilitate oil biodegradation in seawater. Environ. Technol. 1999, 20 (8), 811-824. (28) Silva, C. S.; de Oliveira, O. M.; Moreira, I. T.; Queiroz, A. F.; de Almeida, M.; Silva, J. V.; da

506

Silva Andrade, I. O. Potential application of oil-suspended particulate matter aggregates (OSA)

507

on the remediation of reflective beaches impacted by petroleum: a mesocosm simulation.

508

Environ. Sci. Pollut. R. 2015, 1-13.

509

(29) Rios, M. C.; Moreira, Í. T.; Oliveira, O. M.; Pereira, T. S.; de Almeida, M.; Trindade, M. C. L.;

510

Menezes, L.; Caldas, A. S. Capability of Paraguaçu estuary (Todos os Santos Bay, Brazil) to

511

form oil–SPM aggregates (OSA) and their ecotoxicological effects on pelagic and benthic

512

organisms. Mar. Pollut. Bull. 2017, 114 (1), 364-371.

513

(30) Sun, J.; Khelifa, A.; Zheng, X.; Wang, Z.; So, L. L.; Wong, S.; Yang, C.; Fieldhouse, B. A

514

laboratory study on the kinetics of the formation of oil-suspended particulate matter aggregates

515

using the NIST-1941b sediment. Mar. Pollut. Bull. 2010, 60 (10), 1701-1707.

516

(31) Khelifa, A. Sediment contamination due to oil-suspended particulate matter aggregation during

517

oil spills in coastal waters. In Contaminated Sediments: 5th Volume, Restoration of Aquatic

518

Environment, Am. Soc. Test. Mater. 2012, 1554 STP, 208-228.

519 520

(32) Loh, A.; Shim, W. J.; Ha, S. Y.; Yim, U. H. Oil-suspended particulate matter aggregates: Formation mechanism and fate in the marine environment. Ocean Sci. J. 2014, 49 (4), 329-341. 24

ACS Paragon Plus Environment

Page 24 of 37

Page 25 of 37

521

Environmental Science & Technology

(33) Ryu, J.; Kim, H.-C.; Khim, J. S.; Kim, Y. H.; Park, J.; Kang, D.; Hwang, J. H.; Lee, C.-H.; Koh,

522

C.-H. Prediction of macrozoobenthic species distribution in the Korean Saemangeum tidal flat

523

based on a logistic regression model of environmental parameters. Ecol. Res. 2011, 26 (3), 659-

524

668.

525

(34) Jonsson, G.; Bechmann, R. K.; Bamber, S. D.; Baussant, T. Bioconcentration, biotransformation,

526

and elimination of polycyclic aromatic hydrocarbons in sheepshead minnows (Cyprinodon

527

variegatus) exposed to contaminated seawater. Environ. Toxicol. Chem. 2004, 23 (6), 1538-1548.

528

(35) Edgar, R. C. Search and clustering orders of magnitude faster than BLAST. Bioinformatics 2010,

529 530

26 (19), 2460-2461. (36) Cole, J. R.; Wang, Q.; Fish, J. A.; Chai, B.; McGarrell, D. M.; Sun, Y.; Brown, C. T.; Porras-

531

Alfaro, A.; Kuske, C. R.; Tiedje, J. M. Ribosomal Database Project: data and tools for high

532

throughput rRNA analysis. Nucleic Acids Res. 2013, 42 (D1), D633-D642.

533

(37) Clarke, K.; Gorley, R. PRIMER v6: User manual-tutorial. Plymouth Marine Laboratory, 2006.

534

(38) Noether, G. E. Introduction to statistics: A nonparametic approach. Houghton Mifflin Company,

535 536 537 538 539 540

Boston, 1976. (39) Rosenthal, R. An application of the Kolmogorov-Smirnov test for normality with estimated mean and variance. Psychol. Report. 1968, 22, 570. (40) Shannon, C. E.; Weaver, W. The mathematical theory of communication. University of Illinois Press, 1998. (41) Baumard, P.; Budzinski, H.; Garrigues, P.; Sorbe, J. C.; Burgeot, T.; Bellocq, J. Concentrations

541

of PAHs (polycyclic aromatic hydrocarbons) in various marine organisms in relation to those in

542

sediments and to trophic level. Mar. Pollut. Bull. 1998, 36 (12), 951-960.

543

(42) Zakaria, M. P.; Okuda, T.; Takada, H. Polycyclic aromatic hydrocarbon (PAHs) and hopanes in 25

ACS Paragon Plus Environment

Environmental Science & Technology

544

stranded tar-balls on the coasts of Peninsular Malaysia: Applications of biomarkers for

545

identifying sources of oil pollution. Mar. Pollut. Bull. 2001, 42 (12), 1357-1366.

546

(43) Wan, Y.; Jin, X.; Hu, J.; Jin, F. Trophic dilution of polycyclic aromatic hydrocarbons (PAHs) in a

547

marine food web from Bohai Bay, North China. Environ. Sci. Technol. 2007, 41 (9), 3109-3114.

548

(44) Rewitz, K. F.; Styrishave, B.; Løbner-Olesen, A.; Andersen, O. Marine invertebrate cytochrome

549

P450: emerging insights from vertebrate and insect analogies. Comp. Biochem. Phys. C. 2006,

550

143 (4), 363-381.

551

(45) Bebianno, M. J.; Lopes, B.; Guerra, L.; Hoarau, P.; Ferreira, A. M. Glutathione S-tranferases and

552

cytochrome P450 activities in Mytilus galloprovincialis from the South coast of Portugal: effect

553

of abiotic factors. Environ. Int. 2007, 33 (4), 550-558.

554

(46) Zanette, J.; Goldstone, J. V.; Bainy, A. C.; Stegeman, J. J. Identification of CYP genes in Mytilus

555

(mussel) and Crassostrea (oyster) species: first approach to the full complement of cytochrome

556

P450 genes in bivalves. Mar. Environ. Res. 2010, 69, S1-S3.

557

Page 26 of 37

(47) Baussant, T.; Sanni, S.; Jonsson, G.; Skadsheim, A.; Børseth, J. F. Bioaccumulation of polycyclic

558

aromatic compounds: 1. Bioconcentration in two marine species and in semipermeable

559

membrane devices during chronic exposure to dispersed crude oil. Environ. Toxicol. Chem. 2001,

560

20 (6), 1175-1184.

561

(48) Meador, J.; Casillas, E.; Sloan, C.; Varanasi, U. Comparative bioaccumulation of polycyclic

562

aromatic hydrocarbons from sediment by two infaunal invertebrates. Mar. Ecol. Prog. Ser. 1995,

563

123(1-3), 107-124.

564

(49) Lee, C.-H.; Lee, J.-H.; Sung, C.-G.; Moon, S.-D.; Kang, S.-K.; Lee, J.-H.; Yim, U. H.; Shim, W.

565

J.; Ha, S. Y. Bioaccumulation of polycyclic aromatic hydrocarbons in Manila clam (Ruditapes

566

philippinarum) exposed to crude oil-contaminated sediments. Korean J. Malacol. 2014, 30 (4), 26

ACS Paragon Plus Environment

Page 27 of 37

567 568

Environmental Science & Technology

371-381. (50) Arnosti, C.; Ziervogel, K.; Yang, T.; Teske, A. Oil-derived marine aggregates–hot spots of

569

polysaccharide degradation by specialized bacterial communities. Deep Sea Res. Part II Top.

570

Stud. Oceanogr. 2016, 129, 179-186.

571

(51)Beazley, M. J.; Martinez, R. J.; Rajan, S.; Powell, J.; Piceno, Y. M.; Tom, L. M.; Andersen, G. L.;

572

Hazen, T. C.; Van Nostrand, J. D.; Zhou, J. Microbial community analysis of a coastal salt marsh

573

affected by the Deepwater Horizon oil spill. PloS one 2012, 7 (7), e41305.

574

(52) Rivers, A. R.; Sharma, S.; Tringe, S. G.; Martin, J.; Joye, S. B.; Moran, M. A. Transcriptional

575

response of bathypelagic marine bacterioplankton to the Deepwater Horizon oil spill. ISME J.

576

2013, 7 (12), 2315-2329.

577

(53) Kappell, A. D.; Wei, Y.; Newton, R. J.; Van Nostrand, J. D.; Zhou, J.; McLellan, S. L.; Hristova,

578

K. R. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico native

579

coastal microbial communities after the Deepwater Horizon oil spill. Front. Microbiol. 2014,

580

5(MAY), Article number 205.

581

(54) Lamendella, R.; Strutt, S.; Borglin, S.; Chakraborty, R.; Tas, N.; Mason, O. U.; Hultman, J.;

582

Prestat, E.; Hazen, T. C.; Jansson, J. K. Assessment of the Deepwater Horizon oil spill impact on

583

Gulf coast microbial communities. Front. Microbiol. 2014, 5(APR), Article number 130.

584

(55) Dyksterhouse, S. E.; Gray, J. P.; Herwig, R. P.; Lara, J. C.; Staley, J. T. Cycloclasticus pugetii

585

gen. nov., sp. nov., an aromatic hydrocarbon-degrading bacterium from marine sediments. Int. J.

586

Syst. Evol. Micr. 1995, 45 (1), 116-123.

587

(56) Geiselbrecht, A. D.; Hedlund, B. P.; Tichi, M. A.; Staley, J. T. Isolation of marine polycyclic

588

aromatic hydrocarbon (PAH)-degrading Cycloclasticus strains from the Gulf of Mexico and

589

comparison of their PAH degradation ability with that of Puget Sound Cycloclasticus strains. 27

ACS Paragon Plus Environment

Environmental Science & Technology

590 591

Page 28 of 37

Appl. Environ. Microb. 1998, 64 (12), 4703-4710. (57) Kasai, Y.; Kishira, H.; Sasaki, T.; Syutsubo, K.; Watanabe, K.; Harayama, S. Predominant

592

growth of Alcanivorax strains in oil‐contaminated and nutrient‐supplemented sea water. Environ.

593

Microbiol. 2002, 4 (3), 141-147.

594

(58) McKew, B. A.; Coulon, F.; Yakimov, M. M.; Denaro, R.; Genovese, M.; Smith, C. J.; Osborn, A.

595

M.; Timmis, K. N.; McGenity, T. J. Efficacy of intervention strategies for bioremediation of

596

crude oil in marine systems and effects on indigenous hydrocarbonoclastic bacteria. Environ.

597

Microbiol. 2007, 9 (6), 1562-1571.

598

(59) Cui, Z.; Lai, Q.; Dong, C.; Shao, Z. Biodiversity of polycyclic aromatic hydrocarbon‐degrading

599

bacteria from deep sea sediments of the Middle Atlantic ridge. Environ. Microbiol. 2008, 10 (8),

600

2138-2149.

601

(60) Wang, B.; Lai, Q.; Cui, Z.; Tan, T.; Shao, Z. A pyrene‐degrading consortium from deep‐sea

602

sediment of the West Pacific and its key member Cycloclasticus sp. P1. Environ. Microbiol.

603

2008, 10 (8), 1948-1963.

604

(61) Genovese, M.; Crisafi, F.; Denaro, R.; Cappello, S.; Russo, D.; Calogero, R.; Santisi, S.;

605

Catalfamo, M.; Modica, A.; Smedile, F. Effective bioremediation strategy for rapid in situ

606

cleanup of anoxic marine sediments in mesocosm oil spill simulation. Front. Microbiol. 2014,

607

5(APR), Article number 162.

608

(62) Tagger, S.; Truffaut, N.; Petit, J. L. Preliminary study on relationships among strains forming a

609

bacterial community selected on naphthalene from a marine sediment. Can. J. Microbiol. 1990,

610

36 (10), 676-681.

611 612

(63) Ashok, B.; Saxena, S.; Musarrat, J. Isolation and characterization of four polycyclic aromatic hydrocarbon degrading bacteria from soil near an oil refinery. Lett. Appl. Microbiol. 1995, 21 (4), 28

ACS Paragon Plus Environment

Page 29 of 37

613

Environmental Science & Technology

246-248.

614

(64) Whyte, L. G.; Bourbonniere, L.; Greer, C. W. Biodegradation of petroleum hydrocarbons by

615

psychrotrophic Pseudomonas strains possessing both alkane (alk) and naphthalene (nah)

616

catabolic pathways. Appl. Environ. Microb. 1997, 63 (9), 3719-3723.

617 618

(65) Aislabie, J.; Foght, J.; Saul, D. Aromatic hydrocarbon-degrading bacteria from soil near Scott Base, Antarctica. Polar Biol. 2000, 23 (3), 183-188.

619

(66)Andreoni, V.; Cavalca, L.; Rao, M.; Nocerino, G.; Bernasconi, S.; Dell’Amico, E.; Colombo, M.;

620

Gianfreda, L. Bacterial communities and enzyme activities of PAHs polluted soils. Chemosphere

621

2004, 57 (5), 401-412.

622

(67) Trzesicka-Mlynarz, D.; Ward, O. Degradation of polycyclic aromatic hydrocarbons (PAHs) by a

623

mixed culture and its component pure cultures, obtained from PAH-contaminated soil. Can. J.

624

Microbiol. 1995, 41 (6), 470-476.

625

(68) Mori, K.; Suzuki, K.-i.; Urabe, T.; Sugihara, M.; Tanaka, K.; Hamada, M.; Hanada, S.

626

Thioprofundum hispidum sp. nov., an obligately chemolithoautotrophic sulfur-oxidizing

627

gammaproteobacterium isolated from the hydrothermal field on Suiyo Seamount, and proposal

628

of Thioalkalispiraceae fam. nov. in the order Chromatiales. Int. J. Syst. Evol. Micr. 2011, 61 (10),

629

2412-2418.

630

(69) Gutierrez, T.; Nichols, P. D.; Whitman, W. B.; Aitken, M. D. Porticoccus hydrocarbonoclasticus

631

sp. nov., an aromatic hydrocarbon-degrading bacterium identified in laboratory cultures of

632

marine phytoplankton. Appl. Environ. Microb. 2012, 78 (3), 628-637.

633 634

(70)Zhao, J.-X.; Liu, Q.-Q.; Zhou, Y.-X.; Chen, G.-J.; Du, Z.-J. Alkalimarinus sediminis gen. nov., sp. nov., isolated from marine sediment. Int. J. Syst. Evol. Micr. 2015, 65 (10), 3511-3516.

29

ACS Paragon Plus Environment

Environmental Science & Technology

635

FIGURE CAPTIONS

636

Figure 1. Schematic overview showing the study design of the OSAs feeding experiment. (A)

Page 30 of 37

637

Control and OSAs feeding treatments in constant-temperature water bath. (B) Experimental

638

flow chart with information on the feeding materials and interval, water renewal, and sampling

639

time. Seawater, Iranian Heavy Crude oil, and fine sediment particles (0.01%, n = 489) relative to sediment source and experimental treatments over time. A

664

phylogenetic representation of the taxonomic composition in experimental treatments (at Day 1,

665

30, and 50), including Control (inner ring), OSAlow (middle ring), and OSAhigh (outer ring). The

666

average relative abundance of each genus is plotted within the concentric rings, represented by

667

the shaded cells, with higher relative abundance indicated by darker shades. The phylum to

668

which each taxa belongs is indicated by the phylogenetic tree. Abundant taxa in Proteobacteria

669

are labelled by the red outline. (B) Relative abundances of two dominant phyla, Proteobacteria

670

(orange) and Bacteroidetes (blue), with total concentrations of Group II PAHs of OSAhigh

671

treatments (black line) (*C1-, C2-, C3-Dbt, C1-, C2-, and C3-Chr). Acronyms for PAHs

672

compounds refer to SI-Table S4). (C) The most abundant nine species (in the OSAs feeding

673

treatments) belonging to class Gammaproteobacteria. Blue lines and dots denote Control

674

treatments, green lines and dots denote OSAlow treatments, and red lines and dots denote

675

OSAhigh treatments.

31

ACS Paragon Plus Environment

Environmental Science & Technology Page 32 of 37

ACS Paragon Plus Environment

Page 33 of 37

Environmental Science & Technology

ACS Paragon Plus Environment

Environmental Science & Technology

ACS Paragon Plus Environment

Page 34 of 37

Page 35 of 37

Environmental Science & Technology

ACS Paragon Plus Environment

Environmental Science & Technology

ACS Paragon Plus Environment

Page 36 of 37

Page 37 of 37

Environmental Science & Technology

ACS Paragon Plus Environment