Toxicology and Biodegradation of Crude and Dispersed Oil in the Arctic Marine Environment Joint

Industry Program Research

Managed by:Jack WordNewFields4729 NE View DrPort Gamble, WA 98364 And Robert Perkins University of Alaska, FairbanksInstitute of Northern EngineeringFairbanks, AK 99775

Research Partners NewFields, UAF, BASC, BARC, Alpha Analytical

Technical Advisory Committee: USCG, NOAA, USEPA, ADEC, NSB,CEDRE, UAF, COOGER, SINTEF, Akvaplan Niva.

Sponsoring CompaniesShellExxonMobilStatoilConocoPhillips

Program Management

Barrow Arctic Research CenterBarrow, Alaska

JIP Research Objectives Identification of Research Needs

Literature reviewInternational workshopDevelop scopes of work and test protocols

Develop infrastructure to support research work in the Arctic (personnel, facilities, equipment and testing procedures to accomplish tasks)

Conduct work and provide monthly updates to TAC and JIP members on the outcome of the research efforts – modify efforts as needed to address issues and discoveries

This information is provided on an open-access ftp website that is updated regularly

Determine sensitivity of key Arctic species to chemically and physically dispersed petroleum under Arctic conditions (pelagic marine, cold water and ice-free conditions).

Compare sensitivity of key Arctic species to sub-Arctic, temperate and tropical species.

Determine whether the dispersant Corexit 9500 adds to petroleum toxicity.

Key Toxicology Research Objectives

Physically Dispersed Petroleum (WAF)

Chemically Dispersed Petroleum (CEWAF)

Physically and Chemically Dispersed Petroleum Preparation

Key Biodegradation Research Objectives

Respirometer

Study biodegradation of petroleum under Arctic conditions (+5 to -2°C; 24 hour illumination and 24 hour darkness; ice-free) with indigenous microbes contained in natural seawaters. Temperatures reflect summer and winter conditions.

Determine rate of biodegradation of chemically and physically dispersed petroleum.

Determine effect of weathering on biodegradation rates of physically and chemically dispersed petroleum.

Calanus glacialis – pelagic copepod representing significant Tier II food web contribution to Arctic invertebrates, fish, marine mammals and seabirds.

Boreogadus saida – marine fish representing important Tier III food web contribution to Arctic fish, marine mammals and seabirds

Myoxocephalus sp – marine/estuarine fish representing Tier III food web contribution to Arctic fish, marine mammals and seabirds.

• Thysanoessa raschii– pelagic krill species representing important Tier II food web contribution to Arctic fish, marine mammals and seabirds

Calanus glacialis

Boreogadus saida

Myoxocephalus sp Thysanoessa raschii

Bioassay Testing @ 0 ± 1 °C

Key Species Selected for Arctic Toxicology Testing

Arctic Toxicity Findings Pelagic organisms respond to the

concentrations of petroleum in the water column (PAH)

Dispersant concentrations do not add to the petroleum toxicity at recommended dispersant oil ratios (DOR 1:20)

Dispersant (Corexit 9500) by itself at recommended use rates does not show significant toxicity to copepods

Toxicity is expressed over longer periods of time for Arctic copepods versus subarctic and temperate species (12 versus 4 days).

Arctic species show equal or less sensitivity to petroleum exposure than temperate species after appropriate exposure periods.

We have developed a ‘breaking wave WAF’ procedure that physically disperses petroleum into the water column sufficiently to produce biological effects based concentrations.

Comparative Toxicity of Spiked Petroleum & Dispersants

Species

LC50 (µg/L) Corexit or Total PAH -- Aurand et al 2009 (green shading)

Corexit 9500 WAF CE WAF

24h 48h 24h 48h 24h 48h

Eurytoma affinis

Copepod 19,200 15,300 28 79 60 51

Copepodite 14,600 9,600 32 46 43 15

Nauplii 9,500 6,300 81 16 40 10

SpeciesLC50 (µg/L) Corexit or TPAH - JIP Program Results

Corexit 9500 WAF CE WAF

Calanus glacialis (4 d) ~50,000 to 125,000

Calanus glacialis (12 d) ~20,000 to 50,000 60 to 140 150 to 510

Species96h LC50 TPH – Fuller and Bonner, 2001 (pink shading)

Corexit 9500 WAF CE WAF

Menidia berylina 40,000 to 117,000 >14,500 to 32,300 24,900 to 36,900 Mysidopsis bahia

(=Americamysis)

500,000 to 1,305,000 26,100 to 83,100 56,500 to 60,800

Cyprinodon vulgaris 593,000 to 750,000 >5,700 31,900 to 39,500

Vibrio fisheri 104,000 to 242,000 700 to 1,300 12,800 to 27,900

1. Younger stages are more sensitive

2. Corexit 9500 is ~100-fold less toxic than PAH

3. Corexit 9500 is ~3-fold less toxic than total petroleum

4. WAF and CE WAF preparations are equally toxic based on petroleum measurements

5. Arctic species (C. glacialis is less sensitive than temperate copepod (E. affinis)

Comparative Toxicity of Petroleum in Arctic, Subarctic and Temperate Regions

Crassostrea gigas**Crassostrea gigas**

Atherinops affinisAtherinops affinisAtherinops affinisAtherinops affinisAtherinops affinisAtherinops affinis

Americamysis bahiaAtherinops affinisAtherinops affinis

Haliotis rufescens***Calanus glacialis LOEC

Atherinops affinisMenidia beryllina

Americamysis bahiaMenidia beryllina

*Calanus glacialis LC50Cyprinodon vulgaris

Haliotis rufescens **Americamysis bahiaCyprinodon vulgaris

*Calanus glacialis LC50Americamysis bahiaAmericamysis bahia

*Calanus glacialis LC50*Calanus glacialis LC50

0.1 1 10 1001.92

2.283.994.2

5.77.37.4

9.19.5

10.211

12.512.512.6

14.41515.915.9

16.917.717.717.717.8181818.118.118.1

19.920.320.420.5

24.925

3030.331.932.532.733.3

35.736.9

39.548.649.851.9

56.55860.8

68.7757578.7

Effects of Spiked Total Petroleum Hydrocarbons (mg/L)

*=Alaskan ** = Larva Red Bars show Arctic species response

Arctic Biodegradation Findings Indigenous microbes in natural Arctic seawater degrade petroleum

hydrocarbons under Arctic conditions The respirometry studies indicate that there is a lag phase followed

by biodegradation which are comparable to rates under laboratory temperate conditions

Fresh oil biodegrades more rapidly than weathered oil Respirometry is a good surrogate for estimating rates of

biodegradation of total oil (=mineralization) – chemistry evaluates degradation of individual components of oil (primary biodegradation)

The dispersant (Corexit 9500) does not inhibit biodegradation nor does it appear toxic to the microbes

Chemically dispersed fresh oil degrades more rapidly than chemically dispersed weathered oil

Biodegradation of chemically dispersed fresh oil removes ~60% of the chemically measured components over a period of 57 days under Arctic conditions with natural seawater and it’s component microbes

Chemical Assessment of Total Oil Loss During Incubation

Biodegradation of Oil and Dispersed Oil Under Arctic Conditions

(after 57 days in incubator; measured by GCMS)

% Lossweathered 25.7weathered + Corexit 30.3fresh 37.2fresh + Corexit 56.0fresh + Corexit + nutrients 65.6

Summary Arctic species that have been tested

with petroleum and Corexit exposures react with similar or higher resilience than temperate species.

When results from this JIP research are compared to results provided by Akvaplan Niva and CROSERF, similar trends are evident.

Chemically dispersed oil effects are less toxic than physically dispersed oil toxicity on a per unit petroleum basis

Corexit 9500 shows little toxicity by itself or when mixed with oil at appropriate environmental and petroleum based concentrations.

Winter -Close up of Pressure Ridge Ice

Winter - Bear Guard

Summary - Continued

Petroleum biodegrades in the Arctic with indigenous microbes in pelagic waters under summer and winter ice-free conditions.

Chemical dispersants appear to enhance the completeness of degradation of measured components in oil over undispersed petroleum (~60 % compared to <30 %);

Degradation of weathered oil is less than fresh oil under sealed conditions (no evaporation)

Summer – Open Water Conditions

Photo credit: all photos taken by Jack D Word