Presentation on theme: "Toxicology and Biodegradation of Crude and Dispersed Oil in the Arctic Marine Environment Joint Industry Program Research Managed by: Jack Word NewFields."— Presentation transcript:
Toxicology and Biodegradation of Crude and Dispersed Oil in the Arctic Marine Environment Joint Industry Program Research Managed by: Jack Word NewFields 4729 NE View Dr Port Gamble, WA 98364 And Robert Perkins University of Alaska, Fairbanks Institute of Northern Engineering Fairbanks, 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 Companies Shell ExxonMobil Statoil ConocoPhillips Program Management Barrow Arctic Research Center Barrow, Alaska
JIP Research Objectives Identification of Research Needs Literature review International workshop Develop 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 LC 50 ( µg/L) Corexit or Total PAH -- Aurand et al 2009 (green shading) Corexit 9500WAFCE WAF 24h48h24h48h24h48h Eurytoma affinis Copepod19,20015,30028796051 Copepodite14,6009,60032464315 Nauplii9,5006,30081164010 Species LC 50 ( µg/L) Corexit or TPAH - JIP Program Results Corexit 9500 WAFCE WAF Calanus glacialis (4 d) ~50,000 to 125,000 Calanus glacialis (12 d) ~20,000 to 50,000 60 to 140150 to 510 Species 96h LC 50 TPH – Fuller and Bonner, 2001 (pink shading) Corexit 9500WAFCE WAF Menidia berylina 40,000 to 117,000 >14,500 to 32,30024,900 to 36,900 Mysidopsis bahia (=Americamysis) 500,000 to 1,305,000 26,100 to 83,10056,500 to 60,800 Cyprinodon vulgaris 593,000 to 750,000 >5,70031,900 to 39,500 Vibrio fisheri 104,000 to 242,000 700 to 1,30012,800 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 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)
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