Incident Name: Argo Merchant
Subject: USCG Case History
Incident Date: 12/15/1976
Incident Location: 29 miles southeast of Nantucket Island, Massachusetts
Author: USCG Case History
Latitude: 41 02 N
Longitude: 069 27 W
USCG District: 1
Product: No. 6 Fuel Oil, cutter stock
Type: 4
Volume: 183000
Source:Tank Vessel
RAR: Commercial fisheries, fish, diving coastal birds, gulls, marine mammals.
Dispersants: No
Bioremediation: No
In-Situ Burning: Yes
Shoreline Type(s) Impacted:
Summary: At approximately 0600 on December 15, 1976, the Liberian tanker Argo Merchant went aground on Fishing Rip (Nantucket Shoals), 29 nautical miles southeast of Nantucket Island, Massachusetts in high winds and ten foot seas. The vessel was carrying approximately 183,000 barrels of No. 6 Fuel Oil (80%) and cutter stock (20%). The master of the Argo Merchant requested permission to dump cargo in an effort to control draft and re-float the vessel. Permission was denied and attempts to lighter and re-float the vessel using emergency pumps and an Air Deliverable Anti-Pollution Transfer System (ADAPTS) were unsuccessful. The following day the weather worsened and the crew of the Argo Merchant was evacuated. On December 17 the vessel began to pivot clockwise and buckle. On December 21 the vessel broke in two aft of the king post, spilling approximately 36,000 barrels of cargo. The bow section split forward of the bridge and capsized on December 22, resulting in the loss of the remaining cargo. The bow section floated 400-500 yards to the southeast and was eventually sunk by the USCG while the stern section remained aground. Prevailing currents carried the spilled oil away from the shorelines and beaches of Nantucket. Weather conditions and uncharted depths surrounding the wreck made salvage attempts difficult.
Behavior: No. 6 fuel oil is a heavy product with an API gravity that ranges from 7 to 14. The bulk of the spill formed large pancakes (largest observed was 240 feet by 760 feet) and sheens on the surface. Inspection of the pancakes by divers revealed flat bottoms. Fresh oil formed pancakes 1-1.5 inches thick with tiered edges. The pancakes thickened as the oil aged, some heavily weathered pancakes up to 10 inches thick were observed. The weathered pancakes lacked tiered edges and associated sheens. The cutter stock, which was mixed with the fuel oil to improve handling, entered the water column. Levels as high as 250 parts per billion were measured beneath areas of fresh oil.
Extensive efforts were made to monitor and track the spill. Detailed mapping was undertaken due to the level of concern, potential impacts, and to help develop more accurate trajectory models for future spills. Multiple trajectory models were utilized and evaluated during the incident. Accurate measurements of the speed of the spill revealed that oil in pancakes traveled at an average speed of about 1.1% of the wind speed, and the sheens somewhat slower. The spill moved to the south-southeast of the wreck site, out over the continental shelf, and into the prevailing North Atlantic circulation pattern. As the oil moved further offshore, wind direction and weather conditions became less of a concern. Six thousand drift cards were deployed between the spill and the coast in an attempt to give advance warning at locations of imminent shoreline impacts.
Large tar balls (up to 70 pounds) came ashore in the Nantucket area during March of 1977. Analysis of the oil confirmed that it was No. 6 Fuel Oil, but it could not be directly identified as product from the Argo Merchant.
Some impacts to the bottom sediments were observed in the area of the sunken bow section of the vessel. In addition to this localized area, one sediment sample taken from the area of the spill showed oil contamination.
Countermeasures/Mitigation: In-situ burning was attempted on two occasions. The material used was composed of fine grained, fumed silica particles treated with silane to render the material hydrophobic. Originally marketed as CAB-O-SIL ST-2-0, the product was later marketed under the trade name Tullanox 500.\\In the first burning attempt, conducted on December 27, a USCG helicopter dropped isolated boxes of Tullanox 500 charged with JP-4 jet fuel onto the oil and ignited the boxes using a timed grenade. The isolated boxes burned, but the flame failed to spread. It was believed that the wicking agent was not sufficiently dispersed to allow spreading of the flames.\\The second attempt was conducted on December 31. The USCG vessel Spar, aided by aircraft, located a 90 foot by 120 foot elliptically shaped slick that was of a heavy, tarry consistency, and 6 to 8 feet thick. The slick broke into smaller pancakes as the Spar maneuvered alongside. Sixty-six pounds of Tullanox 500, in 11 pound bags, were thrown near the center of a 30 foot by 60 foot slick. The bags were torn open and much of the material was blown off of the slick. Another application of six bags was applied along the edge of the slick and charged with JP-4. The experiment was terminated after attempts to ignite the slick failed to sustain a burn.
Other Special Interest(s): Due to the offshore movement of the spill, concern for resources shifted from potential shoreline impacts to the economically important fishing grounds in the area of Georges Bank. Benthic fish and invertebrate populations and their associated planktonic stages were at risk. Evidence of oil contamination was observed in fish, shellfish, ichthyoplankton and zooplankton collected in the area of the spill. Mortalities of Cod and Pollack embryos occurred in eggs contaminated with oil, and large numbers of zooplankton were observed to be contaminated with hydrocarbons. A decline in the population of Sandlance, an important prey species, was reported during and following the spill, however, the decrease in numbers of Sandlance could not be directly attributed to the spill.\\Observers aboard vessels in the area reported that 25 to 75% of the seabirds seen were fouled with oil. Fouling was observed mostly on the breast and abdominal areas. Herring Gulls and Black-backed Gulls appeared to be the most heavily impacted. Many boats in the area of the spill reported heavily oiled gulls landing on-board their vessels. The birds often appeared weak and overly tame. Diving birds that were reported oiled included Gannets and murres, but few of these species were observed to be heavily oiled. A total of 43 marine mammals were observed in the area of the spill, but none were in obvious distress or in direct contact with oil pancakes or sheens.\\The grounding of the Argo Merchant initiated intense scientific activity between December 15 and February 12. Studies related to the fate and effects of the oil as well as the modeling of trajectories were conducted to begin the process of assessing ecological impacts.\\Shortly after the grounding, research vessels from NOAA and Woods Hole Oceanographic Institute (WHOI) were diverted from their scheduled itineraries to begin special operations concerned with the fate and effects of the spilled oil. Personnel from National Marine Fisheries Service (NMFS), WHOI and NOAA aboard two vessels began assessment of water column contamination. Cruises involving USCG, NOAA, WHOI, U.S. Geological Survey, and University of Rhode Island (URI) vessels collected more than 200 water and sediment samples. Fish and shellfish samples were collected at 43 biological stations during a subsequent NMFS cruise. Benthic sampling was conducted throughout the area of the continental shelf over which the oil spill passed on two cruises by personnel from URI, NOAA, and the USCG.\\Considerable credit for the success of the research operation was attributed to the Federal On-Scene Coordinator's efforts to combine the research activities rather than allowing fragmentation of the effort. The OSC was also responsible for making operational resources, such as aircraft and vessels, available for research purposes.\\Media attention during the Argo Merchant spill was considerable. Though the oil never impacted the coast, public perception a year after the spill was that widespread and serious damage had occurred. The USCG was the target of increasing criticism during the incident. Criticism of the Coast Guard's handling of the incident was noted at a U.S. Senate hearing. A problem of conflicting information had developed due to the release of information from two different sources, the district office and the Coast Guard air station. After the two command posts were consolidated, public information problems were minimized.\\Shore-based cleanup of oiled seabirds was funded by the OSC under the direction of the Massachusetts Division of Fisheries and Wildlife. A total of 160 oiled birds were recovered. The relatively low number of birds collected was attributed to the winter conditions and the scarcity of beach patrols. Oiled birds were recovered as far away as Dartmouth, Nova Scotia. A total of 47 birds were released after cleaning at either the Sandwich, Massachusetts, or Felix Neck Audubon Society facilities. Although oiling of gulls was the most commonly observed impact in the spill area, Common Murres were the most common birds recovered from the beaches.
References: 1991 World Almanac
8/9/91 & 8/28/91 Letters from Daniel Owen at ITOPF
Hooke, N. Modern Shipping Disasters 1963-1987. Lloyds of London Press. 1987.
Meidt, R.M. 1987. On-scene coordinators can effectively inform the public through the news media. Oil Spill Conference Proceedings, 1987, pp. 583-585.
MMS Worldwide Tanker Spill Database
Rappaport, et al. 1981. The media and oil spills: Does the press influence damage perceptions. Oil Spill Conference Proceedings, 1981, pp. 707-712.
Review of Oil Spill Occurrences and Impacts, Exxon Production Research Company, 1989.
Tanker Advisory Center, Inc. 1991 Guide for the Selection of Tankers. T.A.C. Inc. 1991.
The Argo Merchant Oil Spill, a Preliminary Scientific Report, NOAA, March 1977
The socioeconomic Impacts of Oil Spills, Final Report, WAPORA, March 1984.
USCG Pollution Incident Case Analysis of the Argo Merchant.
Last Edit: 9/18/92
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