It is wrong to assume that the oil spill was entirely cleaned up by the end of 1970. The task force quickly realized that all they could do was remove the pollutant that was recoverable or roughly 15% (190 miles) of the coastline. As a result, only the beaches could be cleaned without dispersants and much of the rocky coast remained as black as the day it landed ashore.

The 2.5 million gallons of Bunker ' C ' spilled from the "Arrow" formed a very stable emulsion containing between 33-35% water. This type of mixture made burning very difficult, made the use of dispersants less effective and hindered absorption agents such as peat moss, eelgrass, and straw. The stiffness of the emulsion did assist in the mechanical removal of the contamination and it probably prevented contamination of sandy beaches because it inhibited the tendency of the oil to flow through sand.

Biodegradation was the main hope for destroying oil pollution along the shores of Chedabucto Bay. Bacteria attacked the lighter fractions of oil eagerly but those taking on the complicated molecules were very slow in acting. Some oil disappeared by being buried in the sediments on the bottom. Other oil disappeared into the bodies of plants and animals.

The heaviest oiling was observed in the western Isle Madame, Lennox Passage, and Inhabitants Bay areas, where some sections were re-oiled on several occasions. In this part of Chedabucto Bay, the oil bands were thick, continuous and in the area of 6-10 miles wide. Away from the area adjacent to the spill site, oil was stranded as late as mid- April 1970 on previously unoiled shorelines. The oil was washed ashore to varying degrees over an estimated 305 km (196 miles) of the 604 km (377 miles) of shoreline, of which only 48 km (30 miles) were cleaned during "Operation Oil."

From March to May 1970 about one-third of the oiled shoreline was cleaned, partly due to the clean up efforts of the task force and partly due to natural cleaning by wave action. By June, much of the exposed rock, high wave energy shoreline of the south coast, and the northeast corner of the bay, around Point Michaud, were clear of oil. The general impression is that most of the stranded oil disappeared. Self-cleaning occurred remarkably quickly during the first two years after the spill with 75% of the heavily oiled shoreline cleansed by 1973. (Vandermeulen, 1970).

Beaches were the most heavily cleaned segments of the shoreline because of the ecological ramifications as well as their recreational appeal for locals and tourists. However, secluded coves like Black Duck Cove near Canso received so much oil that it became completely paralyzed. This is because of the geographic location where these beaches are not exposed to strong surf action that could help carry some of the oil away. In most cases, as soon as oil touched the seashore, it no longer behaved as a liquid and could not be pushed back to sea by the wind, but in exposed seashores, oil covered sediments were eroded. However, this was not the case for a protected location like Black Duck Cove.

By 1973, oil cover was reduced to a patchy distribution in the low-energy lagoons and estuaries on the north shore of the Bay. By 1976, a survey found only traces of oil. The high-energy rocky shorelines were clean, with traces in low energy spots. The exception was Black Duck Cove that remained heavily oiled.

In 1975, a preliminary inspection of twelve sites along the southern coastline of Isle Madame and Janvrin's Island revealed visual evidence of oil in eleven of twelve beaches. The degree of contamination ranged from the appearance of an iridescent oil sheen on water in Arichat Harbor to crusts of tar 2-3 cm thick covering both rocky high-energy beaches like Crichton Island and sheltered low-energy beaches like Moussiliers Passage. Tar deposits were found generally at the upper high tide mark.

On rocky, exposed high-energy beaches, the tar was found under boulders and in the lee of rocky outcroppings in the upperspray zone. On more gently sloping low-energy beaches, the tar layer consisted of a compacted mass of tar, beach gravel and stranded kelp. In some places, this layer formed a thick pavement 2-3 cm thick with the consistency of firm "asphalt". Whereas the upper or exposed surface of stranded tar was covered by a rind of dull gray appearance, the tar in the protected surface retained the glossy, sticky texture of freshly spilled oil.

The situation was farther compounded by the continued input of freshly leached oil by daily inflow from the high tide mark. This large amount of stranded tar continuously replenished sediment-bound tar. This demonstrated that the leaching of oil from sediments by water flow alone occurs very slowly and emphasized the extreme longevity of sediment bound tar.

By 1978, of the southern and western shores of the Bay, only the area around Durelle Island remained heavily oiled. Oil mixed with sand, gravel, and rocks in a "pavement-like" consistency covered the upper half of the intertidal zone in most of the sheltered locations in the area.

The northern shore was the most heavily oiled. By this time only an occasional patch of oil remained on the exposed northern coast with exceptions of Crichton Island, Janvrin's Island, and Inhabitants Bay. In sheltered area like Haddock and Port Royal harbours, oil mixed with coarse sand and gravel, was found in layers several centimeters thick, 5-10 cm below the surface. This oiled layer often extended from high to low tide but tended to be very patchy.

The shores of Rabbit Island and shores in Guysborough are visibly the most heavily oiled areas remaining in Chedabucto Bay. "Pavement" up to 15 cm thick covers much of the upper half of the intertidal zone and on hot days, oily films spread out among the rocks into the waters of the Bay. Oiling on the remaining shoreline and the other islands of Inhabitants Bay and Haddock harbour has diminished since October 1973. Only the eastern and western ends of Evan's Island remain heavily oiled while only scattered patches of "pavement" remain on the rest of the shoreline. Occasionally, deposits of a subsurface oil and sand mixture were uncovered in this area, but as in the Haddock harbour and Port Royal areas, the distribution was patchy.

In 1993, the observed changes from the previous site visit were significant. In 1989 the residual surface oil was concentrated in continuous narrow bands at the high water level. By August, 1993, the residual surface oil was no longer distributed in patterns that could be defined or mapped easily, demonstrating the further reduction of the amount of oil in the surface sediments.

As of 1994, oil was present on 13.3 km (16 miles) of shoreline in Chedabucto Bay. Heavy oiling is restricted to a mere 1.3 km (1.56 miles), concentrated primarily in the Black Duck Cove and Lennox Passage areas. Some of this residual oil has been identified as coming from the "Arrow" based on circumstantial evidence; however, chemical analysis identifies one sample from Black Duck Cove as probably being "Arrow" oil.

Natural weathering accounts for the majority of oil clean-up, since only 50 of 300 km that were oiled, were treated. Where oil remains, it occurs as a thin stain on bedrock or coarse sediments or it occurs as a resistant oil-sediment, asphalt-like mixture.

Areas in low wave-energy environments such as Haddock Harbour and Inhabitants Bay, heavily oiled and uncleaned in 1970, are now virtually free of oil. These areas have a plentiful supply of fine-grained sediments that may have contributed to weathering. The most heavily oiled area is Black Duck Lagoon where asphalt "pavement" and pooled interstitial oil remain in three distinct areas of predominantly coarse sediments. Resistant asphalt balls still remain on the beaches of Arichat Harbour where sediments were reworked by the action of a bulldozer.

Where oil remains after 22 years in exposed areas, residues are restricted to small amounts of thin, scattered oil on the higher parts of the beach on bedrock outcrops, above the limit of most wave activity. The majority of the segments with documented oil residues are in low wave-energy environments and the few sites with heavy oiling conditions probably account for over 90% of the remaining oil by volume. A key finding is that many of the originally heavily oiled shorelines with low energy levels are now free of oil. It is significant that, near the spill location, oil was found in only 78 of the 111 segments, primarily in the sheltered Inhabitants Bay and Haddock Harbour areas.

Apart from the pollution of the picturesque coastline, it should be noted that those living around the Bay suffered the full inconvenience and aesthetic disturbance generated by the spill. They are the ones who had to put up with the period of uncertainty as to the oil's effects on their lives. Wives had to do extra cleaning when their children and their pets brought the oil indoors. Sources of water used for generations had to be abandoned and new supplies found. Beaches could not be enjoyed without the threat of contamination, and the waters where children used to swim, had ever-present films of oil, which took the real enjoyment out of this amenity. Most of the shoreline was black, and entry to the water over the oil-polluted shore was a constant reminder of the damage. Understandably, Chedabucto Bay residents wanted answers, and more importantly compensation for this accident, which forever tarnished their pristine environment.