Oil Tanker Spill Statistics 2021

Background

ITOPF maintains a database of oil spills from tank vessels, including combined carriers, FPSOs and barges. This contains information on accidental spillages of persistent and non-persistent hydrocarbon oil since 1970, except those resulting from acts of war. The data held includes the location and cause of the incident, the vessel involved, the type of oil spilt and the spill amount. For historical reasons, spills are generally categorised by size, <7 tonnes, 7-700 tonnes and >700 tonnes (<50 bbls, 50-5,000 bbls, >5,000 bbls), although the actual amount spilt is also recorded. Information is now held on over 10,000 incidents, the vast majority of which fall into the smallest category i.e. <7 tonnes.

Information is gathered from published sources, such as the shipping press and other specialist publications, as well as from vessel owners, their insurers and from ITOPF's own experience at incidents. Historically, information from published sources mostly related to large spills, often resulting from collisions, groundings, structural damage, fires or explosions. In recent decades, however, reporting of smaller spills has improved.

Important Information

It should be noted that the figures for the amount of oil spilt in an incident include all oil lost to the environment, including that which burnt or remained in a sunken vessel. There is considerable annual variation in both the incidence of oil spills and the amounts of oil lost. While we strive to maintain precise records for all spill information, we cannot guarantee that the information taken from the shipping press and other sources is complete or accurate. The number of incidents and volumes of oil spilt are recorded based on the most up to date information. From time to time, data is received after publication and, in which case, adjustment to previous entries may be made. Consequently, the figures in the following tables, and any averages derived from them, should be viewed with a degree of caution.

We regret that it is not possible to provide direct access to our database or to release the names of individual tanker incidents (unless already in the public domain).

Number of oil spills from tankers in 2021

For the year 2021, one large spill (>700 tonnes) and five medium spills (7-700 tonnes) were recorded.

The large spill occurred in Asia and the medium spills occurred in Africa, Asia and North America.

This is a small increase on 2020, when four spills ≥7 tonnes were recorded, but on a par with the annual average for the 2010s.

(This data relates to spills with confirmed volumes.)

Quantity of oil spilt from tanker incidents in 2021

The total volume of oil lost to the environment from tanker spills in 2021 was approximately 10,000 tonnes. This is higher than the previous two years and is largely attributed to the one large incident recorded.

Global oil spill trend

Spill frequency

Over the past half century, statistics for the frequency of spills greater than 7 tonnes from tankers have shown a marked downward trend, as illustrated in Figure 1 below.

The average number of spills per year in the 1970s was approximately 79. This decreased by over 90% to 6 in the 2010s. So far this decade, the annual average is 5.

Figure 1: Number of medium (7-700 tonnes) and large (>700 tonnes) tanker spills, 1970-2021

It is interesting to note the progressive reduction in the number of spills when data is analysed per decade, as demonstrated below (Figure 2).

Figure 2: Number of medium (7-700 tonnes) and large (>7 tonnes) tanker spills by decade, 1970 - 2021. *Only two years of data available for the 2020s

A quarter of all spills over 7 tonnes recorded in the last 52 years have been large (>700 tonnes). More than half (52%) of the large spills occurred in the 1970s (see Figure 3 below).

Figure 3: Medium (7-700 tonnes) and large (>700 tonnes) tanker spills as a percentage of those recorded per decade, 1970 - 2021

Tanker spills vs seaborne oil trade

While increased tanker movements might imply increased risk, it is encouraging to observe that the downward trend in oil spills continues despite an overall increase in oil trading over the period, as illustrated below (Figure 4).

Figure 4: Decline in number of tanker spills vs growth in crude and other tanker trade loaded, 1970-2020 *UNCTADStat information is not yet available for 2021

Spill quantity

Alongside the reduction in spill frequency, there has been a significant decrease in the quantity of oil spilt through the decades. In the 2010s approximately 164,000 tonnes of oil were lost from tanker spills of 7 tonnes and above, a 95% reduction since the 1970s. The figure for the present decade is currently 11,000 tonnes (two years of data).

In terms of the volume of oil spilt, the figures for a particular year may be severely distorted by a single large incident. This is illustrated clearly by incidents such as ATLANTIC EMPRESS (1979), 287,000 tonnes spilt; CASTILLO DE BELLVER (1983), 252,000 tonnes spilt; ABT SUMMER (1991), 260,000 tonnes spilt and SANCHI (2018), 113,000 tonnes spilt (see Figure 5 below),

Figure 5: Quantities of oil spilt 7 tonnes and over (rounded to nearest thousand) from tanker incidents, 1970 to 2021

Frequency & quantity

When the frequency and quantity of oil spilt in recent decades are reviewed together the following can be seen (Figure 6):

In the 1990s there were 358 spills of 7 tonnes and over, resulting in 1,134,000 tonnes of oil lost; 73% of this amount was spilt in just 10 incidents.
In the 2000s there were 181 spills of 7 tonnes and over, resulting in 196,000 tonnes of oil lost; 75% of this amount was spilt in just 10 incidents.
In the 2010s there were 63 spills of 7 tonnes and over, resulting in 164,000 tonnes of oil lost; 91% of this amount was spilt in just 10 incidents. One incident was responsible for about 70% of the quantity of oil spilt.

Figure 6: Tanker spills 7 tonnes and over per decade showing the influence of a relatively small number of comparatively large spills on the overall figure *2020s excluded. Only two years of data

Causes of tanker spills

Most oil spills (>7 tonnes) recorded between 1970 and 2021 were caused by Allisions/Collisions and Groundings (Figure 7).

Major Oil Spills in History

A summary of the 20 largest tanker spills that have occurred since the TORREY CANYON in 1967 is given below. It is of note that 19 of the 20 largest spills recorded occurred before the year 2000. SANCHI, the latest addition to the list, is the only major spill of non-persistent oil featured here and it resulted in significantly lower environmental impacts compared to some crude oil spills listed.

A number of the incidents, despite their large size, necessitated little or no response as the oil was spilt some distance offshore and did not impact coastlines. For this reason some of the names listed may be unfamiliar.

PRESTIGE, EXXON VALDEZ and HEBEI SPIRIT are included for comparison although these incidents are further down the list.

Top 20 Major Spills Table

Position	Shipname	Year	Location	Spill Size (tonnes)
1	ATLANTIC EMPRESS	1979	Off Tobago, West Indies	287,000
2	ABT SUMMER	1991	700 nautical miles off Angola	260,000
3	CASTILLO DE BELLVER	1983	Off Saldanha Bay, South Africa	252,000
4	AMOCO CADIZ	1978	Off Brittany, France	223,000
5	HAVEN	1991	Genoa, Italy	144,000
6	ODYSSEY	1988	700 nautical miles off Nova Scotia, Canada	132,000
7	TORREY CANYON	1967	Scilly Isles, UK	119,000
8	SEA STAR	1972	Gulf of Oman	115,000
9	SANCHI	2018	Off Shanghai, China	113,000
10	IRENES SERENADE	1980	Navarino Bay, Greece	100,000
11	URQUIOLA	1976	La Coruna, Spain	100,000
12	HAWAIIAN PATRIOT	1977	300 nautical miles off Honolulu	95,000
13	INDEPENDENTA	1979	Bosphorus, Turkey	94,000
14	JAKOB MAERSK	1975	Oporto, Portugal	88,000
15	BRAER	1993	Shetland Islands, UK	85,000
16	AEGEAN SEA	1992	La Coruna, Spain	74,000
17	SEA EMPRESS	1996	Milford Haven, UK	72000
18	KHARK 5	1989	120 nautical miles off Atlantic coast of Morocco	70,000
19	NOVA	1985	Off Kharg Island, Gulf of Iran	70,000
20	KATINA P	1992	Off Maputo, Mozambique	67,000
21	PRESTIGE	2002	Off Galicia, Spain	63,000
36	EXXON VALDEZ	1989	Prince William Sound, Alaska, USA	37,000
132	HEBEI SPIRIT	2007	South Korea	11,000

Figure 8: Location of top 20 major spills (All rights reserved © ITOPF)

2021 Oil Tanker Spill Statistics full report

For further information, please contact Naa Sackeyfio, Information Data Analyst