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Atlantic ocean pollution and biota observed by the ‘Ra’ expeditions
Atlantic Ocean Pollution and Biota Observed by the 'Ra' Expeditions THOR HEYERDAHL,Ph.D. (Oslo) Kon-Tiki Museum, Oslo, Norway; Colla Micheri, Laigueglia, Italy
ABSTRACT On two voyages virtually across the Atlantic Ocean in papyrus raft-ships in 1969 and 1970, surface pollution was observed from very close quarters. Visible pollution was recorded during six days o f the eight weeks' sailing in 1969 and on forty o f the first forty-three days o f sailing in 1970, although the remainder o f that voyage was in relatively clean water. The pollution was mainly in the form o f floating asphalt-like material, mostly in tiny lumps but sometimes up to fist size, though other forms were also observed. The older lumps were often beset with living barnacles and Algae, while quantities o f dead coelenterates were in some places observed floating among them. Continued indiscriminate use o f the worM's oceans as a dumping-ground for durable human waste seems likely to have very serious and perhaps irreversible effects on their productivity.
experiment with Ra I, created such wide interest that a more systematic survey with daily records and a wider range of samples were planned for the second crossing, on board Ra H. As the water in the latitudes of our observations is not stagnant but is constantly on the move from east to west at an average speed of 0-5 knots, it is of some importance to repeat even the sparse observations recorded from Ra L For the bulk of the surface water encountered on its move westwards in 1969 had already joined the Gulf Stream and was thus on its way back to northern Europe by the time we made our new observations in 1970.
OBSERVATIONSFROM R a I IN 1969 The North Atlantic surface current which flows constantly from north-west Africa to tropical America The seven men on board Ra I became aware of is polluted by a continuity of drifting oil-clots. This is travelling in polluted water for the first time on 6 June the essence of close-range observations made at sea- 1969 at 24038 ' N and 17°06 ' W, about a hundred miles level aboard the papyrus vessels Ra I and Ra H during (160km) off the coast of Mauritania, north-west two consecutive voyages in 1969 and 1970. Africa (Fig. 1). The surface was 'filled' with brownish In organizing our marine experiment with the first to pitch-black lumps of asphalt-like material as big papyrus boat to be tested at sea in modern times, our as large particles of gravel and floating at close interexpedition group was initially unprepared for pollution vals on and just below the surface. Knowing that we studies. The objectives of the enterprize were to were near the circum-African shipping-lane, we began investigate the sea-going qualities and possible range to scout for ships, being convinced that we had of a papyrus raft-ship and to test multi-national entered the wake of a near-by oil tanker that had just cooperation under stress. However, early in the voyage cleaned its tanks. On 8 June, having advanced about of Ra I, pollution observations were forced upon all a hundred miles farther to the south-west, we found expedition members by its grave nature and because ourselves again sailing though similarly polluted of our own proximity to the ocean surface coupled water, still with no ships in sight. On 9 June, reaching with our slow progress through the water (Heyerdahl, a position of 22043 ' N and 17059 ' W, we sailed into an 1970, 1971). At an average speed of respectively 2 area where the same flotsam included pieces of larger and 2.5 knots, and rarely exceeding 3 knots, we size, some of them appearing as thick, black flakes of covered with Ra 1 2,700 nautical miles (ca 5,000 km) irregular shape up to 10-15 cm in diameter. The local from 25 May to 18 July 1969, and with R a H 3,270 ocean water itself gradually assumed an opaque, nautical miles (ca 6,100 km) from 17 May to 12 July greyish-green colour instead of being transparent and 1970. clear blue; it thus resembled harbour water at the outThe brief report accompanied by a pollution let of city sewers. sample delivered to the Permanent Norwegian DelegaAlthough sporadic lumps were noted, no subsequent tion at the United Nations upon termination of the entry was made in the expedition log until 30 June, 164 Biological Conservation, Vol. 3, No. 3, April 1971--O Elsevier Publishing Company Ltd, England--Printed in Great Britain
165
Heyerdahl : Atlantic Ocean Pollution Observed by the ' Ra' Expeditions
EUROPE
NORTHAMERICA Ra11"observed
Fromhere
oil-clots Islands
,,'*"
' Mauritania AFRICA
Barbados ~
-
"~'-' . . . . . . .
SOUTH AMERICA
S
Cape Verde Islands
Area of extreme pollution
'~
"1
Ra1" Ra"IT
Fig. 1.
Sketch-map indicating trans-Atlantic voyages o f Ra I in 1969 and o f Ra H in 1970. The arrows indicate areas o f extreme pollution.
when we were at 15045' N and 35008 , W--virtually in mid-Atlantic. Thus the coasts of Africa and America were almost equally distant when we suddenly entered another area which was so polluted that we had to be attentive in washing ourselves, to avoid seemingly endless quantities of oil-clots of sizes ranging from that of a wheat-grain or pea to that of a sandwich. On 15 and 16 July, shortly before Ra I was abandoned, we found ourselves in the same general type of polluted water once again. Our position on 15 July was 13°32'N and 47020 ' W, or some six hundred miles (960 km) east of Barbados, and slightly nearer to the coast of Guiana. Some of the samples which we collected and preserved had an eroded or pitted surface, and small barnacles as well as Algae were occasionally seen growing on the drifting lumps. Although no intentional or preconceived observations were made, the voyage with Ra I resulted in the involuntary recording of six days' travelling through visibly strongly-polluted water in the course of eight weeks of trans-Atlantic sailing. Thus, more than 10 per cent of the surface water traversed by R a I
carried a rich flotsam of non-organic material of rather homogeneous appearance and undoubtedly resulting from modern commercial activity.
SUBSEQUENT
CONSIDERATIONS
Prepared for what we might encounter a second time, and encouraged by the interest at the United Nations as well as among scientists and shipping authorities, we decided to keep a systematic record of our daily observations during the subsequent voyage of Ra H into the same general ocean area. Apart from regular expedition log entries, a special pollution record was kept by Madani Ait Ouhanni, who also collected the samples that were handed to the United Nations' research vessel Calamar, for subsequent transfer to the Norwegian U N Delegation. The samples were taken by means of a fine-meshed dip-net. Oil-clots were difficult to detect in rippled seas and unless they were drifting past very close to our papyrus deck. Only when the wave surface was smooth, or the floating objects were of conspicuous
166
Biological Conservation
size, could we record pollution much beyond a fathom's (1.8 m) distance from Ra. Thus, the considerable quantities of oil-clots and other floating refuse which were found to pass close alongside our papyrus bundles reflect the gravity of the pollution if estimated in a wider geographical scope. It should also be noted that the route followed by Ra H was somewhat more northerly than that of Ra L which was forced on a drift voyage down beyond Cape Verde Islands (Fig. 1). Bearing finally in mind the 0.5 knots drift of the current, the surface water observed by us from Ra I had been displaced more than four thousand nautical miles (ca 7,412 km) during the year that had passed between the departures of the two consecutive raft expeditions. In other words, the water which we saw along the African coast in May 1969, had long since deposited its flotsam along the Caribbean shores or else carried it into the initial part of the Gulf Stream, by the time we embarked on Ra H in May 1970. Correspondingly, the water seen by us as we abandoned Ra I short of Barbados in July 1969, would probably be approaching Europe early in the subsequent year, on its return flow across the North Atlantic. At any rate, the surface waters traversed by Ra H represented a fresh supply from the southward turn of the North Equatorial Current north-east of the Canary Islands.
OBSERVATIONSFROM Ra H IN 1970 It is disheartening to report that, in the period from May 17 when we left the Moroccan port of Sail (at 32°20'N and 9o20 ' W) until and including June 28 when we had reached 15°54'N and 45°56 ' W, we recorded oil pollution on forty days out of fortythree (of. Fig. 1). On the three days when pelagic oil lumps were not seen, Ouhanni's entries in the pollution record state that the sea was too rough for proper observation. It may thus safely be assumed that the 2,407 nautical miles (4,350 km) covered by Ra H during the initial 43 days of this voyage represented a continuous stretch of polluted surface water, the degree of pollution varying from slight to very grave. It is encouraging to note, however, that with the exception of some sporadic lumps observed on July 30, no record of such particles was made during the remaining 700 nautical miles (1,297 km) to Barbados. This curious fact is somewhat less comforting when we recall that the same geographical area was found to be strongly polluted the previous year. Furthermore, on our arrival at Barbados, the owner of our east-coast hotel informed us that oil-clots were sometimes so common on his beach that it was a
problem to keep carpets clean from lumps that had stuck to the feet of his clients. Although plastic containers and other imperishable refuse were observed sporadically until the last day of our crossing, the apparent absence, or at least sudden scarcity, of drifting oil-clots might perhaps have been due to temporal irregularities in the strength of the southern feeders, which enter as new components into the North Atlantic current east of the West Indies. The presence of these feeders from the South Equatorial Current was noticed both in our own drift and as indicated by sudden changes in water temperature. The average extent of oil pollution recorded during the voyage of Ra H amounted to lumps of asphaltlike material of the size of finger-tips or smaller, scattered far apart in otherwise clear water. There would be days, however, when only a very few such lumps could be seen from sunrise to sunset, whereas in exceptional cases the water was so polluted that a bucket could not be filled with water without some floating lumps being caught at the same time. The first very seriously polluted water was entered by Ra H on 21 May, at 29°26 ' N and 11°40 ' W, about 100 nautical miles (ca 180 kin) off the African coast before we entered the passage between the Canary Islands and Morocco. From early that morning until the evening of the following day, Ra H was drifting very slowly through calm water that was thickly polluted by clusters of solidified oil lumps which were commonly of the size of prunes or even potatoes. Many of these lumps were dark-brown and pitted, more or less densely overgrown by barnacles, whereas others were smooth and black, with the appearance of being quite fresh. Multiped crustaceans were repeatedly seen riding on such lumps, as were sometimes also pelagic crabs and marine worms. For a duration of two days, the surface water, containing large quantities of these lumps, was also covered intermittently by a shallow white foam such as develops from soap or synthetic washing-powder, while occasionally the ocean's surface was even shining in all manner of colours as from gasolene. A vast quantity of dead coelenterates were floating among these oil lumps. Thanks to the remarkably calm surface, the polluted water with the oil lumps and dead coelenterates could be seen for great distances on both sides of our track, and the expedition log recorded that 'the degree of pollution is shocking'. A week then passed and our position was 25°43 ' N and 16°23'W when on 29 May our log once more recorded that 'the pollution is terrible'. During the previous night oil lumps, of which the biggest were the size of a large fist, had been washed on board, to remain as the water filtered through the papyrus
Heyerdahl: Atlantic Ocean Pollution Observed by the "Ra' Expeditions
167
reeds and disappeared. Barnacles, crustaceans, and ocean pollution is a mere offence to human aesthetics; bird feathers, were found attached to the oil lumps. if left unchecked it can scarcely avoid affecting future The high degree of pollution was this time witnessed world economy. for three consecutive days, when swimming inevitably Without entering into speculations as to the effect meant collision with oil-clots. Next, on 31 May, at of pelagic pollution upon the chemical and biological 25o00 ' N and 17°07 ' W, the log reads: 'An incredible factors guiding the life functions of plankton and other quantity of shell-covered asphalt lumps today, big as microorganisms, it suffices here to stress its evident horse-droppings and in clusters everywhere. One effect upon tens of thousands of invertebrates which plastic bottle and one metal oil-can also observed, were unable to survive in water with a strong degree plus a large cluster of greenish rope, and nylon-like of pollution. Nor shall we discuss the consequences material besides a wooden box and a carton. It is of the constant flow of oil-clots upon biota that are shocking to see how the Atlantic is getting polluted carried along in the drift, or upon the metabolism of by Man.' No ships were sighted in the vicinity. the filter-feeding species among whales and fishes, The next entry into seriously polluted waters was though the pollution observed must inevitably reduce on 16 June, at 18026 ' N and 34°28 ' W, virtually in the light-penetration and hence photosynthesis by phytomid-Atlantic, when the water on (and as far as we plankton on which virtually all other life in the oceans could see also below) the surface contained endless depends. quantities of large and small oil lumps. Although Ra H The present report has no other object than to seemed to sail out of the main drift of oil pollution call attention to the alarming fact that the Atlantic westwards of 15039' N and 47029 ' W, pollution in the Ocean is becoming seriously polluted, and that a form of plastic containers, metal cans, glass bottles, continued indiscriminate use of the world's oceans as and other perishable and non-perishable refuse from an international dumping-ground for imperishable ships or shores, kept on appearing at the side of our human refuse may have irreparable effects on the raft-ship at intervals from the day of departure to the productivity and very survival of plant and animal day of landing. species.
ALARMING PROSPECTS
It was not the objective of the Ra expedition to draw biological or ecological conclusions from our observations. Our intention is merely to call attention to observations that were virtually forced upon us. Yet, there is no doubt that the time has passed when
Health Rules for Monkeys and Apes More than 200,000 monkeys and apes move every year in international commerce, many of them to be used in medical research or for the manufacture of vaccines--especially polio vaccine. Until recently, neither veterinary nor medical authorities were much concerned with the international trade in these animals. But the greatly increased use of monkeys resulting from the development of polio vaccines in the late 1950s gave rise to a number of public health problems emphasizing the need for control over the trade and use of these animals. Another reason for concern is that most monkeys and apes reaching laboratories fall short of the standards of health expected of animals used for producing and testing vaccines, and for the many other experimental purposes for which non-human
References HEYERDAHL, Thor (1970). Atlantic Ocean pollution observed by Expedition Ra. Biol. Conserv., 2(3), pp. 2212, illustr. HEYERDAHL, Thor (1971). The Ra Expeditions. Allen & Unwin, London, and Doubleday, New York: Chapters 8-11, illustr.
primates have proved so valuable. A third problem raised by the greatly increased use of these animals is the depletion of wild stocks and the consequent likely shortage of the future supplies for medical purposes. The World Health Organization, because of its concern with these problems, has recently convened a group of scientists to survey the health hazards connected with the supply and use of non-human primates for biomedical purposes. Three main aspects were reviewed: (1) The hazards to human health arising from nonhuman primates, (2) The need to improve the health status of these laboratory animals, and (3) How best to ensure their continued supply.
ABSTRACT On two voyages virtually across the Atlantic Ocean in papyrus raft-ships in 1969 and 1970, surface pollution was observed from very close quarters. Visible pollution was recorded during six days o f the eight weeks' sailing in 1969 and on forty o f the first forty-three days o f sailing in 1970, although the remainder o f that voyage was in relatively clean water. The pollution was mainly in the form o f floating asphalt-like material, mostly in tiny lumps but sometimes up to fist size, though other forms were also observed. The older lumps were often beset with living barnacles and Algae, while quantities o f dead coelenterates were in some places observed floating among them. Continued indiscriminate use o f the worM's oceans as a dumping-ground for durable human waste seems likely to have very serious and perhaps irreversible effects on their productivity.
experiment with Ra I, created such wide interest that a more systematic survey with daily records and a wider range of samples were planned for the second crossing, on board Ra H. As the water in the latitudes of our observations is not stagnant but is constantly on the move from east to west at an average speed of 0-5 knots, it is of some importance to repeat even the sparse observations recorded from Ra L For the bulk of the surface water encountered on its move westwards in 1969 had already joined the Gulf Stream and was thus on its way back to northern Europe by the time we made our new observations in 1970.
OBSERVATIONSFROM R a I IN 1969 The North Atlantic surface current which flows constantly from north-west Africa to tropical America The seven men on board Ra I became aware of is polluted by a continuity of drifting oil-clots. This is travelling in polluted water for the first time on 6 June the essence of close-range observations made at sea- 1969 at 24038 ' N and 17°06 ' W, about a hundred miles level aboard the papyrus vessels Ra I and Ra H during (160km) off the coast of Mauritania, north-west two consecutive voyages in 1969 and 1970. Africa (Fig. 1). The surface was 'filled' with brownish In organizing our marine experiment with the first to pitch-black lumps of asphalt-like material as big papyrus boat to be tested at sea in modern times, our as large particles of gravel and floating at close interexpedition group was initially unprepared for pollution vals on and just below the surface. Knowing that we studies. The objectives of the enterprize were to were near the circum-African shipping-lane, we began investigate the sea-going qualities and possible range to scout for ships, being convinced that we had of a papyrus raft-ship and to test multi-national entered the wake of a near-by oil tanker that had just cooperation under stress. However, early in the voyage cleaned its tanks. On 8 June, having advanced about of Ra I, pollution observations were forced upon all a hundred miles farther to the south-west, we found expedition members by its grave nature and because ourselves again sailing though similarly polluted of our own proximity to the ocean surface coupled water, still with no ships in sight. On 9 June, reaching with our slow progress through the water (Heyerdahl, a position of 22043 ' N and 17059 ' W, we sailed into an 1970, 1971). At an average speed of respectively 2 area where the same flotsam included pieces of larger and 2.5 knots, and rarely exceeding 3 knots, we size, some of them appearing as thick, black flakes of covered with Ra 1 2,700 nautical miles (ca 5,000 km) irregular shape up to 10-15 cm in diameter. The local from 25 May to 18 July 1969, and with R a H 3,270 ocean water itself gradually assumed an opaque, nautical miles (ca 6,100 km) from 17 May to 12 July greyish-green colour instead of being transparent and 1970. clear blue; it thus resembled harbour water at the outThe brief report accompanied by a pollution let of city sewers. sample delivered to the Permanent Norwegian DelegaAlthough sporadic lumps were noted, no subsequent tion at the United Nations upon termination of the entry was made in the expedition log until 30 June, 164 Biological Conservation, Vol. 3, No. 3, April 1971--O Elsevier Publishing Company Ltd, England--Printed in Great Britain
165
Heyerdahl : Atlantic Ocean Pollution Observed by the ' Ra' Expeditions
EUROPE
NORTHAMERICA Ra11"observed
Fromhere
oil-clots Islands
,,'*"
' Mauritania AFRICA
Barbados ~
-
"~'-' . . . . . . .
SOUTH AMERICA
S
Cape Verde Islands
Area of extreme pollution
'~
"1
Ra1" Ra"IT
Fig. 1.
Sketch-map indicating trans-Atlantic voyages o f Ra I in 1969 and o f Ra H in 1970. The arrows indicate areas o f extreme pollution.
when we were at 15045' N and 35008 , W--virtually in mid-Atlantic. Thus the coasts of Africa and America were almost equally distant when we suddenly entered another area which was so polluted that we had to be attentive in washing ourselves, to avoid seemingly endless quantities of oil-clots of sizes ranging from that of a wheat-grain or pea to that of a sandwich. On 15 and 16 July, shortly before Ra I was abandoned, we found ourselves in the same general type of polluted water once again. Our position on 15 July was 13°32'N and 47020 ' W, or some six hundred miles (960 km) east of Barbados, and slightly nearer to the coast of Guiana. Some of the samples which we collected and preserved had an eroded or pitted surface, and small barnacles as well as Algae were occasionally seen growing on the drifting lumps. Although no intentional or preconceived observations were made, the voyage with Ra I resulted in the involuntary recording of six days' travelling through visibly strongly-polluted water in the course of eight weeks of trans-Atlantic sailing. Thus, more than 10 per cent of the surface water traversed by R a I
carried a rich flotsam of non-organic material of rather homogeneous appearance and undoubtedly resulting from modern commercial activity.
SUBSEQUENT
CONSIDERATIONS
Prepared for what we might encounter a second time, and encouraged by the interest at the United Nations as well as among scientists and shipping authorities, we decided to keep a systematic record of our daily observations during the subsequent voyage of Ra H into the same general ocean area. Apart from regular expedition log entries, a special pollution record was kept by Madani Ait Ouhanni, who also collected the samples that were handed to the United Nations' research vessel Calamar, for subsequent transfer to the Norwegian U N Delegation. The samples were taken by means of a fine-meshed dip-net. Oil-clots were difficult to detect in rippled seas and unless they were drifting past very close to our papyrus deck. Only when the wave surface was smooth, or the floating objects were of conspicuous
166
Biological Conservation
size, could we record pollution much beyond a fathom's (1.8 m) distance from Ra. Thus, the considerable quantities of oil-clots and other floating refuse which were found to pass close alongside our papyrus bundles reflect the gravity of the pollution if estimated in a wider geographical scope. It should also be noted that the route followed by Ra H was somewhat more northerly than that of Ra L which was forced on a drift voyage down beyond Cape Verde Islands (Fig. 1). Bearing finally in mind the 0.5 knots drift of the current, the surface water observed by us from Ra I had been displaced more than four thousand nautical miles (ca 7,412 km) during the year that had passed between the departures of the two consecutive raft expeditions. In other words, the water which we saw along the African coast in May 1969, had long since deposited its flotsam along the Caribbean shores or else carried it into the initial part of the Gulf Stream, by the time we embarked on Ra H in May 1970. Correspondingly, the water seen by us as we abandoned Ra I short of Barbados in July 1969, would probably be approaching Europe early in the subsequent year, on its return flow across the North Atlantic. At any rate, the surface waters traversed by Ra H represented a fresh supply from the southward turn of the North Equatorial Current north-east of the Canary Islands.
OBSERVATIONSFROM Ra H IN 1970 It is disheartening to report that, in the period from May 17 when we left the Moroccan port of Sail (at 32°20'N and 9o20 ' W) until and including June 28 when we had reached 15°54'N and 45°56 ' W, we recorded oil pollution on forty days out of fortythree (of. Fig. 1). On the three days when pelagic oil lumps were not seen, Ouhanni's entries in the pollution record state that the sea was too rough for proper observation. It may thus safely be assumed that the 2,407 nautical miles (4,350 km) covered by Ra H during the initial 43 days of this voyage represented a continuous stretch of polluted surface water, the degree of pollution varying from slight to very grave. It is encouraging to note, however, that with the exception of some sporadic lumps observed on July 30, no record of such particles was made during the remaining 700 nautical miles (1,297 km) to Barbados. This curious fact is somewhat less comforting when we recall that the same geographical area was found to be strongly polluted the previous year. Furthermore, on our arrival at Barbados, the owner of our east-coast hotel informed us that oil-clots were sometimes so common on his beach that it was a
problem to keep carpets clean from lumps that had stuck to the feet of his clients. Although plastic containers and other imperishable refuse were observed sporadically until the last day of our crossing, the apparent absence, or at least sudden scarcity, of drifting oil-clots might perhaps have been due to temporal irregularities in the strength of the southern feeders, which enter as new components into the North Atlantic current east of the West Indies. The presence of these feeders from the South Equatorial Current was noticed both in our own drift and as indicated by sudden changes in water temperature. The average extent of oil pollution recorded during the voyage of Ra H amounted to lumps of asphaltlike material of the size of finger-tips or smaller, scattered far apart in otherwise clear water. There would be days, however, when only a very few such lumps could be seen from sunrise to sunset, whereas in exceptional cases the water was so polluted that a bucket could not be filled with water without some floating lumps being caught at the same time. The first very seriously polluted water was entered by Ra H on 21 May, at 29°26 ' N and 11°40 ' W, about 100 nautical miles (ca 180 kin) off the African coast before we entered the passage between the Canary Islands and Morocco. From early that morning until the evening of the following day, Ra H was drifting very slowly through calm water that was thickly polluted by clusters of solidified oil lumps which were commonly of the size of prunes or even potatoes. Many of these lumps were dark-brown and pitted, more or less densely overgrown by barnacles, whereas others were smooth and black, with the appearance of being quite fresh. Multiped crustaceans were repeatedly seen riding on such lumps, as were sometimes also pelagic crabs and marine worms. For a duration of two days, the surface water, containing large quantities of these lumps, was also covered intermittently by a shallow white foam such as develops from soap or synthetic washing-powder, while occasionally the ocean's surface was even shining in all manner of colours as from gasolene. A vast quantity of dead coelenterates were floating among these oil lumps. Thanks to the remarkably calm surface, the polluted water with the oil lumps and dead coelenterates could be seen for great distances on both sides of our track, and the expedition log recorded that 'the degree of pollution is shocking'. A week then passed and our position was 25°43 ' N and 16°23'W when on 29 May our log once more recorded that 'the pollution is terrible'. During the previous night oil lumps, of which the biggest were the size of a large fist, had been washed on board, to remain as the water filtered through the papyrus
Heyerdahl: Atlantic Ocean Pollution Observed by the "Ra' Expeditions
167
reeds and disappeared. Barnacles, crustaceans, and ocean pollution is a mere offence to human aesthetics; bird feathers, were found attached to the oil lumps. if left unchecked it can scarcely avoid affecting future The high degree of pollution was this time witnessed world economy. for three consecutive days, when swimming inevitably Without entering into speculations as to the effect meant collision with oil-clots. Next, on 31 May, at of pelagic pollution upon the chemical and biological 25o00 ' N and 17°07 ' W, the log reads: 'An incredible factors guiding the life functions of plankton and other quantity of shell-covered asphalt lumps today, big as microorganisms, it suffices here to stress its evident horse-droppings and in clusters everywhere. One effect upon tens of thousands of invertebrates which plastic bottle and one metal oil-can also observed, were unable to survive in water with a strong degree plus a large cluster of greenish rope, and nylon-like of pollution. Nor shall we discuss the consequences material besides a wooden box and a carton. It is of the constant flow of oil-clots upon biota that are shocking to see how the Atlantic is getting polluted carried along in the drift, or upon the metabolism of by Man.' No ships were sighted in the vicinity. the filter-feeding species among whales and fishes, The next entry into seriously polluted waters was though the pollution observed must inevitably reduce on 16 June, at 18026 ' N and 34°28 ' W, virtually in the light-penetration and hence photosynthesis by phytomid-Atlantic, when the water on (and as far as we plankton on which virtually all other life in the oceans could see also below) the surface contained endless depends. quantities of large and small oil lumps. Although Ra H The present report has no other object than to seemed to sail out of the main drift of oil pollution call attention to the alarming fact that the Atlantic westwards of 15039' N and 47029 ' W, pollution in the Ocean is becoming seriously polluted, and that a form of plastic containers, metal cans, glass bottles, continued indiscriminate use of the world's oceans as and other perishable and non-perishable refuse from an international dumping-ground for imperishable ships or shores, kept on appearing at the side of our human refuse may have irreparable effects on the raft-ship at intervals from the day of departure to the productivity and very survival of plant and animal day of landing. species.
ALARMING PROSPECTS
It was not the objective of the Ra expedition to draw biological or ecological conclusions from our observations. Our intention is merely to call attention to observations that were virtually forced upon us. Yet, there is no doubt that the time has passed when
Health Rules for Monkeys and Apes More than 200,000 monkeys and apes move every year in international commerce, many of them to be used in medical research or for the manufacture of vaccines--especially polio vaccine. Until recently, neither veterinary nor medical authorities were much concerned with the international trade in these animals. But the greatly increased use of monkeys resulting from the development of polio vaccines in the late 1950s gave rise to a number of public health problems emphasizing the need for control over the trade and use of these animals. Another reason for concern is that most monkeys and apes reaching laboratories fall short of the standards of health expected of animals used for producing and testing vaccines, and for the many other experimental purposes for which non-human
References HEYERDAHL, Thor (1970). Atlantic Ocean pollution observed by Expedition Ra. Biol. Conserv., 2(3), pp. 2212, illustr. HEYERDAHL, Thor (1971). The Ra Expeditions. Allen & Unwin, London, and Doubleday, New York: Chapters 8-11, illustr.
primates have proved so valuable. A third problem raised by the greatly increased use of these animals is the depletion of wild stocks and the consequent likely shortage of the future supplies for medical purposes. The World Health Organization, because of its concern with these problems, has recently convened a group of scientists to survey the health hazards connected with the supply and use of non-human primates for biomedical purposes. Three main aspects were reviewed: (1) The hazards to human health arising from nonhuman primates, (2) The need to improve the health status of these laboratory animals, and (3) How best to ensure their continued supply.