Feb. 4. 1886] 



NA TURE 



Perhaps the constant-controversy is not quite so 

 obviously settled as some English physicists seem to 

 think. But, however the future may regard it, history will 

 record that on January 6 of this year died one of the 

 greatest mathematical physicists and undoubtedly the 

 greatest elastician that Europe has seen since the age of 

 Poisson and Cauchy. Karl Pearson 



ON SOME INTERESTING CASES OF MIGRA- 

 TIONS OF MARINE FISHES, ON THE COAST 

 OF VENEZUELA AT CARUPANO 



CARUPANO is a thriving seaport on the northern 

 coast of Venezuela, midway between the peninsulas 

 of Araya and Paria, in lat. 10° 14' 15" N., and long. 

 63" 18' W. from Greenwich, and therefore inclose vicinity 

 to the channel which leads from the Atlantic into the 

 Caribbean Sea between Tobago and Grenada on the one 

 side, and Trinidad and the South American mainland on 

 the other side. Through this channel enters the great 

 western current of the Caribbean Sea, running at the 

 rate of about one mile and a half an hour, though not 

 with much regularity. The coast-line forms the western 

 prolongation of the northern shore of Trinidad, trending 

 almost due west. The water is rather shallow to a con- 

 siderable distance from the land, the loo-fathom line due 

 north of Carupano being about 60 miles off the shore,^ 

 which gives for the sea-bottom a gradient of but i'67 per 

 1000.- 



Such are, in a few words, the general hydrographic 

 conditions of that locality, famous in this country for the 

 frequent occurrence of immense shoals of fish of different 

 kinds, which, either alive or dead, are finally thrown by 

 the surf on the beach. The inhabitants call the shoals 

 rihazones when the fish arrive alive ; in the other case 

 they are called tiirbios, on account of the turbid appear- 

 ance the sea presents in such circumstances. 



Though the ribazoiies may occur at any time of the 

 year, it appears that there is a greater probability of their 

 advent during the rainy season, or from May to Novem- 

 ber. The weather must be fine, with a moderate breeze 

 from the sea. The shoals are composed of a great many 

 different species ; most of the fish are, however, of small 

 size. They are followed by large numbers of predatory 

 denizens of the deep, sharks being generally prominent 

 amongst them. In some cases the presence of whales 

 has been recorded ; it is undoubtedly the cachalot [Cato- 

 don mac7-occphahts), which occasionally visits the Carib- 

 bean Sea.' At the same time large flights of sea-gulls 

 accompany the shoal, picking up a considerable number 

 of fish, and, with their deafening shrieks and endless 

 whirls, adding to the picturesque vividness of the scene. 

 Owing to these manifold persecutions the frightened fish 

 make towards the shallow water of the shore in such 

 haste and with such impetuosity that the sea is almost 

 boiling with foam for many miles. Most of the fish are 

 still alive when they reach the beach, where the in- 

 habitants, gathered in large crowds, are not slow in secur- 

 ing as many as they are able to carry away. By far the 

 greatest number die on the shore, however, and their 

 remains form a true cordon littoral, several feet in width 



I '• Deep-Sd Soundings in the Gulf of Mexico and Caribbean Sea " 

 (Chart No. ii in Report of the U.S. Coast and Geodetic Survey, i88i, 

 Washington, 1883). 



- I take the nautical mile, equal to one-sixtieth part of the length of a 

 degree on the great circle of a sphere whose surface is equal to the surface of 

 the earth = i853*2.(8m. or 608070 feet (J. E. Hilgard, " On the Length of 

 the Nautical Mile," in the Report mentioned in the foregoing note, pp. 354- 

 356). 



3 There is in the Museo Nacional of Caracas a tooth of this species, 

 from a specimen which was stranded some years ago on the shores of Mar- 

 garita. I saw myself, in 1873, another whale, but only for about one 

 minute, in the sea between the islands of Tortuga and Margarita. The 

 animal swam with its mouth wide open and the head partially raised above 

 the surface of the water. The upper jaw was small and narrow, so that it 

 certainly was not a cachalot. Though I could not see the back, I supposed 

 then it might be a Balasnoptera, perhaps B. rostrata. However, I do not 

 know whether this species comes so far to the south. 



and height, which soon fills the air with a most offensive 

 smell. 



The latest ribazon occurred on the morning of Oct. lo 

 last. The shoal seems to have come from the north-west, 

 and was extraordinarily large. It contained such species 

 as the '■' pargo " {Eiitjanus profundus, Poey, the same as 

 Mcsoprion aya, Cuv. and Val.), which, as I am informed, 

 had never been observed in any other ribazon. The 

 Royal Mail-steamer Severn, going eastward at a speed of 

 about eight miles an hour, was for two hours (from seven 

 to nine in the morning) literally cutting through the shoal, 

 and as she struck its main course at an angle of 45°, 

 approximately, the breadth of the shoal must have been 

 ten miles at least. ^ The shoal finally ran on shore to 

 the east of Carupano, and such was the quantity of 

 stranded fish, especially between the places called Hernan 

 Vazquez and Guayacan, that the local authorities deemed 

 it necessary to summon a large number of workmen, in 

 order to have trenches dug in which to bury the dead 

 fish. 



With respect to the causes of these migrations, I think 

 they cannot differ from those which give rise to the 

 well-known migrations of marine fish in other parts, the 

 search for food being no doubt the most important. The 

 waters of the great western Caribbean current are richer 

 in food than the comparatively quiet part of the sea north 

 of the current. The fish travel, therefore, in this direc- 

 tion, and attract of course a gradually increasing number 

 of their enemies. On the coast of Carupano the fisheries 

 are insignificant, and thus the shoals are not disturbed in 

 their migrations until they reach the shore. Farther to 

 the west, in the waters of Margarita, the case is different, 

 the large fishery establishments of this island having con- 

 stantly boats and crews in readiness to intercept the 

 shoals, as soon as their arrival is announced by the fire- 

 and-smoke signals of the look-out men stationed on the 

 different headlands and other places known to be favour- 

 ably situated. With regard to Canipano, it is certainly 

 a great pity that the fisheries are so neglected that every 

 year a large amount of what ought to be a rich harvest is 

 lost, and left to turn into noxious and fever-breeding 

 carrion. 



The turbios are rihazones during the arrival of which 

 submarine eruptions of deleterious gases, principally 

 sulphuretted hydrogen, happen to break out, so that the 

 fish are killed before they reach the shore, the water at 

 the same time becoming turbid with the mud from the 

 bottom, which is violently stirred up by the outbreak of 

 the gas. The quantity of the latter must be very con- 

 siderable indeed, as the foul smell on such occasions is 

 noticed all over land and sea. 



Gaseous eruptions of the same nature, as well as 

 sulphurous springs, are not at all uncommon in the 

 neighbourhood of Carupano ; the two azufrales, about 

 twenty miles to the south of the town, being the most 

 important.2 The whole region, in fact, was at the end of 

 the Tertiary period the theatre of a great geological 

 catastrophe, when the Golfo Triste was formed by a 

 sudden subsidence, which was rlso the origin of the 

 so-called delta of the Orinoco,' the Gulf of Cariaco, and 

 the many lagoons in the provinces of Cumand and 

 Maturin. At the same time extensive tracts of land 

 were submerged to the north of the mountains which 

 run through the whole length of the peninsulas of Araya 



I From information given to me by Seiior Bastardo, a medical student at 

 our University, who was a passenger on board the Severn. 



- Wall and Sawkins, " Report on the Geology of Trinidad," London, 

 i860, p. 198. 



3 'I he Orinoco has no delta in the true geological sense of this word, as 

 the land comprised between the outer branches of the intricate fluviatile 

 plexus of its mouth has not been formed by the river. The southern branch 

 is the old river channel ; when the above-mentioned subsidence took place, 

 the land on the left bank sank gradually towards the north, and part of the 

 waters, following the new slope of this n.^rlhern plane, cut into it the 

 different ch.uinels with iheir connecting branches which, after a slow and 

 tortuous course, empty into the sea beiween the old mouth of the river and 

 the southern entrance of the Golfo Triste. 



