Larger agglutinated foraminifera from the Faeroe Channel and Rockall Trough collected by W. B. Carpenter

The Carpenter collection contains numerous slides of larger agglutinated foraminifera from the Faeroe Channel area. These have been re-identified during the preparation of a catalogue. The Faeroe Channel has a cold bottom water mass to the north (temperature ∼ 0°C) overlying sandy sediment with few larger agglutinated foraminifera, and a somewhat warmer water mass to the south (temperature > 2°C) overlying carbonate ooze with a diverse fauna of larger agglutinated foraminifera.


INTRODUCTION
In 1844 Edward Forbes had put forward the view that life would not be found below 300 fathoms (-550 m) in the oceans. However, not all the marine scientists of the time believed this to be correct and sampling was extended into deeper water to test the hypothesis. In 1868, the Swedish Government Inspector of Fisheries, Mr. M. Sars, dredged to a depth of 300fms off the Lofoten Islands and recovered abundant animal life. This was shown to Prof. Wyville Thomson of Belfast during a visit to Norway. On May 30th 1868 he wrote to Dr. W. B. Carpenter suggesting a programme of research into deep sea life.
" I have little doubt that it is quite practicable, with a small heavy dredge, and a couple of miles of stout Manilla rope, to dredge to a depth of 1000 fathoms." (Carpenter, 1869, p. 199). Carpenter wrote to the President of the Royal Society on June 18th 1868 to seek help from the Admiralty and on July 14th he received a letter from the Admiralty telling him that the steam-vessel 'Lightning' was being prepared immediately for their use and the cruise took place during August and September of that year.
The area selected for study was the Faeroe Channel. Surface and bottom water temperature readings were made at 16 stations, the depth ranging from 60 to 650fms 110 to 1189 m). Dredging was also carried out and that at 650 fms was the deepest ever taken. In their preliminary results Carpenter (1869) reported the presence of life to 650 fms, the existence of cold bottom water to the north of the Faeroe Ridge (now the Wyville-Thomson Ridge) and warm bottom water to the south, and he suggested that the distribution of life was controlled more by water temperature than by depth or substrate. H e also drew comparisons between deep sea ooze and Cretaceous chalk. The geological consequences of these observations were regarded with some excitement, and a programme of further research formed the concluding remarks in the Preliminary Report. Carpenter also wrote "I shall myself lose no time in preparing an account of the Rhizopods we have collected . . ." In the summer of 1869, the Admiralty made available H.M. Surveying-Vessel 'Porcupine ' to continue the research. The area examined was extended to include Rockall Bank, Rockall Trough, and the west margin of the British Isles. (Carpenter et al., 1870). Bottom, surface, and serial water temperature measurements were made together with chemical analyses and samples of sediment were dredged from 90 stations. Much of the report is by Carpenter on the physics and chemistry of the water. The presence of a cold bottom water mass to the north of the Wyville Thomson Ridge was confirmed as was the warm water mass to the south. It was recognised that ". . . a general interchange of Equatorial and Polar waters is continually taking place in the great Oceanic Basins." (ibid., p. 454). This was further elaborated (ibid., p. 472): 1) The movement of a vast body of warm water, extending to a depth of several hundred fathoms, in a northeast direction, which moderates the cold of the Boreal area by bringing into it the warmth of that vast expanse of the North Atlantic Ocean which is heated beneath the Tropical sun.
2) The existence of a flow of ice-cold water, at depths greater than 300 fathoms, in a southwest direction along the floor of the channel between the North of Scotland and the Faeroe Islands, which contributes, with other frigid streams from the Arctic basin, to diffuse over the North Atlantic sea-bed, at depths greater than 1000 fathoms, a temperature below 39", ranging downwards with increase of depth to about 35". (i.e., 4" to 2.7"C). Thus, an important contribution was made to understanding the complexities of oceanic circulation.
The narrative of the Porcupine cruises includes many references to the occurrence of Foraminifera. Agglutinated forms were abundant together with miliolids and large and diverse 'Cristellariae', i.e. Nodosariaceans. All these characterised the Globigerina ooze of the warm area; the sandy bottom of cold area yielded few larger Foraminifera. In the area intermediate between the two (Porcupine sta. 51 (Fig. 1)) there were large numbers of the tubes of Botellina (ibid., 1870, p. 444).
Although Carpenter published a succession of papers on Foraminifera throughout the period 1870 to 1885, he never gave any detailed results from either the Lightning or Porcupine cruises to the Faeroe area. However, his collection of agglutinated Foraminifera was made available to H. B. Brady who used it in the preparation of the "Report on the Foraminifera dredged by H.M.S. Challenger, during the years 1873-1876" (Brady, 1884). In addition, Brady received unwashed samples of dried sediment from the Porcupine cruise from the Rev. A. Norman. Nuttall (1927Nuttall ( ,1931) compiled a list of localities for material illustrated by Brady (1884) from an examination of the Brady collection of slides. It must be assumed that in the cases where Lightning or Porcupine material was preserved in the Brady collection, Brady had mounted his own specimens. However, a number of illustrated specimens are not represented by slides in the Brady collection and in some cases this was because Carpenter's slides were used (see Murray & Taplin, 1984).
The Carpenter Collection of Foraminifera is housed in the Royal Albert Memorial Museum, Exeter (Murray, 1971). A catalogue has been compiled and copies have been deposited in the British Museum (Natural History) and the Linnean Society (Murray & Taplin, 1984). The Lightning and Porcupine material has been revised taxonomically mainly with reference to Barker (1960) and Loeblich & Tappan (1964). Carpenter worked only with larger material and few of the specimens are smaller than 1 mm but because he processed a large volume of sediment there are many specimens of large, rare Foraminifera. This gives the collection particular interest and makes further study worthwhile.

RE-EXAMINATION OF THE CARPENTER MATERIAL
The Porcupine slides are labelled 263/1903,1-156 and the Lightning slides 252-287. It is not known whether the number of specimens mounted reflects their true abundance in the dredge samples. Only Porcupine sta. 64 is in the cold area. In Table 1 the records are based on the presence or absence of the taxa. Additional data from Brady (1882) and Pearcey (1890) have been included for the cold area. Pearcey clearly looked at a smaller size fraction than that used by Carpenter and he records the following additional species in the cold area:
There is some confusion surrounding the distribution of Reophax sabulosa. This was said by Brady (1882, p. 710) to be present at Knight Errant sta. 8 (cold area, ". . . only previously known by specimens from one of the 'Porcupine' stations." However, in the Carpenter collection, the four slides of this species are labelled Lightning. No station number is give but the depths and bottom temperatures are given for three. In each case the depth is 530 fm. In one case the temperature is given Larger Agglutinated Foraminifera as 32", in another 32" has been crossed out and 47" added, and in the third the temperature is given as 47". The depth suggests Lightning sta. 12 (warm area) and the 32" temperature suggests sta. 8 (cold area). However, from the narrative (Carpenter, 1870, p. 172) it is clear that bad weather prevented sampling at sta. 8. So the Lightning. No station number is given but the depths and warm area, perhaps sta. 12. There are no records from the Porcupine samples. In the 'Challenger' Report, Brady (1884) states that the species is known only from the cold area of the Faeroe Channel and that the illustrated specimens are from the Lightning cruise. Furthermore, he notes that the Knight Errant material came from "near the same spot". But the position of Knight Errant sta. 8 is close to Lightning sta. 8 from which no sample was obtained! Perhaps the species occurs in both cold and warm areas. Botellina labyrinthica is known only from Porcupine sta. 51, said by Carpenter (1869) to be on the border line between the warm and cold areas. (The records from shallow waters, quoted by Cushman, 1920, are very doubtful).

DISCUSSION
The general absence of larger agglutinated foraminifera from northern polar areas is confirmed by recent results from the Norwegian-Greenland Sea (Belanger & Streeter, 1980) and the Arctic Ocean (Green, 1960;Lagoe, 1977Lagoe, , 1979 although these authors had only small samples to work with. The causes of their absence are not known. Detrital material is readily available so this cannot be a limiting factor. Low water temperature is the obvious explanation but there is no proof that this is correct.