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The Influence of an Electric Light on the Capture of Oceanic Cephalopods by a Midwater Trawl

  • Malcolm R. Clarke (a1) and P.L. Pascoe (a2)

Extract

A total of 57 comparative hauls using a rectangular midwater trawl with a fishing mouth area of 50 m2 (RMT 50) were carried out along the sides of an imaginary triangle south of Madeira in 1986. A total of 1258 cephalopods were caught, giving a mean of 22 per haul with a range from 0 to 67. The nets were used with a diver's light on the top bar which was either switched off or was operated with a 20, 70 or 150 W bulb, powered by a car battery. A significantly greater number of individuals per haul was caught with lights on than without lights, increasing from a mean of 13·5–25·1, a factor of 1·8. Similarly, the number of species caught was increased from a mean of 7 to 10·4, a factor of 1·5 and the volume of cephalopods was increased from a mean of 41·1–162·3ml, a factor of 3·9. Similar comparisons made for catches during day or night separately and on the three courses separately also showed marked increases with the lights. Samples show that increase in power of the lights increased the total number of cephalopod individuals caught. In the 12 species with more than ten individuals, in 33 of the 36 comparisons (of number of individuals, species and volumes) there is an increase with the light. The most influenced species was Taonius pavo which increased in numbers by a mean factor of 3·9 times with 20W, 4·0 times with 70W and 6·1 times with 150W when compared with the numbers caught with no light.

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References

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Baker, A. De C., Clarke, M.R. & Harris, M.J., 1973. The N.I.O. combination net (RMT 1+8) and further developmment of rectangular midwater trawls. Journal of the Marine Biological Association of the United Kingdom, 53, 167184.
Clarke, M.R., 1977. A brief review of sampling techniques and tools of marine biology. In A voyage of discovery (ed. M., Angel), p. 439. Oxford: Pergamon Press. [Deep Sea Research, supplement.]
Clarke, M.R., 1969. A new midwater trawl for sampling discrete depth horizons. Journal of the Marine Biological Association of the United Kingdom, 49, 945960.
Clarke, M.R., 1996. Conclusions and future. In Role of cephalopods in the world's oceans (ed. M.R., Clarke), pp. 11051112. [Philosophical Transactions of the Royal Society, special volume, 351.]
Clarke, M.R. & Lu, C.C., 1974. Vertical distribution of cephalopods at 30°N 23°W in the North Atlantic. Journal of the Marine Biological Association of the United Kingdom, 54, 99984.
Clarke, M.R. & Lu, C.C., 1975. Vertical distribution of cephalopods at 18°N 25°W in the North Atlantic. Journal of the Marine Biological Association of the United Kingdom, 55, 165182.
Clarke, M.R. & Lu, C.C., 1996. Cephalopods from Madeira waters. Boletim do Museu Municipal do Funchal, supplement no. 4, 181200.
Clarke, M.R. & Pascoe, P.L., 1985. The influence of an electric light on the capture of deep-sea animals by a midwater trawl. Journal of the Marine Biological Association of the United Kingdom, 65, 373393.
Clarke, M.R., Pascoe, P.L. & Maddock, L., 1986. Influence of 70 watt electric lights on the capture of fish by otter trawl off Plymouth. Journal of the Marine Biological Association of the United Kingdom, 66, 711720.
Denton, E.J., 1990. Light and vision at depths greater than 200 metres. In Light and life in the sea (ed. P.J., Herring et al.), pp. 127148. Cambridge: Cambridge University Press.
Flores, E.E.C., 1982. Light attraction techniques in squid fishing. Fisheries Research Journal of the Philippines, 7, 101110.
Flores, E.E.C., Igarashi, S. & Mikami, T., 1978. Studies on squid behaviour in relation to fishing. III. On the optomotor responses of squid, Todarodes pacificus Steenstrup, to various colours. Bulletin of the Faculty of Fisheries, Hokkaido University, 29, 131140.
Land, M.F., 1990. Optics of the eyes of marine animals. In Light and life in the sea (ed. P.J., Herring et al.), pp. 149166. Cambridge: Cambridge University Press.
Lu, C.C. & Clarke, M.R., 1975a. Vertical distribution of cephalopods at 40°N, 53°N and 60°N at 20°W in the North Atlantic. Journal of the Marine Biological Association of the United Kingdom, 55, 143164.
Lu, C.C. & Clarke, M.R., 1975b. Vertical distribution of cephalopods at 11°N 20°W in the North Atlantic. Journal of the Marine Biological Association of the United Kingdom, 55, 369389.
Ogura, M. & Nasumi, T., 1976. Fishing lamps and light attraction for squid jigging. FAO Fisheries Reports, no. 170, supplement 1, 9396.
Pascoe, P.L., 1990. Light and the capture of marine animals. In Light and life in the sea (ed. P.J., Herring et al.), pp. 229244. Cambridge: Cambridge University Press.
Roper, C.F.E. & Young, R.E., 1975. Vertical distribution of pelagic cephalopods. Smithsonian Contributions to Zoology, no. 209, 151.
Supongpan, M., Sinoda, M. & Boongerd, S., 1992. Catch analysis of Indian squid, Loligo duvauceli, by light luring fishing in the Gulf of Thailand. Nippon Suisan Gakkaishi, 58, 439444.
Swinney, G.N., Clarke, M.R. & Maddock, L., 1986. Influence of an electric light on the capture of oceanic deep-sea fish in Biscay. Journal of the Marine Biological Association of the United Kingdom, 66, 483496.

The Influence of an Electric Light on the Capture of Oceanic Cephalopods by a Midwater Trawl

  • Malcolm R. Clarke (a1) and P.L. Pascoe (a2)

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