2.1 Background Information
2.2 Acknowledgements
Repeated resources surveys starting in January 1975, conducted by the Institute of Marine Research, Bergen, Norway, in contract with FAO, ascertained with the RV DR FRIDTJOF NANSEN, using scientific acoustic techniques (echo integration) and sample fishing (mainly midwater trawling) in the northern Arabian Sea, a very substantial resource of mesopelagic lanternfish. The estimates for the Gulf of Oman for the predominant species, Benthosema pterotum, range between about 8 to 13 million tons. This small fish (about 35 mm length) (Fig. 5) occurs almost exclusively above and outside the edge of the continental shelf in depths from the surface down to about 350 m. The resource is so far completely untapped. Because of its offshore distribution, even intensive fishing would not at all interfere with traditional small-scale fisheries. There is also no indication that this fish forms a significant part of food for other marine organisms. The species is short-lived (probably less than one year) and abundance fluctuations according to season and from year to year are to be expected.
Midwater trawling trials with gear of conventional size (estimated opening area 250 to 400 m2) yielded encouraging catches of up to 10 t/h in the Gulf of Oman, particularly in 1975-1976. The fishmeal and oil produced from a sample in Norway was found to be of a quality within the range of products from conventional fish. This indicated the possibility of commercial exploitation, provided that sustained catches of about 100 t/day at a cost of less than US$ 50/t could be obtained by a medium-sized trawler or purse seiner.
As a first step in promoting the development of the mesopelagic fish resources in the northern Arabian Sea, FAO in March 1981 invited representatives of the coastal countries to assess interest and available facilities for a multinational pilot project. During the consultation it was agreed that FAO should arrange a follow-up mission to the countries concerned (Oman, Pakistan, People’s Democratic Republic of Yemen and Somalia) to survey the existing vessels and shore facilities in detail. This mission was fielded in April/May 1982. This consultant participated in both the consultation and the mission. Subsequently, FAO finalized the draft for a Mesopelagic Fishery Pilot Project in the Western Arabian Sea for submission to prospective donors. The budget of this 2 1/2 year project asks for US$ 13.6 million.
The present trials were meant as a rather modest forerunner of the pilot project. The objective was to assess possible commercial catch rates more reliably than are available so far from the sampling and trial fishing during previous resource surveys. The catch/hour of these exercises are often extrapolations from shorter tows on particularly dense concentration and, therefore, are not necessarily valid for commercial considerations.
In agreement between FAO and the Norwegian Institute of Marine Research, about two weeks of a survey cruise of RV DR FRIDTJOF NANSEN were allocated to midwater trawling trials with significantly enlarged nets and more adequate SÜBERKRÜB otter boards (Fig. 2), and for more intensive light experiments. The FAO consultant was assigned to assist with the preparation of the trawl gear and to supervise the actual trawling trials in the Gulf of Oman. This included a short mission from 11-17 December 1982 to Hamburg and Bergen to discuss suitable net designs with the Institute for Fishing Technology (Institut für Fangtechnik) and the netmaker H.H. Engel (Hermann Engel & Co., Netzfabrikation GmbH, Bremerhaven), and the work plan and timing with the Institute of Marine Research in Bergen.
The Consultant’s preliminary mission to discuss net designs and the work plan, as well as his participation in the survey mission to the countries concerned with the pilot project were funded by Norway as part of the project GCP/INT/368/NOR Utilization of Mesopelagic Fish Resources of the Western Indian Ocean.
Due to main engine breakdown in Dubai, the time schedule had to be revised. A major disadvantage was the enforced abandonment of a proper survey of the lanternfish resources in the Gulf of Oman prior to the fishing trials which was meant to ensure the best possible fishing conditions available at the time. Furthermore, some time had to be deducted from the fishing trials to conduct at least a limited acoustic survey needed for the continued monitoring of the pelagic stocks. Consequently, only 11.5 full days were available for trial fishing.
The consultant boarded the DR FRIDTJOF NANSEN on 10 February in Dubai and returned on 28 February from Muscat to Rome. His itinerary is given in Appendix 1. The main persons met are listed in Appendix 2. A cruise map is shown in Appendix 3.
The consultant wishes to express his sincere thanks and appreciation for the excellent cooperation and assistance extended to him by Mr G. Saetersdal, Director, and related staff of the Institute of Marine Research, Bergen: Prof. J. Gjøsaeter, University of Bergen, who was the Cruise Leader, and his staff on board, and Capt. R. Drange, Master, and the officers and crew of RV DR FRIDTJOF NANSEN. Thanks are also due to Prof. R. Steinberg, Institute for Fishing Technology, Hamburg, and Mr H.H. Engel for useful discussions on gear design, and the latter for the efficient delivery of the gear parts required for net modifications to Dubai on very short notice. Special mention should also be made of the generous assistance of Capt. Bob S. Kluzniak, Fleet Manager of the Oman National Fisheries Co., Muscat, who provided without charge about one ton of anchor chain needed as front weights for the trawls. The consultant is most grateful to Mr J. Fitzpatrick and Mr S. Venema of FAO for getting him involved in a fishing technology problem which has interested him for quite some years (bulk catch of very small fish) and for their assistance in tackling administrative and other related problems.
