November 1976 • Volume 7 • Number 11

E D I T O R I A L

Farmed Fish or Soya Beans? . . . . . . . . . . . . . . 201

N E W S

A Collision in the Forth . . . . . . . . . . . . . . . . . . . 202

Peterhead versus Fife • Cromarty . . . . . . . . . 203

Shetland • O i l /Water Separation • Skomer Island Mar ine Reserve • Chemviron A w a r d f o r W a t e r T r e a t m e n t Technology • Pollution of Long Island Beaches . . . . . . . 204

Underwater Conservation Year • US Water Pollution Standards for PCBs . . . . . . . . . . . 205

PCBs in the Hudson River . . . . . . . . . . . . . . . . 206

R E P O R T S

A Comparat ive Survey of Petroleum Hydrocarbons in Lake Sediments by Stuart G. Wakeharn . . . . . . . . . . . . . . . . . . 206

Interactions of Lead wi th Sediments and Meiofauna by D. Roberts and C. Maguire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

Barium Build-up in the Teign Estuary byJ . R. Merefield . . . . . . . . . . . . . . . . . . . . . . . 214

Farmed Fish or Soya Beans? During the last two or three years, mounting pressure

on fish stocks has led to a situation verging on anarchy. Regulation of the level of exploitation of food-fish populations in the north-east Atlantic, which was never all that strong, is in danger of becoming weaker than ever and there is a panicky rush to lay claim to the more important fishing grounds. First, the Icelandic declara- tion of a 200-mile economic zone and the "Co d War" severely reduced access by non-Icelandic fishing vessels to the rich grounds around that country. Next, Norway is confidently expected to declare a 200-mile economic zone and the EEC will follow suit and claim much of the rest of the north-east Atlantic fishing grounds.

While in theory allocating responsibility for manage- ment of the fish stocks in this way might be supposed to control exploitation to a rational, sustainable level, this parcelling out of the natural resources does little to reduce the scramble for fish or alleviate the tensions that have built up. Ireland and the United Kingdom are at loggerheads with the rest of the EEC because, naturally enough, they would like to hang on to ' their ' productive fishing grounds and not share them with other members of the Community. And even in the unlikely event of agreement to reserve large slices of national fishing grounds, this would not bring peace and harmony. The Cornish mackerel fishermen are just as incensed to see large Scottish fishing vessels as Russian ones, sweeping up ' their ' mackerel.

An important source of all this tension has been the development of large fishing vessels and much increased efficiency at catching fish. Built partly for economic reasons and partly to exploit fish stocks far from shore, as these big vessels are squeezed out of one distant ground after another they come increasingly into competition with inshore fishermen whose small vessels can operate only in the immediate neighbourhood of their home port. The inshore fishermen see not only the end of their own livelihood, but also the exhaustion of local fish stocks through the vastly greater fishing capability of the large modern vessels.

It is hardly surprising in these circumstances that several countries are taking an interest in fish farming as a means of augmenting supplies of fish taken by traditional methods. Fish production moved from the

P E R G A M O N PRESS" Oxford • N e w York" Paris- Frankfurt 20!

hunting to the agricultural stage of development a long time ago. Fish farming has been practised in south-east Asia for at least a millenium and carp ponds provided a lot of winter protein in mediaeval Europe, but the relative ease with which abundant supplies of fish could be caught by netting the wild population has kept this industry locked to primitive hunting. But the fact that almost all the world's natural fish stocks are exploited to the full, if not over-exploited, has given a new impetus to aquaculture and the fishery departments of several countries are researching with varying degrees of enthusiasm into it.

The recently published 1975 report of the National Marine Fisheries Service of the US Department of Commerce suggests that aquaculture "has a high potential for augmenting the national supply of aquatic prote in" . In Britain the authorities take a more cautious attitude. It is noteworthy in fact that the present effort in Britain is directed very much to the luxury end of the market: salmon, trout, turbot and sole, and oysters and a few clams. This does not sound as though aquaculture will produce a lot of cheap protein, and the economics of fish farming will make sure it stays that way for the present. Even with the high price of conventionally- caught fish, the products of aquaculture must fetch an even higher price to be economically viable and that, in turn, does not allow for flooding the market with large quantities of farmed fish protein.

Indeed, the latest annual report of the UK Fisheries Research and Development Board includes an estimate to how much salmon and trout could be framed "without upsetting the marke t" . The projected increase is from the present modest 50 tons of salmon and 700 tons of trout (the fish farming industry is still in its infancy) to several thousand tons a year, with much of this increase coming in the next 10 years. But even that figure does not look very impressive against the annual landings of conven- tionally caught fish. It does not look from this as though there is an easy way, yet, of aquaculture yielding cheap protein and it is only when it is cheap that it will make a signficant contribution to our annual protein production.

This does not mean that aquaculture has only an insignificant and largely frivolous role for the future, although this may be true of factory farming of fish from spawn to table in artificially maintained enclosures. There are a number of half-way houses by which aquaculture can give a helping hand to nature and improve the yields of conventional fishing. At the Fishery Laboratory at Auke Bay in Alaska a salmon hatchery is used to produce juvenile salmon to restore depressed salmon stocks. (Salmon have the advantage of returning to the river in which they were released, so you stand some chance of getting you own back instead of charitably helping all-comers by your efforts.) In a pilot study, the number of fish returning per spawner was 15 to 45, compared with only three fish per spawner by natural recruitment.

Shellfish like oysters and clams, stay in one place and providing the system of culture works, can yield a return on investment. This is why the culture of oysters, clams and mussels has such a venerable history: nature is helped along by placing young shellfish in favourable spots where feeding is good and the growth rate is at a

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Marine Pollution Bulletin

maximum. This is now being improved upon by thinking about artificial diets for the shellfish to get even faster growth.

One thing that has been surprisingly lacking until recently, in view of the very long history of fish farming, is stock selection. Man would never have evolved from hunters to settled urban dwellers if agriculture had depended on wild strains, and the deliberate selection of faster growing, better yielding crops, whether of grain or domestic animals has been a feature of agriculture throughout its history. Only now is there starting to be research into the genetics of marine animals which might be candidates for aquaculture and scientific breeding programmes should obviously be an early objective if and when fish farming expands.

Even so, we are still a long way from augmenting world protein supplies by this means. It is a gastronomically sad fact that we shall probably have to look to the soya bean and natural gas for that.

A Collision in the Forth An unfortunate incident when the German container ship Plainsman ran down the 1136 ton oil protection vessel H M S Reward in a fog in the Firth of Forth on the after- noon of 10 August has shed a flood of light on the safety of navigation in the area and the effectiveness of our defence of the North Sea oilfields. It appears that the Reward was a 33-yr-old tug commissioned as an offshore patrol vessel and sometimes required to carry out the duties of a frigate. She had very old-fashioned diesel engines which failed to restart on average twice in any 17 day patrol because the air admittance valves jammed, so that her commander was reluctant to stop her in case of navigational difficulties. He passed under the Forth railway bridge at a safe speed of six knots, failed to locate the approaching Plainsman with his radar at first, and when he did, failed to realise that with an experienced pilot aboard she could be approaching at over twice his own speed under such conditions. Fortunately when she ran the Reward down the crew were able to escape aboard the Plainsman before their vessel sank.

The captain of the Reward was cleared at the subsequent court martial of losing his vessel through negligence, but reprimanded for adopting an unsafe approach route to Rosyth dockyard. It has been pointed out that if a collision at that point had involved a vessel with an inflammable cargo of the sort likely to be using the Forth in increasing numbers the resulting conflagra- tion would have engulfed both the Forth road and rail bridges which provide two of the main lines of communi- cation with the north of Scotland. It is also of interest