In the preparation of this report we have incorporated as much modern data as possible. The subject itself dates back some 130 years, and since the voyage of "HMS Challenger" and Dittmar's subsequent publication of its findings formulae have been proposed that simulate natural seawater. There are many reasons for wanting to produce a substance
which in nature covers over seven-tenths of our native planet , but undoubtedly a major one is convenience.
Approximately ninety six percent of seawater is water, only
the remainder being salts and transportation of any bulk liquid is both tedious and expensive. Even assuming that one is willing and able to undertake the collection of one's own seawater there are problems:
(1) If collected close on-shore it may be polluted , a fact that is often not immediately obvious but may often result in later losses of stock.
(2) The waters of the European (or indeed any ) Continental Shelf, which includes most off-shore areas around our coasts differ in many respects both from oceanic waters and to those present in tropical seas.
In these times of 'Convenience Products' it is far simpler to think in terms of a 'Convenience Seawater', one either made from easily obtainable laboratory chemicals, or pre-package salt mixes from your local aquarium supply shop. And then ? -Hey Presto - instant seawater . But is it ?
How does it compare with the real thing ? How consistent is its formulation?
Is it the nearest possible synthesis, or just a mixture designed to keep things going for a while ?
These were some of the questions we asked ourselves prior to this report being
commissioned. It may answer some of them. It
certainly caused us to ask more as we proceeded. It may even
cause you to ask a few yourself - we hope so.
For those about to become interested in the field
we have included a chapter on
basic marine chemistry. We hope that
it will even appeal to those who are apprehensive even at the mention of the
word chemistry. We make no apologies for its simplicity, and wherever possible it uses non-technical and very easy-to-understand terms. For those already interested
we have included a bibliography
The text of the report proper covers an assessment of nine formulae for synthesising seawaters. Some of these are old, some are relatively modern and one is as yet unpublished in the marine biological paper for which it was intended .All of these nine formulae are in everyday use, some throughout the world, others only in the U. K. and
Europe. Many of them have been commercially marketed under an assortment of
trade names , either in their original form , or as a modification. Some of the marketed products have been 'modified' for use in tropical marine aquaria, where permission has been given either by precedent or in writing ,the names under which the formulae discussed have been marketed are given in the text.
The following are some of the trade names under which salts have been marketed for aquarium use. Legal protection exists in all cases.
'Aqua-Sea' , Dr.Axelrod's Formula , 'C-Water' , Meereswasser
,'Instant Ocean', Marina 69C and Marina 70, H.W.Meeressalz , Rila Marine Mix,
Reef Salts, 'Synthetica' , 'Tropic-Marin' , 'Triton Marine TM Salts ' .
*This list is not comprehensive and not all of these thirteen formulae have been examined.