Why not?
Fired clay items have been found in large quantities on shipwrecks, even though the ships themselves have deteriorated (even vanished), but fired clay absorbs water. Over long periods of time the clay objects fall apart.
"An indirect method measuring the relative pore volume in a clay body is to measure its maximum water retention. Measurements of the Ashkelon vessels taken at the time of treatment showed that they contained an average of 2 1 % of their dry weight in water. A few of them contained over 30% in water. As a comparison, modern bisque-fired clays absorb only 10 - 14% of their dry weight in water."
Iron Age Shipwrecks in Deep Water off Ashkelon, Israel
Robert D. Ballard and Lawrence E. Stager et al
http://web.mit.edu/deeparch/www/publications/papers/BallardEtAl2002.pdf
If there were huge quantities of these shards with writing on them spread across an entire submerged site, then I'd say that the site itself isn't 8000 years old. The script looks Mediterranean, so my guess is that it's in the area of 2500-3000 years old, and came off a wreck. [cont'd in next post]
Here's a quote from page 77:The Lost Civilization of the Stone Age"The proposition that Ice Age reindeer hunters invented writing fifteen thousand years ago or more is utterly inadmissible and unthinkable. All the data that archaeologists have amassed during the last one hundred years reinforce the assumption that Sumerians and Egyptians invented true writing during the second half of the fourth millennium. The Palaeolithic-Mesolithic-Neolithic progression to civilisation is almost as fundamental an article of contemporary scientific faith as heliocentrism. Writing is the diagnostic trait, the quintessential feature of civilisation. Writing, says I.J. Gelb, 'distinguishes civilised man from barbarian.' If Franco-Cantabrians [i.e. Ice Age inhabitants of parts of France and Spain] invented writing thousands of years before civilisation arose in the Near East, then our most cherished beliefs about the nature of society and the course of human development would be demolished."
by Richard Rudgley
"Forbes and Crowder's justification for reviving the idea that writing may perhaps be traced back to the Ice Age is based on the fact that a considerable number of the deliberate markes found on both parietal and mobile art from the Franco-Cantabrian region are remarkably similar to numerous characters in ancient written languages extending from the Mediterranean to China."The table Rudgley produces from Forbes and Crowder is much more extensive than the one found in Settegast, but the idea is the same. From pp 67-68:
"Petrie... made an extended study of Predynastic... and made it quite clear that... they were, in fact, a separate system that existed before and then later alongside the hieroglyphs. Petrie was also aware of the similiarities between the Egyptian signs and those found elsewhere in the Mediterranean... He also expressed the belief that because of their similarity of form with the signs that were later used in alphabetical scripts, these early signs may well have something to do with the origins of the alphabet... Winn could only bring himself to describe the Vinca signs as pre-writing, but for Gimbutas, and for others such as Harald Haarman... they are the real thing... most of those who had previously characterized the Tartaria tablets and analogous Vinca signs as genuine writing did so on the mistaken assumption that they were later than Sumerian and could always be neatly 'explained' as somewhat pale imitations of Near Eastern intellectual innovations. We have also seen how many scholars, on realising that the Vinca signs were simply too early to be derived from Mesopotamia, abruptly dropped the question... For others, who had tried and failed to bolster the traditional chronology for prehistoric southeastern Europe by invoking the Tartaria tablets as a refutation of radiocarbon dates, the tablets were simply dismissed as meaningless jumbles of signs."