Mr Gray, a former physics teacher, said Scotland’s proud tradition in science and engineering was unlikely to be maintained unless more is invested at classroom level.
He also cited reports that more than seven million jobs in the UK would depend on science skills by 2030, meaning many of the necessary science graduates were already at school now.
“The Scottish government’s own figures show a fall in numeracy levels at all levels, primary and secondary, which means science teaching in Scottish schools is facing a perfect storm,” he told MSPs.
“Low investment, teacher shortages and falling numeracy levels are all adding to concerns about the impact of the new curriculum on pupil numbers choosing science.
“To make matters worse, much lower pass rates in the new National 4 examinations for maths and science than for other subjects are fuelling fears that this will discourage pupils from choosing to take these subjects in the first place.”
Funding per-pupil of science teaching in Scottish secondaries is about a third less than in England and about half in primaries, where 45 per cent of schools also reported having no access to safety equipment, Mr Gray said.
He was citing a recent survey by the Learned Societies Group on Scottish Science Education suggesting that 98 per cent of primary and secondary schools depended on external funding for practical science work, including from parents and teachers.
Mr Gray welcomed the Royal Society of Chemistry’s recommendations on improving science learning in school through access to teaching specialists.? However, he was disappointed to learn that in 2015/16 science societies and festivals would receive a real-terms cut in funding from the Scottish government.
However, education minister Alasdair Allan said there was no evidence pupils were being put off science subjects and pass rates were holding up well. The Scottish government recognises the vital role of STEM subjects and they are enshrined in Curriculum for Excellence, he said.
Education minister committee convener Stewart Maxwell said the surveys mentioned by Mr Gray were based on small samples, and investment in science had risen across Scotland. About 50 per cent of local authorities also back a science championing scheme funded by the government, he said.