Initially I was quite surprised by this and so I then performed a search for genomics, only to see the same sort of trend:
According to Google the Y-axis of these graphs reflect "how many searches have been done for a particular term, relative to the total number of searches done on Google over time" (emphasis on the word 'relative' is mine). This could just mean that the absolute number of search terms for 'bioinformatics' and 'genomics' is the same, or has even grown, but has been swamped by an increase in the frequency of all other search terms. To a lesser degree, there seems to be fewer searches occurring for many different biologically-related terms, e.g. here is the graph for the word biology.
On top of the overall declining trend, I noticed that you can clearly see a dip in the middle of each year. Possibly, this corresponds to when millions of high-school kids take their long summer vacation and are therefore not searching about anything to do with school work. You can see similar annual 'wobbles' if you also search for chemistry or physics. So does this mean that all science-related searches are declining? Well, you might expect there to be growing interest in the newer fields of biology (and bioinformatics in particular) and related technologies. This does seem to be the case. Here is the graph for the search term next generation sequencing (note, I do not advocate using this phrase):
So clearly, some topics are becoming more popular, and more searched for. However I still feel that the decline for the term bioinformatics might indeed represent a real decline in the whole field of bioinformatics. That is not to say that I think less bioinformatics is being done these days, or that it is less 'worthy' as a field. Rather, I think bioinformatics has moved from being a specialist field that was carried out somewhat separately from 'traditional' wet-lab research, to something which is much more integrated with many other fields of research. There are still many dedicated bioinformatics group (the lab where I work is one such group), but I think that it is increasingly common that biologists need to — and want to — undertake some bioinformatics as part of their wider research. To me, bioinformatics has become part of mainstream biological research and that means that it no longer makes sense to think of it as a separate field as such.
Anyway, regardless of whether any particular biological term is rising or falling in popularity, I think it is more interesting to see what search terms remain eternally popular. Despite changing governments, economic turmoil, and global uncertainty what is it that we search for with any degree of constancy? My first guess seemed to be a good one. So let me end by presenting the Google Insights graph for the search term shoes: