on its head and Cruitment of fish species

[ian2]

!. Changes in the administration and funding of science over the last decade or so have turned the whole sector on its head. Scientists I have talked to have identified a number of problems, while at the same time recognising that we do have to reassess constantly whether we are spending public money in the best way

Question: "on its head" could mean change something completely, and also mean something negative. What is the best interpretation here?

We cannot divorce the functioning of the gene from that of the whole genome; the recruitment of the fish species from its place in the marine ecosystem; the initial and primary effects of a chemical from its long term and secondary effects.

What does "recruitment of the fish species" mean? The whole paragraph means to suggest that humans should stop taking the current benefit at the expense of the long term benefit. The recruitment of fish species should fall into this general theme. But what does this mean anyway? Recruitment? We recruit people to training them to do things. But in this case? Thanks a lot in advance.

[Tdol]

1 I'd say change completely, because the scientists are not wholly negative.
2 It's very unclear to me. If it is about genes, it could be a reference to the fact that fish genes have been implanted in fruit to protect them from the cold, but that's guesswork on my part.