>Experts believe the large-scale earthworks are the remains of a fish farm
>that provided a food source for native people at least 300 years ago....

it is misleading to call this a farm , the concept of a farm now is
generally understood as, little bit  more,  than  just changing the
distribution of the biodiversity in a given ecosystem.
It looks more to me a system of traps to extend the season of wild  fish
harvesting than a fish farm where fishes are removed from their naturally
supporting environment ,  crowded in pens  and fed artificially with
processed foods extracted from other regions .

this extensive network of  waterways in amazonia could look land (or water)
consuming in comparaison of the surface used by the modern fish farm .
the fact is that the ecological impact of those abherations are way beyond
than their immediate surrouding.
a modern farm can look productive when in fact it is completly
counterproductive ( using up more energy than it is produced)

>But the researcher believes the abandoned earthworks still influence the
>vegetation, drainage and biodiversity of the region today.

that was a "permaculture " type of farm ( permanent agriculture).

>"Humans have been altering, changing, constructing, transforming the
>landscape for a long, long time," he said.

I see ! A statement like that could be used   like a rationalisation ,a
justification of our past and present farming and industrial practices.

if we did it since eons and survived why not continue?

there is a fondamental difference between this changing constructing,
transforming of natural  landscape and the  presently" managed" artificial
landscape.

>
>"What we recognise out there as nature or wilderness in most cases is the
>product of thousands, and in some parts of the world, tens of thousands of
>years, of humans transforming the environment".

It is very true , the difference   with a modern farm is that with the
technological means of a native tribe of amazonia , the transformations have
proven themselves sustainable for thousands of years .

that ,  is and will not be the case of technological agriculture or animal
raising.


>
>"We're finding more and more, at least in areas of the Amazon, that humans
>played an important role in the creation and maintenance of biodiversity."

exactely ,that is the fondamental difference , the respect of  biodiversity
was still the basic building stone of human activity in amazonia .
The concept of self was way broader than the domesticated mind of today

jean-claude