Internal Disturbance on the Rio Aguarico

Bethany Hoye & Andrew Glover

June 2006

We have already highlighted some of the environmental issues inherent in petroleum-based power generation and transportation, as they are inevitably tied to economic sustainability. While these are considerable sources of environmental degradation, they are not the only ones.

Land Clearing for agriculture not only results in reduced forest area, and hence reduced biodiversity, but also greatly increases the sediment load of the creeks and river. Total area of clearing is not all that is important, the spatial pattern of forest reserves is critical to the diversity and abundance of flora and fauna in the region. Highly fragmented patches of forest, with relatively large edge area and little connectivity are the most likely to dramatically reduce biodiversity (the ‘island biogeography effect’), through reduced recruitment of pollens, decreased variety and availability of microhabitats (for plants and animals), and increased predation. Unfortunately, this is the pattern that is being created by all of these communities as a whole, but is only recognised by the leaders of the Siecoya Nation, who are powerless in controlling the spatial dynamics of the invading communities.

The colonist populations all seemed to place little inherent value on the forest as a resource in its current form. It is simply viewed as a source of raw materials (particularly wood for construction), some food, and a barrier to greater agricultural expansion and economic prosperity. The teacher at Los Angeles remarked on the extent of forest clearing, but made it clear that it wasn’t an issue for those doing the clearing.

The implementation of sustainable agricultural practises would go a long way to reducing the need to clear more land.

One of the most destructive uses of cleared land, increasing erosion and decreasing soil fertility, is high density cattle grazing, as we saw particularly in Centro Union. Decreasing the density of cattle, through a reduction in the number of cattle, not increased land clearing, is required to prevent further clearing in the near future. In order to achieve this, some communities need to reduce dependence (for food and income) on these animals ill-suited to the local ecosystem. Similarly, large numbers of unrestricted domestic chickens are likely to be diminishing invertebrate diversity and abundance. So too, large numbers of domestic dogs and cats are likely to be decimating the local fauna, both trough direct predation of some species, and removal of food source of others.

Despite reportedly low mortality, there seemed to be relatively high levels disease and sickness within the populations. The river was often cited as the source of illness, but people continue to pollute the river, while also bathing, and in some cases even drinking from it.

There are significant health risks associated with San Pablo’s lack of an adequate human waste disposal system. With very few pit toilets and the high rainfall of the area, human waste deposited “behind a tree” by 230 people, is likely to be being washed down river, thus contaminating the river water of communities downstream.

Disposal of inorganic waste, particularly plastic and metal packaging, appeared to present a major problem to most communities. All communities ostensibly burnt or buried this rubbish, however, many of the communities had varying degrees of litter scattered throughout the community. This ‘drop it where you finish with it’ philosophy was not restricted to land, with none of our travel companions having any hesitation about repeatedly disposing of inorganic waste in the river. Of course, there is no ‘good’ way to dispose of inorganic waste, however, concentrated efforts to confine them to one area would have less impact on biodiversity, of the river in particular. Perhaps the most appropriate option would be for the people to consciously avoid these waste products when purchasing, particularly multi packaged confectionary and drinks in disposable containers.