
Stroud Water Research Center Project in Madre de Dios, Peru
Conservation Issues
The following is a series of questions regarding important
conservation issues facing the Madre de Dios region and answers based on
insights gained from this study:
1.
Can streams and rivers in the region be broadly classified for conservation
purposes? If so, are certain characteristics more important than others with
regard to conservation? Answer
2. Does the presence and abundance of “keystone”
terrestrial animals (jaguars, monkeys, tapirs, macaws) accurately indicate the
health of a watershed and its water resources and/or the degree of conservation
success in the region?
Answer
3. Can the chemistry of the water give us a good
indication of water quality and the type of human impacts in the watershed?
Answer
4. Are there specific aquatic animals whose presence and
abundance indicate overall water/watershed health and potential for supporting
viable populations of “keystone” terrestrial animals?
Answer
5. Do water quality data that indicate watersheds incapable of supporting
important wildlife also indicate high risk for human health?
Answer
6. Can small pockets of human activity broadly
jeopardize watershed health and hence on-going conservation activities?
Answer
7. Does urbanization have a greater impact on water
quality than agricultural development?
Answer
8. Should best
management practices (BMPs) and policies, such as riparian forest buffers, which
are common in temperate zones, be an integral part of watershed conservation
efforts in neo-tropical watersheds?
Answer
9. Beyond global
warming and impacts associated with increased UV radiation, are the watersheds,
and their human and wildlife populations, at risk from exposure to toxic
substances via aerial transport from industrial areas in South America (hence
the need to conserve elsewhere in the region to assure success)?
Answer
10. Do conserved watersheds contain high levels
of aquatic biodiversity? Is the biodiversity unique? And can it play a critical
role in measuring water quality and watershed health in the region and in
gauging conservation success?
Answer
11. Is the approach to water quality monitoring in the
Andes Amazon region and the knowledge gained about its value to help plan,
guide, and evaluate watershed conservation applicable elsewhere in the
neo-tropics?
Answer
Answers:
1. Can streams and rivers in the region be broadly
classified for conservation purposes? If so, are certain characteristics more
important than others with regard to conservation?
Answer: Yes on
both counts.
- Streams and rivers fall into three
major biogeochemical categories with distinct microbial communities
associated with each: (1) Clearwater [low levels of dissolved ions,
dissolved organic carbon (DOC) and fine suspended solids (FSS)]; (2)
Blackwater (low levels of ions and FSS but high levels of DOC); and (3)
Whitewater (intermediate levels of DOC and high levels of ions and FSS).
Conservation workers and others can distinguish among these three types
visually and/or with simple field instruments.
- Most small streams in the region have
unusually low levels of nutrients but high levels of nitrogen as ammonia.
This combination makes them vulnerable to oxygen depletion if exposed to
excess nutrient loadings associated with human impact. Q. LaJoya, which can
support virtually no living organisms and is dangerously toxic to humans, is
a case in point.
- Because of the low nutrients and low
in-stream algal production caused by heavy shading, organic inputs from the
riparian forests, such as leaves, wood, fruit, and seeds, dominate the food
base, metabolism, and type and abundance of aquatic animals of most natural
streams in the region. This means that maintaining the quality and quantity
of riparian forest cover is a critical conservation priority throughout the
region because it will help sustain the natural food web of the stream.
- Nutrient uptake in natural forested
streams was lower than in most undisturbed temperate streams, which suggests
that the local streams are highly vulnerable to anthropogenic impacts from
farm fertilizers and sewage inputs.
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2. Does the presence and abundance of “keystone”
terrestrial animals (jaguars, monkeys, tapirs, macaws) accurately indicate the
health of a watershed and its water resources and/or the degree of conservation
success in the region?
Answer: Not always.
Watersheds containing an
abundance of these keystone animals had streams indicating poor watershed health
and/or on-going pollution. For example:
- A stream (Q. TRC4) in the “pristine”
Tambopata reserve was relatively clean and natural in most respects but had
concentrations of one pesticide (Chloropyrifos) that were higher than Q.
LaJoya, which is heavily polluted by contaminants from Puerto Maldonado.
- A stream (Q. 2miradoricra) in the
“pristine” Los Amigos Research Center and Conservation Concession was
missing more than half its pollution-sensitive macroinvertebrate species.
This indicates severe watershed disturbance, which could be either on-going
or historical.
- A stream (Q. ATI8) associated with the
relatively “pristine” watershed near the ACEER-Inkaterra research facility
had the second highest concentrations of the herbicide Atrazine measured in
this study.
Since the forest food web
depends on fresh water, it is likely that such water contaminants will
accumulate in the terrestrial food web and place animals in the highest levels
(e.g., keystone taxa) in jeopardy.
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questions
3. Can the chemistry
of the water give us a good indication of water quality and the type of human
impacts in the watershed?
Answer: Yes.
- High ion and nutrient concentrations
reflect high human impact in the region (case in point Q. LaJoya with the
highest level of degradation and human impact as well as the highest ion and
nutrient levels).
- The ratios of ammonium nitrogen to
total dissolved inorganic nitrogen (DIN) were higher at sites receiving
sewage or manure inputs.
- Stable nitrogen isotopes (δ15N)
of nitrate and of fine particulate organic matter at most agricultural sites
revealed enrichment due to both manure and sewage inputs.
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4. Are there specific
aquatic animals whose presence and abundance indicate overall water/watershed
health and potential for supporting viable populations of “keystone” terrestrial
animals?
Answer: Yes.
- Streams containing four out of five of
the following aquatic macroinvertebrate groups [crabs (Grapsidae), mayflies
(Campylocia), stoneflies (Anacroneuria), and two caddisflies (Phylloicus,
Triplectides) always drained watersheds containing keystone terrestrial
wildlife.
- All study streams lacking three or more
of the five aquatic groups were associated with highly impacted watersheds.
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5. Do water quality
data that indicate watersheds incapable of supporting important wildlife also
indicate high risk for human health?
Answer: We think so -- but on a case-by-case basis.
- Pesticides found in three streams at
levels toxic to aquatic life are also carcinogenic to humans.
- Fecal steroid ratios indicate that Q.
LaJoya is contaminated with human waste, and the level of fecal steroids
indicates that dangerous human pathogens are also likely to be present.
- Some streams have high fecal steroid
levels of non-human origin, but do not have dangerous levels of human
pathogens (e.g., Q Abejitas, whose fecal steroid ratio indicates
contamination from cattle).
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6. Can small pockets of
human activity broadly jeopardize watershed health and hence on-going
conservation activities?
Answer: Yes.
A very small stream (Q. Infierno
3), which drained a small banana plantation, contained exceptionally high
concentrations of the insecticide Chlorpyrifos and the fungicide Metalayxl,
whose negative influences are transported downstream to other parts of the
watershed.
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7. Does urbanization have a
greater impact on water quality than agricultural development?
Answer: Both types of land use can severely impact a
stream and often occur together.
- An urban stream (Q. LaJoya) had
elevated concentrations of every pesticide and PCB measured and a 100% loss
of pollution-sensitive species, both of which indicate severe impact.
- An agricultural stream (Q. INF3) had
significant levels of insecticides and fungicides and an 80% loss of
pollution-sensitive species, both of which indicate severe impact.
- Stable nitrogen isotopes (δ15N) of
nitrate and of fine particulate organic matter (FPOM) at most agricultural
sites show the characteristic enrichment of both manure and sewage inputs.
- Q. Inf 5, whose watershed is partially
deforested for cattle and row crop agriculture but has a wide and intact
riparian forest along most of its length, had levels of pollution-sensitive
taxa comparable to streams in conserved areas.
- Q. Abejitas, whose watershed is largely
deforested for cattle pasture, was able to retain 40% of its
pollution-sensitive taxa and most of its ability to process nitrogen and
phosphorus by keeping intact a 5-10 m riparian buffer.
- Stable carbon isotope (δ13C) of fine
particulate organic matter at Q. Km14 stream suggests that the partial
removal of riparian forest along its length has already increased the
relative abundance of algae in the stream’s food base relative to heavily
shaded conserved streams — arguing for a policy to assure the long-term
integrity of riparian forest in the region.
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- PAHs, which are carcinogenic compounds
from petroleum and combustion-generated soot, were uniformly low in all
streams – and below all USEPA toxicity criteria for water quality. (For
perspective, the Stroud Water Research Center recently studied 180 streams supplying
drinking water to New York City and found 54 of them to have PAH levels
exceeding the EPA water quality guidance values.)
- Pesticides in some study streams
throughout the region were undetectable (note: the study did not look for
bioaccumulation of pesticides in the tissue of key wildlife.)
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10.
Do
conserved watersheds contain high levels of aquatic biodiversity? Is the
biodiversity unique? And can it play a critical role in measuring water quality
and watershed health in the region and in gauging conservation success?
Answer: Yes on all counts.
Biodiversity
- Our 12 most extensively studied small
streams contained 204 macroinvertebrate taxa (mostly genera).
- 50% of the macroinvertebrate taxa were
found in only one or two streams – suggesting a high level of both alpha and
beta species diversity.
- The microbial survey, which was the
first of its kind in the Amazon basin, revealed distinct bacterial
communities in the blackwater and clearwater streams of the conserved areas.
Uniqueness of Biodiversity
- A significant percentage (> 30%) of
macroinvertebrates collected appear to be new species to science.
- It appears that the microbial community
specializing in processing ammonia (a common chemical in Andes Amazon
streams) is not composed primarily of Bacteria (as in non-tropical
streams) but rather Archaea (microbes that look like bacteria but are
genetically distinct).
- The failure to detect bacteria in the
ammonia processing community of the Andes Amazon streams, if confirmed,
would represent an important and novel observation in the field of microbial
stream ecology and would help increase the capacity of microbial ecologists
working in the Moore Foundation’s marine program to understand what is
emerging as an important issue.
Role in water quality monitoring
- Macroinvertebrate groups sensitive to
pollution in the Andes Amazon region (e.g., mayflies, stoneflies,
caddisflies, hereafter the "EPT" group) appear to be similar, but not
identical, to those that the Stroud Water Research Center has worked with elsewhere in
Latin America and the temperate zone.
- The extinction of pollution-sensitive
macroinvertebrate taxa (EPT) from a stream ranged from 100% (highly polluted
stream in the town of Puerto Maldonado) to 0% (a pristine stream in a
conservation area), with most clean streams in the region losing less than
20% and most polluted streams losing more than 50%.
- The presence of five aquatic
macroinvertebrate animal groups (Grapsidae, Campylocia ,
Anacroneuria ,Phylloicus, Triplectides) consistently seems to
indicate very high water quality.
Gauging conservation success
Loss of EPT taxa indicates that
some streams (e.g., Q. 2miradorcicra) in conserved areas are not healthy and
that their watersheds are either suffering from a legacy of previous impacts
(and need pro-active restoration) or are in need of better and more widespread
protection.
Back to questions
11. Is the approach to
water quality monitoring in the Andes Amazon region and the knowledge gained
about its value to help plan, guide, and evaluate watershed conservation
applicable elsewhere in the neo-tropics?
Answer: Yes.
For example, on December 17,
2006, Bern Sweeney, director of the Stroud Water Research Center, arrived at “Nectandra,”
a neo-tropical cloud forest preserve in Costa Rica (www.nectandra.org),
just after having finished leading a weeklong series of “water quality
monitoring” workshops as part of a Moore Foundation grant on Costa Rica’s Osa
Peninsula. He had come to Nectandra at the request of its president, Alvaro
Ugalde, and co-founders, David and Evelyn Lennette of San Francisco, CA. The
Lennettes had purchased 99.9% of the Nectandra watershed in 1999 and had built
and furnished a magnificent education/research center focused on conserving the
virgin cloud forest and its jaguars, tapirs, and other native wildlife. Sweeney
was asked to confirm the purity of the water of a stream called Quebrada Verde,
in anticipation of using it for education purposes and for growing organic rice
as a demonstration of sustainable agriculture. Employing the same
macroinvertebrate sampling techniques he had taught his Moore Foundation
students the week before, Sweeney determined almost immediately that the stream
ecosystem was “dead” as a result of heavily polluted sediments and probably
toxic chemicals in its water. These pollutants came from a tiny parcel of
upstream land that the Lennettes did not own and which was used for growing
ornamental plants for market. In subsequent visits that day to nearby streams
whose watersheds were completely within Nectandra’s conserved area, Sweeney
found water of consistently high quality. Thus, his quick and simple stream
survey not only provided a direct measure of Nectandra’s conservation success,
but it also revealed the immediate need to acquire the tiny piece of the
watershed that was being poorly farmed and whose contaminated water and soil was
washing into Q. Verde.
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