the ecosystem are specifically affected by hypoxia.” The report also concludes, “The
economic assessment based on fisheries data, however, failed to detect effects
attributable to hypoxia”. This report does not make a compelling argument ecologically
or economically for a nutrient management strategy based on hypoxia reduction.

Topic #3. Flux and Sources of Nutrients in the Mississippi-Atchafalaya River Basin

The report is a comprehensive examination of the flux and sources of nutrients in the
MARB. It makes the connection that nutrients in the lakes and streams of Iowa that are a
water quality concern within our borders eventually reach the Mississippi River and flow
to the Gulf of Mexico. It emphasizes the importance of state nonpoint-source reduction
programs that encourage efficient use of nutrients in agricultural production

In Section 6.1, the authors discuss the importance of nutrient point sources. The
estimates indicate that if all N released from point sources reached the Gulf, they would
account for 18% of the estimated Mississippi River N-flux. Although less than
agricultural nonpoint sources, these contributions also should be addressed in the Task
Force Action Plan. For the three Iowa basins, point source inputs appear even less
important, accounting for less than 5% of estimated N-flux (Table 4.3). While these
estimates describe the maximum possible impact of point sources, they provide a useful
perspective. It also is important to note that point source inputs to streams are direct and
bypass most of the N-output mechanisms discussed in the report.

In Section 6.1, the authors state that the estimated total N-flux to the Gulf via the
Mississippi River accounts for only about 7.5% of agricultural N-inputs (the comparable
figure for the Iowa basins is 9%). This relatively small percentage must be kept in mind
when practices to control N-loss are considered. Even substantial changes in N-
management may have a small impact on the portion of the inputs that reach the Gulf.

Topic #4. Effects of Reducing Nutrient Loads to Surface Waters within the
Mississippi River Basin and the Gulf of Mexico

The report portrays agriculture as one of the main sources of nitrogen to the Gulf of
Mexico and nitrogen as the main causative agent of hypoxia. The report indicates that
the types of agriculture practiced in Iowa are those having the greatest-nitrogen loss rates.
Many of the management practices recommended in the report have been researched,
reviewed, and discussed previously in Iowa and for Iowa conditions. These specific
results should be utilized whenever possible to determine potential courses of action for
reducing nutrient loading to Iowa surface water systems and to the Mississippi river from
Iowa. Although many Iowa farmers have already adopted more nutrient-effective
strategies, producer behavior changes slowly, especially when the market causes them to
be risk-averse.

The report suggests that Iowa's agricultural producers will need to decrease field losses of
nitrogen substantially (e.g., 30% or more) to help protect down-stream aquatic resources.
The complexity of this issue makes firm numbers hard to nail down, but the report


Again, a comprehensive strategy to reduce nutrient flux should address all nutrient
sources including point sources and non-agricultural nonpoint-sources of nutrient
discharge into the Mississippi/Atchafalaya River system.

Topic #6. Evaluation of Economic Costs and Benefits of Methods for Reducing
Nutrient Loads to the Gulf of Mexico

In the Topic #6 report, Table 5.1-1 (p. 128, reproduced below) shows that there are no
direct estimated benefits from reducing nitrogen loads to the Gulf of Mexico. Therefore,
there is not a Gulf of Mexico justification for establishing policies to reduce nitrogen
loading.

Table 5.1-1 Summary of Estimated Benefits Associated with Hypoxia Reduction in the
Gulf of Mexico as Reported by Topic Group 2: Ecological and Economic Consequences
of Hypoxia

Potential Benefits of Hypoxia Reduction ‘onclusion from Topic Group 2
Restoration of Ecological Communities Data Not Available to Estimate Benefits
In the Gulf of Mexico .
Increased Commercial Harvesting of Given Available Data, No Estimable
White and Brown Shrimp Benefits From Hypoxia Reduction
Increased Commercial Harvesting of Given Available Data, No Estimable
Gulf Menhaden Benefits From Hypoxia Reduction
Increased Commercial Harvesting of Given Available Data, No Estimable
Red Snapper Benefits From Hypoxia Reduction
Increased Recreational Harvestin, ita Not Availabi timate Benefits

The authors correctly point out that environmental benefits would accrue from adopting
the policies that they consider, namely soil erosion reductions and the values associated
with wetland restoration. But none of these values are derived from a reduction in
nitrogen loading. They derive from increased recreational opportunities, improved water
clarity, wildlife benefits, etc. Policy should be formulated to meet policy goals, not
justified on the basis of benefits only indirectly related. The number of wetlands to
restore, a fertilizer tax level or fertilizer restrictions should be based on the impact on N-
loading to the Gulf. It is quite likely, for example, that the optimal acreage of wetlands to
restore based directly on wetlands values is quite different from 5 millions acres.
Likewise, the amount of soil erosion reductions should be determined based on the
benefits of reduced erosion, not on N loading reductions.

There is little justification in the report for a policy objective of reducing nitrogen loading
by 20%. On page 30 (fourth paragraph) the authors justify a 20% scenario as being a


USGS, EPA, NOAA, USDA and other groups having a sufficiently broad constituency to
provide a basis for national and regional policy actions.

In the summary section on “Nutrient Intervention,” the authors conclude that “success
stories” from efforts undertaken on a relatively small scale in Florida and Louisiana are
justification for basin-wide nutrient management efforts throughout a major portion of
the United States. However, the relevant sections of the complete report seem to paint a
more pessimistic picture, noting that a decade of nutrient management effort in the
Chesapeake Bay watershed has failed to produce measurable improvement, and that
“decades of data may be necessary to statistically demonstrate that remedial actions have
helped recovery of oxygen concentrations." It is not appropriate to establish nutrient
management policy for the MARB on the basis of two small scale “success stories.”

The report mentions incidents of hypoxia around the world (Baltic Sea and Adriatic Sea),
~ some of which apparently have longer periods of record than are available in the Gulf of
Mexico, yet relatively little is said about what has been learned from these sites or what
governments at these locations are doing about hypoxia. In view of the relatively short
period of record in the Gulf, it would be desirable to further evaluate the data, causes of

hypoxia, and effect of any remedial programs at other locations in the world.

In the Executive Summary of the report, a section titled "River discharge and flux of
materials," makes passing reference to efforts aimed at "managing the birdfoot delta for
greater discharge through the Southwest Pass..." Little more is said about this in the
main report other than on p. 35 where it is noted that the percentage of Mississippi River
water flowing eastward onto the Mississippi-Alabama shelf is unknown. This raises
questions as to whether the Gulf hypoxic zone that has been monitored the most (transect
"C" in the core of the hypoxic zone, and which is claimed on p.3 to be "representative" of
the Louisiana shelf) is not unduly influenced by efforts to channel flow to the west
through a particular outlet from the delta. The Corps of Engineers should be asked to
clarify current policies on management of flow in the delta. If nutrient concentration and
hypoxia off the Terrebonne Bay area is being exacerbated by delta flow control strategies
designed to facilitate maintenance of shipping channels, this contribution to the problem
should be brought to light. This does not relieve basin states from the responsibility to
strive for reduced nutrient losses. However, a comprehensive strategy to reduce nutrient

’ flux should address the Gulf of Mexico impact of channel management on behalf of the
shipping industry.

Topic #2. Ecological and Economic Consequences of Hypoxia

The report evaluating the economic and ecological consequences of hypoxia in the Gulf
of Mexico indicates that the shallow continental shelf area affected by hypoxia does show
signs of hypoxia-related stress. However, the report also concludes, “Any effect of
hypoxia in the northern Gulf of Mexico is intertwined with other environmental stressors.
To understand specifically how hypoxia affects populations in the Gulf we first need to
determine the contribution of alj natural and anthropogenic sources of mortality and
growth to population dynamics. We also need to determine what functional aspects of


implies that the solution to hypoxia and other coastal eutrophication issues relies upon
changes in Midwestern agriculture. The report also acknowledges that much uncertainty
remains concerning what will happen to hypoxia in the Gulf if changes in N and P
use/management or other crop practices take place in Iowa and the rest of the Mississippi
River watershed. This uncertainty includes the magnitude of change — what load
reduction in Iowa will be necessary to achieve a positive change in the Gulf? The
potential impact on Iowa's agriculture depends upon the exact degree of change that is
required. Some suggested remedies are relatively benign and follow currently
recommended nutrient-use practices in lowa. These methods could be potentially
positive agronomically and environmentally, especially when viewed on a situation-
specific and practice-specific basis. Other remedial measures could be seriously
detrimental agronomically and economically. Without better cause and effect
understanding, nutrient reductions below university recommended, science based
agronomic needs should not be recommended or expected.

In the Executive Summary (p.xiii), the authors state “Moreover, human responses to
changes in agricultural practices tend to be buffered as well. For example, imposition of
restraints on application of fertilizer and manure in targeted areas will cause some
reduction of agricultural production...” There are many good reasons to reduce nutrient
flux from agriculture. There also are many ways to achieve these reductions. The report
should put its greatest emphasis on those pathways that are most likely to succeed.

Means of nutrient-flux reduction other than “imposition of restraints” should be :
emphasized. Incentives and voluntary efforts backed by farmer education are more likely
to gain acceptance and achieve results.

Many of the N-reduction strategies listed in 3.2.1.5 of the report are costly. Emphasis
should be placed on broad use of low-cost methods; especially given the farm crisis we
are currently experiencing. The percentages for reduction in nitrate losses listed for each
practice should be documented for conditions within individual states. These reductions
are extremely site-specific. Also, it is uncertain if implementing these practices will result
in decreases in nitrate loss to surface waters large enough to effect necessary N-load
changes to the Gulf. Changing rates and the timing of N application cannot stop nitrate
movement from soiis. Unpredictability in climate also increases the difficulty in
implementing these changes.

Education regarding N management should be targeted to specific fields, farms,
producers, or watersheds. This is an excellent role for agricultural extension. To
improve producer accounting for N and P contained in manure, there also must be
increased confidence regarding variability in nutrient analysis, application, and
availability. In Iowa, there are recommendations for best nutrient and crop production
practices in addition to those outlined in this section. The salient question is, if all crop
acres had these practices implemented on them, would the cumulative effects be enough
that nitrate loading is reduced to levels needed to effect changes in the Gulf of Mexico?

Discussions in the report concerning the modeling work indicate considerable uncertainty
about the potential impacts of source N and P changes on loading reduction and water


“win-win” situation in that both the environment and the agricultural sector can both
benefit. Yet on the top of page 31, they justify the 20% scenario because it produces
“relatively modest impacts” which include a 6% reduction in crop acreage, significant
yield reductions, and associated price increases. These estimated impacts of 20% N
reduction do not suggest a win-win situation.

However, there can be economic benefits from improved nutrient management for
individual farmers. Choosing a policy that maximizes the economic and environmental
benefits of nutrient management for individual farmers is justifiable on the basis of the
reports.

Summary

The information and findings contained in the six CENR reports are valuable. They
make the case for continued and accelerated efforts on the part of states to address point
and nonpoint-sources of nutrient contamination. Improved nutrient management will
result in improved local water quality and reduced nutrient flux in the
Mississippi/Atchafalaya River Basin. Reduced nutrient flux may reduce the extent or
duration of hypoxic conditions in the Gulf of Mexico. Unfortunately, the reports
discount potential benefits of improved nutrient management for other industrial and
municipal sources of nutrients.

The CENR reports demonstrate the need for additional monitoring within the entire
Mississippi/Atchafalaya River Basin to better document the sources, nature and extent of
the problem. This monitoring will also be important to document changes in nutrient flux
as better management and control practices are implemented across the basin. They also
support the need for additional research regarding nutrient management in the upper
Midwest, and the effects of nutrient enrichment, Mississippi River management, and
channelization on coastal environments and hypoxia in the Gulf of Mexico.

The six reports do not do not provide evidence to support nutrient management
regulations in the agricultural production areas of the Mississippi/Atchafalaya River
Basin as a hypoxia reduction strategy.


THOMAS J. VILSACK OFFICE OF THE GOVERNOR SALLY J. PEDERSON

GOVERNOR STATE CAPITOL LT. GOVERNOR
DES MOINES, 1OWA 50319
515 261-5211
FAX 515-261-6611

August 2, 1999

Mr. John Field

Gulf of Mexico Hypoxia Working Group
National Centers for Coastal Ocean Science
WS 13446 SSMC4

1305 East-West Highway

Silver Spring, MD 20910

Dear Mr. Field:

Attached are comments of the State of Iowa regarding the six CENR reports regarding
the causes and consequences of hypoxia in the Gulf of Mexico. They have been prepared with
the assistance of faculty and researches of Jowa State University and staff of lowa’s Department
of Natural Resources and Department of Agriculture and Land Stewardship.

The issue of nutrient flux in Jowa’s lakes, rivers and streams is very important to Iowans
as we utilize these waters as sources of drinking water, recreation, and habitat. We believe it is
in our interest to manage sources of nutrients from agriculture, industry and communities in a
manner that protects these resources. We also believe that there are opportunities to improve
nutrient management. This is consistent with out state non-point source management plan.

While there remains a lot to learn about nutrient flux and hypoxia in the Gulf of Mexico,
we hope that efforts we undertake in Iowa to improve nutrient management indirectly have a
positive impact on water quality in the Mississippi/Atchafalaya River Basin, and ultimately the
Gulf. However, I share the concern of our review team that the six reports do not provide
evidence to support nutrient management regulations as a hypoxia reduction strategy.

Sincerely,

6 Ce

Thom: ilsack
Governor

T3V/nsf
HYPOXIA


quality reactions in the Gulf of Mexico. Adding to the uncertainty is the complexity of
interactions, impacts from other elements such as silicon and freshwater load. This raises
questions and concerns about recommending major nutrient use changes in the
Mississippi watershed, and specifically Iowa, when one cannot predict the quantifiable
extent of improvements to the Gulf. Also, if the large-scale landscape modeling used in
the report is correct, then, as reported, a 34% reduction of fertilizer N to corn, corn-
soybean, and sorghum fields would only reduce the total N load from the Upper
Mississippi and Ohio rivers by 2 to 5% (although as mentioned in the report, fully
accounting for tile drainage may change these results). It is important to the agricultural
industry that significant efforts to change agricultural inputs be repaid by significant
improvements in water quality and that any economic costs of these changes be
adequately compensated.

Topic #5. Reducing Nutrient Loads, Especially Nitrate-Nitrogen, to Surface Water,
Groundwater, and the Gulf of Mexico

The goal of the report was to “identify and evaluate approaches for solving the problem
of hypoxia in the Gulf of Mexico” based on the conclusion that the problem is “due to
excess nutrients, particularly nitrate-nitrogen.” Care must be taken when making
recommendations. First it must be proven that they will solve the problem, and second,
the potential drawbacks or costs of implementing these recommendations must be
carefully evaluated. The authors use the term "slight" to describe the 12 bu/ac yield
teduction that would come with a 20% reduction in N application to corn. In some years,
this 12 bu/ac may represent most if not all of the farmers net profit.

In the Executive Summary (p. xi) the authors state that they “gave recommendations as to
the most reasonable combination of approaches that would be necessary to solve the
problem” (hypoxia in the Gulf). Determining what is “most reasonable” may not be
appropriate until the questions ‘what cost?’ and ‘who pays?’ are answered.

The report states that “Improved manure management, including uniform application of
known nutrient amounts...is critical.” However, current reality is that economics and
technology available do not allow adequate uniformity of manure application or
knowledge of manure nutrient content/availability to allow a producer to give precise
credit for N. Also, its availability in terms of time and location can be critical to yield
and economic viability of production.

In Section 6. Conclusions and Recommendations, the authors state that “Point sources of
nitrogen appear to be of little consequence (<5%) in the overall Mississippi River Basin
nitrogen load....” This statement confuses what is loaded to the land and what is directly
loaded into the Mississippi River. The 0.27 million metric tons of N from municipal and
industrial sources are direct inputs into the MARB system. Although they represent less
than 5% of the overall input for the basin, they represent 17% of the N output from the
river to the Gulf.



State of lowa Comments
Committee on Environment and Natural Resources Hypoxia Work Group
Six Committee Reports

The Committee on Environment and Natural Resources (CENR) Hypoxia Work Group
for the Mississippi River/Gulf of Mexico Watershed Nutrient (MR/GMWN) Task Force
has done a credible job examining the scientific literature and archived data related to-the
issue of hypoxia in the Gulf of Mexico. The six committee reports describe the hypoxic
condition that exists, its ecological and economic consequences, and the flux and source
of nutrients within the Mississippi/Atchafalaya River Basin (MARB). They project the
in-Gulf effects of reducing nutrient loads to surface waters within the basin, evaluate
approaches to reduce nutrient loads, and evaluate the economic costs and benefits of
agricultural nutrient reduction measures.

. The reports point out limitations in scientific understanding of hypoxia and related issues,
data and research needs, and the existence of complex scientific, social, and economic
interactions. The reports also are unable to identify direct economic or environmental
benefits from reducing nitrogen loads from the Gulf of Mexico. These limitations make
it impossible to identify a singular course of action that, applied over the entire MARB,
can be expected to result in a predictable consequence of reduced nutrient delivery to the
Gulf, reduced hypoxic zone extent and duration, and improved economic and/or
environmental conditions within the Gulf, without ‘marginal’ (in reality, major)
economic and social impact on the agricultural industry and the states of the Upper
Mississippi River Basin.

In the absence of such a course of action, it is important that the strategy focus on
win/win opportunities to reduce nutrient flux and improve environmental conditions
without negative economic impact across the MARB. These benefits can be quantified
and should form the basis for MARB policy.

The information in the CENR study offers important insight into the need for better
nutrient and waste management in agriculture, industry, and urban and municipal
wastewater treatment. These needs are well documented in individual state plans and
programs to address point and nonpoint-sources of pollution. The strongest argument
that can be made from the CENR study is that all states within the MARB, with
continued and increased support from federal agencies, must increase their efforts to
develop and implement effective point and nonpoint-source pollution prevention
programs. There is strong evidence that nutrient and waste management prevention
programs can provide measurable improvements locally in water quality, plant and
biological communities, and in-stream habitat without adverse economic implications for
producers. It follows that these improvements should eventually be felt downstream as
far as the Gulf, although the CENR study does not provide evidence of direct correlation.

For this reason, as supported in the following review of the six CENR reports, it is
important that MR/GMWN Task Force Action Pian support:


¢ awatershed based approach by states of the MARB to address nutrient
management as one element of state water quality protection goals; rather than a
hypoxia reduction strategy or regulation imposed over state nonpoint-pollution
prevention plans

© increased water quality monitoring to better identify and quantify nutrient sources
and flux, and to measure the impact of state nutrient management and discharge ~
reduction programs

© increased research emphasis to better understand (1) the impacts of nutrient
management on crop production and nutrient loss in the Midwest, and (2) the
effects of nutrient enrichment, Mississippi River management and channelization
on coastal environments and hypoxia in the Gulf of Mexico

Finally, regardless of what sector provides the majority of nutrient input into the
Mississippi River, programs to reduce nutrient flux must fairly address all contributing
sectors in all states of the MARB. This is the only way that the plan recommendations
will gain any level of consensus support basinwide.

The following review comments of the six CENR reports substantively support the above
recommendation.

Topic #1. Characterization of Hypoxia

The report provides a comprehensive review of the physical, chemical and biological
consequences of hypoxia. It sets the stage for deliberation of the proximate causes of
increased phytoplankton production and the role of human-induced factors. However, a
significant knowledge gap appears to be a more complete understanding of the role of
current or modified fluxes of nitrogen (N), phosphorus (P), and silicon (Si) in controlling
hypoxia. The report presents evidence and analyses that identify the nitrate load in the
Mississippi River as the likely cause of hypoxia. However, the authors also present data
documenting instances where either P or Si limit primary production. It is important that
the interactions of these elements also be understood and factored into the design of
effective hypoxia reduction strategies.

The authors make a case that there can be no determination of a marine response to any
nutrient changes within the Mississippi River system without continued acquisition of
basic hydrographic, chemical and biological data related to the development and
maintenance of hypoxia over seasonal cycles (Pg. 127, par. 3). In view of what currently
is not understood about the scope and mechanisms of the hypoxia problem and the size of
the watershed that may ultimately be affected, basin and coastal states should insist on
continued research. The language of the report should make it clear to policymakers that
Gulf hypoxia is not yet totally understood. While there are positive nutrient management
actions that can be taken to reduce nutrient flux, further research is essential. It should be
conducted not only by researchers representing Louisiana, but also by universities,