Post on 19-Mar-2018
Dealing with downstream effects of excessive
agricultural fertilizer use at a watershed scaleHow ecologically engineered wetlands can help
William J. Mitsch, Ph.D.
Eminent Scholar and Director,
Everglades Wetland Research Park
Sproul Chair for Southwest Florida Habitat Restoration
and Management
Florida Gulf Coast University
Naples Florida, USA
Editor-in-Chief, Ecological Engineering
• Water purification
• Flood
regulation/storm
protection
• Biodiversity islands
and corridors
• Climate regulation
(Carbon
sequestration)
• Locations for human
relaxation and nature
observation/education
Wetlands provide
valuable “ecosystem
services”:
Excess nitrogen and phosphorus are causing changes to aquatic ecosystems
far in excess of any changes we have seen so far due to climate
“More than 750 aquatic ecosystems worldwide currently suffer from degraded
ecosystem services due to urban and agricultural inputs that cause water
quality impairments such as hypoxic ‘dead zones’ and harmful algal blooms”
Prof. Jay Martin, Ohio State University
Source: World
Resource
Institute
g-N m-2 y-1
Nitrogen Budget
Denitrification
Annual Pattern
Batson et al., 2012.
J. Env. Qual. 41: 2024-2032.
Song et al., 2014
Ecol. Eng. 72: 40-46.
Better Fertilizer Management
Created/Restored
Wetlands
Restored
Riparian
Bottomlands
Mitsch et al. 2001
2 million ha of these ecosystems are needed
Mississippi-Ohio-Missouri (MOM) Basin Restoration
Mid-term grades for the six large-scale wetland restorations*A = excellent; B = good; C = average; D = poor; F=failure; I = incomplete
*Mitsch, W.J. 2014. When will ecologists learn engineering and engineers learn
ecology? Eco. Eng. 65: 9-14.
Restoration
Case Study
Type of
restoration
Ecosystem
being
restored
Scale of
restoration,
km2
Ecosystem
services
sought
Mid-Term
Grade
Indian Ocean
Mangroves
(Post-Tsunami)
Coastal Mangrove
swamps 15,000
Coastal
protection C
Louisiana
(Mississippi
River) Delta
Coastal Mostly salt
marshes 36,000
Coastal
protection;
regional ecology
enhancement
D-
Delaware Bay
Salt Marshes
Coastal Salt marshes
670
Fisheries and
aquatic food
chain
enhancement
A-
Mississippi-
Ohio-Missouri
(MOM) River
Basin
Watershed Freshwater
wetlands and
riparian forests
20,000 Water quality
improvement I
Mesopotamian
Marshlands
Watershed Phragmites
marshes 20,000
Return of lost
culture and
landscape
A
Florida
Everglades
Watershed Freshwater
streams and
marshes
46,000
Water quality
and hydrologic
improvement
D+
The Greater Florida Everglades
Kissimmee
RiverLake Okeechobee
The Everglades
“River of Grass”Gulf of
Mexico
Big Cypress
Swamp
Coastal Mangroves
“Everglades Forever”
"There are no other Everglades in
the world. They are, they have
always been, one of the unique
regions of the earth; remote,
never wholly known. Nothing
anywhere else is like them..."
Everglades: River of Grass (1947)
Marjory Stoneman Douglass
Mid-term grades for the six large-scale wetland restorations*A = excellent; B = good; C = average; D = poor; F=failure; I = incomplete
*Mitsch, W.J. 2014. When will ecologists learn engineering and engineers learn
ecology? Eco. Eng. 65: 9-14.
Restoration
Case Study
Type of
restoration
Ecosystem
being
restored
Scale of
restoration,
km2
Ecosystem
services
sought
Mid-Term
Grade
Indian Ocean
Mangroves
(Post-Tsunami)
Coastal Mangrove
swamps 15,000
Coastal
protection C
Louisiana
(Mississippi
River) Delta
Coastal Mostly salt
marshes 36,000
Coastal
protection;
regional ecology
enhancement
D-
Delaware Bay
Salt Marshes
Coastal Salt marshes
670
Fisheries and
aquatic food
chain
enhancement
A-
Mississippi-
Ohio-Missouri
(MOM) River
Basin
Watershed Freshwater
wetlands and
riparian forests
20,000 Water quality
improvement I
Mesopotamian
Marshlands
Watershed Phragmites
marshes 20,000
Return of lost
culture and
landscape
A
Florida
Everglades
Watershed Freshwater
streams and
marshes
46,000
Water quality
and hydrologic
improvement
D+
Stormwater
Treatment
Areas (light
green)
Treatment Wetlands in the Everglades
aka Stormwater Treatment Area (STA’s)
Lake
Okeechobee
Everglades
Agricultural
Area
23,000 ha of
these wetlands
have been
created
Everglades National Park
Stormwater Treatment Areas (all 6 STAs)
Mitsch et al.
2000
0,00
0,20
0,40
0,60
0,80
1,00
1,20
1,40
1,60
1,80
2,00
2004 2005 2006 2007 2008 2009
Pho
sp
horu
s r
eta
ine
d, g
-P m
-2 y
r-1
Stormwater Treatment Areas (STAs) upstream of Everglades
!
" !
#!
$!
%!
&! !
&" !
&#!
&$!
&%!
" ! !
" " !
" #!
" $!
" ! ! % " ! ! ' " ! &! " ! && " ! &"
STA 1W Phosphorus (last 5 years)
Stormwater Treatment Areas (STAs) upstream of Everglades
10 ppbAVERAGE INFLOW 191 ppb
AVERAGE OUTFLOW 35 ppb
AVERAGE REDUCTION 82%
240
200
160
120
80
40
0
2008 2010 2012
The Mesocosm Experiment
Plant Community Treatments1. Sawgrass (Cladium jamaicense)
2. Cattail (Typha domengensis)
3. Water lily (Nymphaea odorata)
4. Water lily-Eleocharis sp. mixed community
5. Submerged Aquatic Vegetation (SAV) including
Najas guadalupensis, Chara sp.
6. Control- soil without introduction vegetation**Through the first two years of the study, the control system became dominated by
Najas guadalupensis and Chara sp. It is sometimes referred to by us as the
“self-design” treatment.
Stormwater Treatment Area (STA) mesocosm experiment
Sierra Club EndorsementJanuary 11, 2015
Larry E. Fink, M.S., Waterwise Consulting, LLC
For those who think I have engaged in hyperbole as regards my claim
that SFWMD systematically under-designed the STAs, here is a hot
off the presses analysis by William Mitsch, formerly at Ohio State
University and now at Florida Gulf Coast University, et al., who, in
the paper, "Protecting the Florida Everglades Wetlands with
Wetlands: Can Stormwater Phosphorus be Reduced to Oligotrophic
Conditions?" concludes as follows:
"-- Achieving 10 ppb phosphorus concentrations consistently from
created wetlands in the Florida Everglades remains problematic but
this research confirms that it may be possible with low loading rates,
the right vegetation communities, and low-nutrient soils.”
Satellite Image from Sept 3, 2011 of Western Lake Erie (Michalak et al. 2013) PNAS
Lake Erie
Algal Blooms
“Nutrient
impairment
continues to
plague Lake Erie,
impacting an
$11.5 billion
tourism industry” Ohio Lake Erie
Phosphorus Task Force
(Nov 2013)
Thursday, August 21, 2014
Mayor says water crisis is similar to 9/11Both were wake-up calls, led to second-guessing
BY TOM TROY, BLADE POLITICS WRITER
Mayor D. Michael Collins said on Monday that the water emergency that crippled
Toledo’s water supply Aug. 2 was like the terrorist attack suffered by the United
States on Sept. 11, 2001 — a wake-up call to community action.
And Toledo City Council’s utilities committee on Monday delved into the Aug. 2-4
crisis that made Toledo a national byword for the health threat posed by blooming
algae.
Mr. Collins said in an interview with The Blade’s editorial board and a Blade
reporter that just as 9/11 created a change in Americans’ attitude toward terrorism
preparedness, so the great algae bloom of 2014 should not be ignored.
Source: Dolan and Chapra (2012) J. Great Lakes Res, 38, 730-
740
Sources of Phosphorus
to Lake Erie, 2003-2011
Metric tons
P/yr
Non-point source inputs 6,183
Point-source inputs 1,884
Atmospheric inputs 525
Inputs from upstream Lake
Huron
336
TOTAL 8,929
Source: Scavia et al (2012) J. Great Lakes Res
The western basin received approximately
60% of the 2003-2011 average TP loads
Most of that load
comes from the
Maumee River Basin
Restoring the Black Swamp to Save
Lake Erie
By William J. Mitsch
Sept. 4, 2014 Water Environment Federation
The harmful algal blooms in western Lake Erie for the past few years and the toxic
algae that caused Toledo Ohio to shut down the municipal water supply in August 2014
are symptomatic that there is something very wrong with the way we are managing our
landscapes. Nutrients, especially phosphorus are pouring into this shallowest (18 m
average) portion of the shallowest Great Lake, mostly as runoff from agricultural fields,
are causing seasonal bursts in algal production with their accompanying problems of
slimy aesthetics, dissolved oxygen depletion in bottom waters, fish kills, and toxicity.
www.wef.org
• Wetlands can be designed to remove significant amounts of
nitrogen and phosphorus from agricultural runoff in large-scale
watersheds. Concentrations on the order of 20-30 ppb of total
phosphorus and 1 ppm total N are reasonable expectations
but lower concentrations can be achieved.
• While 10 ppb of phosphorus from treatment wetlands is a
challenging goal in the Florida Everglades, it may be possible
for storm waters from the Everglades Agricultural Area to
achieve those levels if extensive wetlands downstream of the
current stormwater treatment wetlands (STAs) are
implemented.
• Another strategy in the Florida Everglades is to simply
recognize that the current water conservation areas and other
basins south of the STAs may already be providing that
ecosystem service.
Conclusions
• The fact that wetlands do improve water quality (and
sequester carbon) sustainably does not automatically mean
that they will be implemented. There are large land
requirements and some land managers still fear committing to
wetlands for a variety of non-scientific reasons.
• Wetland restoration and creation are not easy. They require
attention to Mother Nature (self-design) and Father Time
(new wetlands take time to reach their potential).
Conclusions
Available on line at John
Wiley and Amazon.com
Mitsch, W.J. and J.G.
Gosselink. 2015.
Wetlands, 5th ed. John
Wiley & Sons, Inc.,
Hoboken, NJ. 744 pp.