1

Atmospheric Deposition of Phosphorus to Freshwater Lakes

Jennifer Boehme1, Rachel Schulhauser

1, Raj Bejankiwar

1

1 Great Lakes Regional Office, International Joint Commission, 100 Ouellette Avenue, Windsor,

ON N9A 6T3

This document is a working draft prepared for the IJC’s Lake Erie Ecosystem Priority (LEEP) by the GLRO Staff and is not for citation. Views expressed are solely those of the authors. See the draft LEEP report for findings and recommendations from the IJC.

2

T

CONTENTS

Abstract ...................................................................................................................................... 3

Introduction ............................................................................................................................... 3

Methodology ............................................................................................................................... 6

Phosphorus Production ............................................................................................................. 6

Sources of Atmospheric Phosphorus ....................................................................................... 7

Deposition Variability ............................................................................................................... 9

Dominance of Deposition Pathways – Wet or Dry? ............................................................. 11

Implications for Lake Erie ...................................................................................................... 13

Conclusion ................................................................................................................................ 16

References ................................................................................................................................. 20

Table 1. The annual percentage (%) of a lake’s total phosphorus load as atmospheric deposition

....................................................................................................................................................... 12

Figure 1. Average estimated phosphorus loadings (MTA) for Lake Erie (1996-2002); data from

Dolan and McGunagle, 2005. Data includes estimates for contributions from Lake Huron and

unmonitored areas. Direct sources are point sources that discharge into Lakes Erie or St. Clair,

the Detroit or St. Clair Rivers or unmonitored areas. ................................................................... 18

Figure 2. Total phosphorus loadings for Lake Erie, 1967-2007. Includes point and non-point

source loads from the United States and Canada. Figure reproduced from Baker, 2011, data from

David Rockwell, (U.S. EPA and David Dolan (Univ. of Wisconsin, Green Bay) ....................... 19

3

ABSTRACT

This paper is a critical review of the contribution of atmospheric phosphorus deposition

to the total phosphorus loadings to lake ecosystems, with a special focus on the relevance of this

source to Lake Erie and the Laurentian Great Lakes. It suggests that atmospheric phosphorus is

not negligible to total phosphorus loadings to lakes of varying surface areas, and may contribute

a significant portion of soluble reactive phosphorus to lake ecosystems. The relative proportions

of dry and wet phosphorus deposition are poorly characterized for many lakes, including Lake

Erie, and both pools demonstrate appreciable, though location-specific, contributions of soluble

reactive phosphorus to respective lake systems. No general trends in lake geographic

distribution or seasonality can be determined from the literature for atmospheric phosphorus

deposition in the lakes examined for this review. This high variability between lake systems,

along with the potential significance of atmospheric phosphorus deposition, provides support for

further study of Lake Erie and the Great Lakes to understand the phosphorus cycle for this large

freshwater system and its potential effect on nutrient modeling for the region.

INTRODUCTION

The global freshwater supply is approximately 2.5% of the world’s total water, with 0.1

million km3

of available freshwater in the form of lakes and marshlands (Worldwater.org). The

Laurentian Great Lakes contain approximately 18% of the world’s freshwater (Environment

Canada, 2009) and encompasses more than 765,000 km2

between 8 US states and the Canadian

province of Ontario with 10% and 30% of the American and Canadian populations residing in

the basin, respectively (Danz et al., 2007). In addition to their use as a drinking water source,

lakes and marshlands support biodiversity, wildlife habitat and other ecosystem services that

enhance human enjoyment and advance commercial activities. Globally, freshwater lake

4

systems are impacted by the delivery of essential nutrients such as phosphorus via natural

pathways often influenced by anthropogenic activities, giving rise to unintended effects on

freshwater ecosystems.

Phosphorus is a limiting nutrient in aquatic ecosystems (Blake & Downing, 2009; Reutter

et al., 2011), and excesses of phosphorus from natural and anthropogenic activities have been

attributed as the principal driver of eutrophication in lakes, causing a diverse range of associated

water-related problems including hypoxia, harmful algal blooms, loss of biodiversity and other

adverse effects (Schindler, 1971; Pollman et al., 2002; Paytan & McLaughlin, 2011; Rossignol et

al., 2011).

One lake historically associated with eutrophication is Lake Erie in the North American

Great Lakes. Lake Erie is the twelfth-largest lake in the world with an area of 35,696 km2

(Herdendorf, 1983) and provides drinking water for over 11 million Americans and Canadians

located with its basin (North et al., 2007). In the 1960s and 70s, excessive phosphorus loading to

Lake Erie was a main driver of the lake’s eutrophication (Baker, 2011) which coincided with

high growth rates and nuisance accumulations of algae, particularly cladophora and

cyanobacteria (Herdendorf, 1983; Higgins et al., 2005; Han et al., 2010). The onset of hypoxia

in Lake Erie also has a long-recognized link to total phosphorus concentrations and loadings

from external sources (Burns & Ross, 1972; El-Shaarawi, 1987).

Lake Erie is situated within some of the most urbanized areas of the Great Lakes basin.

Phosphorus deposition rates to Lake Erie may be higher than to the upper Great Lakes due to

increased impacts of population and industrialization which add additional sources of

phosphorus to the lake (Shaw et al., 1989; Danz et al., 2007). In 1978, an established total

5

phosphorus target load of 11,000 tonnes was set for Lake Erie under the Great Lakes Water

Quality Agreement (Fraser, 1987; Baker, 2011) in order to combat eutrophication, algae blooms

and other related water quality issues. There was a 56% decline in the total phosphorus loadings

to Lake Erie from 1968 to 1982 (Fraser, 1987), which improved the eutrophic conditions of the

lake. However, levels of phosphorus in Lake Erie have been rapidly rising in recent years (Baker,

2011), and have been tied to increased algae biomass during the summer months (Conroy et al.,

2005). The connection between algae growth rates and phosphorus sources in Lake Erie has

shifted, and clearer understanding of this shift is needed to provide for effective long term

management of eutrophication in all lake ecosystems.

Atmospheric deposition is one natural nutrient transportation pathway that provides a

non-controllable source, can prove difficult to quantify and measure and has a high potential for

human impact. Atmospheric sources can provide significant contributions of nutrients to

freshwater lake systems (Chen & Fontaine, 1997; Anderson & Downing, 2006) although this is

one of the least understood mechanisms of nutrient delivery. Phosphorus can find its way from

the airshed into lake ecosystems via inputs from 1) rain or snowfall, known as wet deposition;

and (2) gaseous and particulate wind transported particles, or dry deposition (Anderson &

Downing, 2006; Zhai et al., 2009). Wet and dry nutrient loadings to aquatic ecosystems,

particularly phosphorus, have increased over the years as a direct result of anthropogenic

activities (Herut et al., 1999; Zhai et al., 2009). Thus, it is essential to examine the atmospheric

deposition pathways of phosphorus in order to understand the host of water quality issues that

arise in aquatic systems due to phosphorus enrichment.

6

METHODOLOGY

This study comprised a review of available literature on atmospheric phosphorus deposition in

fresh and saltwater environments to obtain a complete description of the sources and transfer

mechanisms. Lakes of all sizes were included though relevance to the Great Lake Basin,

especially Lake Erie, was a primary consideration for this study. Research examining both wet

and dry deposition was rare as direct measurements of wet deposition are especially difficult to

collect and prone to method contamination. In limited cases studies identified levels of soluble

reactive phosphorus within the wet or dry fractions of atmospheric phosphorus delivered to

aquatic systems, but comprehensive studies on this question were not available for the Great

Lakes Basin. The resulting synthesis was undertaken to better describe current understanding of

atmospheric phosphorus inputs to Lake Erie and its potential impact the occurrence of harmful

algal blooms within the Great Lakes.

PHOSPHORUS PRODUCTION

The global biogeochemical cycle of phosphorus predominantly involves flows between

sources of biomass, land and water, with the atmospheric contribution being smallest and

consisting of phosphorus affixed to particulate material (Pierrou, 1976). The flow of phosphorus

between sources has been greatly accelerated by human activities, with food production and

consumption requirements estimated to comprise 90% of the global phosphorus demands

(Cordell et al., 2009), specifically for its demand in fertilizers. Phosphorus has many applications

outside of agriculture, including but not limited to detergents, steel production, water softening,

military applications, and ethanol fuel production.

7

Phosphorus for human activities is presently sourced from mined phosphate rock.

Reserves are restricted to a small handful of countries, with the largest reserves in the United

States, China and Morocco (Cordell et al., 2009). The US is estimated to have approximately 25

years of phosphate from remaining domestic reserves, even though it was once the world’s

largest producer, consumer, importer and exporter (Cordell et al., 2009). Morocco and its near

monopoly on the Western Sahara’s phosphate supply represents more than a third of the global

supply of phosphate (Cordell et al., 2009).

Studies have suggested that the current reserves of phosphate are expected to be depleted

within the next 50-100 years, (Cordell et al., 2009; Paytan & McLaughlin, 2011), and yet food

production rates are expected to increase in response to a larger global population. The

phosphate that is extracted will be of lower grade then previously extracted and it will be

expensive to extract, process, and transport (Cordell et al., 2009). Mining activities increase the

physical transport of phosphate rock and its exposure to the natural aeolian (wind) erosional

processes that play an important role in nutrient dispersal within ecosystems. A portion of

phosphate that is extracted can become mobile within the atmosphere in the form of dust.

SOURCES OF ATMOSPHERIC PHOSPHORUS

As a medium for atmospheric transport, dust can travel great distances from its source

location depending on its particle size and eventually can be deposited into water bodies. In

addition to the example of phosphate rock particulates, numerous alternative natural and

anthropogenic sources of phosphorus are available to wind transport, and can contribute to

eutrophication and algae blooms in lakes from atmospheric deposition. Natural sources include a

combination of ocean aerosols (Ahn & James, 2001; J. Luo et al., 2011), vegetation detritus

8

(Dolislager et al., 2012), biomass burning due to lightning (Grimshaw & Dolske, 2002), pollen

(Winter et al., 2002; Report on the Phosphorus Loads to Lake Simcoe 2004-2007, 2009; Blake &

Downing, 2009), insects (Tsukuda et al., 2004), volcanic activity (Tsukuda et al. 2006.pdf, n.d.;

Winter et al., 2002), guano (Tsukuda et al., 2004, 2006), erosive processes providing dust

aerosols (Herut et al., 1999), and microbial reduction of sewage sludge landfill and compost

heaps (Winter et al., 2002). Anthropogenic sources include coal combustion(Winter et al., 2002;

Hartmann et al., 2008; Report on the Phosphorus Loads to Lake Simcoe 2004-2007, 2009),

biomass burning (Morales et al., 2001; Winter et al., 2002; Zhang et al., 2002; Tamatamah et al.,

2005; Tsukuda et al., 2006; Blake & Downing, 2009; Dolislager et al., 2012), aeolian re-

suspension of phosphorus from disturbed soils including quarries, deforestation, agricultural

fields, soil tilling and ploughing, and unpaved roads (Herut et al., 1999; Morales et al., 2001;

Grimshaw & Dolske, 2002; Winter et al., 2002; Koelliker et al., 2004; Tsukuda et al., 2006;

Report on the Phosphorus Loads to Lake Simcoe 2004-2007, 2009; Blake & Downing, 2009;

Brown et al., 2011; Dolislager et al., 2012), urban inputs primarily associated with automobile

combustion emissions exhaust (Connor et al., 1992; L. Luo et al., 2007; Dolislager et al., 2012)

and industrial activities such as fertilizer production and coal combustion

(Grimshaw & Dolske, 2002; Koelliker et al., 2004; Tsukuda et al., 2006; Brown et al., 2011; L

uo et al., 2011). It is recognized that the largest source of atmospheric phosphorus is dust

aerosols followed by anthropogenic activities such as fuel combustion that release phosphorus

(Hargan et al., 2011). Phosphorus sources local to Lake Erie could also include sewage sludge

and compost heaps in the Lake Erie basin.

It is important to note that dust aerosols can originate within a local lake, watershed or

ecosystem. Generally, phosphorus originating from outside the local area of interest is attributed

9

to true atmospheric deposition while sources from within an area of interest can be viewed as

contamination or local recycling rather than true deposition (Ahn & James, 2001). The

importance of these local vs. external sources to atmospheric deposition to lakes is dependent on

air circulation patterns between the sources relative to the lake of interest. It has been suggested

through several lake-wide studies that local emissions can have a larger impact on the lake than

long-range transported materials (Tsukuda et al., 2004; Tamatamah et al., 2005; Dolislager et al.,

2012). Differentiating local recycling from true deposition from external sources is important for

understanding the atmospheric contribution to a region’s phosphorus cycle. However, local

recycling is important from a management standpoint in that it can provide a transfer mechanism

between the airshed and watershed that significantly impacts the phosphorus loadings for lakes.

Atmospheric phosphorus deposition to Lake Erie can be attributed to a variety of natural

and anthropogenic sources from local and external locations. However, unique tracer methods

for known or suspected sources are required to assign an exact origin of atmospheric phosphorus

(Grimshaw & Dolske, 2002; Dolislager et al., 2012), and such methods for geographic

fingerprinting can be extremely difficult to develop.

DEPOSITION VARIABILITY

Weather conditions are a primary driver mobilizing phosphorus within the atmosphere

and can provide significant fluctuations in observed phosphorus levels, similar to observations

for dissolved phosphorus associated with river discharge, and anthropogenic activities also play a

major role (Baker, 2011). Significant regional variability for particulate phosphorus

concentration has been observed due to local particulate sources ( Tsukuda et al., 2004), and

high annual and seasonal variability accompanied by inconsistent long-term trends have been

10

observed ( Ahn & James, 2001). Several global atmospheric deposition studies have found no

consistent seasonal trend for phosphorus deposition in Iowa ( Anderson & Downing, 2006), New

Jersey ( Koelliker et al., 2004), Florida ( Pollman et al., 2002), Lake Michigan (Miller et al.,

2000), and Lake Taihu in China(L. Luo et al., 2007).

However, other studies have found evidence for patterns in phosphorus deposition.

Seasonal activities related to agriculture were found to disturb soil and release phosphorus to the

air shed that was consequently available for deposition ( Anderson & Downing, 2006). A

maximum loading of phosphorus to lakes in the summer and spring periods and lowest rates in

the winter season were found at several locations around the globe, including Lake Simcoe in

Canada ( Brown et al., 2011), South Central Ontario, Canada(Hargan et al., 2011), Lake

Michigan in the United States( Eisenreich et al., 1977), Lake Victoria in East Africa (

Tamatamah et al., 2005), Japan ( T. Kunimatsu & Sudo, 2006), and Lake Taihu in China(Li et

al., 2011). Thus human activities can add detectable variability to particulate mobilization within

an airshed, which overcomes randomness observed elsewhere and is expressed within the

atmospheric phosphorus signal as anthropogenically-induced seasonal variability.

While agricultural activities have been identified here, and mining sites mentioned

previously, the EPA has identified unpaved roads, aggregate storage piles, and heavy

construction as additional potential sources of particulate matter of no greater than 10

micrometers in aerodynamic diameter, in the form of what it terms “fugitive” dust, so named due

to it being discharged into the atmosphere outside of a controlled flow stream ( US EPA, 2000).

Dust from such sites of elevated human activity could also act as distributed sources for

atmospheric particulate phosphorus.

11

DOMINANCE OF DEPOSITION PATHWAYS – WET OR DRY?

Atmospheric deposition of phosphorus is known to be mainly derived from particulate

and aerosol materials found in dry deposition ( Zhai et al., 2009) with lesser inputs of

phosphorus identified in wet deposition such as rainwater ( Migon & Sandroni, 1999). The

fraction of particulate phosphorus dissolved in rainwater has been estimated as high as 13% (

Ridame & Guieu, 2002). As there is no natural gaseous form of phosphorus, it has no

atmospheric component in its global biogeochemical cycle.

Atmospheric deposition can contribute significantly to a lake’s total phosphorus load

(Table 1). A combination of wet and dry deposition to a lake is described by its total bulk

loading rate. However, a phosphorus deposition study performed in South Florida found that wet

and dry deposition are two independent processes with low correlation ( Ahn & James, 2001).

Thus, it is critical to determine whether wet or dry deposition is the most relevant for evaluating

a lake’s total phosphorus load.

Concentrations of P by dry deposition has been reported as 4 to 10 times greater than wet

deposition (Hicks et al., 1993; Ahn & James, 2001), attributed to the origin of phosphorus in

soils and its low incorporation into rainfall( Anderson & Downing, 2006). The deposition

pathway of phosphorus also determines the type of phosphorus that is deposited. Previous studies

have indicated that soluble (or bioavailable) fractions of phosphates on particulates will vary

based on the particulates’ source. For instance, soil-derived dust originating in the Sahara was

found to contain less soluble, bioavailable phosphorus relative to particulates of anthropogenic

origin( Migon & Sandroni, 1999). Additionally, the ions with which phosphates on mineral

particulates such as soils tend to associate (calcium, magnesium, aluminum and iron) or bind

12

Table 1. The annual percentage (%) of a lake’s total phosphorus load as atmospheric deposition

Location

Study

Area

(km2)

Lake

Surface

Area (km2)

Study Duration

% of total

phosphorus

load as

atmospheric

deposition

Reference

Three Gorges

Reservoir, China 11531 1080 1995-2007 21.1 (Ma et al., 2011)

Lake Tahoe,

California and

Nevada, USA

812 512 1998-2001 25 (Zhang et al., 2002)

Silver Lake,

Wisconsin, USA 18 1.4 2004-2008 22

(Robertson et al.,

2009)

Lake Victoria, East

Africa 33700 68800 1999-2000 55

(Tamatamah et al.,

2005)

Lake Biwa, Japan 3144 675 1992-1993 8 (T. Kunimatsu &

Sudo, 2006)

Lake Simcoe, Canada 350 722 2004-2007 25-50 (Brown et al., 2011)

Lake of the Woods,

Canada and USA 14860 4349

1970-2005

13

(Hargan et al., 2011) Rainy River

Catchment, Canada

and USA

54887 75

Lake Michigan 117800 58000 1976 15.7 (Eisenreich et al.,

1977)

Lake Ontario 64030 18960 1972-1973 10 (Casey and Salbach,

1974)

Lake Huron 134100 59600 1973-1975 12.1 (IJC, 1976)

Lake Superior 127000 82100 1973-1975 19.3 (IJC, 1976)

13

with (iron oxides) are only weakly soluble in water( Guieu, 2002). Indeed, particles from

anthropogenic sources have been found to release a greater proportion of their soluble

phosphorus into water more quickly than crustal sources( Mackey et al., 2012). For land use

areas devoted to agriculture, there is a greater percentage of soluble reactive phosphorus (SRP)

(Anderson & Downing, 2006) present in dry deposition. Specific atmospheric particulate

sources for Lake Erie and their relative contribution to total SRP content have not been studied in

detail; however, the land surrounding this lake is at once the most highly urbanized and highly

farmed of any Great Lake. A statistical study examining relative impacts of anthropogenic-

induced stress in the Great Lakes characterized certain Lake Erie watersheds is subject to

elevated levels of stress related to atmospheric deposition, based on 11 atmospheric variables as

measured by the National Atmospheric Deposition program ( Danz et al., 2007).

While dry atmospheric deposition is proportionally higher than wet deposition,

researchers have found that wet deposition accounts for the majority of the bulk loading rate

(Chen et al., 1985; Yang et al., 1996; Izquierdo et al., 2012). Phosphorus in rainwater is found

predominantly in its soluble or bioavailable form ( Ridame & Guieu, 2002) implying that the

relative magnitude of phosphorus provided by wet deposition can be a substantial fraction of

atmospheric phosphorus. While the details of pathways appear variable, the importance of

atmospheric deposition in delivering phosphorus to aquatic systems, and the resulting quality

impairments, is increasingly recognized ( Winter et al., 2002).

IMPLICATIONS FOR LAKE ERIE

14

The atmospheric phosphorus contribution estimates for Lake Erie have been determined

by various long term studies, and have been generally attributed limited importance, which

reflects the assumptions of the broader community.

Recent results from Lake Simcoe in Ontario indicate there is reason to revisit such

assumptions, given the shifts in population and land usage surrounding the Lake Simcoe

tributaries and basin over time. As part of the Great Lakes Basin, Lake Simcoe is one of the

largest lakes in Canada outside the Laurentian Great Lakes. While its volume is much smaller

compared to Lake Erie, it is similar to Lake Erie in the proximity of its watershed to both major

urban and farming centers, and as such can be considered a bellweather for the Great Lakes

system. Early estimates of atmospheric phosphorus contributions to Lake Simcoe phosphorus

loadings were estimated as fraction of total phosphorus multiplied by regional precipitation, and

therefore encompassed only wet deposition (Winter et al., 2002). More recent direct monitoring

of atmospheric phosphorus allow for loadings to be calculated from measurements of bulk

deposition of total P, without distinguishing wet from dry atmospheric phosphorus (Winter et al.,

2007). Bulk deposition atmospheric phosphorus is thought to contribute a significant 25-50% of

the total phosphorus loadings to Lake Simcoe (Table 1).

The available information for Lake Erie indicates that atmospheric phosphorus is a small

but not inconsequential contribution to total phosphorus in the system. Previous efforts to

quantify regional phosphorus loading into Lake Erie (Figure 1) framed the question in terms of

monitoring programs characterizing total phosphorus rather than specifically targeting the

soluble reactive phosphorus fraction, and found that atmospheric deposition contributed higher

levels of total phosphorus than direct industrial discharge for 1996-2002 (Dolan & McGunagle,

15

2005). Summaries over time from the Heidelberg Project and combined data from the United

States and Canada indicate that annual loads for the atmospheric fractions of total phosphorus

have been reasonably consistent and were considered a minor component for the years data are

available between 1974 and 2007 (Figure 2). However, unlike the most recent measurements of

bulk deposition for Lake Simcoe, these estimates were developed based on reported precipitation

in the area and therefore represent only a fraction of bulk phosphorus deposition, namely wet

deposition of total phosphorus. Using the same methodologies, the most recent estimates for the

percent contribution of atmospheric wet deposition to total phosphorus to Lake Erie ranged

between < 10% for 1996-2002 (Dolan & McGunagle, 2005) and 7.1% estimated for 2002-2006

(Baker, 2011). While previous work indicates this approach would characterize a significant

fraction of dissolved reactive phosphorus (from atmospheric wet deposition), these estimates

omit dry deposition from reported values and thus do not encompass the total soluble reactive

fraction of atmospheric phosphorus.

Looking towards the future, the impacts of climate change on the water quality and

quantity of lakes and regional weather patterns are expected to have the potential to alter nutrient

transport within the Great Lakes region. Lakes have been termed sentinels for climate change

due to their relatively fast response to changes in surrounding terrestrial environment and

atmosphere (Williamson et al., 2008; Adrian et al., 2009). In the Midwest, storms of greater

frequency and intensity are generally expected to bring more extreme precipitation, followed by

longer periods between storms without rain. (Parry et al., 2007; McBean & Motiee, 2008; Karl

et al., 2009) Increased evaporation during warmer summers is also expected, leading to more

frequent regional water shortages or another extreme event, drought. Climate change is predicted

to shift both lake temperature and the overall level of water within lakes (Koonce & Czapla,

16

1996), and large increases in phosphorus inputs to lakes are also expected due to increased

storm events, largely in the form of surface runoff (Jeppesen et al., 2009). However, the impact

of more frequent, higher intensity storms with the likelihood of more frequent drought events on

future phosphorus loadings via atmospheric deposition is poorly understood. For instance, the

USGS SPARROW model does not include contributions from atmospheric phosphorus as a

nutrient term for base calculations and nutrient model projections, and the recent report on

another large regional watershed, the Chesapeake Bay (Pyke, 2008), did not describe loadings of

atmospheric phosphorus.

The potential impacts of climate shifts on phosphorus inputs to Lake Erie should be

considered in light of current observations and model predictions of phytoplankton bloom

dynamics in lakes. North temperate lakes have experienced a warming trend resulting in the

advancement of spring plankton bloom timing. This has been attributed to early lake

stratification or the relaxation of turbulent vertical mixing of the upper water-column depth, but

regardless of its cause, this trend effectively extends the length of time for favorable growth

conditions for all algal species (Shimoda et al., 2011), and increases the potential for lake algal

overgrowth in the presence of excess nutrients .

CONCLUSION

External to lakes themselves, results from some climate models predict a shift in future

precipitation patterns in the Great Lake region to include less snowfall and more heavy episodic

rain events. Intense storm events coupled with effects of human activity have the potential to

increase atmospheric phosphorus input into regional lakes; however, climate impacts on nutrient

budgets require more research. For example, for atmospheric contributions of phosphorus, a

17

better understanding of the sources of particulates to the Great Lakes and their role in nutrient

budgets for the lakes is needed.

While inputs from atmospheric phosphorus are low, they are not negligible in Lake Erie.

The delivery pathways and constituents of atmospheric phosphorus deposition may have special

relevance for supporting primary production in oligotrophic interior portions of the other Great

Lakes, while the contribution of atmospheric phosphorus to Lake Erie’s total phosphorus load is

currently understood to be relatively minor. The sources of atmospheric phosphorus in the Great

Lakes are not currently well understood, with the fraction from wet deposition more thoroughly

monitored and reported than from dry deposition. The question surrounding levels of soluble

reactive phosphorus within both wet and dry fractions is also currently unresolved. Given the

importance of developing effective management frameworks for phosphorus inputs to the Great

Lakes that reflect the current state of human impacts on nutrient cycling, phosphorus budgets and

nutrient models should be examined across the region for improvement, especially as such

models are modified to examine regional effects of climate.

18

Figure 1. Average estimated phosphorus loadings (MTA) for Lake Erie (1996-2002); data from Dolan and

McGunagle, 2005. Data includes estimates for contributions from Lake Huron and unmonitored areas.

Direct sources are point sources that discharge into Lakes Erie or St. Clair, the Detroit or St. Clair Rivers or

unmonitored areas.

5128

2162

605

55

1438

1080

Monitored Tributary

Unmonitored Area

Atmospheric

Direct Industrial

Direct Municipal

Lake Huron

Average estimated phosphorus loadings (MTA) for Lake Erie

(1996-2002)

19

Figure 2. Total phosphorus loadings for Lake Erie, 1967-2007. Includes point and non-point source loads

from the United States and Canada. Figure reproduced from Baker, 2011, data from David Rockwell, (U.S.

EPA and David Dolan (Univ. of Wisconsin, Green Bay)

20

REFERENCES

Adrian, R., O’Reilly, C.M., Zagarese, H., Baines, S.B., Hessen, D.O., Keller, W., et al. 2009.

Lakes as sentinels of climate change. Limnology and oceanography 54: 2283.

Ahn, H. & James, R.T. 2001. Variability, uncertainty, and sensitivity of phosphorus deposition

load estimates in South Florida. Water, Air, & Soil Pollution 126: 37–51.

Anderson, K.A. & Downing, J.A. 2006. Dry and wet atmospheric deposition of nitrogen,

phosphorus and silicon in an agricultural region. Water, Air, and Soil Pollution 176: 351–

374.

Baker, D. 2011. Final Report: Part 1 Trends in Bioavailable Phosphorus Loading at River

Monitoring Stations. U.S. EPA, Heidelberg University.

Blake, T.W. & Downing, J.A. 2009. Measuring atmospheric nutrient deposition to inland waters:

Evaluation of direct methods. Limnology and Oceanography: Methods 7: 638–647.

Brown, L.J., Taleban, V., Gharabaghi, B. & Weiss, L. 2011. Seasonal and spatial distribution

patterns of atmospheric phosphorus deposition to Lake Simcoe, ON. Journal of Great

Lakes Research 37: 15–25.

Burns, N.M. & Ross, C. 1972. Project Hypo. Paper No. 6. U.S. EPA, Burlington, Ontario.

Chen, L., Arimoto, R. & Duce, R.A. 1985. The sources and forms of phosphorus in marine

aerosol-particles and rain from Northern New Zealand. Atmospheric Environment 19:

779 –787.

Chen, Z. & Fontaine, T.D. 1997. Simulation the Impact of Rainfall Phosphorus Inputs on the

Phosphorus Concentrations in the Everglades Protection Area. In: Proceeding of the

Conference on Atmospheric Depostion in South Florida: Measuring Net Atmospheric

Inputs of Nutrients, October 20-22, 1997, pp. 19–20. South Florida Water Management

District, West Palm Beach, Florida.

Connor, McCarthy, P. & O`Loan, M. 1992. Mendums Pond Diagostic Feasibility Study Final

Report. New Hampshire Department of Environmental Services, Water Supply and

Control Division, Concord, NH.

Conroy, J.D., Kane, D.D., Dolan, D.M., Edwards, W.J., Charlton, M.N. & Culver, D.A. 2005.

Temporal trends in Lake Erie plankton biomass: roles of external phosphorus loading and

dreissenid mussels. Journal of Great Lakes Research 31: 89–110.

Cordell, D., Drangert, J.-O. & White, S. 2009. The story of phosphorus: Global food security and

food for thought. Global Environmental Change 19: 292–305.

21

Danz, N.P., Niemi, G.J., Regal, R.R., Hollenhorst, T., Johnson, L.B., Hanowski, J.M., et al.

2007. Integrated Measures of Anthropogenic Stress in the U.S. Great Lakes Basin.

Environmental Management 39: 631–647.

Dolan, D.M. & McGunagle, K.P. 2005. Lake Erie total phosphorus loading analysis and update:

1996-2002. Journal of Great Lakes Research 31: 11–22.

Dolislager, L.J., VanCuren, R., Pederson, J.R., Lashgari, A. & McCauley, E. 2012. A summary

of the Lake Tahoe Atmospheric Deposition Study (LTADS). Atmospheric Environment

46: 618–630.

Eisenreich, S.J., Emmling, P.J. & Beeton, A.M. 1977. Atmospheric loading of phosphorus and

other chemicals to Lake Michigan. Journal of Great Lakes Research 3: 291–304.

El-Shaarawi, A.H. 1987. Water Quality Changes in Lake Erie. J. Great Lakes Res. 13: 674–683.

Environment Canada. 2009. State of the Great Lakes 2009.

Fraser, A.S. 1987. Tributary and point source total phosphorus loading to Lake Erie. Journal of

Great Lakes Research 13: 659–666.

Grimshaw, H.J. & Dolske, D.A. 2002. Rainfall concentrations and wet atmospheric deposition of

phosphorus and other constituents in Florida, USA. Water, Air, & Soil Pollution 137:

117–140.

Guieu, C. 2002. Chemical characterization of the Saharan dust end-member: Some

biogeochemical implications for the western Mediterranean Sea. Journal of Geophysical

Research 107.

Han, H., Bosch, N. & Allan, J.D. 2010. Spatial and temporal variation in phosphorus budgets for

24 watersheds in the Lake Erie and Lake Michigan basins. Biogeochemistry 102: 45–58.

Hargan, K.E., Paterson, A.M. & Dillon, Peter J. 2011. A total phosphorus budget for the Lake of

the Woods and the Rainy River catchment. Journal of Great Lakes Research 37: 753–

763.

Hartmann, J., Kunimatsu, Takao & Levy, J.K. 2008. The impact of Eurasian dust storms and

anthropogenic emissions on atmospheric nutrient deposition rates in forested Japanese

catchments and adjacent regional seas. Global and Planetary Change 61: 117–134.

Herdendorf, C.E. 1983. Lake Erie water quality: 1970-1982 management assessment for

USEPA. The Ohio State University, Center for Lake Erie Area Research, Columbus, OH.

Herut, B., Krom, M.D., Pan, G. & Mortimer, R. 1999. Atmospheric input of nitrogen and

phosphorus to the Southeast Mediterranean: Sources, fluxes, and possible impact.

Limnology and Oceanography 1683–1692.

22

Hicks, B., McMillan, R., Turner, R.S., Holdren Jr, G.R. & Strickland, T.C. 1993. A national

critical loads framework for atmospheric deposition e!ects assessment: III. Deposition

Characterization. Environmental Management 17: 343–353.

Higgins, S.N., Howell, E.T., Hecky, R. E., Guildford, S.J. & Smith, R.E. 2005. The Wall of

Green: The Status of Cladophora glomerata on the Northern Shores of Lake Erie’s

Eastern Basin, 1995? 2002. Journal of Great Lakes Research 31: 547–563.

Izquierdo, R., Benítez-Nelson, C.R., Masqué, P., Castillo, S., Alastuey, A. & Àvila, A. 2012.

Atmospheric phosphorus deposition in a near-coastal rural site in the NE Iberian

Peninsula and its role in marine productivity. Atmospheric Environment 49: 361–370.

Jeppesen, E., Kronvang, B., Meerhoff, M., Søndergaard, M., Hansen, K.M., Andersen, H.E., et

al. 2009. Climate Change Effects on Runoff, Catchment Phosphorus Loading and Lake

Ecological State, and Potential Adaptations. Journal of Environment Quality 38: 1930.

Karl, T.K., Melillo, J.M. & Peterson, T.C. 2009. Global Climate Change Impacts in the United

States. Cambridge University Press, New York.

Koelliker, Y., Totten, L.A., Gigliotti, C.L., Offenberg, J.H., Reinfelder, J.R., Zhuang, Y., et al.

2004. Atmospheric wet deposition of total phosphorus in New Jersey. Water, Air, & Soil

Pollution 154: 139–150.

Koonce, J.F. & Czapla, T. 1996. Restoration of Lake Erie: contribution of water quality and

natural resource management. Canadian Journal of Fisheries and Aquatic Sciences 53:

105–112.

Kunimatsu, T. & Sudo, M. 2006. Long-term fluctuation and regional variation of nutrient loads

from the atmosphere to lakes. Water Science & Technology 53: 53.

Li, Y., Acharya, K., Stone, M.C., Yu, Z., Young, M.H., Shafer, D.S., et al. 2011. Spatiotemporal

patterns in nutrient loads, nutrient concentrations, and algal biomass in Lake Taihu,

China. Lake and Reservoir Management 27: 298–309.

Luo, J., Wang, X., Yang, H., Yu, J.Z., Yang, L. & Qin, B. 2011. Atmospheric phosphorus in the

northern part of Lake Taihu, China. Chemosphere 84: 785–791.

Luo, L., Qin, B., Yang, L. & Song, Y. 2007. Total inputs of phosphorus and nitrogen by wet

deposition into Lake Taihu, China. Hydrobiologia 581: 63–70.

Mackey, K.R., Roberts, K., W Lomas, M., Saito, M.A., F Post, A. & Paytan, A. 2012. Enhanced

Solubility and Ecological Impact of Atmospheric Phosphorus Deposition upon Extended

Seawater Exposure. Environmental Science & Technology 120518071627004.

McBean, E. & Motiee, H. 2008. Assessment of impact of climate change on water resources: a

long term analysis of the Great Lakes of North America. Hydrology and Earth System

Sciences Discussions 12: 239–255.

23

Migon, C. & Sandroni, V. 1999. Phosphorus in rainwater: Partitioning inputs and impact on the

surface coastal ocean. Limnology and Oceanography 44: 1160–1164.

Miller, S.M., Sweet, C.W., DePinto, J.V. & Hornbuckle, K.C. 2000. Atrazine and Nutrients in

Precipitation: Results from the Lake Michigan Mass Balance Study. Environmental

Science & Technology 34: 55–61.

Morales, J.A., Albornoz, A., Socorro, E. & Morillo, A. 2001. An estimation of the nitrogen and

phosphorus loading by wet deposition over Lake Maracaibo, Venezuela. Water, Air, &

Soil Pollution 128: 207–221.

North, R.L., Guildford, S.J., Smith, R.E.H., Havens, S.M. & Twiss, M.R. 2007. Evidence for

phosphorus, nitrogen, and iron colimitation of phytoplankton communities in Lake Erie.

Limnology and Oceanography 315–328.

Parry, M.L., Canziani, O.F., Palutikof, J.P., van der Linden, P.J. & Hanson, C.E. 2007. IPCC

Fourth Assessment Report: Climate Change 2007 (AR4):: impacts, adaptation and

vulnerability.

Paytan, A. & McLaughlin, K. 2011. Tracing the Sources and Biogeochemical Cycling of

Phosphorus in Aquatic Systems Using Isotopes of Oxygen in Phosphate. In: Handbook of

Environmental Isotope Geochemistry (M. Baskaran, ed), pp. 419–436. Springer Berlin

Heidelberg, Berlin, Heidelberg.

Pierrou, U. 1976. The global phosphorus cycle. Ecological Bulletins 75–88.

Pollman, C.D., Landing, W.M., Perry Jr, J.J. & Fitzpatrick, T. 2002. Wet deposition of

phosphorus in Florida. Atmospheric Environment 36: 2309–2318.

Pyke, C.R. 2008. Climate Change and the Chesapeake Bay: State-of-the-Science Review and

Recommendations. A Report from the Chesapeake Bay Program Science and Technical

Advisory Committee (STAC). Annapolis, MD.

Report on the Phosphorus Loads to Lake Simcoe 2004-2007. 2009. Lake Simcoe Region

Conservation Authority, Ontario.

Reutter, J.M., Ciborowski, J.H., DePinto, J.V., Bade, D., Baker, D., Bridgeman, T.B., et al. 2011.

Lake Erie Nutrient Loading and Harmful Algal Blooms: Research Findings and

Management Implications. Final Report of the Lake Erie Millennium Network Synthesis

Team.

Ridame, C. & Guieu, C. 2002. Saharan input of phosphate to the oligotrophic water of the open

western Mediterranean Sea. Limnology and Oceanography 856–869.

Rossignol, K.L., Paerl, H.W., Fear, J.M. & Braddy, J.S. 2011. Nutrients in precipitation and the

phytoplankton responses to enrichment in surface waters of the Albemarle Peninsula,

24

NC, USA after the establishment of a large-scale chicken egg farm. Hydrobiologia 671:

181–191.

Schindler, D.W. 1971. Carbon, nitrogen and phosphorus and the eutrophication of freshwater

lakes. Journal of Phycology 7: 321–329.

Shaw, R.D., Trimbee, A.M., Minty, A., Fricker, H. & Prepas, E.E. 1989. Atmospheric deposition

of phosphorus and nitrogen in central Alberta with emphasis on Narrow Lake. Water, Air,

& Soil Pollution 43: 119–134.

Shimoda, Y., Azim, M.E., Perhar, G., Ramin, M., Kenney, M.A., Sadraddini, S., et al. 2011. Our

current understanding of lake ecosystem response to climate change: What have we really

learned from the north temperate deep lakes? Journal of Great Lakes Research 37: 173–

193.

Tamatamah, R.A., Hecky, Robert E. & Duthie, H. 2005. The atmospheric deposition of

phosphorus in Lake Victoria (East Africa). Biogeochemistry 73: 325–344.

Tsukuda et al. 2006.pdf. n.d.

Tsukuda, S., Sugiyama, M., Harita, Y. & Nishimura, K. 2004. A methodological re-examination

of atmospheric phosphorus input estimates based on spatial microheterogeneity. Water,

Air, & Soil Pollution 152: 333–347.

Tsukuda, S., Sugiyama, Masahito, Harita, Yunosuke & Nishimura, Kazuo. 2006. Atmospheric

Phosphorus Deposition in Ashiu, Central Japan – Source Apportionment for the

Estimation of True Input to a Terrestrial Ecosystem. Biogeochemistry 77: 117–138.

US EPA. 2000. AP-42 Compilation of Air Pollutant Emission Factors, Chapter 13:

Miscellaneous Sources, 5th ed. U.S Environmental Protection Agency.

Williamson, C.E., Dodds, W., Kratz, T.K. & Palmer, M.A. 2008. Lakes and streams as sentinels

of environmental change in terrestrial and atmospheric processes. Frontiers in Ecology

and the Environment 6: 247–254.

Winter, J.G., Dillon, P. J., Futter, M.N., Nicholls, K.H., Scheider, W.A. & Scott, L.D. 2002.

Total phosphorus budgets and nitrogen loads: Lake Simcoe, Ontario (1990 to 1998).

Journal of Great Lakes Research 28: 301–314.

Winter, J.G., Eimers, M.C., Dillon, P. J., Scott, L.D., Scheider, W.A. & Willox, C.C. 2007.

Phosphorus inputs to Lake Simcoe from 1990 to 2003: declines in tributary loads and

observations on lake water quality. Journal of Great Lakes Research 33: 381–396.

Yang, X., Miller, D.R., Xu, X., Yang, L.H., Chen, H.-M. & Nikolaidis, N.P. 1996. Spatial and

temporal variations of atmospheric deposition in interior and coastal Connecticut. Atmos.

Env. 30: 3801–3810.

25

Zhai, S., Yang, L. & Hu, W. 2009. Observations of Atmospheric Nitrogen and Phosphorus

Deposition During the Period of Algal Bloom Formation in Northern Lake Taihu, China.

Environmental Management 44: 542–551.

Zhang, Q., Carroll, J.J., Dixon, A.J. & Anastasio, C. 2002. Aircraft Measurements of Nitrogen

and Phosphorus in and around the Lake Tahoe Basin: Implications for Possible Sources

of Atmospheric Pollutants to Lake Tahoe. Environmental Science & Technology 36:

4981–4989.