Eutrophication 5Case Histories

Alice NewtonNancy RabalaisMingyuan ZhuLaurence Mee

Global Eutrophication Increase N fluxes~ North Sea 11x~ N.E. Atlantic 10x~ Chesapeake Bay 8x~ N.Carolina 5x~ Gulf of Mexico 4.5x~ Mississipi Basin 4x~ Baltic Sea 4x~ Iberia 3x

Global Distribution of DocumentedOxygen Depletion, 2007

n = 146

(Diaz et al., 2004)

USAhttp://state-of-coast.noaa.gov/bulletins/html/hyp_09/references.html#web

~ Animal wastes = 130x human waste

~ 5 tonnes animal wastes per human capita pa

~ 60% of coastal rivers and bays affected by nutrient pollution (in 2000)

~ 20 year plan to reduce nutrient pollution by 25%

U.S. Coastal ecosystemsexperiencing high levels of

eutrophication

Boesch et al. 2001

Mississippi catchment~ 4 million tonnes fertilizer produced in

Louisiana and barged or piped to Midwest granaries

~ Drains into Mississippi basin tripling N concentrations

~ 1997 Mississippi floods diverted into Lake Pontchartrain, 670 sq mile lake

~ Lake Pontchartrain supports fisheries for redfish, white shrimp, blue crab, flounder & mullet

~ Mass mortality of aquatic life

500 km

0.6%58%18%21%[w & w2.4%]

(Goolsby et al., 1999, Rabalais 2002)

N Source Distribution

(Goolsby et al., 1999)

(Goolsby et al., 1999)(Goolsby et al., 1999)

P Source Distribution

Gulf of Mexico

Natural gas (cheap methane)fuels fertilizerplants in Louisiana

136 petrochemical & fertilizer plantsbetween NewOrleans & BatonRouge

Gulf of Mexico~ From 1950’s to 1980’s, supply of Si decreased

by 50% due to upstream eutrophication in Mississippi

~ N 3x increase in 50 years

~ 1990s extensive area of oxygen under-saturation (9500 sq Km from mouth of Mississippi)

~ Fishery worth $2.8 billion pa½ oyster catch for USA 2/3 shrimp for USA

~ 1999 hypoxic area 20 000 sq Kmwww.cast-science.org/hypo/hypo.htmwww.nos.noaa.gov/products/pubs_hypox.html

Overwhelming Source of NutrientsEffects are more far reaching

than suspended sediment plume

dominant wind direction

More Nutrients >>> More Phytoplankton >>>

More Carbon Reaches the Bottom >>>More Oxygen Consumed >>>

More Hypoxia

(Photo: N. Rabalais, LUMCON)

-94 -93.5 -93 -92.5 -92 -91.5 -91 -90.5 -90 -89.5

28.5

29

29.5

30L. Calcasieu Atchafalaya R.

Mississippi R.

Terrebonne Bay

Sabine L.

100 km

Bottom-Water Hypoxia July 20-25, 2001

Dissolved oxygen less than 2 (mg/L)

Rabalais, Turner and Wiseman

-94 -93.5 -93 -92.5 -92 -91.5 -91 -90.5 -90 -89.5

28.5

29

29.5

30L. Calcasieu Atchafalaya R.

Mississippi R.

Terrebonne Bay

Sabine L.

100 km

Bottom-Water Hypoxia July 21-26, 2002

Dissolved oxygen less than 2 (mg/L)

Rabalais, Turner and Wiseman

-94 -93.5 -93 -92.5 -92 -91.5 -91 -90.5 -90 -89.5

28.5

29

29.5

30L. Calcasieu Atchafalaya R.

Mississippi R.

Terrebonne Bay

Sabine L.

100 km

Rabalais, Turner and Wiseman

Bottom-Water Hypoxia July 23-28, 2003

7/15 7/14

Tropical Storm Claudette

Chesapeake Bay~N 7x more than pristine condition~ In summer hypoxia / anoxia of 1/3 of

estuary~SAV Sea grasses disappearing~HAB Pfiesteria outbreaks 1997~Fish kills & human memory effects~Hog, chicken farm and municipal waste~Pfiesteria utilizes DONutrients directly~Pfiesteria can graze other abundant

algae

N & P in Chesapeake bay

Concentrations of dissolved inorganic nitrogen and phosphorus measured during the summer months in surface waters. Nutrient concentrations are higher than optimum in most of the rivers and upper bays.

Colonial map of oyster bars

Historical Oyster Grounds

SAV biomass v. water depth with oyster biomass = 25 g/m^2

0

1000

2000

3000

4000

5000

6000

7000

0 0.5 1 1.5 2 2.5 3 3.5 4

Water depth (m)

SA

V b

iom

as

s (

sh

oo

ts/m

^2

)

H=0H=0.1H=0.2H=0.3H=0.4

SAV v. water depth with oyster biomass

0

1000

2000

3000

4000

5000

6000

7000

0 0.5 1 1.5 2 2.5 3 3.5 4

Water depth (m)

SA

V b

iom

as

s (

sh

oo

ts/m

^2

)

Bb=0Bb=25Bb=50Bb=75Bb=100

Biomass (g m-2)

Wave height (m)

Effects of oyster filtration on aquatic vascular plants

Interaction of waves and oyster filtration (oyster biomass 25 g m-2) on vascular plants

Pl a

nt

den

sit y

(s

ho

ot s

m-2)

Pl a

nt

den

sit y

(s

ho

ot s

m-2)

Source: Raleigh Hood, UMCES

Oyster Restoration Issues

Goal 10X increase by 2010 Diseases (Perkinsus & Haplosporidium) Substrate Architecture Harvesting Introducing C. ariakensis Role in ameliorating effects of eutrophication

North Carolina

~ Waste from hog production is 3x all human sewage output for NewYork city

~ Little or no treatment in the absence of regulations

~ HAB Pfiesteria outbreaks

Florida Keys~ 1970s coral cover was 70%

~ 2000 coral cover 17%

~ Algal turf or seaweeds 48-84% cover

~ Algal growth stimulated by eutrophication

~ Hypoxia decreases the number of algal grazers that keep coral clear

Chinawww.sepa.gov.cn

~ Pop.:~1.3 billion~ Since 1960’s Chinese “green” agricultural

revolution Fertilizer use increased 5x, will triple again by 2020.Also pig & poultry farms

~ Fertilizers drain into Yangtze, East China sea, Hangzhou bay, Zhelin bay, Hong-Kong.. Also Thailand, Malaysia, Indonesia

~ 20-30 HAB p.a.

~Main causes ~Increase fertilizer~Reduction of effluent~Reduction of zooplankton

~Main consequences~HABs, some toxic

Fertilizer Use and HAB Events in China

Fertilizer Use

HAB events

Increased frequency of HAB’s in China

~1930’s: 1

~1950’s: 1

~1960’s: 2

~1970’s: 6

~1980’s: 30

~1990’s: 229

~2000 － 2005 ： 481

#Y

#Y

#Y#Y

#Y

#Y

#Y

#Y

#Y

#Y

#Y

#Y

#Y

#Y

#Y

#Y#Y

#Y

#Y

#Y

#Y

#Y

#Y

#Y #Y

#

#

#

#

#

#

#

#

#

#

# ##

#

#

#

###

#

#

#

##

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

# #

#

#

#

#

#

#

#

#

#

#

##

#

#

#

##

#

##

###

#

#

##

#

#

####

###

##

######

#

#############

#

#

###

#

###

##

#

##

###

#

#

##

#

#

##

# ##

#

#

#

##

#

#

#

##

#

#

####

#

##

#

#

#

#

#

##

#

#

#

#

#

#

#

#

####

##

#

#

#

#

#

#

###

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

##

###

#

#

# #

##

#

##

#

#

#

#

#

#

##

#

#

#

#

#

#

#####

##

#

#

#

#

#

#

#

#

#

##

#

#

#

#

####

#

#

#

##

#

#

#

#

###

#

#

#

#

#

#

# ##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

# #

#

#

##

#

#

#

#

#

#

#

#

#

###

#

#

## #

#

#

##

#

#

#

#

#

#####

####

##

# ########

#

# ########

##

#

########

#

#

#

#

## ##

#

#####

#

#

####

# ## ####

####

##

# #

#

##

#

##

###

#

####

#

#####

#

#

3 main areas with frequent HAB Bohai Sea

Yangtze River Estuary and coastalwater of Zhejiang

Coastal water of Guangdong

0

2

4

6

8

10

12

赤潮

次数

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

0.30

污染

物浓

度 (m

g/L

)

赤潮次数

无机氮（mg/L）

磷酸盐（mg/L）

N & P and HAB in Bohai Sea 1985-2000

Number of HAB

DIN(mg/L)

PO43-(mg/L) Nu

mb

er of HA

B

Con

.of pollu

tants(m

g/L)

Nutrient enrichment of Bohai Sea

2002 2003

辽 宁

河 北

山 东

天津

北京

197219771989199019911995199619971998199920002001

HAB sites

HAB in Bohai SeaHAB in Bohai Sea

0

5

10

15

20

1952

1954

1956

1958

1960

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

年份

赤潮

次数

(195

2-20

05)

From 1952 to 2005, there were 130 events recorded in HAB. It increased since the80’s

Nutrient InputsE. ChinaSea

Distribution of HABs in East China Sea

HAB Area

Noctiluca and Skeletonema are main species of HAB and are not toxicIn recent years, Prorocentrum and Karenia mikiimotoi became the causative species for large scale HAB Other toxic species include Alexandrium and Mesodinium rubrum

Noctiluca and Skeletonema are main species of HAB and are not toxicIn recent years, Prorocentrum and Karenia mikiimotoi became the causative species for large scale HAB Other toxic species include Alexandrium and Mesodinium rubrum

Main species in East China Sea

Aquaculture and Eutrophication

~ Nutrients and Organic Matter are elevated near fish cages

~ Dissolved Oxygen is low near fish cages

~ Filter feeding bivalves exert top down control on phytoplankton

Exploitation of Sanggou Bay

Direct Economic loss

1989: 300 million RMB

(~40 million US$)

1998: 560 million RMB

(~70 million US$)

Lac de TunisUNESCO 1984

Unesco report in marine science, 29, 53pp

~ area 48.6 km2 ~ mean depth is only 1 m ~ only 1 main inlet~ urbanised for several thousand years, treated

and untreated sewage discharge into Lac de tunis

~ extreme symptoms of eutrophication~ dense blooms of Ulva ~ water becomes anoxic ~ massive fish mortalities. ~ Red, sulphur-reducing bacteria bloom~ Bubbling of methane and hydrogen sulphide

stench. ~ “Clean-up” operation has been successful

The Black Sea

See text below slides

Black Sea catchment and coastBlack Sea catchment and coast

Black Sea countries and riversBlack Sea countries and rivers

The Danube transboundary River

© World Bank

Black Sea ‘Liquid bottom’

deep basin

Black sea N-W Black sea N-W continental shelfcontinental shelf

Wetland Destruction and Coastal

Development

Productive and diverse shelf system

Phyllophora nervosa

Seagrass (Zostera marina and

Zostera noltii) and Cystoseira beds

?

1950s 1970s

1980s 2000sZernov’s Phyllophora field

2004 – meta populations of Phyllophora located, partial recovery of mussel beds

Bivalves

Mytilus galloprovincialis and Modiolus phaseolinus createa highly diverse habitat and exerttop down grazing control on phytoplankton

1973 1978

1990 2004Development of a ‘dead zone’

Fish kills 5 million tonnes in 20 years

Pelagic fish stocks

24 commercial spp of fish disappeared

Current political and social context

~ Bulgaria, Romania recently joined EU (Jan 2007)

~ Turkey gearing up to join EU~ ‘Command control’ in Russia, Ukraine

and Georgia ~ New policy framework for protecting the

Black Sea, but poor implementation~ Move from enforced collectivism to

rampant individualism affecting environmental values

Total N & P fertiliser application, Danube Basin

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

Me

tric

to

ns

Total-P

Total-N

A crisis in agriculture … an opportunity for the Black Sea

The green revolution

End of centrally planned economy

-50

-40

-30

-20

-10

0

10

20

Bulgaria Georgia Romania Russian Federation Turkey Ukraine

Central planning Chaos and transition ?

GDP per capita growth (annual %)

A social and economic discontinuity…A social and economic discontinuity…

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Bulgaria Georgia Romania Russian Federation Turkey Ukraine

Population growth (annual %)Annual population growth (%, outliers removed)