Top 4 Threatsto Lake Huron

WaterContamination

Herring Gulls• Indicator of environmental health

and contamination

• DDT, dieldrin, PCBs, PCDDs

• 1970s 1980s 1990s present

PhosphorusSources - agricultural runoff - residential contamination

The Problem - increased nutrient loading The Effects - massive algal blooms (right) - eutrophication/hypoxia - loss of habitat for species - poor conditions for human activities

New Threats PBDE (polybrominated diphenyl ethers)=

flame retardants

PFOS (perfluorooctane sulfonate) = surfactants

Why does it matter Recent introduction don’t know the impact Persistent pollutant maintained in a system

until consumed Few point sources atmospheric deposition

Areas of Concern St. Clair River

Industrial, agricultural and residential pollutants

High concentrations of chemical/nutrient pollutants

Loss of habitat, poor water quality, impact on benthic level, species deformities

Climate Change &

Water Levels

With increased temperatures occurring globally, water levels have been increasing

around the world, except for the Great Lakes.

Why?

The Whys Increased temperature = increased

evaporation Shorter winters with less snowfall with less

ice cover (not including this winter OK) Human consumption and use Artificial shoreline

Impacts Temperature

Increased aquatic plant growth

Lower dissolved oxygen levels Some areas made inhospitable

Displacement Alewife (temperature dependent)

Impact on cellular biology Increases metabolic rate of fish

Impacts Water Level

Lower Water Levels = Higher Demand

Cut off from the Wetlands Habitat Loss Water Purification Oliphant

The Conundrum

What we don’t know

Vs.

What we do know

St. Clair dredgingCreating artificial walls

Increased carbon dioxide levels

Habitat Loss

Agricultural

Industrial

Residential/Public

Invasive Species

Zebra & Quagga Mussel Habits

Reproduce rapidly Dense colonies Filter vacuum

Impacts/IssuesZebra - aggressive filter compete with other v benthic organisms - change the nature of lake bottom - bioaccumulation of toxinsQuagga - deep/cold water potential

Diporeia 2000 2003 2007

Bio

mas

s (

mg/

m3)

0246810

0 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 3

Length

0

2

4

6

8

100

24

6

8100

2

46

8

10

0

24

6

810

0

2

4

6

8

10 North Central South

Adult Calanoids

Immature Calanoids

Adult Cyclopoids

Immature Cyclopoids

Other Cladocerans

Bosmina

Daphnia

2001

2002

2003

2004

2000

2005

The Round GobyHabits

Aggressive competitor Food: bivalves, fish eggs

Impacts/Issues Relationship with zebra mussel Feed on native fish eggs/fry Devastation of fisheries Competition for native species

Mottled Sculpin

Sea Lamprey Habit

Aggressive fish predator (40lbs)

No natural predators

Impact/Issues Devastating fisheries

Spiny Water Flea Habit

Feed on daphnia zooplankton Resilient reproductive method Adapted to cool ecosystems

Impact/Issues Consume large amounts of zooplankton (daphnia) Reproduce during all times of the year Few predators

Viral Hemorrhagic Septicemia

Habit New virus to the Great

Lakes Causes the

hemorraging of body and organs

Non-discriminatory at colder temperatures

Impact/Issues Highly contagious Devastation of

fisheries

Asian Carp

Habit Refers to four species

(bighead, grass, silver, black)

Huge consumers of aquatic plant life

Temperature tolerance Various diets

Impact/Issues Varied diets =

devastation Decline in commercial

fisheries