CILERTom Johengen, Ashley Burtner,

Sander Robinson

Wayne State Wayne State UniversityUniversity

Donna Kashian, Donna Kashian, Vijay Kannappan, Vijay Kannappan,

Hunter Oates, Hunter Oates, Carly CollinsCarly Collins

Fall 2010 Multiple Stressors PI

Workshop

Experimental work

x

• Predict and manage: - muck deposition on beaches &

- E. coli/pathogens outbreaks

• Identify management efforts or policy changes that would reduce the impacts of contaminants

(i.e. dredging of hot spots)

• Manage sediment loading

• Manage and understand the impacts of agriculture in Saginaw Bay (i.e. nutrient loads, sedimentation, E. coli)

Water Quality GroupWater Quality GroupTop Management ObjectivesTop Management Objectives

• What are the primary drivers of muck deposition on beaches? What is the composition of muck?

• What and where are the primary sources of pathogens?

Are there pathogens in the muck?

• What are the impacts of contaminants to water quality?

• How much is sediment loading contributing to nutrient loading?

• What aspects of agriculture impact water quality & what can be effectively implemented to mitigate impacts?

Water Quality GroupWater Quality Group Primary Knowledge Gaps Primary Knowledge Gaps

2010 Project Overviews and Results

• Assess the physicalphysical and bioticbiotic influences on internal phosphorus loading in Saginaw Bay

• Identify Hexagenia benthic habitats

• Determine the prevalence, persistence and proliferation of

E. coli and enterococci in muck

Objective 1 : Field Survey

• light• temperature • moisture

Fecal Indicators in Beach Muck

Objective 2: Laboratory Mesocosm Study

Determine the prevalence of E. coli and enterococci in two different types of muck deposits (dry vs. wet)

Asses the influence of environmental variables on the persistence and proliferation of E. coli and enterococci.

Prevalence of E. coli and enterococci in wet vs. dry muck deposits

Most

pro

bable

num

ber

(MPN

) per

gra

m

Wet Muck Dry Muck

Effects of temp. & moisture on fecal indicators

E. Coli Enterococci

Days

Most

pro

bab

le n

um

ber

(MPN

)p

er

gra

m

Top panels hydrated: Bottom dry heat

E. Coli Enterococci

Enterococci

E. Coli

E. coli and enterococci survived in muck over 5

months at 40C

Days of exposure to sunlight

Most

pro

bab

le n

um

ber

(MPN

)per

gra

m

Cold Storage at 4°C

Muck provides a suitable environment for fecal bacteria to persist and proliferate for extended periods under natural conditions. MAY CONTRIBUTE TO BEACH CLOSURES

Direct sunlight inhibits growth

- Characterize the sediments-nutrients/carbon/particle size

1) Determine the role of sediment flux in phosphorus availability

under aerobic and anoxic conditions.

2) Determine the role of dreissenid mussels in nutrient cycling and availability.

- Identify “hot spots” of P recycling in the Bay

Assess the physicalphysical and bioticbiotic influences on internal phosphorus loading in Saginaw Bay Michigan.

Objectives

QuaggaZebra

Hypothesis

H1: Under anoxic conditions sediment bound phosphorus will resuspended and become more available.

- This phenomenon will be greater in depositional zones

H2: Dreissena excrement will contribute to phosphorus loading

(Woods 1964)

510

14

Sampling Sampling sitessites

Site 5 Sandy, mussel beds, macrophytesdepth = 3 m

Site 10 Silt, loose depositional basin; depth = 12 m

Site 14 sand-pebble substrate; depth = 5 m

Treatments

aerobic anoxic

10

5 +O2 - O2

- O2+ O2

14 - O2+ O2

Site

Methods: Methods: Hypoxia experimentsHypoxia experiments

• Sediment cores collected by divers and incubated under ambient temperature & light.

• Hypoxia simulated by removing oxygen by continuously

purging with helium; aerobic cores bubbled with air

• Nutrients monitored daily (10 days)

10%67%42%Capillary Pore Space

347247Pore Space (%)

1.770.721.66Bulk Density (g/cm3)

SandClay LoamSandy Clay

LoamTextural Class

1410

5Site

Results: Sediment Characterization Results: Sediment Characterization

5017896Iron (ppm)

5%93%25%Water holding Capacity (1/10 Bar)

Have this data for sites 1,7,11, 13,16, 20

Site 5 Site 10Site 14

P (

µg

P/L

)

0

20

40

60

80

P (

µg

P/L

)

020406080

100120140

Time (Day)1 2 3 4 5 6 7 8 9 10

020406080100120140

02

4

6

8

10

12

1 2 3 4 5 6 7 8 9 10

Results : Influence of hypoxia on P availability

TDP - aerobic TDP - anoxic

SRP - aerobic SRP - anoxic

Surface vs bottom TP – avg for 2008-10

SB2

SB5

SB14

SB10

SB20

SB10 – 12m

SRP Flux Values

0

aerobicanoxic

TDP Flux

-1500-500

0500

1500

2500

5 10 14

Average P Fluxes

-400

0

400

800

aerobic anoxicP fl

ux (

µg

P/m

2 d

ay)

SRPTDP

P F

lux (

µg

P/m

2 d

ay)

Location (Site)

-500

5001500

2500

3500

2009: Influence of hypoxia on P availability(Validated with 2010 data)

Summary/Conclusion

• Internal loading of P from sediments in Saginaw Bay likely to occur under hypoxic conditions.

• Majority of P returning from sediments occurs in sediment type observed at Site 10.

Prediction and modeling of anoxia in Bay waters may lead to better forecasting of

nutrient loads.

• Cores were collected in same manner as experiment 1– site 5 only– nutrients monitored daily

• Dreissena excretion was collected and applied (27μg/L/core) as a treatment

Treatments

aerobic anoxic

No inputs

+ Dreissena Excretion (DE)

+O2 + DE - O2 + DE

- O2

Effects of dreissenid excretion on P recycling

+ O2

Dreissenid Excretion Impacts

-1000

-800

-600

-400

-200

0

200

TP TDP SRP

P F

lux (

µg

P/m

2/d

ay)

aerobic DE

aerobic control

anoxic DEanoxic control

Excrement Degradation Timescales

• Incubation of water amended with excrement (no sediments)

• Suggests water column process at work (Bacterial uptake?)

Bacterial Conc’ in cores

Excrement amended

Control

CFU

s/ 1

00 µ

L

• The presence of dreissenid excretion results in less phos. in the water column under

anoxic and aerobic conditions (over 10 days).

Effects of dreissenid excretion on P recycling

• Excrement degradation experiment showed P removal in oxic filtered river water.

• Bacterial counts were significantly greater (p <.001) in cores amended with dreissenid excretion

Hexagenia hatch 2009

Hexagenia mayfly hatch in Tawas, Michigan, July 2009

Hexagenia nymph sampling (June 21-24, 2010)

• Collected using 4in diameter cores - Where possible, established 100 ft parallel transects 4-5ft

from embankments; one sample collected every 20ft- Invertebrates quantified at the lab

• ONLY 3 nymphs FOUND, all in Big Creek

Hexagenia adult sampling (June 22-24)

Locals reported seeing larger swarms the previous week

Tawas Pier, Tawas City Park, Tawas gas station

- Circular quadrants were placed over non-reflective white material and positioned under local street lamps- Hexagenia were counted inside each quadrant every 10 min from 10:00 pm-12:00 am

AcknowledgementsAcknowledgements

Funding: NOAA Center for Sponsored Coastal Ocean Research

Thanks to our divers and ship captains:Thanks to our divers and ship captains:Tane Casserley, Russ Green, Tom JoyceTane Casserley, Russ Green, Tom Joyce, ,

Wayne Lusardi and Jack WorkmanWayne Lusardi and Jack Workman

SRP Flux-200

-100

0

50

Aerobic DEAerobic Control

Anoxic DEAnoxic Control

TDP Flux-200

-100

0

100

P F

lux (

µg

P/m

2/d

ay)

Ex 1:TDP & SRP Fluxes

-80

-40

0

40

80

SRP Aerobic

SRP Anoxic

TDP Aerobic

TDP Anoxic

Effects of dreissenid excretion on P recycling