The Mississippi River Basin Initiative (MRBI) Watershed Water Quality Monitoring of Bayou

Chene an Lacassine Bayou

Presented to:NPS Project Review Meeting

Wednesday, December 12, 2012LDEQ Baton Rouge, LA

Presented by:

Durga D PoudelUL Lafayette

• Introduction

• Objectives

• Materials and Methods

• Results and Discussions

• Summary

• Acknowledgements

Introduction

Zone ACREAGE

Zone I Thornwell Drainage Canal 9392

Zone II Lacassine Bayou 59394

Zone III Indian Bayou Canal 12756

Zone IV Bayou Chene 37364

Zone V West Bayou Lacassine 13303

Zone VI East Bayou Lacassine 29471

Zone VII West Bayou Grand Marias 9998

Zone VIII Middle Bayou Grand Marias 6607

Zone IX Gum Gully 34190

Materials and Methods

Weekly field measurements and sampling: Water depth, DO, temp. pH, turb., cond.

Laboratory determination:

TSS, TDS, TS, Nitrite, Nitrate, TKN, TP, SRP, Cl, Fl, SO4, BOD5

Fish and macroinvertibrates sampling

For each castnet (12ft radius cast net with 3/8th inch mesh size) sample, we combined the fish from 5 cast net throws. 

For each dipnet sample, we sample 5 minutes. 

We do this 4 times per site (resulting in the 4 replicates) for a total of 20 cast net throws and 20 minutes of dipnetting per site. 

Collecting the fish and benthic samples takes 2.5 to 3 hours per site, for a crew of three people. 

Benthic samples were taken with a petite Ponar grab, and sieved in the field (500 micron screen). Sample sorting/identification is ongoing.

Petite Ponar Grab sampler

> 500 µm fraction to be preserved in 10% formalin with Rose Bengal stain.

Results and Discussion

site #/ cast #/dip min #/dip min excl. G.a.*1L 1.15 12.85 0.602L 1.35 14.70 0.353L 0.65 107.15 0.004L 0.60 4.35 0.255L 0.30 5.20 0.151C 0.90 4.00 0.252C 0.15 9.85 0.253C 0.10 17.10 0.304C 0.05 20.25 0.40

Lacassine mean 0.81 28.85 0.27Bayou Chene mean 0.30 12.80 0.30Overall mean 0.58 21.72 0.28Overall min 0.05 4.00 0.00Overall max 1.35 107.15 0.60Overall SD 0.47 32.56 0.17

Fish abundance measures, by site, bayou and overall. Shown are mean numbers per cast throw (5 throws/replicate) and numbers per minute of collection by dipnet (5 min. per replicate) for the four replicates at each site combined.

* Mosquitofish (Gambusia affinis) excluded due to sometimes extreme numerical dominance (up to 99% of total number of individuals)

FAMILY SPECIES COMMON NAMEBelonidae Strongylura sp. Needle fishCatostomidae Carpiodes cyprinus Quillback

Centrarchidae Elassoma okefenokeeOkefenokee pygmy sunfish

Centrarchidae Lepomis auritus Redbreast sunfishCentrarchidae Lepomis cyanellys Green sunfishCentrarchidae Lepomis gibbosus Pumpkinseed sunfishCentrarchidae Lepomis humilis Orange-spotted sunfishCentrarchidae Lepomis macrochirus Bluegill sunfishCentrarchidae Lepomis symmetricus Bantam sunfishCentrarchidae Pomoxis annularis White crappie

CentrarchidaePomoxis nigromaculatus Black crappie

Clupeidae Dorosoma cepedianum Gizzard shadFundulidae Fundulus chrysotus Golden topminnowHiodontidae Hiodon tergisus MooneyeIctaluridae Ictalurus punctatus Channel catfishMugilidae Mugil cephalus Striped mulletPoeciliidae Gambusia affinis Western mosquitofishPoeciliidae Heterandria formosa Least killifish

Fish species collected

June-July fish and benthic organisms Diversity measures

# fish species Div. index H'Div. index H" (w/o

G.a.)1L 7 0.583 1.6512L 9 0.485 1.3863L 5 0.044 1.2214L 9 0.817 1.9215L 7 0.425 1.7351C 8 0.814 1.1462C 6 0.204 1.3523C 4 0.128 0.7364C 5 0.132 1.149

Lacassine B. mean 7.4 0.471 1.583

Bayou Chene mean 5.8 0.320 1.096Overall mean 6.7 0.404 1.366Overall min 4 0.044 0.736Overall max 9 0.817 1.921Overall SD 1.80 0.295 0.360

Field observations

Summary

Weekly data collection helps in understanding water quality variability and watershed conditions better.

Monthly flow data for sampling locations are being collected with the help of LDEQ which will allow us in calculating loading rates for the 9 Zones per unit area and determining the effectiveness of BMPs in reducing nutrients, sediments, and biological oxygen demanding substances entering the bayous.

Biological data on species diversity and abundance will be useful in assessing the effectiveness of BMPs on improving watershed health and aquatic life.

Acknowledgements

We like to acknowledge LDEQ and EPA Region 6 for funding this project. We also like to thank NRCS, LDAF, LDEQ staff and other stakeholders for helping us in this project