Astrid R. Jacobson1, Colleen Jones2, Palak Vesudeva1, David Powelson1 and Paul R. Grossl1, (1) Utah State University, Logan, UT, (2) Utah State University, Vernal, UT

We thank the Utah Agriculture Experiment Station for funding this research through project UTAO+1090, the Utah Division of Water Quality for funding sample collection

ACKNOWLEDGMENTS

Boron Concentrations in the Pariette Wetlands and the Hazard Posed to Aquatic Birds and Fish

Pariette Wetland is the largest US Bureau of Land Management(BLM) wetland development in Utah. The wetlands containdiverse vegetation and wildlife in an arid climate.Concentrations of boron (B) exceed the total maximum dailyloads developed to meet the US EPA’s water quality planningand management regulations (40CFR 130) based on irrigationand water for livestock. The objectives of the study were tomeasure B concentrations in environmental compartments andestimate the hazard posed by B to aquatic-dependent birds.Although B is heterogeneously distributed in the wetlands, itposes a minimal risk to aquatic biota.

BACKGROUND

Astrid R. Jacobson1, Palak Vasudeva1, Colleen Jones2, and David Powelson1

Department of Plants, Soils & Climate, (1) Utah State University, Logan, UT, (2) Utah State University, Vernal, UT

Sampling along 25 pond complex (May-July 2014)

Waters, sediments, vegetation, & benthic macroinvertebrates were collected at 3 sites within 6 ponds, in triplicate.

Sediments were sampled from 0-2 cm and 2-5 cm using a corer

Water samples were filtered through a 0.45 µm membrane filter

Benthic macroinvertebrates were captured with 500 µm mesh kick nets just above the sediment surface

Whole fish were collected with nets (n=54)

One egg was sampled per located nest (n=36)

MATERIALS AND METHODS

Analytical Methods ECe and pH were measured in

saturated paste extracts of the sediments.

B was extracted from the sediments with sorbitol and analyzed by colorimetry(azomethine-H)

Mixed organism samples were digested with HNO3/HClO4 and analyzed for Se by HGAAS and B by colorimetry.

High lipid egg and fish samples were analyzed by TERL

BORON DISTRIBUTION SUMMARY

CORRELATIONS

A. Concentration at which adverse effects to aquatic plants are anticipated, B. Concentration range for the NOAEL and LOAEL for Daphnia magna, C. Concentration range at which adverse effects are anticipated for freshwater fish.

BORON in ENVIRONMENTAL COMPONENTS

The highest B concentrations were observed in American Cooteggs. Coots are dabblers that feed on plants, seeds andinvertebrates.

Boron concentration range in Potamogeton sp. A. growing infreshwater, B. growing in contaminated irrigation drain waterat Kesterson National Wildlife Refuge, CA, (1983). Submergedvegetation has been observed to accumulate boron.

The lines indicate A. Concentration at which adverse effects toaquatic plants are anticipated, B. LOAEL for Daphnia magna,C. Boron concentration at which adverse effects areanticipated for freshwater fish. pH = 8.7 ± 0.6, EC = 9.1 mS/cm

Divers (e.g., Pied-Billed Grebes) feed on benthic macro-invertebrates and fish. Ground Foragers (e.g., Marsh Wrensand Yellow-headed Black Birds, eat insects and seeds.

Taxa richness (< 13) was low in all ponds. Boron concentrationswas higher in samples rich in beetles (Corixidae), crustaceans(Physidae), and dragonflies (Odonates). The lines indicateconcentrations of boron (dw) in foodstuff observed to reduceweight and weight gain in Mallard ducklings A. less than 21days old; and B. all ducklings.

The highest B levels were found in Green sunfish, which feedon larvae, snails and small invertebrates. They were welldistributed throughout all wetland. Black bullhead catfish (n=3in 1 unit; B = 9.5 ± 1.7 mg/kg (dw)) feed on invertebrates, plantmaterial and insects, Red shiners (n=10 in 2 units; B = 2.1 ± 0.6mg/kg (dw)), feed on benthic insects and algae.

CONCLUSIONS

Although B concentrations in Pariette pond water often exceeds TMDLs, the concentrations are unlikely to impact adult birds or fish tolerant of the pond water quality (high pH and EC).

Correlations between B in bird eggs or fish and B in water, sediment, vegetation, or benthic macroinvertebrates were generally poor to non-existent. However, a few moderate correlations suggest that dietary intake of B has the largest impact. Dietary samples to monitor include submerged vegetation and seeds.

Emergent vegetation (particularly monocot) has not beenobserved to accumulate boron, which is consistent with ourresults.

Boron concentrations were highest in the top 2 cm of thesediments and decreased with depth.