Advisor

Kaminski, Richard M.

Committee Member

Avery, Jimmy L.

Committee Member

D’Abramo, Louis R.

Committee Member

Grado, Stephen C.

Committee Member

Kröger, Robert

Date of Degree

1-1-2014

Document Type

Dissertation - Open Access

Abstract

I estimated yield, population metrics, production costs, and evaluated consumer acceptability and nutritive content of crayfish (Procambarus clarkii, P. zonangulus) harvested from moist-soil wetlands in the Lower Mississippi Alluvial Valley (MAV) during springs 2009-2011. I also compared nutrient and sediment concentrations and loads exported from moist-soil wetlands and nearest agriculture fields in the MAV during winters 2010-2012. Daily yield of crayfish from moist-soil wetlands was 2.4 kg (wet) ha-1 (SE = 0.50; 95% CI = 1.3-3.4). When graded by size, yield of large crayfish (> 30 g) from wetlands dominated by P. clarkii was four times greater (P < 0.05) than yield of large crayfish from wetlands dominated by P. zonangulus. Crayfish harvesting costs (2013 US dollars [$]) ranged from $405.69 ha-1 to $917.88 ha-1 and breakeven selling prices ranged from $3.74 kg-1 to $8.49 kg-1. Consumer acceptability, proximate composition, and total fatty acid content of P. clarkii did not differ (0.73 > P > 0.11) between crayfish harvested from moist-soil wetlands and rice-crayfish culture fields in Louisiana. Although selling prices likely will not compete with prices for crayfish harvested from Louisiana rice fields ($2.75 kg-1; 2012 US$), harvesting crayfish from moist-soil wetlands may enhance recreational opportunities while increasing awareness of ecosystem benefits of these wetlands. Although concentrations (mg L-1) of soluble reactive phosphorus (SRP) in runoff from moist-soil wetlands and adjoining croplands did not differ (P = 0.95), concentrations of total and particulate phosphorus, nitrate-nitrogen, and total suspended solids were 42, 52, 86, and 89% lower (P < 0.03) in runoff from moist-soil wetlands. However, the load (kg ha-1) of SRP from moist-soil wetlands was six times (P = 0.08) greater than load from croplands. Estimated loading rate of total phosphorus from moistsoil wetlands (2.36 kg ha-1 year-1) was greater than the rate reported by regulatory agencies in Mississippi (1 kg ha-1 year-1), but field replication is needed to verify these results. Nearly 80% of the total loads exported from moist-soil wetlands occurred during < 30% runoff events. Retention of runoff from storm events may reduce phosphorus loss from moist-soil wetlands while not interfering with conservation objectives.

URI

https://hdl.handle.net/11668/19532

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