Mitigating Impacts of Natural Hazards on Fishery Ecosystems

Developing a Framework for Fisheries Restoration in the Pascagoula River Basin following Hurricane Katrina

J. Brian Alford, Daniel M. O’Keefe, and Donald C. Jackson

doi: https://doi.org/10.47886/9781934874011.ch16

Abstract.—Extensive fish kills, primarily from dissolved oxygen depletion, were reported in rivers and associated backwaters throughout southern Mississippi following Hurricane Katrina. Of particular concern were fisheries associated with the Pascagoula River, the last physically unmodified large river system in the contiguous United States. Posthurricane stock assessments were conducted in 2006 to ascertain appropriate fisheries restoration actions for this internationally recognized natural resource. Emphasis focused on fishes that traditionally supported recreational, artisanal, and subsistence fisheries, primarily sunfish (Centrarchidae) and catfish (Ictaluridae). These fisheries were considered some of the more productive inland fisheries in the state prior to the storm.

Posthurricane catch per unit effort (CPUE) of adult (harvestable-size) catfish in the main stem of the Pascagoula River were very low, with only seven fish caught in 110 hoop nets (mean CPUE = 0.14 kg/net-night). Black bass Micropterus spp. and crappie Pomoxis spp. CPUE of Pascagoula River oxbow lakes were in the 25th percentile of statewide oxbow lake CPUE. Although bluegill Lepomis macrochirus relative abundances were in the 75th percentile of statewide oxbow lake relative abundances, age-frequency distribution of bluegill suggested that most were age-0 individuals spawned the year after the hurricane. Largemouth bass young-to-adult ratios were very low throughout the system, suggesting that there were few spawning adults. Catch rates of black bass and proportion of bluegill ≥ age 2 increased as conductivity increased, suggesting that downstream reaches of the system, with more brackish water influence and greater connectivity to the main channel, may have provided refuge for these fish during the storm. Although natural recovery of fish stocks will likely occur in the system, angler outcry for immediate reconnection to the Pascagoula River fisheries was staunch, ultimately prompting the decision by Mississippi Department of Wildlife, Fisheries and Parks (MDWFP) to initiate a fisheries restoration program oriented towards mitigating hurricane impacts.

In order to expedite angling opportunities in coastal rivers impacted by Hurricane Katrina, a large-scale, multiyear experimental stocking program has been implemented by MDWFP involving selective stocking of harvestable-size channel catfish Ictalurus punctatus in several coastal rivers and advanced fingerling Florida strain largemouth bass Micropterus salmoides floridanus in the Pascagoula River. A roving creel survey was initiated in May 2007 in the Pascagoula River main channel to assess sport fish exploitation, monitor trends in angler effort following Hurricane Katrina, and gauge angler perceptions of fisheries recovery. Stock assessments are being conducted on flathead catfish Pylodictis olivaris, and future studies include status updates for species of conservation concern, including paddlefish Polyodon spathula, striped bass Morone saxatilis, and Gulf sturgeon Acipenser oxyrhincus desotoi. These stocking and assessment programs will serve as baseline data for fisheries managers responding to the next hurricane that impacts the Mississippi Gulf Coast.