Conservation, Ecology, and Management of Catfish: The Second International Symposium

Conservation, Ecology, and Management of Catfish: The Second International Symposium ◽

10.47886/9781934874257.ch35 ◽

2011 ◽

Keyword(s):

Ictalurus Punctatus ◽

Channel Catfish ◽

River Estuary ◽

Current Status ◽

Catch Per Unit Effort ◽

Delaware River ◽

Conservation Ecology ◽

Delaware River Estuary ◽

Variable Recruitment ◽

Native White

Abstract.—In the Delaware River estuary, native white catfish Ameiurus catus have appeared to decline as the introduced channel catfish Ictalurus punctatus has become more abundant. To determine the current status of these populations and the habitats they use, I surveyed four zones of the Delaware River estuary from April to November 2007. Hoop nets (N = 497) were set in main-stem river, lower tributary, and middle tributary habitats. Upper tributary habitats near the head of tide were angled. Our findings indicated that the ratio of channel catfish to white catfish was less than documented in the early 1990s. Channel catfish and white catfish were found throughout the study area, during all seasons. Channel catfish catch per unit effort was significantly greater in the river than in tributary habitats. Relative condition differed seasonally among zones and zone groups. Both species had unstable age structures, indicating variable recruitment. Variable recruitment may account for past differences in ratios of channel catfish to white catfish. Channel catfish in this study lived longer (22 years) when compared to channel catfish collected in other nearby river systems. Few brown bullhead A. nebulosus and no yellow bullhead A. natalis or ﬂathead catfish Pylodictis olivaris were collected.

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Salinity investigations in the Delaware River estuary

Open-File Report ◽

10.3133/ofr566 ◽

1956 ◽

Author(s):

N.H. Beamer

Keyword(s):

River Estuary ◽

Delaware River ◽

Delaware River Estuary

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A graphical summary of dissolved-oxygen data for the Delaware River Estuary for water years 1965-1969

Open-File Report ◽

10.3133/ofr70223 ◽

1970 ◽

Author(s):

C.F. Merk

Keyword(s):

Dissolved Oxygen ◽

River Estuary ◽

Delaware River ◽

Delaware River Estuary ◽

Graphical Summary

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Conservation, Ecology, and Management of Catfish: The Second International Symposium

Conservation, Ecology, and Management of Catfish: The Second International Symposium ◽

10.47886/9781934874257.ch21 ◽

2011 ◽

Keyword(s):

United States ◽

Body Condition ◽

Ictalurus Punctatus ◽

Channel Catfish ◽

Aeromonas Hydrophila ◽

Condition Index ◽

The United States ◽

Southern United States ◽

Conservation Ecology ◽

Columnaris Disease

Abstract.—U.S. Game and Fish agencies and farm-pond owners throughout the United States use commercially produced channel catfish Ictalurus punctatus fingerlings transported from the southern United States for supplemental stocking. We conducted six trials to examine whether pathogen load, body condition, and select environmental factors influence fingerling survival following transport and cage stocking. Fingerlings were sampled prior to stocking and weekly for the following 3 weeks. Weights and lengths were measured, and a relative condition index was used to quantify body condition. Skin scrapings and gill clippings were examined microscopically for pathogens, and posterior kidney was assayed for Aeromonas hydrophila. Mortality was either less than 10% (four trials) or catastrophic (two trials). A Columnaris disease epizootic was associated with ~50% mortality in one trial, and a red sore disease epizootic was associated with ~80% mortality in another. Body condition or other pathogens, present initially or acquired in study ponds, were not associated with high mortality. The first week appears to be critical for the survival of channel catfish fingerlings following transport.

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Conservation, Ecology, and Management of Catfish: The Second International Symposium

Conservation, Ecology, and Management of Catfish: The Second International Symposium ◽

10.47886/9781934874257.ch46 ◽

2011 ◽

Keyword(s):

International Symposium ◽

Ictalurus Punctatus ◽

Channel Catfish ◽

High Abundance ◽

Sampling Effort ◽

Conservation Ecology ◽

Standard Work ◽

Second International

Abstract.—Baited, tandem hoop nets are increasingly being used to sample channel catfish Ictalurus punctatus populations in reservoirs. However, there have been no published studies to address the effect of soak duration on precision of catch. The effect of soak duration on precision of channel catfish catch in baited, tandem hoop nets was evaluated in three Texas reservoirs. Precision of channel catfish catch was inconsistent among reservoirs when one-night soak durations were used but improved with two-night and three-night soak durations. Although catch precision was similar for two- and three-night soak durations, sampling effort could be doubled using two-night rather than three-night soak durations during a standard work week if a manager did not prefer to leave gear unattended during a weekend. Thus, we recommend use of baited, tandem hoop-net series with two-night soak durations to sample high-abundance channel catfish populations in reservoirs.

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