Environmental Assessment of Channel Catfish Ictalurus punctatus Farming in Alabama

Abstract

An environmental assessment was made of Alabama channel catfish Ictalurus punctatus farming which is concentrated in the west‐central region of the state. There are about 10,000 ha of production ponds with 10.7% of the area for fry and fingerlings and 89.3% for food fish. Food fish production was about 40,800 tons in 1997. Watershed ponds filled by rainfall and runoff make up 76% of total pond area. Water levels in many of these ponds are maintained in dry weather with well water. The other ponds are embankment ponds supplied by well water. Harvest is primarily by seine‐through procedures and ponds are not drained frequently. The main points related to Alabama catfish farming and environment issues are as follows: 1) catfish farming in Alabama is conservative of water, and excluding storm overflow, about two pond volumes are intentionally discharged from each pond in 15 yr; 2) overflow from ponds following rains occurs mostly in winter and early spring when pond water quality is good and stream discharge volume is high; 3) total suspended solids concentrations in pond effluents were high, and the main sources of total suspended solids were erosion of embankments, pond bottoms, and discharge ditches; 4) concentrations of nitrogen and phosphorus in effluents were not high, but annual effluent loads of these two nutrients were greater than for typical row crops in Alabama; 5) ground water use by the industry is about 86,000 m3/d, but seepage from ponds returns water to aquifers; 6) there is little use of medicated feeds; 7) copper sulfate is used to control blue‐green algae and off‐flavor in ponds, but copper is rapidly lost from pond water; 8) although sodium chloride is applied to ponds to control nitrite toxicity, stream or ground water salinization has not resulted from this practice; 9) fertilizers are applied two or three times annually to fry and fingerling ponds and occasionally to grow‐out ponds; 10) hydrated lime is applied occasionally at 50 to 100 kg/ha but this does not cause high pH in pond waters or effluents; 11) accumulated sediment removed from pond bottoms is used to repair embankments and not discarded outside ponds; 12) sampling above and below catfish pond outfalls on eight streams revealed few differences in stream water quality; 13) electricity used for pumping water and mechanical aeration is only 0.90 kW h/kg of production; 14) each metric ton of fish meal used in feeds yields about 10 tons of dressed catfish. Reduction in effluent volume through water reuse and effluent treatment in settling basins or wetlands does not appear feasible on most farms. However, some management practices are recommended for reducing the volume and improving the quality of channel catfish pond effluents.

Growth, yield, water and effluent quality in ponds with different management during tambaqui juvenile production

“…Boyd et al (2000) described values of 540 mg L -1 for channel catfish, and pointed out TSS as one of the main pollutant in channel catfish ponds, which were not observed in the present work, where TSS were around 100 times lower. Mean values for settleable matter varied between 0.01 and 0.02 mg L -1 among treatments.…”

“…The results show that fertilization is an unnecessary procedure, mainly in ponds that receive fish ration. Boyd et al (2000) and Boyd (2003) evaluated the concentrations of several parameters from channel catfish ponds drained water, and most of the values were not potentially pollutant; only total phosphorus concentration and TSS indicated a potential pollutant problem for receiving water bodies. Among data obtained in this study, only phosphorus presented elevated values.…”

“…Pond management is a common aquaculture practice which has a direct impact on effluent quality (Boyd et al, 2000). Well-managed ponds tend to have a better water and effluent quality.…”

Caractérisation de l'effluent de vidange d'un étang de pisciculture extensive

“…De nombreux travaux font état de la problématique environnementale posée par l'exploitation piscicole intensive et notamment de la question des effluents en termes d'apports en matières en suspension, azote et phosphore (Boyd, 1978(Boyd, , 2003Schwartz & Boyd, 1994, 1995Boyd et al, 2000;Tucker & Hargreaves, 2003). Peu d'approches en revanche concernent des (Schwartz & Boyd, 1994).…”

Effects of Two Environmental Best Management Practices on Pond Water and Effluent Quality and Growth of Nile Tilapia, Oreochromis niloticus

“…For example, almost all forms of aquaculture in the United States came under severe scrutiny and criticism in the 1990s for alleged poor environmental stewardship [7,8] and the US, for example, responded with increased regulatory activity that led to a frenzy of research to respond to the new rules (e.g., [9]). Much research preceding and immediately following the imminent regulations focused on the characterization of effluents from various types of aquaculture under a range of management conditions [10][11][12][13][14] and assessments of the impacts of aquaculture effluent on receiving waters [15,16]. Consensus has emerged that pond aquaculture effluents are generally too dilute for conventional treatment options and that certain management practices, if applied properly, would help aquaculture achieve an equal or better environmental performance with less economic burden on producers [17][18][19][20][21][22][23][24][25].…”