Robert M. Durborow

Aquacultural Safety and Health

Worldwide, 11,289,000 people worked in aquaculture in 2004—up nearly three-fold from 3,832,000 workers in 1990 (Watterson et al., 2008). Aquaculture, including mariculture, is a fast growing sector of worldwide agriculture but has unaddressed occupational safety and health issues. Many fish farming tasks are dangerous; working around water poses a particular danger, and Working at night and alone compounds the danger. A safety or health hazard is any work design or property (physiological, physical, chemical, biological, or psychological) that may cause harm to workers or bystanders.

Safety on North Carolina and Kentucky Trout Farms

The objective of this study was to identify and describe work-related safety hazards, injuries, and near-injury events (close calls) that occurred on trout farms in North Carolina and Kentucky. An interview instrument was used to collect information on occupational hazards, injuries, and near-injury events that resulted from work-related activities. Trout farmers reported occupational hazards including falling live tank lids, slippery surfaces on hauling trucks, lifting strains, falls from raceway walls and walkways, needlesticks while vaccinating fish, allergies, hypothermia/drowning, falls from cranes, chemical exposure, fire/explosions related to oxygen exposure, and electrical contact with overhead power lines. This study also reports solutions suggested by farm safety researchers or used by farmers to prevent the safety hazards found on trout farms.

Management of Aquatic Weeds

Plants growing in aquatic environments can have positive impacts, such as producing dissolved oxygen and absorbing toxins. However, they are usually regarded as a nuisance and therefore labeled as “weeds.” Prevention is a much more reliable approach than trying to treat them after they are established. Proper pond construction (providing adequate water depth), fertilization (to promote phytoplankton rather than macrophytes), aquatic dye application (to block out sunlight), manual harvest as the weeds appear, stocking grass carp (eat the weeds) or koi (create water turbidity), and water drawdowns (stranding weeds along the shore) can be effective preventive measures. Once the weeds are present, however, controlling them with herbicides is usually the most effective recourse. Algae are typically controlled with copper sulfate or copper-based complexes, while higher aquatic plants/weeds are controlled by properly selected herbicides that include bispyribac-sodium, carfentrazone-ethyl, diquat dibromide, endothall compounds, flumioxazin, fluridone, 2,4-D, glyphosate, imazamox, imazapyr, triclopyr, penoxsulam, sodium carbonate peroxyhydrate, and nutrient reducers.

Toxicity of Rotenone to Giant River Freshwater Prawn Macrobrachium rosenbergii

Abstract Aquaculturists have often suffered predation losses in the production of freshwater giant river prawn Macrobrachium rosenbergii due to the presence of wild fish species in culture ponds. The piscicide rotenone is widely used to remove undesirable fish species from ponds. Although evidence in the technical literature suggests that crustaceans generally have a higher tolerance to rotenone than fish, there are currently no data on the acute or chronic toxicity of rotenone to juvenile freshwater prawns. In this study, two static acute-toxicity bioassays (96 h) were conducted using Prentox Prenfish (5% active ingredient) rotenone to determine the median lethal concentration (LC50) for juvenile freshwater prawns (average weight = 0.55 g, SD = 0.25; length = 41.43 mm, SD = 6.45). In bioassay 1, prawns were exposed to rotenone concentrations of 1.0, 3.0, 5.0, and 10.0 mg/L. In bioassay 2, prawns were exposed to rotenone concentrations of 2.2, 3.6, 6.0, 10.0, and 16.7 mg/L. All rotenone concentrations use...

Hierarchical Aquacultural Hazard Controls for Inherently Safer Work

In more than 50 onsite farm surveys in ten states, fish farmers identified occupational hazards, most of which the farming population knew well. Less well known were the innovative countermeasures that farmers created to control the hazards. The purpose of this study is to report on farmer innovations to reduce or eliminate occupational risk of injuries or illnesses on fish farms. The methodology used is to identify hazards and classify their controls as created by farmers by a hierarchy of controls. All models of hierarchical controls move from active controls, depending on human action, to passive controls, designed for protection independent of human action. A complex hierarchy from industrial hygiene involves six levels of control, while a simple approach evolved through litigations involves three levels—warning of to guarding against to eliminating the hazard. The first is an active control while the latter two are passive controls. The implications of this study are two-fold: (1) informing the general fish farming community of the inherently safer controls, and (2) demonstrating the application of the hierarchy of controls as a design tool for inherently safer technologies.