Impact of an Acute Sublethal Exposure of Endosulfan on Early Juvenile Lobster (Homarus americanus)

Abstract

Anthropogenic chemicals in the environment during critical periods could potentially affect the physiology of the economically valuable American lobster (Homarus americanus). Endosulfan (Thiodan™ WP) is a broad-spectrum organochlorine insecticide widely used in agricultural areas in Canada that significantly affects survival and growth of lobster larvae based on acute exposure studies. To detect more subtle physiological effects of an acute (96-h) sub-lethal level (0.1 μg•L-1) of formulated endosulfan exposure on early juvenile lobsters, investigations of metabolic rates, growth and the tissue structure of the

Effects of Sublethal Chlorpyrifos Exposure on Postlarval American Lobster (Homarus americanus)

“…The cessation of normal movement patterns observed during chlorpyrifos exposure may reduce the lobster's control of swimming and hiding behavior when confronted with the threat of predation. Lobsters exposed to the organophosphate pesticide azamethiphos, used in the treatment of sea lice in the salmon aquaculture industry, have shown abnormal movements similar to those in the present study (Pahl and Opitz ; Daoud et al ). Azamethiphos exposure resulted in loss of muscle control in stage II lobsters (twitching and morbidity) in concentrations as low as 0.1 µg/L and death by hypoxia in adult male lobsters attributable to decreased volume of water crossing the gills (Pahl and Opitz ; Daoud et al ).…”

“…Lobsters exposed to control conditions and concentrations <0.82 µg/L displayed specific growth rate and moult increment within the expected range (Cobb and Castro 2006;Daoud et al 2014). Exposure to 0.82 µg/L chlorpyrifos significantly affected growth by decreasing specific growth rate and moult increment as well as increasing intermoult period when compared to control lobsters, decreasing the amount of growth while increasing the time to reach moult.…”

Energy metabolism and survival of the juvenile recruits of the American lobster (Homarus americanus) exposed to a gradient of elevated seawater pCO2

“…Within the 72 h following transfer, dead individuals were replaced before testing the biological effects of post-larval exposure at elevated pCO2 levels on stage V juvenile lobsters. Incoming water entering the two header tanks responsible for filling each experimental tank was supplied from Brandy Cove in the Passamaquoddy Bay (NB, Canada), passing through a series of sand filters (20 μm), a UV-treatment, heated at 18 °C, mimicking the optimal temperature for growth and survival of juvenile lobster from Baie des Chaleurs in the laboratory (Daoud et al, 2014) and bubbled with ambient air. Header tanks were bubbled with ambient air to oxygenate incoming seawater.…”