Mammalian young are especially vulnerable to harm because of their small size, poorly developed survival skills, and strong dependence on maternal care. Tactics for rearing young, including avoiding harm, vary largely by environment type. Off Kaikoura, New Zealand, mother–calf pairs of dusky dolphins ( Lagenorhynchus obscurus (Gray, 1828)) are often found in small groups with other mother–calf pairs, with calves of roughly the same age. These groups, termed “nursery groups”, may distance vulnerable calves from hazards associated with males seeking mating opportunities, predation by sharks and killer whales ( Orcinus orca (L., 1758)), and boat traffic. We conducted systematic boat-based surveys to determine the relative distribution of dusky dolphin group types, predators, and boats in the area. Nursery groups were encountered in shallow waters (≤20 m) significantly more often than in deeper waters (p < 0.001). Boats were found more in shallow water, while predators were almost exclusively encountered in deeper water. Other dusky dolphin group types did not show a preference for deep or shallow waters. Potential harassment from males and the presence of boats were both significant predictors of the depth category in which a group was found (p < 0.03). We recommend that managers focus efforts on protecting this vulnerable subgroup of the dusky dolphin population by protecting their preferred nearshore shallow habitat and by reducing recreational boating and fishing in these areas.

Management of the fishery for California sea cucumbers Parastichopus californicus in the Pacific Northwest is limited by a lack of natural growth rate estimates. Growth rates of caged juvenile California sea cucumbers (from Departure Bay, British Columbia) consuming a natural diet for 12 months (September 2008–September 2009) were examined. Growth was low between September and March but significantly increased thereafter, appearing to follow seasonal physiological processes, temperature, and natural sedimentation rates. Over the 12‐month period, whole wet weight in air (WWA) increased by an average of 164%, immersed whole weight (IWW) increased by 251%, and the size index (SI) increased by 85%. Average standard growth rates were 0.267%/d for WWA, 0.346%/d for IWW, and 0.169%/d for SI. Measurement accuracy, effects of body content, and relationships between size and weight metrics are discussed. These findings are an important addition to the knowledge of California sea cucumber biology and are valuable for the stock assessment, fisheries management, and aquaculture of this species. Received January 1, 2011; accepted November 10, 2011

No abstract

No abstract

No abstract