Winter-spring recruitment pattern of epiphytic harpacticoid copepods in a temperate-zone seagrass bed

Abstract

Harpacticoid copepods inhabiting a seagrass (Zostera marina L.) bed on Roberts Bank, British Columbia, Canada, were sampled every 2 wk from late January to mid July in 1986 and 1987. Samples were taken of seagrass leaves and the underlying sediment. The epiphytic copepod community at this study site was composed of typical temperate genera (e.g. Dactylopodia, Harpacticus, Mesochra, Tisbe, Zaus). Total copepod abundance on the leaves generally exceeded that in the sediment. Densities on seagrass leaves were markedly lower in 1987 than in 1986. Temporal patterns of abundance of individual species were different between years, contrasting with the stability of successional patterns in sediment-dwelling harpacticoid communities. Some seagrass-dwelling copepod populations may be seeded in the spring from sediment-dwelling individuals. Also, possible movement from the leaf surface to the sediment was observed for 1 species. This study underscores the importance of sampling multiple subhabitats in seagrass beds when assessing the dynamics of the epiphytic copepod community.

Eelgrass as Valuable Nearshore Foraging Habitat for Juvenile Pacific Salmon in the Early Marine Period

“…Like juvenile Chum Salmon diets, juvenile Chinook Salmon diets were also dominated by harpacticoid copepods by count, as seen also in the Nanaimo Estuary (Healey ). While we did not sample all habitat features in the estuary due to time constraints, Harpacticus uniremus , a common copepod targeted by juvenile Chum Salmon (Healey ; Sibert ; Webb ), is strongly associated with eelgrass beds (Webb and Parsons ; Hosack et al. ).…”

Effects of Seawalls and Piers on Fish Assemblages and Juvenile Salmon Feeding Behavior

“…Our observations of Chum/Pink Salmon occurring farther into shaded areas under piers at low tide may also indicate that out-migrating juvenile salmon wait in corner sections until low tides allow a greater amount of light to penetrate the areas under piers. If piers delay the out-migration of juvenile salmon, this may have negative impacts on their survival by retaining the fish in suboptimal habitats, delaying their access to ephemeral prey resources in more natural habitats (Webb 1991(Webb , 1992Cooney et al 1995), and increasing their vulnerability to predation (Willette et al 1999). Although our study provides indirect evidence that piers cause migration delays, methods such as mark-recapture, acoustic tagging, and visual observations that follow salmon would permit direct testing of pier effects on salmon movements.…”

Harpacticoid copepods:potential link between inbound adult salmon and outbound juvenile salmon

“…indicate that this alga utilizes nutrients derived from adult salmon carcasses during late summer and fall months, and the influence of the salmon derived nutr~ents remains through early spring. Gravid females of some harpacticoid copepod species overwinter, and their offspring are released in early spring (Webb & Parsons 1992). Because food depletion has been experimentally shown to cause slow development and low fecundity in harpacticoids (Lee et al 1976, Hicks 1979, the food availability during fall and winter can influence the population size of harpacticoid copepods in spring when juvenile salmon appear in the estuary.…”