Growth of filter-feeding benthic invertebrates from a region with variable upwelling intensity

Abstract

Coastal upwelling is an ocean feature thought to have important impacts on benthic marine communities by enhancing planktonic productivity in the nearshore environment. In this study, growth rates of 3 species of filter-feeders were examined over a geographic region that includes sites where upwelling is typically weak (south of Point Conception, California, USA) and sites where upwelling is often strong and frequent (at and to the north of Point Conception). The growth of the mussel Mytilus californianus, the gooseneck barnacle Pollicipes polymerus and the acorn barnacle Balanus glandula, as well as the body condition of M. californianus, were all up to 3-6 times higher at sites furthest south of Point Conception, and decreased dramatically moving north around the point. Spatial variation in food availability (measured as chlorophyll a, particulate organic carbon and particulate organic nitrogen) and food quality (measured as C/N ratios) did not explain these patterns of growth. Tidal height of the organisms also failed to account for persistent spatial variation in growth rates. Water temperature varied in a pattern consistent with growth rates (i.e. mean temperatures were warmer in the south), and was the one factor most often selected in stepwise regressions for models contributing to patterns of filter-feeder growth. This study suggests that factors other than, or in conjunction with, productivity may drive large-scale differences in benthic filter-feeder growth rates.

Influence of Basin‐ and Local‐Scale Environmental Conditions on Nearshore Production in the Northeast Pacific Ocean

“…Mixed relationships between the growth of Kelp Greenlings and environmental conditions at different time lags in the California Current could indicate that cooler conditions promote more benthic productivity and a greater abundance of benthic prey, whereas warmer conditions promote increases in prey quality. The veracity of this interpretation could reconcile long-disputed biophysical relationships in benthic production associated with the California Current, which contrast temperature (Phillips 2005(Phillips , 2007Blanchette et al 2007) and food limitation (Menge et al 1997(Menge et al , 2009Menge and Menge 2013); our interpretation follows a number of hypotheses that point to the benefits of intermittently cool and warm conditions at shorter, within-season time scales (Cury and Roy 1989;Gargett 1997;Menge and Menge 2013).…”

“…Warm temperatures increase the rates of filter feeding, providing a plausible mechanism linking temperature to increases in growth (Phillips 2005). Both food availability and temperature were related to mussel growth rates in Oregon, with the direct (i.e., thermal) effects of temperature outweighing the indirect effect of food limitation, suggesting that temperature limitations on physiological rates are more common than food limitation (Menge et al 2008).…”

“…On the other hand, there is also evidence of temperaturelimited growth in benthic invertebrates within the California Current, as faster mussel growth was observed in warmer SSTs despite reduced food availability near Point Conception (central California; Phillips 2005Phillips , 2007, Santa Cruz Island (Channel Islands, California; Blanchette et al 2006), and the Strait of Juan de Fuca (Strom 2004). Warm temperatures increase the rates of filter feeding, providing a plausible mechanism linking temperature to increases in growth (Phillips 2005).…”

“…A priori, we posited that fish growth would be related to basin-and localscale indices (Figure 1), and we categorized relationships in terms of either "warm" water-column-stabilizing effects or "cool" water-column-destabilizing effects. More specifically, we hypothesized that nearshore pelagic Black Rockfish would benefit from cooler conditions in the California Current and from warmer conditions in the Alaska Coastal Current (Polovina et al 1995;Gargett 1997;von Biela et al 2015), whereas nearshore benthic Kelp Greenlings would benefit from warmer conditions in both of the current systems (Phillips 2005;Blanchette et al 2006;von Biela et al 2015). In our analysis, we examined the time lags for which basin-and local-scale indices were related to nearshore fish growth and production.…”

Growth rate variation of the stalked barnacle Pollicipes pollicipes (Crustacea: Cirripedia) using calcein as a chemical marker

“…are mostly based on population size structure analyses and estimates of growth rates of a few aged or un-aged individuals that are marked in the field (e.g. Page 1986, Phillips 2005. Marking techniques of individuals in these studies include mapping individuals in relation to marks made in adjacent substrata, or using marks such as insect tags glued to the capitulum plates of suitably-sized individuals.…”