Abundance of Tesseropora rosea at the margins of its biogeographic range is closely linked to recruitment, but not fecundity

Abstract

Minchinton, T. E. (2013). Abundance of Tesseropora rosea at the margins of its biogeographic range is closely linked to recruitment, but not fecundity. Marine Ecology: Progress Series, Abundance of Tesseropora rosea at the margins of its biogeographic range is closely linked to recruitment, but not fecundity AbstractFor benthic marine invertebrates with planktonic larvae, adult abundance at the species' range limit may depend on local fecundity, and recruitment from central, source populations. We tested the importance of these processes using a hierarchical design at multiple spatial scales (from tens to hundreds of kilometres) to assess relationships between patterns of adult abundance, fecundity and recruitment in the rocky intertidal barnacle Tesseropora rosea, approaching its geographical range limit on the southeast coast of Australia. Across the 600 km region, adult abundance, recruitment and fecundity all declined towards the range limit, but only adult abundance and recruitment were positively correlated, suggesting that recruitment is negatively affected at the range limit and that recruitment plays a significant role in setting the geographical patterns of abundance of T. rosea. In contrast, at smaller spatial scales within this region, adult abundance and recruitment varied by up to 15-and 100-fold, respectively, among some locations only tens of kilometres apart, and no obvious patterns in adult-recruit relationships were revealed towards the range limit. Local patterns of abundance and life-cycle relationships do not, therefore, translate to biogeographic scales, but investigation at this multitude of spatial scales helps to identify the defining processes that account for spatial variation and determine population structure towards the range limits of benthic marine invertebrates. ABSTRACTFor benthic marine invertebrates with planktonic larvae, adult abundance at the species' range limit may depend on local fecundity, and recruitment from central, source populations. We test the importance of these processes using a hierarchical design at multiple spatial scales (from tens to hundreds of kilometres) to assess relationships between patterns of adult abundance, fecundity, and recruitment for the rocky intertidal barnacle, Tesseropora rosea, approaching its geographical range limit on the southeast coast of Australia. Across the 600 km region, adult abundance, recruitment and fecundity all declined towards the range limit, but only adult abundance and recruitment were positively correlated, suggesting that recruitment is negatively impacted at the range limit and, that recruitment plays a significant role in setting the geographical patterns of abundance of T. rosea. In contrast, at smaller spatial scales within this region, adult abundance and recruitment varied by up to 15-and 100-fold respectively, among some locations only tens of kilometres apart, and no obvious patterns in adult-recruit relationships were revealed towards the range limit. Local patterns of abundance and lifecycle relationshi...

Biogeographical patterns of rocky shore community structure in south‐east Australia: effects of oceanographic conditions and heat stress

“…Importantly, we show that these patterns are consistent through time and that these differences are largely attributable to the absence of the barnacle T. rosea and increased abundances of the mussel A. rostratus amongst locations south of the SEABB. This corresponds well with previous studies that demonstrate T. rosea reaches its southern range limit at the northern extent of Ninety‐mile Beach (Hidas et al ., , ; Lathlean et al ., ). The observed differences in these two species alone could be enough to alter the composition of the broader biological communities as both T. rosea and A. rostratus could be considered habitat‐forming species, each with different associated organisms.…”

Matching spatial scales of variation in mussel recruitment and adult densities across southwestern Atlantic rocky shores

“…This suggests that there were location-specific factors aside from larval supply that affected recruitment on either substrate. For instance, larval recruitment onto natural substrates can be affected by the density of adult conspecifics (Alvarado and Castilla, 1996;Hidas et al, 2013). On the other hand, and in contrast to natural substrates, artificial substrates like Tuffy pads provide an attachment site that is free from any potential influence of adult conspecifics (Ricciardi et al, 1997).…”

“…4). Variations in larval recruitment at a scale like this (tens of kilometers) are generally associated to differences in larval supply rates (Hidas et al, 2013;Jenkins et al, 2000). Larval supply can vary because of differences in local larval production and oceanographic factors that affect the size of the larval pool and the fluxes of larvae toward the intertidal zone (Bertness et al, 1992;Jenkins et al, 2000).…”

Coupling and Decoupling of Reproduction and Larval Recruitment

“…Large-scale studies on two species detected regional but not small-scale coupling, likely because stressful temperatures disrupted reproduction at small scales. Surveying 600 km of the southeast coast of Australia using a hierarchical sampling design four times per year, determined that the density of adult Tesseropora rosea explained 38% of the variance in recruits with the densities of recruits mirroring those of adults across four 70 to 110 km sectors that were spaced 30 to 100 km apart but not at smaller scales (Hidas et al 2013). However, fecundity was not correlated with either the densities of adults or recruits.…”