MEPS 440:79-94 (2011)  -  DOI: https://doi.org/10.3354/meps09350

ABSTRACT: Environmental sensitivities that represent reproductive adaptations are well enough known in some species of marine broadcast spawners, including fucoid algae, to consider wider ecological implications of gamete release. Here, we test and refine a preliminary model for gamete release in the intertidal foundation species Fucus vesiculosus L., one of the most abundant broadcast spawners of the North Atlantic rocky shore. Local environmental conditions and levels of gamete release were determined during 2 reproductive seasons at 4 sites on the Schoodic Peninsula (Maine, USA). These studies supported the hypothesis that asynchrony in the incidence and magnitude of natural gamete release occur when environmental conditions (i.e. light, water motion) across projections of the coastline are uneven. Gamete release occurs on sunny days when winds speeds are <6.6 m s⁻¹. Using these data, we modeled historical meteorological data for part of the Gulf of Maine (GOM) to hindcast gamete release in F. vesiculosus. The regional model predicted that gamete release increased at many GOM sites over 22 yr (1985−2006). Combining local fucoid density, zone width, and linear coastline data with C and N analysis of eggs, we found that fucoid egg release is an uncharacterized subsidy available to many trophic levels, which is pulsed into the nearshore GOM. Our results provide important insights into the consequences of ocean-climate variability on biological processes.

KEY WORDS: Broadcast spawning · Fucoid algae · Fucus · Gamete release · Gametophagy · Gulf of Maine · Intertidal · Reproductive ecology · Reproductive modeling · Spatial subsidy