Studies of thermotolerance in North and South Atlantic Laminaria, their gametogenesis and hybrid reproductive success.

Mikel Gutiérrez Muto
room 1
Session 3, August 26, 14:00-15:30

Kelps are the dominant ecological components of temperate and polar regions and some of the most productive ecosystems on the planet. Kelps also show an important economic value. Nonetheless, the rise of ocean water temperatures caused by global climate change is provoking shifts in their distribution due to their marked thermal limits. This study aims to assess differences in thermal tolerance between several North and South Atlantic Laminaria species (L. digitata, L. hyperborea, L. ochroleuca, L. pallida and L. solidungula) and to compare the pace of gametogenesis and recruitment success between unisexual female cultures, intraspecific crosses and interspecific crosses of two allopatric Laminaria species (N Atlantic L. digitata and S Atlantic L. abyssalis). The cold temperate species (L. digitata, L. hyperborea and L. solidungula) performed better at cooler temperatures within the 10-15°C range while warmer temperatures of 15-18°C were better for the warm temperate species (L. ochroleuca and L. pallida). We further show that the presence of males generally accelerated female gametogenesis and increased reproductive success in intraspecific crosses, while varying results were obtained for the different interspecific (hybrid) crosses.