Temperature resilience in different life cycle stages of the kelp Alaria esculenta
Authors
Pia Anissa Dittmer (presenting author) [1]
Inka Bartsch [2]
Alexander Jüterbock [1]
Niko Steiner [2]
Affiliations
- Nord University, Faculty of Biosciences and Aquaculture, Bodø, Norway
Email (presenting author): pidit5070@student.nord.no - Alfred Wegener Institute, Bremerhaven, Germany
Keywords
kelp; temperature response; temperature priming; climate change; aquaculture resilience; restoration
Abstract
Winged kelp (Alaria esculenta), an important ecosystem engineer and farming crop, will face rising sea water temperatures and an increased frequency of marine heatwaves in the rapidly warming Arctic. Until now, its temperature responses throughout the life cycle are largely unknown. As A. esculenta has a biphasic lifecycle with a diploid macroscopic stage (sporophyte) and haploid microscopic life stages (spores, gametophytes), it can easily be manipulated in laboratory settings. We tested the effect of temperature on the growth and reproduction of macroscopic sporophytes, as well as the recruitment of microscopic sporophytes, across a temperature gradient ranging from 0 to 15°C and 0 to 21°C, respectively. In addition, we applied a cold and warm temperature pre-treatment to the haploid gametophyte stage, to test how this influences subsequent recruitment responses. Interestingly and hitherto unknown, the temperature optima for macroscopic sporophyte growth differed by several degrees Celsius from the optima for microscopic sporophyte recruitment. In contrast, the fastest reproduction in macroscopic sporophytes (sporogenesis) and microscopic gametophytes (gametogenesis) occurred in a similar temperature range. After 14 days, warm pre-treatment of gametophytes resulted in higher sporophyte recruitment at the tested warm edge (6-12°C) and also induced better survival at lethal temperatures (21°C). These findings can be relevant for application in farming and restoration contexts in a changing climate.
Funding
Norwegian Research Council, KELPRIME, Grant Nr. 334327. The fund has been granted to A. Jüterbock.