Elevated pCO2 is less detrimental than increased temperature to early development of the giant kelp, Macrocystis pyrifera (Phaeophyceae, Laminariales)

Global climate change is increasing ocean temperature and partial pressure of CO2 (pCO2) in coastal and marine ecosystems. Research in this field has largely focused on how limited CO32− availability and low pH adversely affect early development of calcifying organisms, but noncalcareous organisms are comparatively understudied despite their prevalence in many coastal communities. We investigated how present-day and future levels of ocean temperature (12°C vs 15°C, respectively) and pCO2(400 μatm vs 1500 μatm, respectively) influence successful germling production, gametophyte survival, growth, and sex ratio, and embryonic sporophyte production and growth in the habitat-forming kelp Macrocystis pyrifera over a 15-wk period in San Diego, California, USA. Our results indicate that relative to present-day conditions, successful germling production was reduced fourfold under elevated temperature alone, and fivefold under combined elevated temperature and pCO2 (i.e. “future conditions”). Similarly, survival and growth of male and female gametophytes were lower under elevated temperature alone than under either present-day, elevated pCO2 alone, or future conditions. Gametophyte sex ratios skewed slightly toward males across all treatments. Sporophyte recruitment and growth were greatest and occurred earliest under elevated pCO2alone, but were delayed under elevated temperature alone. Although elevated pCO2 and temperature adversely affected germling production independently and cumulatively, elevated pCO2 enhanced gametophyte and sporophyte survival under both present-day and elevated temperatures. Thus, under projected climate change conditions, elevated pCO2 may be less detrimental than increased temperature for development beyond germling production. Given that M. pyrifera is globally distributed and provides numerous ecosystem services including the potential to mitigate ocean acidification, impacts of climate change on its complex life history merit further exploration.

Shukla P. & Edwards M. S., 2017. Elevated pCO2 is less detrimental than increased temperature to early development of the giant kelp, Macrocystis pyrifera (Phaeophyceae, Laminariales). Phycologia 56(6):638-648. Article (subscription required).



0 Responses to “Elevated pCO2 is less detrimental than increased temperature to early development of the giant kelp, Macrocystis pyrifera (Phaeophyceae, Laminariales)”

  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,124,355 hits


Ocean acidification in the IPCC AR5 WG II

OUP book