Physiological response of fucoid algae to environmental stress: comparing range centre and southern populations

Abstract

Climate change has led to alterations in assemblage composition. Species of temperate macroalgae at their southern limits in the Iberian Peninsula have shown shifts in geographical range and a decline in abundance ultimately related to climate, but with the proximate factors largely unknown. We performed manipulative experiments to compare physiological responses of Fucus vesiculosus and Fucus spiralis from Portugal and Wales (UK), representing, respectively, southern and central areas of their distribution, to different intensities of solar radiation and different air temperatures. Following exposure to stressful emerged conditions, Portuguese and Welsh individuals of both fucoid species showed increased frond temperature, high desiccation levels and reduced photophysiological performance that was evident even after a 16 h recovery period, with light and temperature acting in an additive, not an interactive, manner. The level of physiological decline was influenced by geographical origin of populations and species identity, with algae from the south and those living higher on the shore coping better with stressful conditions. The negative effect of summer conditions on photophysiology may contribute to changes in fucoid abundance and distribution in southern Europe. Our results emphasise how physiological performance of geographically distinct populations can differ, which is particularly relevant when predicting responses to climate change.

Closer to the rear edge: ecology and genetic diversity down the core‐edge gradient of a marine macroalga

“…Research has mainly targeted high latitude limits of species' distributions also favoured by the relatively easier access to sampling sites and funding availability. On the other hand, populations residing at the low-latitude margin of species distribution ranges or trailing edges have only recently started to receive deserved attention (e.g., Hampe and Petit 2005, Araú jo et al 2011, Lepais et al 2013, Ferreira et al 2014.…”

Alternative state? Experimentally induced Fucus canopy persists 38 yr in an Ascophyllum‐dominated community

“…Rapid climate change in the Gulf of Maine is associated with negative effects on other marine biota including cod (Pershing et al 2015) and with shifts in subtidal community composition (Dijkstra et al 2011). Temperature stress is a major factor underlying actual or expected shifts in distribution, but other aspects of climate change such as pH and salinity changes are also likely to influence algal species including fucoids (Harley et al 2012, Jueterbock et al 2013, Ferreira et al 2014). Effects are usually negative, but in some cases positive effects of temperature have been documented (Yesson et al 2015, Schiel et al 2016.…”

“…Effects are usually negative, but in some cases positive effects of temperature have been documented (Yesson et al 2015, Schiel et al 2016. Temperature stress is a major factor underlying actual or expected shifts in distribution, but other aspects of climate change such as pH and salinity changes are also likely to influence algal species including fucoids (Harley et al 2012, Jueterbock et al 2013, Ferreira et al 2014). Thus, we hypothesize that the consistent decreases in abundance seen in our study likely are due to climate change impacts, most probably warmer temperatures.…”

Physiological responses of Ulva fasciata Delile (Ulvales, Chlorophyta): comparison of two populations from thermally distinct sites from Brazilian coast

“…Temperature dramatically influences biological processes, acting from molecules to the whole biota (Turra et al 2013, Ferreira et al 2014. Thus, global warming is expected to produce major changes in the marine environment, such as changes in the distribution and abundance of species and also changes in the structure of communities, including local extinctions (Harley et al 2012, Turra et al 2013, Ferreira et al 2014. Hereof, recent studies show that climate change is a major threat to marine macroalgae (Wernberg et al 2011, Harley et al 2012, Ferreira et al 2014.…”

“…Species naturally exposed to a wider temperature range between summer and winter (temperate species) generally have a higher thermal tolerance when compared to individuals from environments with lower annual thermal amplitude (tropical species) (Padilla-Gamiño and Carpenter 2007). At a smaller scale, marine species that occur in habitats characterized by large temperature variations (e.g., supra and mesolittoral) tend to live closer to their physiological temperature limits, so they may be more vulnerable to global warming than species less tolerant to temperature rising, such as those present on the infra-littoral (Stillman 2003, Ferreira et al 2014. Under a background of global warming, organisms living close to their physiological limits are likely to be the first to be affected (i.e., tropical species habiting mesolittoral, e.g., species of the genus Ulva).…”