Future phytoplankton diversity in a changing climate

Abstract

The future response of marine ecosystem diversity to continued anthropogenic forcing is poorly constrained. Phytoplankton are a diverse set of organisms that form the base of the marine ecosystem. Currently, ocean biogeochemistry and ecosystem models used for climate change projections typically include only 2−3 phytoplankton types and are, therefore, too simple to adequately assess the potential for changes in plankton community structure. Here, we analyse a complex ecosystem model with 35 phytoplankton types to evaluate the changes in phytoplankton community composition, turnover and size structure over the 21st century. We find that the rate of turnover in the phytoplankton community becomes faster during this century, that is, the community structure becomes increasingly unstable in response to climate change. Combined with alterations to phytoplankton diversity, our results imply a loss of ecological resilience with likely knock-on effects on the productivity and functioning of the marine environment.

Climate Change Impacts on Microbiota in Beach Sand and Water: Looking Ahead

“…These two may affect the expected behaviour of FIB in coastal waters and their interactions with sediments, which may be controlled in part by pH. These pH alterations, increases in DOC and DON, and also the increase in water temperature can lead to microbial growth, and changes to some phytoplankton communities (cyanobacteria, diatoms, dinoflagellates, green algae, and chalk-coated Coccolithophores) [19]. Subsequently, these changing communities may result in changes to light penetration in the water column, affecting solar-mediated inactivation of indicator organisms and pathogens [20], or perhaps their growth.…”

“…The case of cyanobacteria and dinoflagellates is of particular concern since these phytoplanktonic groups are able to develop Harmful Algal Blooms (HABs), as some of their species are able to produce diverse types of toxins, thus causing adverse effects [19,21,22]. These toxins may have a nefarious effect on water associated activities and/or ecology.…”

“…• Range shifts and expansions due to habitat suitability changes [36,[38][39][40][41][42][43][44] • Increases in harmful algal blooms occurrence and persistence (dinoflagellates and cyanobacteria) that may produce toxins and also provide refugia to other microbes [19,22,31,32,45] Indirect Effects: • Stormwater runoff, introducing upstream microbes to the nearshore zone [47,55,56] Indirect Effects: [20,49,57] • Increased dissolved organic matter that changes solar inactivation dynamics and persistence of microbes in the water • Tidal re-wetting may allow increased persistence in the sand [54,68] Both empirical data collection and mechanistic modelling of FIB are useful tools to help understand the relative importance of the various faecal sources, fate processes, and transport pathways, and for making predictions concerning possible climate change generated phenomena. However, it is important to note that while FIB have been useful to monitor faecal contamination of waterways, there may be differential responses of different microbiota to climate-induced environmental changes, especially once we look into the backshore.…”

Disentangling the Ecological Processes Shaping the Latitudinal Pattern of Phytoplankton Communities in the Pacific Ocean

“…We showed that both high temperature (i.e., high average temperature in a region) and high temperature divergence (between two sites) can cause more phylogenetic turnover in Synechococcus communities and lead the community assembly to be more deterministic with dominance of heterogeneous selection. Thus, our results may suggest an increasing species richness and greater community difference of Synechococcus in the ocean under warming effects, which would provide group-specific information for the global study of phytoplankton during climate changes ( 12 , 13 ). Temperature-driven selection was also reported as the main factor shaping prokaryotic β-diversity but showed much less effect on picoeukaryotic communities in a global ocean survey ( 22 ).…”

“…This could be explained by the varied zonal contribution of heterogeneous selection, which causes high community turnover due to the among-taxa fitness difference and leads to low community similarity ( 15 , 20 ). Global model estimations showed that both present species richness and future changes in species richness, evenness, biomass, community turnover rate, and size structure have latitudinal patterns and vary greatly among climatic zones, which could indicate that the ecological processes (or their relative contributions) governing phytoplankton communities could vary across spaces ( 12 , 13 ). Thus, our results suggest that a proper or multiscale analysis on the ecological processes in phytoplankton communities is necessary for a better understanding of their biogeography.…”