Rise of the rare biosphere

Abstract

Ocean ecosystems are changing, and the climate envelope paradigm predicts a steady shift, approximately poleward, of species ranges. The Gulf of Maine presents a test case of this paradigm, as temperatures have warmed extremely rapidly. Some species have shifted northeastward, matching predictions. Others—namely harmful algal species like Pseudo-nitzschia australis and Karenia mikimotoi—do not appear to have followed climate trajectories, arriving as surprises in the Gulf of Maine. Rare-biosphere dynamics offer one possible ecological lens for understanding and predicting this type of surprise. Rare species in the plankton, possibly more so than southerly ones, may provide management challenges in the future. Improved monitoring and broader coordination of monitoring of the rare biosphere could help develop early warning systems for harmful and toxic algae. A better theoretical understanding of rare biosphere dynamics is also needed. A challenge for the next cohort of ecosystem projections is to predict the newly emerging harmful species of the type that catch us by surprise.

Climate impacts on the Gulf of Maine ecosystem

“…Oyster pathogens such as Haplosporidium nelsoni and Perkinsus marinus that, respectively, cause the diseases "MSX" (Multinucleated Sphere Unknown) and "Dermo" have become more prevalent in the Gulf of Maine as ocean temperatures have warmed (Marquis et al, 2015;Robledo et al, 2018). While there is no evidence to date that harmful algal blooms are increasing in the Gulf of Maine, blooms of species previously unreported in the Gulf of Maine like Karenia mikimotoi and Pseudonitzschia australis have occurred in the last several years (Clark et al, 2019;Record et al, 2021). Outbreaks of these organisms have been linked to fish and wildlife mortality events in other regions (e.g., Pacific coast) and represent an emerging threat if changing conditions in the Gulf of Maine support them (de la Riva et al, 2009;Record et al, 2021).…”

“…While there is no evidence to date that harmful algal blooms are increasing in the Gulf of Maine, blooms of species previously unreported in the Gulf of Maine like Karenia mikimotoi and Pseudonitzschia australis have occurred in the last several years (Clark et al, 2019;Record et al, 2021). Outbreaks of these organisms have been linked to fish and wildlife mortality events in other regions (e.g., Pacific coast) and represent an emerging threat if changing conditions in the Gulf of Maine support them (de la Riva et al, 2009;Record et al, 2021).…”