It’s about time: A synthesis of changing phenology in the Gulf of Maine ecosystem

Abstract

The timing of recurring biological and seasonal environmental events is changing on a global scale relative to temperature and other climate drivers. This study considers the Gulf of Maine ecosystem, a region of high social and ecological importance in the Northwest Atlantic Ocean and synthesizes current knowledge of (a) key seasonal processes, patterns, and events; (b) direct evidence for shifts in timing; (c) implications of phenological responses for linked ecological‐human systems; and (d) potential phenology‐focused adaptation strategies and actions. Twenty studies demonstrated shifts in timing of regional marine organisms and seasonal environmental events. The most common response was earlier timing, observed in spring onset, spring and winter hydrology, zooplankton abundance, occurrence of several larval fishes, and diadromous fish migrations. Later timing was documented for fall onset, reproduction and fledging in Atlantic puffins, spring and fall phytoplankton blooms, and occurrence of additional larval fishes. Changes in event duration generally increased and were detected in zooplankton peak abundance, early life history periods of macro‐invertebrates, and lobster fishery landings. Reduced duration was observed in winter–spring ice‐affected stream flows. Two studies projected phenological changes, both finding diapause duration would decrease in zooplankton under future climate scenarios. Phenological responses were species‐specific and varied depending on the environmental driver, spatial, and temporal scales evaluated. Overall, a wide range of baseline phenology and relevant modeling studies exist, yet surprisingly few document long‐term shifts. Results reveal a need for increased emphasis on phenological shifts in the Gulf of Maine and identify opportunities for future research and consideration of phenological changes in adaptation efforts.

The role of sand lances (Ammodytes sp.) in the Northwest Atlantic Ecosystem: A synthesis of current knowledge with implications for conservation and management

“…Historically, older stages were transported from the Gulf of St. Lawrence during summer and fall into the eastern Gulf of Maine, with contributions by the subsurface Labrador Subarctic Slope Water (Head, Harris, & Petrie, 1999; MERCINA Working Group et al, 2001; Record et al, 2019) in the Nova Scotia Current (Appendix S1: Supplemental 1) (Kane, 2007; Pershing et al, 2005). However, shifts in seasonal oceanographic conditions, circulation and the phenology of lower trophic level species are affecting established patterns in regional timing and availability of resources (see Sections 4.1 and 4.2; Staudinger et al, 2019; Thomas et al, 2017). Production from the Maine Coastal Current also supplied predators, including NWA Ammodytes, in the western Gulf of Maine during summer and fall with lipid‐rich older stages of C. finmarchicus (Ji et al, 2017; Runge et al, 2015).…”

“…One source of variability is the match or mismatch of food available to C. finmarchicus emerging from diapause in spring, which has already advanced in time, and is predicted to continue advancing, due to earlier spring warming (Maps et al, 2011; Pierson, Batchelder, Saumweber, Leising, & Runge, 2013). Shifts in the timing of seasonal events during recent decades are linked to changes in primary productivity and growth cycles leading to large earlier cohorts of C. finmarchicus , despite reduced overwintering stock (Record et al, 2019; Staudinger et al, 2019). Changes in spring production affect the supply of C. finmarchicus in subsequent seasons, particularly on Stellwagen Bank, Georges Bank and elsewhere in coastal waters of Southern New England (Greene & Pershing, 2007).…”

“…The NWA region is of critical importance to the life cycles of many long‐distance seasonal migrants that come to feed on Ammodytes and other forage resources during the summer and fall months (Diamond, 2012; Staudinger et al, 2019). Data from seabird provisioning studies likely reflect nearshore availability of NWA Ammodytes (Goyert, 2014), but are skewed towards chick diets during the summer rearing season.…”

Climate Change Vulnerability of American Lobster Fishing Communities in Atlantic Canada

“…Since phytoplankton are the primary source of nutrients for C. finmarchicus, their lifecycle is highly dependent on the timing and magnitude of seasonal blooms. Therefore, shifts in the spatial and temporal components of the bloom are highly relevant to C. finmarchicus distributions and abundances (Record et al, 2019a,b;Staudinger et al, 2019). Shifts in C. finmarchicus abundance can also lead to timing mismatches for migratory species and reduced availability of anticipated food (Record et al, 2019b;Staudinger et al, 2019).…”

Mud, microbes, and macrofauna: seasonal dynamics of the iron biogeochemical cycle in an intertidal mudflat

“…to-year variation (Staudinger et al, 2019). Thus, it is essential to understand the seasonal 109 dynamics of these interconnected processes, in order to predict how they might respond to 110 effects of anthropogenic climate change in coastal sedimentary ecosystems such as increased 111 temperature, declines in oxygen, and eutrophication (Doney, 2010).…”