Johnson Catherine L.

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Last Name
Johnson
First Name
Catherine L.
ORCID
0000-0001-5291-3141

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  • Article
    Rapid climate-driven circulation changes threaten conservation of endangered North Atlantic right whales.
    (Oceanography Society, 2019-05-03) Record, Nicholas R. ; Runge, Jeffrey A. ; Pendleton, Daniel E. ; Balch, William M. ; Davies, Kimberley T.A. ; Pershing, Andrew J. ; Johnson, Catherine L. ; Stamieszkin, Karen ; Ji, Rubao ; Feng, Zhixuan ; Kraus, Scott D. ; Kenney, Robert D. ; Hudak, Christy A. ; Mayo, Charles A. ; Chen, Changsheng ; Salisbury, Joseph E. ; Thompson, Cameron R.S.
    As climate trends accelerate, ecosystems will be pushed rapidly into new states, reducing the potential efficacy of conservation strategies based on historical patterns. In the Gulf of Maine, climate-driven changes have restructured the ecosystem rapidly over the past decade. Changes in the Atlantic meridional overturning circulation have altered deepwater dynamics, driving warming rates twice as high as the fastest surface rates. This has had implications for the copepod Calanus finmarchicus, a critical food supply for the endangered North Atlantic right whale (Eubalaena glacialis). The oceanographic changes have driven a deviation in the seasonal foraging patterns of E. glacialis upon which conservation strategies depend, making the whales more vulnerable to ship strikes and gear entanglements. The effects of rapid climate-driven changes on a species at risk undermine current management approaches.
  • Article
    Changes in deep ocean contribute to a “See‐Sawing” Gulf Stream Path
    (American Geophysical Union, 2022-10-31) Wang, Zeliang ; Yang, Jiayan ; Johnson, Catherine ; DeTracey, Brendan
    This study demonstrates that a decrease of the water‐mass density below 1,000 m has led to a pattern of see‐saw shift in the Gulf Stream (GS) position between 74 and 50°W in longitude during 1993–2017, with the New England Seamounts as the pivot point. The GS moved northward in the upstream region and shifted southward in the downstream. Our empirical orthogonal function analyses of satellite altimeter data demonstrate that the second mode (EOF2) represents changes in the GS strength and therefore can be used as an index for the Atlantic Meridional Overturning Circulation. Decreasing water density below 1,000 m is also the principal mechanism driving the weakening of the GS.
  • Article
    It's about time: a synthesis of changing phenology in the Gulf of Maine ecosystem
    (Wiley, 2019-04-22) Staudinger, Michelle D. ; Mills, Katherine E. ; Stamieszkin, Karen ; Record, Nicholas R. ; Hudak, Christine A. ; Allyn, Andrew ; Diamond, Antony ; Friedland, Kevin D. ; Golet, Walter J. ; Henderson, Meghan Elisabeth ; Hernandez, Christina M. ; Huntington, Thomas G. ; Ji, Rubao ; Johnson, Catherine L. ; Johnson, David Samuel ; Jordaan, Adrian ; Kocik, John ; Li, Yun ; Liebman, Matthew ; Nichols, Owen C. ; Pendleton, Daniel ; Richards, R. Anne ; Robben, Thomas ; Thomas, Andrew C. ; Walsh, Harvey J. ; Yakola, Keenan
    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.