Recurrent seascape units identify key ecological processes along the western Antarctic Peninsula

TitleRecurrent seascape units identify key ecological processes along the western Antarctic Peninsula
Publication TypeJournal Article
Year of Publication2018
AuthorsBowman J.S, Kavanaugh M.T, Doney SC, Ducklow H.W
JournalGlobal Change Biology
Volume24
Pagination3065-3078
Date Published2018/07
Type of ArticleArticle
ISBN Number1354-1013
Accession NumberWOS:000437281500027
Keywordsantarctic; bellingshausen sea; Biodiversity & Conservation; circumpolar deep-water; continental-shelf; diatoms; ecosystem; Environmental Sciences & Ecology; marine ecosystems; mixed-layer; nutrients; Palmer Long-Term Ecological; ratio; Research; sea-ice; seascapes; variability; zone
Abstract

The western Antarctic Peninsula (WAP) is a bellwether of global climate change and natural laboratory for identifying interactions between climate and ecosystems. The Palmer Long-Term Ecological Research (LTER) project has collected data on key ecological and environmental processes along the WAP since 1993. To better understand how key ecological parameters are changing across space and time, we developed a novel seascape classification approach based on insitu temperature, salinity, chlorophyll a, nitrate+nitrite, phosphate, and silicate. We anticipate that this approach will be broadly applicable to other geographical areas. Through the application of self-organizing maps (SOMs), we identified eight recurrent seascape units (SUs) in these data. These SUs have strong fidelity to known regional water masses but with an additional layer of biogeochemical detail, allowing us to identify multiple distinct nutrient profiles in several water masses. To identify the temporal and spatial distribution of these SUs, we mapped them across the Palmer LTER sampling grid via objective mapping of the original parameters. Analysis of the abundance and distribution of SUs since 1993 suggests two year types characterized by the partitioning of chlorophyll a into SUs with different spatial characteristics. By developing generalized linear models for correlated, time-lagged external drivers, we conclude that early spring sea ice conditions exert a strong influence on the distribution of chlorophyll a and nutrients along the WAP, but not necessarily the total chlorophyll a inventory. Because the distribution and density of phytoplankton biomass can have an impact on biomass transfer to the upper trophic levels, these results highlight anticipated links between the WAP marine ecosystem and climate.

DOI10.1111/gcb.14161
Short TitleGlob. Change Biol.
Student Publication: 
No