کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6386817 1627285 2015 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Interactions between seasonality and oceanic forcing drive the phytoplankton variability in the tropical-temperate transition zone (~ 30°S) of Eastern Australia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات اقیانوس شناسی
پیش نمایش صفحه اول مقاله
Interactions between seasonality and oceanic forcing drive the phytoplankton variability in the tropical-temperate transition zone (~ 30°S) of Eastern Australia
چکیده انگلیسی


- First phytoplankton time-series survey off 30°S, Eastern Australia (2011/2012).
- Phytoplankton are classified into five water-type categories via statistics.
- Intrinsic seasonal cycles and EAC drive temporal phytoplankton variability.
- EAC encroachment determines cross-shelf phytoplankton composition and distribution.
- Trichodesmium erythraeum seems permanently established off 30°S, Eastern Australia.

The East Australian Current (EAC) has been shown to be warming rapidly, which is expected to cause latitudinal shifts in phytoplankton abundance, distribution and composition along the east Australian coast. Yet a lack of phytoplankton information exists northward of 34°S. Here, we provide the first detailed taxonomic time-series survey (monthly sampling for about one annual cycle, 2011-2012) in the east Australian tropical-temperate transition zone (~ 30°S, upstream of the EAC separation point at ~ 31-32°S). All phytoplankton (categorised depending on their association with specific water-types) show a seasonal signal with abundance maxima (minima) during summer (winter). This seasonal signal is most pronounced in the seasonal/bloom category and least expressed by deep-water taxa, which prefer cold, saline and dense bottom water independent of the season. Different extents of EAC encroachment onto the continental shelf drive the cross-shelf phytoplankton composition and distribution, such that a weak EAC is associated with phytoplankton community being organised along 'depth' and 'distance from the coast' gradients with high phytoplankton abundances inshore. A strong EAC favours the occurrence of warm-water taxa offshore and an increase in diatom abundance on the mid-shelf (53% shelf width). We conclude that the phytoplankton community in the tropical-temperate transition zone of Eastern Australia is driven by an interaction of intrinsic seasonal cycles and primarily EAC-driven oceanic forcing. Our findings benefit studies located in Western Boundary Current systems worldwide, in which warming and strengthening of these currents are predicted to severely impact phytoplankton dynamics.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Marine Systems - Volume 144, April 2015, Pages 92-106
نویسندگان
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