Dinoflagellates as indicators of changes in marine conditions in northern high latitudes

本提案旨在记录巴芬湾北部（努纳武特）、詹姆斯湾（魁北克）和米拉米奇河河口（新不伦瑞克省）十年时间尺度的气候自然变化。通过使用现代模拟技术的传递函数，将利用保存在海洋沉积物中的鞭毛藻囊和花粉粒组合来重建海洋表面条件（温度、盐度、海冰覆盖和初级生产）的演变。然后将重建结果与有充分记录的近期气候振荡（中世纪暖期、小冰期、北大西洋涛动和大西洋多年代际涛动）、可用的仪器数据以及保存在沉积物中的人为信号（自工业时代开始以来二氧化碳水平的增加、桥梁和水坝的建设、自然资源的开采、气候变化和气候变化）进行比较。所有这些都可能影响沉积物或初级生产条件)。重建的时间分辨率与气候建模者用来建立未来气候变化情景的时间分辨率相似。

This proposal aims at documenting the natural variability of climate at decennial time scales in northern Baffin Bay (Nunavut), James Bay (Quebec), and the estuary of the Miramichi River (New Brunswick). The evolution of sea surface conditions (temperature, salinity, sea ice cover and primary production) will be reconstructed using dinoflagellate cyst and pollen grain assemblages preserved in marine sediments, through the use of transfer functions using the Modern Analogue Technique. The reconstructions will then be compared with well-documented recent climate oscillations (Medieval Warm Period, Little Ice Age, North Atlantic Oscillation and Atlantic Multidecadal Oscillation), with instrumental data, where available, and with the anthropogenic signal preserved in sediments (increase in CO2 level since the beginning of the industrial era, construction of bridges and dams, exploitation of natural resources, all of which may have affected sediment or primary production conditions). The temporal resolution of the reconstructions is similar to that used by climate modelers to establish climate scenarios of future climate change. We will also document the biological affinities and molecular phylogeny of a number of subarctic and arctic dinocyst species, which are used to reconstruct paleo-sea surface conditions. The ecology of newly described species will also be documented, which will help interpreting the paleoenvironmental records preserved in marine sediment cores. The distribution of dinoflagellates (main toxin-producing microalgae) throughout the Canadian Arctic and in high-risk arctic ports will be documented. This will contribute towards monitoring for the presence of non-indigenous harmful/toxic species that may be transported in ships ballast tanks. Such study will also contribute at preserving the biodiversity of the Canadian Arctic. Finally, we will also asses the risks of harmful/toxic outbreaks in the Estuary and Gulf of St. Lawrence through the analysis of surface sediment samples containing cyst of the toxic species Alexandrium tamarense, that produced a toxic bloom in 2008, which killed fish, birds and marine mammals. The analysis of the cyst content of sediments will provide data on the distribution of cyst beds in the St. Lawrence system. We are also seeking funds to cover the elevated costs involved with sample collection in the Arctic. Plankton and surface sediments samples, as well as sediment cores, will be collected onboard the CCGS Amundsen over a 5 year period. Part of the funds will serve to visit Arctic communities (Cree Nation in Chisasibi, Inuit communities of Iqaluit, Resolute Bay, Arctic Bay and Pond Inlet) and present our results over the next 5 years. These visits will also contribute at involving local northerners in our sampling effort and to increase their awareness at global warming and future climate change that will affect their fishing + hunting resources, as well as their environment.