Sargassum Blooms Research Articles

An increase in new Sargassum (Phaeophyceae) blooms along the coast of the East China Sea and Yellow Sea

ABSTRACTNew macroalgal blooms caused by the genus Sargassum have been occurring along the coast of China. In particular, in 2017, Sargassum blooms covered up to 188 km2 and drifted into the offshore region of Jiangsu Province, the traditional area for Pyropia aquaculture. This resulted in an enormous loss of production of Pyropia. This study was designed to identify the species composition, phylogenetic relationships, and possible origin of the free-floating Sargassum populations in the Yellow Sea and East China Sea. Results from morphological observations and molecular identification showed that Sargassum horneri was the only species comprising the blooms. Based on further satellite remote sensing analysis, the suspected origin of the blooms was the coastal area of Zhejiang Province, where S. horneri is widely distributed. This study increases our understanding of the importance of controlling the spread of macroalgae blooms.

Predicting Sargassum blooms in the Caribbean Sea from MODIS observations

AbstractRecurrent and significant Sargassum beaching events in the Caribbean Sea (CS) have caused serious environmental and economic problems, calling for a long‐term prediction capacity of Sargassum blooms. Here we present predictions based on a hindcast of 2000–2016 observations from Moderate Resolution Imaging Spectroradiometer (MODIS), which showed Sargassum abundance in the CS and the Central West Atlantic (CWA), as well as connectivity between the two regions with time lags. This information was used to derive bloom and nonbloom probability matrices for each 1° square in the CS for the months of May–August, predicted from bloom conditions in a hotspot region in the CWA in February. A suite of standard statistical measures were used to gauge the prediction accuracy, among which the user's accuracy and kappa statistics showed high fidelity of the probability maps in predicting both blooms and nonblooms in the eastern CS with several months of lead time, with overall accuracy often exceeding 80%. The bloom probability maps from this hindcast analysis will provide early warnings to better study Sargassum blooms and prepare for beaching events near the study region. This approach may also be extendable to many other regions around the world that face similar challenges and opportunities of macroalgal blooms and beaching events.

The Subject and Power

The ideas which I would like to discuss here represent neither a theory nor a methodology. I would like to say, first of all, what has been the goal of my work during the last twenty years. It has not been to analyze the phenomena of power, nor to elaborate the foundations of such an analysis. My objective, instead, has been to create a history of the different modes by which, in our culture, human beings are made subjects. My work has dealt with three modes of objectification which transform human beings into subjects. The first is the modes of inquiry which try to give themselves the status of sciences; for example, the objectivizing of the speaking subject in grammaire generale, philology, and linguistics. Or again, in this first mode, the objectivizing of the productive subject, the subject who labors, in the analysis of wealth and of economics. Or, a third example, the objectivizing of the sheer fact of being alive in natural history or biology. In the second part of my work, I have studied the objectivizing of the subject in what I shall call "dividing practices." The subject is either