Five Karenia species along the Chinese coast: With the description of a new species, Karenia hui sp. nov. (Kareniaceae, Dinophyta).

Dinoflagellates within the genus Karenia are well known for their potential to cause harmful algal blooms and induce detrimental ecological consequences. In this study, five Karenia species, Karenia longicanalis, Karenia papilionacea, Karenia mikimotoi, Karenia selliformis, and a new species, Karenia hui sp. nov.

Pre-validation of choriogenin H transgenic medaka eleutheroembryos as a quantitative estrogenic activity test method.

The choriogenin H - EGFP transgenic medaka (Oryzias melastigma) has been used to test estrogenic substances and quantify estrogenic activity into 17β-estradiol (E2) equivalency (EEQ). The method uses 8 eleutheroembryos in 2 ml solution per well and 3 wells per treatment in 24-well plates at 26 ± 1 °C for 24 ± 2 h, with subsequent measurements of induced GFP signal intensity. EEQ measurements are calculated using a E2 probit regression model with a coefficient of determination (R) > 0.

The potential of foodwaste leachate as a phycoremediation substrate for microalgal CO fixation and biodiesel production.

Foodwaste leachate (FWL) is often generated during foodwaste treatment processes. Owing to its high nutrient content, FWL has high potential for phycoremediation, a microalgal technology application for water treatment while acting as CO fixation tank. Additionally, the end product of microalgal from phycoremediation can be potentially used for biodiesel production.

Prioritising local action for water quality improvement using citizen science; a study across three major metropolitan areas of China.

Streams in urban areas are prone to degradation. While urbanization-induced poor water quality is a widely observed and well documented phenomenon, the mechanism to pinpoint local drivers of urban stream degradation, and their relative influence on water quality, is still lacking. Utilizing data from the citizen science project FreshWater Watch, we use a machine learning approach to identify key indicators, potential drivers, and potential controls to water quality across the metropolitan areas of Shanghai, Guangzhou and Hong Kong.

The Mechanism of Diarrhetic Shellfish Poisoning Toxin Production in Prorocentrum spp.: Physiological and Molecular Perspectives.

Diarrhetic shellfish poisoning (DSP) is a gastrointestinal disorder caused by the consumption of seafood contaminated with okadaic acid (OA) and dinophysistoxins (DTXs). OA and DTXs are potent inhibitors of protein phosphatases 2A, 1B, and 2B, which may promote cancer in the human digestive system. Their expression in dinoflagellates is strongly affected by nutritional and environmental factors.

Quantification of phytoplankton bloom dynamics by citizen scientists in urban and peri-urban environments.

Freshwater ecosystems are severely threatened by urban development and agricultural intensification. Increased occurrence of algal blooms is a main issue, and the identification of local dynamics and drivers is hampered by a lack of field data. In this study, data from 13 cities (250 water bodies) were used to examine the capacity of trained community members to assess elevated phytoplankton densities in urban and peri-urban freshwater ecosystems.

Preliminary evaluation of ecological risk for the city area from the Pearl River Estuary.

It is essential to evaluate the ecological risk for the estuary cities area for the environmental restoration of the estuary. The ecological risk of six city areas from the Pearl River Estuary were evaluated by using the relative risk model. The relative risk assessment method was developed by considering the river network density in the sub-region.

Toxicity and estrogenic endocrine disrupting activity of phthalates and their mixtures.

Phthalates, widely used in flexible plastics and consumer products, have become ubiquitous contaminants worldwide. This study evaluated the acute toxicity and estrogenic endocrine disrupting activity of butyl benzyl phthalate (BBP), di(n-butyl) phthalate (DBP), bis(2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP), diisononyl phthalate (DINP), di-n-octyl phthalate (DNOP) and their mixtures. Using a 72 h zebrafish embryo toxicity test, the LC50 values of BBP, DBP and a mixture of the six phthalates were found to be 0.

Effective growth of dinoflagellate Prorocentrum minimum by cultivating the cells using municipal wastewater as nutrient source.

Several studies have been conducted worldwide in order to develop a more economical method for mass algal cultivation so that more cost-effective biomass production can be accessed. One of the directions is to reduce production costs by using wastewater as a nutrient source in algal cell cultivation. The growth ability of a red-tide causative dinoflagellate species, Prorocentrum minimum, in various concentrations of local urban wastewater was examined in this study.

Effects of different nitrate and phosphate concentrations on the growth and toxin production of an Alexandrium tamarense strain collected from Drake Passage.

Nitrate (N) and phosphate (P) are believed to be two of the most important nutrients for the growth and toxin production for Alexandrium species. The study of the growth and toxicity characteristics of the Alexandrium spp. under the change of N and P can help us to understand the dynamics of algal bloom and toxification events in natural environments.

Development of a relative risk model for evaluating ecological risk of water environment in the Haihe River Basin estuary area.

Ecological risk assessment for water environment is significant to water resource management of basin. Effective environmental management and systems restoration such as the Haihe River Basin require holistic understanding of the relative importance of various stressor-related impacts throughout the basin. As an effective technical tool for evaluating the ecological risk, relative risk model (RRM) was applied in regional scale successfully.

Isolation and identification of a new tetrodotoxin-producing bacterial species, Raoultella terrigena, from Hong Kong marine puffer fish Takifugu niphobles.

Puffer fish, Takifugu niphobles, collected from the Hong Kong coastal waters were screened for tetrodotoxin-producing bacteria. A Gram-negative, non-acid-fast, non-sporing and rod shaped bacterial strain (designated as gutB01) was isolated from the intestine of the puffer fish and was shown to produce tetrodotoxin (TTX). Based on the Microbial Identification (MIDI) and 16S-23S rDNA internal transcribed spacer (ITS) phylogenetic analysis, the strain was identified as Raoultella terrigena.