Pigment characterization for the 2011 bloom in Qinhuangdao implicated “brown tide” events in China

Abstract

A large-scale bloom occurred from May to June in 2011 in sea area near Qinhuangdao of the Bohai Sea, leading to huge damage of the scallop culture industry. Similar blooms have been observed in this region for three years. The causative species of the bloom, which dominated the phytoplankton community with the maximum cell density around 10 9 cell/L, could not be identifi ed with morphological features due to the small cell size (~2 m m). A pigment analytical method was then adopted to analyze the pigment profi le of the phytoplankton samples collected from the blooming sea area. It was found that pico-sized (<2 m m), nano-sized (2-20 m m), and bulk phytoplankton samples had similar pigment profi le, representing the pigment signature of the bloom-causative species. The major pigments detected included 19-butanoyloxyfucoxanthin (But-fuco), fucoxanthin (Fuco), diadinoxanthin (Diad) and chlorophyll a (Chl a ), and high content of But-fuco was the most signifi cant characteristics of the phytoplankton samples. Based on the pigment composition and content, the bloom-causative species could be tentatively identifi ed as pelagophyte, "type 8" group of haptophyte, or silicofl agellate. Some unique features of the bloom, such as the extremely high cell density, small-sized and But-fuco containing cells, occurring in early summer, and the feeding-cessation effects on scallops, suggest it be a "brown tide" event similar to those reported in the east coast of the United States of America. The recurrent "brown tide" events and their dramatic impacts on the shellfi sh mariculture industry in Qinhuangdao need close attention in the coming years.

Emergence of brown tides caused by Aureococcus anophagefferens Hargraves et Sieburth in China

“…Picosized Chl a (<2 mm) was about 80% of the total Chl a content, and nano-sized Chl a (2-20 mm) was about 20%, while micro-sized Chl a (>20 mm) was less than 1%. But-fuco, Fuco, Diad and Chl a were the major pigment components in the pico-sized and nano-sized phytoplankton samples (Kong et al, 2012). Station Q3 (119824.660 0 E, 39846.924 0 N), which was outside the bloom area, was located at the Yanghekou Harbor and approximately 4 km away from stations Q1 (Kong et al, 2012).…”

“…Large-scale blooms occurred again in 2011, although the impacts of this bloom are currently unknown. In a previous study (Kong et al, 2012), we reported that the major pigments detected from the bloom were 19 0 -butanoyloxyfucoxanthin (But-fuco), fucoxanthin (Fuco), diadinoxanthin (Diad) and Chlorophyll a (Chl a), and high content of But-fuco was the most significant characteristics of the causative species of the bloom. Based on the pigment composition and content, the causative species could be tentatively identified as a pelagophyte, haptophyte or silicoflagellate (Edvardsen et al, 2007;Zapata et al, 2004).…”

An Algal Specific Growth Rate Relation Model to Assess Dynamical Brown Tide Disasters

“…anophagefferens is a newly documented brown tide algae species in China . Next to America and South Africa, and China is the third-largest regional that suffers from brown tide (Kong et al 2012). However, brown tides in China have been rarely investigated.…”

“…Large-scale brown tide blooms caused by A. anophagefferens occurred in the coastal waters of Qinhuangdao, China from 2009 to 2014 (State Oceanic Administration People's Republic of China 2009;. In particular, the largest scale of all was that in 2010, where 3350 km2 sea surface was affected (State Oceanic Administration People's Republic of China 2010) and Argopecten irradians mariculture was devastated (Kong et al 2012; with an estimated economic loss of 0.2 billion RMB (State Oceanic Administration People's Republic of China 2010).…”

“…Hazard degree is defined as the probability of disaster occurrence, and reflects the nature of the disaster (Huang 1999;, while dynamic assessment evaluates how the hazard degree may change with the environmental condition. Research in brown tide hazard degree started relatively recently, with previous studies focusing on the process of brown tide monitoring (Cosper et al 1987;Bricelj & Lonsdale 1997;Gobler et al 2005), the harmful effects on the mariculture (Probyn et al 2001;Gastrich & Wazniak 2002); the biology and taxonomy of algae (Bailey & Anderson 1999;Ong et al 2010;Gobler et al 2011;Kong et al 2012;, the physiological ecology of algae (LaRoche et al 1997;Liu et al 2001;Gobler et al 2002;Macintyre et al 2004;Sunda et al 2006;Glibert & Sturgis 2007;Probyn et al 2010), and brown tide models (Beltrami 1989), etc. However, quantitative research on the prevention and reduction of brown tide has yet to be performed.…”