Dinoflagellate Cysts In Recent Sediments Research Articles

Strong regionalism in dinoflagellate cysts in recent sediments from the Chukchi-East Siberian Seas, Arctic Ocean

The Pacific sector of the Arctic Ocean, a region with the fastest sea-ice loss in recent decades, is experiencing unprecedented biological regime shifts in its marine ecosystems today. However, a shelf-wide characterization of marine plankton communities over this region and environmental processes behind it remain largely unresolved, despite phytoplankton phenology is now considered to be an important factor for assessing how Arctic Ocean interacts with global climate change. Here, we present the first detailed description of recent dinoflagellate cyst assemblages in 32 surface sediment samples from the Chukchi–East Siberian Sea shelves, the Pacific Arctic Ocean, to examine their biogeographic patterns and associated environmental forcing factors. We find a strong regionalization in the species composition and distribution along the shallow-shelf cyst accumulation zone; in the Chukchi Sea sector, northward flow of warm-Pacific water along with extreme seasonality, sufficient nutrient supplies and higher light availability leads to a large occupation of cosmopolitan, opportunistic-nature taxa, whilst the East Siberian Sea sector with more extensive sea-ice cover and lower temperatures is primarily dominated by “round brown spiny cyst” taxa that have a strong affinity for cold, polar conditions. Specifically, an exclusive dominance of heterotrophic taxa at the East Siberian Sea region is inferred to be closely tied to Atlantic-origin water intrusions that lift nutrient-rich, cold bottom water up to oligotrophic surface layer to grow diatoms and other prey organisms. The observed contrast in this geographical “hot spot”, where the Pacific- and Atlantic-origin waters face each other, clearly manifests a growing expansion of southern waters into an increasingly ice-free Arctic Ocean that reshapes Arctic Ocean biogeography from the base of marine food chains. Our study highlights considerable potential of dinoflagellate cysts as a valuable environmental proxy to indicate complex interactions between ocean physics and marine biology under the rapidly changing Arctic climate system.

Assemblages of dinoflagellate resistance cysts and copepod eggs in superficial sediments at the upper Gulf of California

The diversity, abundance, and geographic distribution of dinoflagellate cysts in recent sediments serve as bioindicators to specific regions' environmental conditions and productivity. We present dinoflagellate cysts assemblages from 53 superficial sediment samples from the upper Gulf of California (uGC) obtained in July 2016 and February 2017. Forty-seven species were identified, of which twenty-seven are considered heterotrophic (Het) and twenty autotrophic (Aut). Ten species of this last group are potentially toxin producers (PTxS). The total concentration (Tot) of cysts in all the samples was 3481 cysts/g in 2016 and 4223 cysts/g in 2017. Aut represented 59%, Het 41%, while the PTxS represented ∼36.5% of the Tot cysts. The higher abundance of the Aut is likely to manifest the local high sea surface temperature and salinity. The increase in the Tot of cysts in the 2017 set was related to a Gymnodinium catenatum harmful algal bloom. Copepod eggs abundance was 7137 eggs/g in 2016 and 6555 eggs/g in 2017. The Aut Gymnodinium spp., Spiniferites spp., Operculodinium spp, and the Het Protoperidinium americanum, Quinquecuspis concreta, Selenopemphix nephroides, Brigantedinium spp., and Echinidinium spp., were typical in both seasons but differed on their concentrations between each season. The cysts distribution between both sampling periods reflects local currents and the sediment dynamics of the uGC, and the high species diversity in this area reflects the elevated primary productivity in this area.

Environmental forcing on the flux of organic-walled dinoflagellate cysts in recent sediments from a subtropical lagoon in the Gulf of California

To evaluate the relationship of changes in organic-walled dinoflagellate cyst (dinocyst) fluxes to sediments with environmental variables (air and sea surface temperatures, El Niño conditions, rainfall, and terrigenous index), cyst assemblages were analyzed in a 210Pb-dated sediment core (~100years) from the pristine San José Lagoon (San José Island, SW Gulf of California). The dinocyst abundance ranged from 3784 to 25,108cystsg−1 and fluxes were of the order of 103–104cystscm−2yr−1. Lingulodinium machaerophorum, Polysphaeridium zoharyi and Spiniferites taxa accounted for 96% of the total dinocyst assemblages, and the abundances of these species increased towards the core surface. P. zoharyi fluxes increased from about 1965 onwards. Redundancy analyses, showed that mean minimum air temperature and terrigenous index were the key factors governing dinocyst fluxes. In this study, dinocyst fluxes of dominant taxa had responded to changes in climate-dependent environmental variables during the past ~20years; this may also be the case in other subtropical coastal lagoons.

Scrippsiella trochoidea cysts in recent sediments from Amur Bay, Sea of Japan: distribution and phylogeny

Abstract A study of vertical distribution of dinoflagellate cysts in recent sediments was conducted for the first time in the Far Eastern seas of Russia. Dinoflagellate cysts were studied in sediment cores retrieved from five stations in Amur Bay (Peter the Great Bay, Sea of Japan) in 2010 and 2013. The Scrippsiella trochoidea complex was the dominant type of cyst, the average proportion of which (in the entire sediment cores) reached 39% of the total cyst abundance. The maximum abundance of S. trochoidea complex reached 5513 cysts g-1 dry sediment. Cysts of the S. trochoidea complex were found to remain viable in the sediments after exposure to sub-zero temperatures. The identification of S. trochoidea in the Far Eastern seas of Russia was first confirmed by using biomolecular genetic analyses. The study of vertical distribution showed that cysts of this species dominate the upper sediment layers (0–10 cm). A tendency for abundance to increase from the shore toward the middle part of the bay was observed in the spatial distribution of cysts.

Dinoflagellate cyst assemblages in recent sediments of Visakhapatnam harbour, east coast of India: Influence of environmental characteristics

The distribution and abundance of dinoflagellate cysts in recent sediments from Visakhapatnam harbour, east coast of India was investigated and compared with sediment characteristics and physico-chemical variables of the overlying water column. The cyst abundance varied from 11 to 1218cystsg–1dry sediment. Changes in the cyst assemblages from phototrophic to heterotrophic forms were observed from inner to outer harbour stations, and related to changes in environmental characteristics. Enhanced cyst production of potentially harmful dinoflagellate Protoceratium reticulatum was recorded in the inner harbour stations with higher nutrient concentrations. Protoperidinium cysts were the most diversified group, and were dominant in the outer harbour stations having improved water conditions and circulation. This study points out the potential use of dinoflagellate cyst populations in providing information on environmental conditions.

Distribution of dinoflagellate cysts in recent sediments from Izmir Bay (Aegean Sea, Eastern Mediterranean)

Abstract To determine the species composition, abundance and horizontal distribution of dinoflagellate cysts in recent marine sediments, samples were collected at 13 stations in Izmir Bay, Aegean Sea. At least thirty-six dinoflagellate cyst types were identified, with the assemblages mainly dominated by Lingulodinium machaerophorum , Polykrikos kofoidii , Operculodinium centrocarpum , Gymnodinium cf. nolleri and Quinquecuspis concreta . Total cyst concentrations ranged from 41 to 3292 cystsg − 1 dry weight sediment. The majority of the cysts occurred in the inner and middle parts of the bay, where higher cyst concentrations were observed. According to the One Way Anova test, the difference between stations was significant statistically (p Gymnodinium cf. nolleri and Oblea acanthocysta . Alexandrium minutum and Alexandrium affine type cyst were observed at almost all stations although the cyst type of the Alexandrium catenella/tamarense complex was only found in the outer bay. These findings indicate potential seedbeds for initiation of future blooms and outbreaks of potentially toxic species in Izmir Bay.

Dinoflagellate cysts in recent sediments from two semi-enclosed areas of the Western Mediterranean Sea subject to high human impact

Abstract Studies were conducted on dinoflagellate cyst assemblages from two semi-enclosed areas of the Western Mediterranean Sea subject to high human impact, Arenys de Mar harbor and the Gulf of Olbia. Sediment cores were taken from seven stations (December 2006 and August 2007) in Arenys and from eight (October 2006) and ten (May 2007) stations in Olbia. Of the 42 morphotypes found in the sediments collected at the two sites, 27 were identified at the species level, representing 10 genera. The most common cysts were those of Scrippsiella trochoidea, Scrippsiella sp. 2, Gymnodiniales type 1, and Scrippsiella precaria. A number of the morphotypes had not been previously described in the literature. Total cyst abundances varied substantially between the two surveys, with an increased total density in Arenys and a decrease in Olbia. However, at the latter site, a higher abundance of cysts was recorded at more confined sampling stations. Calcareous Peridiniales, belonging to the genus Scrippsiella, dominated the cyst assemblages of both sites, while at some stations higher numbers of Gymnodiniales (Olbia) and Gonyaulacales (Arenys) were determined. Cysts of the toxic species Alexandrium minutum and A. catenella/tamarense were also detected. A. minutum was present at both sites whereas A. catenella/tamarense was found only in Olbia. Peridinium quinquecorne was recovered in the sediments of both sites. In Olbia, cysts of this species were present at high densities and were detected even in deep sediments. Species such as Pentapharsodinium cf. tyrrhenicum, Scrippsiella crystallina, S. lachrymosa, S. precaria, S. trochoidea, Protoperidinium avellanum, P. claudicans, P. compressum, P. conicum, P. cf. minutum, P. oblongum, P. pentagonum, P. subinerme, and Zygabikodinium lenticulatum were not detected as motile stages in the study areas. The results of this study, the first on dinoflagellate cyst assemblages at these two sites, further our knowledge of cyst diversity and confirm the importance of embayments and hydrographically confined areas as reservoirs for planktonic dinoflagellates.

Dinoflagellate Cysts in Recent Sediments from Chinese Coastal Waters

Abstract. Surface sediments were collected from 10 locations to study the distribution of dinoflagellate resting cysts in Chinese coastal waters from July 2000 to May 2002. Sixty‐one cyst morphotypes representing 14 genera of three orders were identified in this survey. Seventeen cyst types were recorded for the first time from Chinese coasts. Rich cyst assemblages were recorded in closed or semi‐closed nearshore harbors. Scrippsiella trochoidea was the most dominant and common cyst type in this survey, especially in sediments from Daya Bay, Dapeng Bay and Shenzhen Bay. However, Protoperidinium cysts were the most diversified group, predominating in Changjiang River Estuary, Zhujiang River Estuary, Zhelin bay and the Nanao Island area. Cyst concentrations in the top 2 cm surface sediments varied from 258 to 25,037 cysts·g−1 dry weight sediment, and abundance was lower in Changjiang River Estuary and Zhujiang River Estuary. Cysts of two dinoflagellates capable of producing paralytic shellfish poisoning (PSP) –Alexandrium spp. and Gymnodinium catenatum– were detected almost in all locations. Furthermore, the ellipsoidal Alexandrium catenella and A. tamarense cyst complex was frequently observed in the surface sediment from Daya Bay, where high contents of PSP toxin and PSP episodes have been reported. Detailed descriptions and illustrations are provided of those cysts of newly recorded species, unidentified species, toxic species and dominant species.

Dinoflagellate Cysts in Recent Sediments from Bahía Concepción, Gulf of California

The composition, abundance, and distribution of dinoflagellate resting cysts in recent sediments were analyzed at 12 sites in Bahia ConcepciOn in the subtropical Gulf of California. Calcareous and organic Peridiniales, Gonyaulacales, and Gymnodiniales were identified at species level (25 cyst types). Empty cysts constituted 75-90% of cysts in the samples. Cyst assemblages were dominated by calcareous Peridiniales (30-70%) and Gonyaulacales (13-44%), represented mainly by Scrippsiella trochoidea and Lingulodinium polyedrum. In the first centimeter of sediment, cyst counts varied from 173 to 9, 933 cysts g - 1 wet weight, and increased in abundance in the inner area of the bay. Cysts of the toxic species Gymnodinium catenatum were also detected, and successful cyst germination of Alexandrium margalefii is described. Cyst abundance and distribution patterns suggest that the bay acts as a cyst trap, and that the cyst assemblages reflect the local community of meroplanktonic dinoflagellates.

Dinoflagellate Cysts in Recent Sediments from the Southern Coastal Waters of Korea

Thirty-seven different types of dinoflagellate cysts were recorded in surface sediments, sampled at offshore and inshore stations from the southern coastal waters of Korea. Because of their atypical morphologies, Votadinium calvum, Quinquecuspis concretum, Protoperidinium sp. and two types of Brigantedinium are described and discussed in more detail. The concentrations of dinoflagellate cysts were approximately four times higher at offshore stations than those at inshore stations. This study provides a database on dinoflagellate cyst distribution and composition in the southern coastal waters of Korea, where dinoflagellate cysts have been little studied.

Dinoflagellate Cysts in Recent Sediments from the West Coast of Sweden

This is the first study of dinoflagellate cysts in recent coastal sediments from the Swedish west coast. Sediments from 19 sites were investigated. Fifty-four types of cysts were encountered, of these 40 were identified to species level, representing 13 genera. The most common species were those of Lingulodinium polyedrum, Protoceratium reticulatum, Scrippsiella trochoidea, Pentapharsodinium dalei and Gonyaulax cf. spinifera. Cysts of the potentially toxic species Alexandrium minutum and Alexandrium tamarense were widely distributed as well as Gymnodinium nolleri, the non-toxic G. catenatum-like microreticulate cyst found in Northern Europe. Nine of the species found in this survey have not previously been reported from Sweden: Diplopelta parva, D. symmetrica, Diplopsalopsis latipeltata, Diplopsalis lebourae, Protoperidinium americanum, P. avellana, P. divaricatum, P. nudum and P. stellatum.

Recent dinoflagellate cyst assemblages from the southern Barents Sea

Abstract Assemblages of dinoflagellate cysts in Recent sediments from the southern Barents Sea are dominated by the cyst species Operculo‐dinium centrocarpum (Deflandre & Cookson) Wall, but also contain numbers of elongate Spiniferites specimens referable to both S. elongatus Reid and S. frigidus Reid & Harland. There is considerable intraspecific variability within these Spiniferites species particularly with regard to the amount and form of membrane development. This Arctic dinoflagellate cyst thanatocoenosis differs from dinoflagellate assemblages previously described from the North Atlantic in lacking Bitectatodinium tepikiense Wilson and such Spiniferites species as S. lazus Reid, S. mirabilis (Rossignol) Sarjeant and S. ramosus (Ehrenberg) Loeblich & Loeblich. The apparently unique character of Recent Arctic dinoflagellate cyst assemblages offers the potential of recognizing similar assemblages in the late Quaternary record.