Phytoplankton Research Articles

Review of Genetic Variation in Marine Phytoplankton Species and the Ecological Implications

AbstractGenetic variation within marine phytoplankton species is now well established within local populations: individual cells have different reproduction rates and various biochemical and physiological characteristics that are the result of genetic variability. In general, however, differences among cells within a population are relatively small. In some species that live in more than one habitat or water mass, genetic differentiation has developed. This leads to much larger genetic differences between populations, often as large as the differences between species. Although less information is available on seasonal genetic changes in phytoplankton populations, it appears that significant genetic changes occur in highly seasonal coastal waters but not in the more constant oceanic waters. In addition to individual physiological tolerance, genetic variation is a mechanism by which many marine phytoplankton species have expanded their ecological distribution in time and space and phytoplankton ecological s...

Photosynthetic Characteristics of Picoplankton Compared with Those of Larger Phytoplankton Populations, in Various Water Masses in the Gulf of Maine

AbstractCell numbers of eucaryotes and cyanobacteria in phototrophic picoplankton and ratios of in vivo fluorescence of phycoerythrin: chlorophyll a indicated that chroococcalean cyanobacteria played a more prominent role in phytoplankton communities, at the least productive stations. At stations displaying large vertical density gradients, subsurface maxima of phytoplankton pigments were observed. Ratios of in vivo fluorescence of phycoerythrin: chlorophyll a were always greater at the pigment maximum than at the surface. Cyanobacteria from pigment maxima demonstrated greater phycoerythrin fluorescence intensity and photosynthetic rates than cyanobacteria from the surface. Photosynthetic characteristics of picoplankton ( 3 μm populations. The picoplankton differed from larger phytoplankton, in that (1) their pattern of photosynthetic carbon fixation did not vary significantly with decreasing light intensity, and at optimal intensities ...

Diel Feeding, Laminarinase Activity, and Phytoplankton Consumption by Euphausiids

AbstractThree corroborative techniques—stomach fullness, gut fluorescence, and digestive enzyme activity (laminarinase)—were used to examine the feeding ecology of two common euphausiid species off the California coast. Euphausia pacifica showed a diel feeding periodicity: stomach fullness, gut pigment levels, and laminarinase activity increased at night when this species entered the surface waters (< 80 m). In situ phytoplankton consumption by E. pacifica was quite variable and was positively correlated with surface chlorophyll a concentration at the time of collection. E. pacifica collected during March 1981 in Monterey Bay had the highest ingestion rates, and those collected in the Santa Barbara Channel during October 1980 had the lowest. Diel changes in digestive enzyme activity of E. pacifica were influenced by phytoplankton ingestion during a single feeding period. However, overall digestive enzyme levels (average day or night enzyme activity) were probably influenced by longer-term feeding conditio...

The Availability of Iron in Seawater: A Perspective

AbstractThere is evidence that iron availability may regulate primary production in some oceanic systems, yet we are still unable to determine what proportion of total iron in seawater is available for uptake by phytoplankton. Definitions of available iron that are based on size fractionations (i.e., dissolved vs. particulate) are inadequate; new conceptual approaches are needed for defining what constitutes biologically available iron in seawater. It is argued here that iron availability can be characterized by measurements of chemically labile, or reactive iron. Field data show that the labile proportion of total iron can vary considerably over short time scales, indicating that the chemical nature of iron, and hence its availability to phytoplankton, is a dynamic feature in natural systems. Further, a significant proportion of particulate iron in seawater is chemically labile, suggesting that it may be a ready source of available iron. The vertical and cross-shelf transport of suspended sediments may t...

Adaptive responses of photosynthesis in phytoplankton: specificity to time-scale of change in light

The relationship between photosynthesis and light intensity, as expressed by the P-I curve, is fundamental to models of primary production in the oceans. Adaptive responses of phytoplankton are man...

Regional variation in the size composition of phytoplankton communities in the Western North Pacific Ocean, spring 1985

AbstractThe size composition of phytoplankton communities as measured by chlorophyll a concentration was studied in the subarctic, transition, and subtropical waters of the North Pacific Ocean in spring 1985. Total chlorophyll a concentration observed in surface water was lowest in the subtropical water (0.05 ug · l−1) wherein percent contribution of the 10 um size fraction was large (61%). However, even though in the subarctic water, the size composition in the water of the low chlorophyll a concentration ( 10 um size fraction. Diatoms were the major phytoplankters in the >10 um size fraction that affected the regional and temporal variatio...

Photosynthetic Characteristics of Coral Sea Picoplankton (

AbstractLight-dependent photosynthetic (P-I) responses of size-fractionated (>2 μm, 2 μm fraction. PBm values calculated for near-surface picoplankton (¯ = 6.30) and larger phytoplankton (¯ = 2.87) were five times maximum values in deep-living populations (¯ = 1.24 and 0.57, respectively). Near-surface picoplankton photosynthesized at near-maximal rates over a broad range of irradiances between 400 and 1300 μE m−2s−1, but were photoinhibited at >2200 μE m−2s−1 m−2s−1. Deep-living assemblages of picoplankton and larger phytoplankters became photoinhibited at irradiance levels between 200 and 400 μE m−2s−1. Diurnal time series of photosynthesis measurements made with all size classes of phytoplankton from shallow Great Barrier Reef lagoons had broad midday photosynthesis...

Toward a Cladistic View of Phytoplankton Physiological Ecology

AbstractAdvanced techniques in phytogeny reconstruction have the potential for providing new insights into phytoplankton ecology and physiology. Recent analysis of the phytogeny of algal groups has demonstrated that the traditional biological oceanographic concept of chlorophyll c containing algae (chromophytes) as a natural group is erroneous. This error can lead to problems in experimental design that can affect some models of global primary production. Cladistic analyses of character distributions can be used to identify traits that have adaptive value for ecological physiology. The prospective union of systematics and biological oceanography is threatened by a worldwide decline in the availability of training in systematics.

Biology and Ecology of the Cryptophyceae: Status and Challenges

AbstractThe biology and ecology of the Cryptophyceae are updated from recent papers published and new scientific results. Quick-freezing and fracturing methods have provided amazing details of surface structures of members of the class. New pigments have recently been discovered. An improved basis for taxonomy is thus emerging. Food-web studies and practical results in the aquaculture industry prove the Cryptophyceae to be important food organisms for pelagic herbivorous grazers. But in spite of tight grazer control, blooms of Cryptophyceae have been reported. The physiology of Cryptophyceae, particularly with respect to light sensitivity and response, are presently under investigation in several laboratories. This class of algae will be of major interest in phytoplankton research in the next decade.

Trace Metal Interactions with Marine Phytoplankton

AbstractLarge spatial and temporal differences in both trace metal concentrations and chemical speciation in the sea have led to wide variations in biological availability of metals and their effects on phytoplankton. Trace metals are usually taken up by algae via the formation of coordination complexes with specialized transport ligands in their outer membranes, and metal uptake is determined by the interplay between redox, complexation, or oxide dissolution reactions of metals in seawater and ligand-exchange reactions at these sites. Some metals, such as copper and zinc, are heavily chelated by organic ligands in seawater, and their biological availability is determined by the concentrations of free metal ions or of kinetically labile inorganic species (free ions plus inorganic complexes). Once inside cells, trace metals influence metabolism primarily as a consequence of the role of many of these metals (Fe, Mn, Zn, Cu, Co, Mo, Ni) as essential cofactors in metalloenzymes. Trace metals may also inhibit ...

The influence of mixing frequency and depth on phytoplankton mobility

The influence of mixing frequency and depth on phytoplankton functional group composition (mobile versus immobile species) was studied by enclosure experiments in a shallow, stratified lake. Mixing events were artificially induced at intervals from 2–12 d. The mixing depth was increased from the natural level (4 m) to 6 and 9 m. The mobile phytoplankton in the experiments consisted of cyanobacteria and flagellates. Among the latter, large and rapid swimming species were represented by dinoflagellates. An increase of the relative abundance of gas vacuolated cyanobacteria occurred with increasing frequency of mixing. Additionally Reynolds' hypothesis predicting the occurrence of certain mobile phytoplankton genera in response to the mixing regime could be confirmed for the condition when mixing depth exceeds the euphoric depth.

Biogeochemical origins of particles obtained from the inversion of the volume scattering function and spectral absorption in coastal waters

Abstract. In the aquatic environment, particles can be broadly separated into phytoplankton (PHY), non-algal particle (NAP) and dissolved (or very small particle, VSP) fractions. Typically, absorption spectra are inverted to quantify these fractions, but volume scattering functions (VSFs) can also be used. Both absorption spectra and VSFs were used to estimate particle fractions for an experiment in the Chesapeake Bay. A complete set of water inherent optical properties was measured using a suite of commercial instruments and a prototype Multispectral Volume Scattering Meter (MVSM); the chlorophyll concentration, [Chl] was determined using the HPLC method. The total scattering coefficient measured by an ac-s and the VSF at a few backward angles measured by a HydroScat-6 and an ECO-VSF agreed with the LISST and MVSM data within 5%, thus indicating inter-instrument consistency. The size distribution and scattering parameters for PHY, NAP and VSP were inverted from measured VSFs. For the absorption inversion, the "dissolved" absorption spectra were measured for filtrate passing through a 0.2 μm filter, whereas [Chl] and NAP absorption spectra were inverted from the particulate fraction. Even though the total scattering coefficient showed no correlation with [Chl], estimates of [Chl] from the VSF-inversion agreed well with the HPLC measurements (r = 0.68, mean relative errors = −20%). The scattering associated with NAP and VSP both correlated well with the NAP and "dissolved" absorption coefficients, respectively. While NAP dominated forward, and hence total, scattering, our results also suggest that the scattering by VSP was far from negligible and dominated backscattering. Since the sizes of VSP range from 0.02 to 0.2 μm, covering (a portion of) the operationally defined "dissolved" matter, the typical assumption that colored dissolved organic matter (i.e., CDOM) does not scatter may not hold, particularly in a coastal or estuarine environment.

Remote Sensing of Temporal and Spatial Variations of Suspended Sediment Concentration in Bahmanshir Estuary, Iran

Suspended Sediment Concentration (SSC) in surface waters affects directly on the water quality, phytoplankton's fertility, pollution distribution and redistribution. In this study, temporal and spatial variations of SSC at Bahmnshir Estuary (BE) in the southwest of Iran were investigated using five field campaigns and Moderate Resolution Imaging Spectroradiometer (MODIS) sensor images of a nine-year time series from 2003 to 2011. An Artificial Neural Network (ANN) model with one hidden layer that had good simulation performance (training: R 2 = 0.84; N = 23; validation: RMSE of 59 mg L -1 , N = 6) was used against regression analysis (modeling: R 2 = 0.63; N = 23; validation: RMSE of 261 mg L -1 , N = 6). Results indicated ANN model has higher accuracy than regression analysis to model the SSC because it's higher capability in optimization of non-linear problems. R 2 and RMSE were improved, 25 and 77% respectively when using ANN model. It was found that average annual SSC for years 2008 to 2011 was 10% more than years 2003 to 2007 and the highest SSC accrued at 2008 with a noticeable decrease in the flow discharge of Karun River in this year. Minimum SSC occurs, at the point in 3.2 km before the Estuary Mouth (EM). This point was defined as the boundary of impact of upstream and downstream on the SSC in the BE. High SSCs occur at EM, at the muddy shore of the Abadan Island on right bank and at the Khoure Mousa on the left bank with 2.8 and 1.8 km distance from the EM respectively. This study demonstrated ANN model and MODIS MOD09GQ products are appropriate tools for monitoring surface SSC dynamics within coastal water environments such as BE.

Phytoplankton Density and Diversity in the Waters around the Reclamation Area in Manado Beach

ABSTRACT Phytoplankton is one of the most important aquatic organisms and has a major role in the cycle of life in the waters. Phytoplankton is able to do the process of photosynthesis to produce the organic matter utilized by other organisms living in aquatic environments. Phytoplankton can also be used as one of the ecological parameters that can describe the ecological conditions of the body of water and can be used as bio-indicators of pollution in the water. The purpose of this study is to obtain the types of phytoplankton in the waters around the reclamation area in Manado Beach, to know the diversity and density of phytoplankton species, and to determine the types of phytoplankton which are dominant according to the water depth. The phytoplankton found in the research site belonged to 27 genera. Station 1, 27 species were found in 5m depth, 19 species in 15m depth and 12 species in 30m depth. Station 2, 24 species were found in 5m depth, 20 species in 15m depth and 13 species in 30m depth. For index density, station 1 and 2 at a depth of 5 m has the highest density of 11 individuals/l and 12.333 Individuals/l. Diversity indices for stations 1 and 2 showed at a depth of 5 m, 2.954 and 2.891, respectively. The dominance indices at station 1 and station 2 showed that were no species dominance. Keywords : phytoplankton, density, diversity, reclamation area ABSTRAK Fitoplankton merupakan salah satu organisme perairan yang sangat penting dan mempunyai peran utama dalam siklus kehidupan di perairan. Fitoplankton mampu melakukan proses fotosintesis untuk menghasilkan senyawa organik yang merupakan sumber energi yang dimanfaatkan oleh organisme lain yang hidup di lingkungan perairan. Fitoplankton juga dapat digunakan sebagai salah satu parameter ekologi yang dapat menggambarkan bagaimana kondisi ekologi suatu perairan dan dapat digunakan sebagai bio-indikator pencemaran dalam suatu perairan. Penelitian ini bertujuan untuk mendapatkan data jenis-jenis fitoplankton yang ada di perairan sekitar kawasan reklamasi Pantai Manado, mengetahui keanekaragaman dan kepadatan spesies fitoplankton dan mengetahui jenis-jenis fitoplankton yang dominan menurut kedalaman air. Jenis fitoplankton yang ditemukan di lokasi penelitian totalnya berjumlah 27 genus. Stasiun 1, ditemukan 27 spesies di kedalaman 5m, 19 spesies di kedalaman 15m dan 12 spesies di kedalaman 30m. Stasiun 2, ditemukan 24 spesies di kedalaman 5m, 20 spesies di kedalaman 15m dan 13 spesies di kedalaman 30m.Untuk indeks kepadatan, stasiun 1 dan 2 di kedalaman 5 m memiliki kepadatan tertinggi yaitu 11 Ind/l dan 12,333 Ind/l. Indeks keanekaragaman untuk stasiun 1 dan 2 di kedalaman 5m yaitu 2,954 dan 2,891, indeks dominasi di stasiun 1 dan stasiun 2 menunjukkan tidak adanya dominasi spesies. Kata kunci : fitoplankton, kepadatan, keanekaragaman, kawasan reklamasi 1Bagian dari skripsi 2Mahasiswa Program Studi Manajemen Sumberdaya Perairan FPIK-UNSRAT 3Staf pengajar Fakultas Perikanan dan Ilmu Kelautan Universitas Sam Ratulangi

Dinophyta Characterise Nitrogen Scarcity More Strongly than Cyanobacteria in Moderately Deep Lakes

A survey of the summer phytoplankton communities of thirty-six moderately-deep north temperate lowland lakes showed that the proportions of Dinophyta and non-heterocyst-bearing cyanobacteria taxa, measured as biovolume, were inversely related to the total nitrogen: total phosphorus (TN:TP) ratio and that these groups were predominant in lakes where available nitrogen fell to undetectable concentrations. The proportion of heterocyst-bearing cyanobacteria was positively correlated to the TN:TP ratio and nitrate. Dinophyta and/or non-heterocystous cyanobacteria were prevalent in lakes with the highest epilimnion nutrient concentrations, whilst heterocystous cyanobacteria predominated in lakes with moderate nutrient concentrations. It is argued that the ability of Dinophyta to migrate vertically and to supplement their nutrient requirements though heterotrophy may enable them to be at least as successful as Cyanobacteria in high nutrient lakes and in overcoming nitrogen-scarcity. Our findings provide evidence that Dinophyta can be used as indicators of water quality.

IDENTIFYING SENSITIVE INDICES IN THE RESPONSE OF AQUATIC BIOTA TO LANDSCAPE PATTERN CHANGES: A CASE STUDY OF THE TAIZI RIVER BASIN IN NORTH CHINA

It is widely accepted that riverine ecosystems are influenced by the landscape pattern changes of their corresponding watersheds, but few studies have identified the most sensitive and nonsensitive biotic indices, the most influential landscape metrics and the relationship between aquatic biota and landscape patterns. To address this problem, Taizi river basin of Northeast China is taken as a case study, in which GIS technology and landscape ecology method are adopted. The study is performed at both the basin scale (entire drainage area upstream from certain sample point) and the riparian scale (a certain width buffer on each side of sample point extending the length of drainage network) to direct future landscape pattern design at the corresponding scales. The results show that at the basin scale, the species richness of benthic macroinvertebrate (B-S) and the fish index of biotic integrity (F-IBI) are the most sensitive biotic indices to landscape metrics, whereas the species richness of phytoplankton (P-S), the Shannon–Weaver diversity index of phytoplankton (P-H), zooplankton (Z-H), benthic macroinvertebrate (B-H) and fish density (F-D) are not sensitive to landscape pattern changes; at the riparian scale, F-IBI, B-S and zooplankton density (Z-D) have significant correlations with 9 of 10 landscape metrics calculated in this study, whereas P-S, P-H, Z-H, B-H, F-D and species richness of fish have very low correlations with riparian landscape pattern changes. At the basin scale, no landscape pattern metrics show obviously more influence on the riverine ecosystems than other metrics. At the riparian scale, Shannon's diversity index is a very influential factor. As to both of the two scales, B-S and F-IBI are correlated with most landscape metrics. The information derived above can help understand the impacts of landscape change on river ecosystems more clearly and provide useful scientific information on river ecosystem protection from the viewpoint of landscape. Copyright © 2013 John Wiley & Sons, Ltd.

An Inversion Research of Phytoplankton Biomass of Ebinur Lake based on Data of CBERS-2

An Inversion Research of Phytoplankton Biomass of Ebinur Lake based on Data of CBERS-2

Long-term Change of Phytoplankton Biomass (chlorophyll-a), Environmental Factors and Freshwater Discharge in Youngsan Estuary.

영산강 하구에서 담수 유입이 부유생태와 수질에 미치는 영향을 파악하기 위해 국가해양환경측정망 장기자료(1999~2008년)인 클로로필 a와 수질 항목들에 대한 계절적, 공간적 변화와 장기변동 추세를 분석하였다. 분석결과, 여름철 (8월) 영산강 방조제 인접정점의 염분은 조사기간 중 가장 낮은 분포를 보였고, 영양염류와 클로로필 a는 전반적으로 높은 분포를 나타냈다. 영산강 담수유입의 지시인자인 표-저층의 염분차 ( ${\Delta}salinity$ )와 영양염류, 클로로필 a는 유의한 양의 상관성을 나타냈으나, 지난 10년동안 담수 방류량은 감소하는 추세를 보였고, 영양염류, 클로로필 a는 전반적으로 증가하는 경향을 나타냈다. 이러한 결과는 영산강 하구 해역 영양염의 공급원이 담수유입뿐만 아니라 인근 지역의 발달에 따른 점오염원 증가 등의 추가적인 요인이 존재할 가능성을 제시한다. 따라서 영산강 하구 주변 해역의 부영양화 방지를 위해서는 영산강 방조제의 방류와 연관한 수질개선방안 마련과 더불어 인근 지역의 점 오염원 파악 및 관리가 병행되어야 할 것으로 사료된다. 【In Yeongsan River estuary, located in the southern West Coast, a dike was constructed in December 1981. After the construction of a dike, discharge mechanism of fresh water has been changed, the water quality and chlorophyll-a are expected to be influenced by fresh water discharge. We investigated temporal and spatial variations and long-term trend of phytoplankton biomass (chlorophyll-a) and environmental factors. The concentrations of nutrient and chlorophyll-a were generally high in summer and the concentrations were increased toward downstream. Surface/bottom salinity difference was negatively correlated with salinity in surface water but positively with nutrient and chlorophyll-a. TN, TP and DIN concentrations were generally increased over 10 years. This study can provide information for better management of water quality for Youngsan River estuary.】

First Report of Microcystins and Anatoxin-a Co-occurrence in San Roque Reservoir (Córdoba, Argentina)

Fil: Ruiz, Marcia. Secretaria de Ambiente y Desarr.sustentable de la Nacion. Instituto Nacional del Agua y del Ambiente(cordoba); Argentina

Variable Production by Different Pelagic Energy Mobilizers in Boreal Lakes

We studied production by three key pelagic energy mobilizer communities, phytoplankton (PP), heterotrophic bacteria (HB), and methanotrophic bacteria (MOB), in five boreal lakes of varying size and concentration of dissolved organic carbon (DOC). Production by PP was responsible for most (>55%) of the total pelagic energy mobilization in all five lakes. Production by HB and PP estimated for the whole water column during the ice-free period were positively correlated, but with the exception of the clearest and most eutrophic lake PP apparently could not support the total carbon demand of bacteria. However, the DOC concentration did not explain the variability of heterotrophic bacterial production (HBP) within or between the lakes. Thus, our results provide circumstantial evidence for the “priming effect” whereby labile organic matter from autochthonous production enhances decomposition of allochthonous DOC. However, HBP was only 10–23% of the total pelagic energy mobilization in the lakes, suggesting that only a minor fraction of allochthonous DOC became available for higher trophic levels. High MOB activity was detected in the water columns of the stratified lakes when the molar ratio of CH4:O2 varied between 0.5 and 12. In the small stratified lakes (area 70%) potential food source for zooplankton.