@article{L.2018,
title = {A new dinoflagellate species, Protoperidinium smithii H. Doan-Nhu, L. Phan-Tan et L. Nguyen-Ngoc sp. nov., and an emended description of Protoperidinium defectum (Balech 1965) Balech 1974 from the Ross Sea, Antarctica},
author = {Phan-Tan L., L. Nguyen-Ngoc, W. O. Smith Jr., H. Doan-Nhu},
url = {https://link.springer.com/article/10.1007/s00300-018-2262-0},
doi = {10.1007/s00300-018-2262-0},
issn = {1432-2056},
year = {2018},
date = {2018-05-01},
journal = {Polar Biology},
volume = {41},
number = {5},
pages = {983--992},
abstract = {The Ross Sea is one of the most well studied marginal seas in Antarctica. However, information of phytoplankton and in particular dinoflagellate diversity is limited. In this present study, samples at the surface and depth of the chlorophyll maximum at 40 stations during summer (2011–2012) were investigated for Protoperidinium species. A new species has described: Protoperidinium smithii H. Doan-Nhu, L. Phan-Tan et L. Nguyen-Ngoc sp. nov. This species belongs to subgenus Minusculum and have all of the features of this group. The new species is similar to Protoperidinium bipes (Paulsen) Balech 1974 and Protoperidinium defectum (Balech) Balech 1974. However, it is clearly differentiated from both species by its cell body shape, very short right antapical spine, a short apical horn, and the largest 1′′′ plate among species in subgenus Minusculum. Protoperidinium defectum is also amended by several characteristics including detail plates tabulation since the first description in 1965.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{LUNDHANSEN201828,
title = {Impacts and effects of a historical high and ENSO linked freshwater inflow in the tropical estuary Nha Phu, southeast Vietnam},
author = {Lars Chresten Lund-Hansen and Kurt Thomas Jensen and Thorbjørn Joest Andersen and Morten Holtegaard Nielsen and Hai Doan-Nhu and Lam Nguyen-Ngoc},
url = {http://www.sciencedirect.com/science/article/pii/S235248551730244X},
doi = {https://doi.org/10.1016/j.rsma.2017.11.012},
issn = {2352-4855},
year = {2018},
date = {2018-01-01},
journal = {Regional Studies in Marine Science},
volume = {17},
pages = {28 - 37},
abstract = {The frequency of strong and extreme precipitation events and high river discharges is foreseen to increase in southeast Asia in the future. The aims of the study were to evaluate physical and biological impacts of a historical (one-in-36 years) (1980–2015) extreme freshwater inflow in November 2010 into the small tropical Nha Phu estuary. The extreme event impacts were assessed relative to a dataset of samplings (n=11) through 1.5 year of phytoplankton biomass (chlorophyll a), nutrients, CTD, primary production and suspended particulate matter prior to the extreme event. Results show, that the event significantly decreased salinity, increased chl-a 2–3 times, suspended particulate matter and beam attenuation coefficients by 7 times, and the colored dissolved organic matter absorption coefficient by 3 times. The extreme inflow initiated a phytoplankton bloom fueled by catchment area derived nutrients. The bloom established a considerable carbon production and transport of carbon to the coastal and shelf areas. There was likewise a significant export of suspended particulate matter out of the estuary. Residence time decreased from 4.2 to 3.8 days during the extreme event, and pre-inflow water column conditions were re-established within 4–5 days, shown in a previous study. Annual precipitation in the area was linked to the Pacific ENSO-cycle (El Niño Southern Oscillation) with 2010 as a very strong La Niña year. The entire event accounted for 68% of annual precipitation, 39% of annual discharge, and 53% of annual sediment transport in the Dinh River, which discharges into the Nha Phu estuary.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Nguyen2017,
title = {An Assessment of Heavy Metal Contamination on the Surface Sediment of Seagrass Beds at the Khanh Hoa Coast, Vietnam},
author = {Xuan-Vy Nguyen and Minh-Hue Tran and Trong-Dung Le and Jutta Papenbrock},
url = {https://doi.org/10.1007/s00128-017-2191-6},
doi = {10.1007/s00128-017-2191-6},
issn = {1432-0800},
year = {2017},
date = {2017-12-01},
journal = {Bulletin of Environmental Contamination and Toxicology},
volume = {99},
number = {6},
pages = {728--734},
abstract = {Seagrasses beds are vulnerable ecosystems. Human-induced disturbances, including heavy metal pollution, cause losses in seagrass beds. Assessment of the heavy metal concentration in seagrass meadows is an urgent need in order to protect and sustain these ecosystems. The concentration of eight trace metals in the surface sediment was observed from six seagrass beds at Khanh Hoa's coast, Vietnam. Three pollution indices and statistical analysis were used to evaluate the levels of contamination with these elements. This report on heavy metals within seagrass beds in Vietnam shows that, based on enrichment factors, only one location revealed moderately severe enrichment of Cu. Geo-accumulation indices fall in the uncontaminated class at all locations whereas for the ecological risk factor, values of Cu at My Giang and of Pb at Thuy Trieu were in a moderate risk class. Hence, two of eight locations may be exposed to high Cu and Pb.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Loick-Wilde2017,
title = {Microplankton biomass and diversity in the Vietnamese upwelling area during SW monsoon under normal conditions and after an ENSO event},
author = {Natalie Loick-Wilde and Deniz Bombar and Nguyen-Ngoc Lam and Doan-Nhu Hai and Anh Mai Nguyen-Thi and Maren Voss and Joachim W. Dippner},
url = {http://www.sciencedirect.com/science/article/pii/S0079661116300283},
doi = {doi.org/10.1016/j.pocean.2017.04.007},
issn = {0079-6611},
year = {2017},
date = {2017-04-24},
journal = {Progress in Oceanography},
volume = {153},
pages = {1-15},
abstract = {Investigating microplankton biomass and diversity under different climatological conditions is key to the understanding of cascading effects of climate change on nutrient cycles and biological productivity. Here we have used data collected during two contrasting summers along the coast of Viet Nam to show how climatological-driven changes can have a significant influence on the distribution of microplankton communities and their biomass via its impact on nutrient concentrations in the water column. The first summer in July 2003 followed a weak El-Nino Southern Oscillation (ENSO) event and was characterized by weak coastal upwelling, in the second summer during July 2004, upwelling was normal.
Very low silicate (SiO4) concentrations and SiO4:DIN ratios characterized the source water mass for upwelling in July 2004, and dynamic SiO4 to dissolved inorganic nitrogen ratios (SiO4:DIN) mainly below the Redfield-Brzezinski ratio and DIN to phosphate ratios (DIN:PO43−) below the Redfield ratio were a common feature off Viet Nam. Much higher particle concentrations and PSi/PC ratios during normal upwelling revealed major changes in the microplankton community structure among summers. Small dinoflagellates (10–20 µm) prevailed ubiquitously during reduced upwelling. During normal upwelling, the diatom Rhizosolenia sp. dominated the cell-carbon biomass in the silicate poor upwelling waters. Trichodesmium erythraeum dominated in the Mekong-influenced and nutrient depleted offshore waters, where it co-occurred with Rhizosolenia sp. Both species were directly associated with the much higher primary production (PP) and N2 fixation rates that were quantified in earlier studies, as well as with much higher diversities at these offshore sites. Along the coast, the correlation between Rhizosolenia sp. and PP rates was less clear and the factors regulating the biomass of Rhizosolenia sp. in the upwelling waters are discussed. The very low silicate concentrations in the source water mass for upwelling and the offshore deflection of the Mekong river plume likely triggered the observed ecological differences in the microplankton communities off Viet Nam in the normal upwelling season compared to the post ENSO conditions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Gusevetal2017,
title = {Silica-scaled chrysophytes from Cat Tien National Park (Dong Nai Province, Viet Nam)},
author = {Evgeniy S Gusev, Hai Doan-Nhu, Lam Nguyen-Ngoc},
url = {http://www.ingentaconnect.com/content/schweiz/novh/pre-prints/content-nova_hedwigia_000_0_0_0000_0000_gusev_0416_prepub},
doi = {https://doi.org/10.1127/nova_hedwigia/2017/0416},
issn = {0029-5035},
year = {2017},
date = {2017-04-24},
journal = {Nova Hedwigia},
abstract = {The present paper focuses on flora of silica-scaled chrysophytes from Cat Tien National Park (Vietnam). The use of electron microscopy technique allowed for the discovery of 42 taxa found in reservoirs, lakes, bogs and temporary ponds in the forest. Thirty-six taxa belong to the genus Mallomonas, among them 29 species and seven infraspecific taxa. The others are species of genera Synura (4), Spiniferomonas (1) and Chrysosphaerella (1). Nineteen taxa are reported for the first time in Vietnam. },
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{NguyenXV.2017,
title = {Different organs of Enhalus acoroides (Hydrocharitaceae) can serve as specific bioindicators for sediment contaminated with different heavy metals},
author = {X.-V. Nguyen and H. Tran Thi Minh and J. Papenbrock},
url = {https://www.sciencedirect.com/science/article/pii/S0254629917305975},
doi = {https://doi.org/10.1016/j.sajb.2017.09.018},
issn = {0254-6299},
year = {2017},
date = {2017-04-10},
journal = {South African Journal of Botany},
volume = {113},
pages = {389-395},
abstract = {The tropical seagrass Enhalus acoroides is considered as a potential bioindicator for heavy metals. To date, studies on the accumulation of heavy metals in each specific seagrass organ have been limited. In this study, surface sediment and E. acoroides samples collected at six distinct beds from the coast of Khanh Hoa province, Vietnam, were evaluated for their heavy metal concentrations (Cd, Cu, Pb and Zn) to determine which organs of E. acoroides could be used as bioindicators for heavy metals. The metal concentrations in both the sediment and the seagrass organs were measured using inductively coupled plasma mass spectrometry (ICP-MS). Bio-concentration factor (BCF) and Metal pollution index (MPI) were determined on the seagrass organs, and Pearson's correlation and ANOVA were used for statistical analysis. The results showed that the highest BCF values of Cd and Zn were found in leaves, the highest BCF value of Cu was found in the rhizomes and the highest BCF value of Pb was found in the roots. Generally, MPI was lower in the sediment than in seagrass organs at the same locations. For Cd, Pearson's correlation showed that a significant positive correlation was only observed between sediment and leaves with respect to BCF. A significant positive correlation of BCF for Cu was observed between sediment and rhizome while significant positive correlations of BCF for Cu, Pb and Zn were observed between sediment and roots. Based on the results, it can be concluded that E. acoroides leaves should be used as a bioindicator for Cd and Zn, rhizomes for Cu, and roots for the three metals Cu, Pb and Zn.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Luom2017,
title = {Species diversity of Protoperidinium sect. Oceanica (Dinophyceae, Peridiniales) in Vietnamese waters, with description of the new species P. larsenii sp. nov.},
author = {Phan-Tan Luom and Nguyen-Ngoc Lam and Doan-Nhu Hai and Raine Robin and Larsen Jacob},
url = {http://onlinelibrary.wiley.com/doi/10.1111/njb.01230/abstract},
doi = {10.1111/njb.01230},
issn = {1756-1051},
year = {2017},
date = {2017-03-23},
journal = {Nordic Journal of Botany},
volume = {35},
number = {2},
pages = {129-146},
abstract = {Protoperidinium is one of the most important genera of armoured marine dinoflagellates. Despite its importance and many previous studies on this genus, the descriptions of many species are incomplete, their diagnostic features not properly described and illustrated and most species have been illustrated, if at all, only by line drawings and not documented by micro-photography. As here described, examinations of about 600 phytoplankton net samples collected from Viet Nam and adjacent coastal waters over the last decade revealed about 100 species of Protoperidinium, ten of which belong to the section Oceanica and this paper is the first in a series describing all species of Protoperidinium found in Vietnamese waters. The Oceanica species are described and illustrated by light, and for some also by scanning electron, microscopy. The species are: Protoperidinium claudicans, P. depressum, P. depressum var. claudicanoides, P. larsenii sp. nov., P. murrayi, P. oceanicum f. bisintercalares comb. nov., P. oceanicum var. tenellum comb. nov., P. paraoblongum, P. venustum and P. venustum var. facetum. Protoperidinium larsenii L. Phan Tan, L. Nguyen-Ngoc, and H. Doan-Nhu is new to science. It was found in the coastal waters of Rach Gia in Kien Giang Province, western part of south Viet Nam (Gulf of Thailand). The new species is characterized by its broad shape, conical epitheca and short, non-divergent antapical horns; the 1’ plate is asymmetrical, there are 3 anterior intercalary plates, the 2a plate is quadrangular; and the sutures connecting the 6” plate with the 4’ plate and the 7” form an almost straight line. By these features P. larsenii differs from the similar species P. claudicans and P. latidorsale. Protoperidinium oceanicum (Vanh ffen) Balech () f. bisintercalares (Graham) H. Doan-Nhu, L. Phan-Tan, L. Nguyen-Ngoc, and J. Larsen comb. nov. and Protoperidinium oceanicum (Vanh ffen) Balech () var. tenellum (Graham) L. Nguyen-Ngoc, L. Phan-Tan, H. Doan-Nhu and J. Larsen comb. nov. are two new combinations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Pisapia2017,
title = {Toxicity screening of 13 Gambierdiscus strains using neuro-2a and erythrocyte lysis bioassays},
author = {Pisapia F. and
Holland W.C. and
Hardison D.R. and
Litaker R.W. and
Fraga S. and
Nishimura T. and
Adachi M. and
Nguyen-Ngoc L. and
Séchet V. and
Amzil Z. and
Herrenknecht C. and
Hess P. and
},
url = {https://www.sciencedirect.com/science/article/pii/S1568988316303407},
doi = {https://doi.org/10.1016/j.hal.2017.02.005},
issn = {1568-9883},
year = {2017},
date = {2017-03-09},
journal = {Harmful Algae},
volume = {63},
pages = {173-183},
abstract = {Species in the epi-benthic dinoflagellate genus Gambierdiscus produce ciguatoxins (CTXs) and maitotoxins (MTXs), which are among the most potent marine toxins known. Consumption of fish contaminated with sufficient quantities of CTXs causes Ciguatera Fish Poisoning (CFP), the largest cause of non-bacterial food poisoning worldwide. Maitotoxins, which can be found in the digestive system of fish, could also contribute to CFP if such tissues are consumed. Recently, an increasing number of Gambierdiscus species have been identified; yet, little is known about the variation in toxicity among Gambierdiscus strains or species.

This study is the first assessment of relative CTX- and MTX-toxicity of Gambierdiscus species from areas as widespread as the North-Eastern Atlantic Ocean, Pacific Ocean and the Mediterranean Sea. A total of 13 strains were screened: (i) seven Pacific strains of G. australes, G. balechii, G. caribaeus, G. carpenteri, G. pacificus, G. scabrosus and one strain of an undetermined species (Gambierdiscus sp. Viet Nam), (ii) five strains from the North-Eastern Atlantic Ocean (two G. australes, a single G. excentricus and two G. silvae strains), and (iii) one G. carolinianus strain from the Mediterranean Sea. Cell pellets of Gambierdiscus were extracted with methanol and the crude extracts partitioned into a CTX-containing dichloromethane fraction and a MTX-containing aqueous methanol fraction. CTX-toxicity was estimated using the neuro-2a cytoxicity assay, and MTX-toxicity via a human erythrocyte lysis assay.

Different species were grouped into different ratios of CTX- and MTX-toxicity, however, the ratio was not related to the geographical origin of species (Atlantic, Mediterranean, Pacific). All strains showed MTX-toxicity, ranging from 1.5 to 86 pg MTX equivalents (eq) cell−1. All but one of the strains showed relatively low CTX-toxicity ranging from 0.6 to 50 fg CTX3C eq cell−1. The exception was the highly toxic G. excentricus strain from the Canary Islands, which produced 1426 fg CTX3C eq cell−1. As was true for CTX, the highest MTX-toxicity was also found in G. excentricus. Thus, the present study confirmed that at least one species from the Atlantic Ocean demonstrates similar toxicity as the most toxic strains from the Pacific, even if the metabolites in fish have so far been shown to be more toxic in the Pacific Ocean.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Admid2017,
title = {Additive effects of the herbicide glyphosate and elevated temperature on the branched coral Acropora formosa in Nha Trang, Vietnam},
author = {Amid C and M Olstedt and J S Gunnarsson and H Le Lan and H Tran Thi Minh and P . Van den Brink and M Hellström and M Tedengren},
url = {https://link.springer.com/article/10.1007/s11356-016-8320-7},
doi = {DOI 10.1007/s11356-016-8320-7},
issn = { 0944-1344},
year = {2017},
date = {2017-01-22},
journal = {Environmental Science and Pollution Research},
pages = {1-13},
abstract = {The combined effects of the herbicide glyphosate and elevated temperature were studied on the tropical staghorn coral Acropora formosa, in Nha Trang bay, Vietnam. The corals were collected from two different reefs, one close to a polluted fish farm and one in a marine-protected area (MPA). In the laboratory, branches of the corals were exposed to the herbicide glyphosate at ambient (28 °C) and at 3 °C elevated water temperatures (31 °C). Effects of herbicide and elevated temperature were studied on coral bleaching using photography and digital image analysis (new colorimetric method developed here based on grayscale), chlorophyll a analysis, and symbiotic dinoflagellate (Symbiodinium, referred to as zooxanthellae) counts. All corals from the MPA started to bleach in the laboratory before they were exposed to the treatments, indicating that they were very sensitive, as opposed to the corals collected from the more polluted site, which were more tolerant and showed no bleaching response to temperature increase or herbicide alone. However, the combined exposure to the stressors resulted in significant loss of color, proportional to loss in chlorophyll a and zooxanthellae. The difference in sensitivity of the corals collected from the polluted site versus the MPA site could be explained by different symbiont types: the resilient type C3u and the stress-sensitive types C21 and C23, respectively. The additive effect of elevated temperatures and herbicides adds further weight to the notion that the bleaching of coral reefs is accelerated in the presence of multiple stressors. These results suggest that the corals in Nha Trang bay have adapted to the ongoing pollution to become more tolerant to anthropogenic stressors, and that multiple stressors hamper this resilience. The loss of color and decrease of chlorophyll a suggest that bleaching is related to concentration of chloro-pigments. The colorimetric method could be further fine-tuned and used as a precise, non-intrusive tool for monitoring coral bleaching in situ.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Quangetal2017,
title = {Effects of variations of environmental factors and algal bloom on fish larvae in Southern central Vietnam},
author = {Vo Van Quang, Doan Nhu Hai, Nguyen Ngoc Lam},
url = {http://vjs.ac.vn/index.php/vjbio/article/view/8888},
doi = {http://dx.doi.org/10.15625/0866-7160/v38n4.8888},
issn = {0866-7160},
year = {2016},
date = {2016-12-30},
journal = {Tap chi Sinh hoc},
volume = {38},
number = {4},
pages = {458-466},
abstract = {A multivariate analysis was conducted to assess the impact of variations of environmental factors such as temperature, salinity, dissolved oxygen (DO), total suspended solid (TSS), nitrite (NO2-N), nitrate (NO3-N), ammonium (NH3,4-N), phosphate (PO4-P), and silicate (SiO3-Si) concentrations, chlorophyll (chlor) and algal bloom on natural fish larvae in Binh Thuan waters, Vietnam. Temporal and spatial variations of environmental factors were correlated with the abundance and diversity of fish larvae. The abundance and diversity of fish larvae decreased at the sites of the algal blooms. Five environmental factors - temperature, salinity, nitrite, phosphate and silicates - showed a statistically significant impact on the fish larvae, but other factors showed weaker and statistically not significant effects. In the months of algal blooms, phosphate, silicate, nitrite, nitrate, ammonium and salinity influenced blooms substantially, while the effects of temperature were mainly confined to the months without blooms of algae. Algal blooms were lethal to fish larvae and juveniles leading to a decline in their abundance and diversity. This will affect and restrict the process of recruitment of fish stocks in the region.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Luom2016,
title = {Species diversity of sections conica and tabulata in the genus Protoperidinium (Dinophyceae) from tropical waters of the South China Sea},
author = {Phan-Tan Luom and Nguyen-Ngoc Lam and Doan-Nhu Hai},
url = {http://www.ingentaconnect.com/content/schweiz/novh/2016/00000103/F0020003/art00015},
doi = {doi:10.1127/nova_hedwigia/2016/0369},
issn = {0029-5035},
year = {2016},
date = {2016-11-23},
journal = {Nova Hedwigia},
volume = {103},
number = {3-4},
pages = {515-545},
abstract = {About 600 phytoplankton samples were collected from Vietnamese coastal waters including around the Spratly Islands. Cell morphology and shapes of apical plates (1'), intercalary plates (2a), and other plate patterns were squashed and photographed to support species identification. Fourteen species of the sections conica and tabulata in the genus Protoperidinium were described, among them 8 species including P. decollatum, P. laciniosum, P. rhombiforme, P. symmetricum and P. tohrui (conica section); these are the first reports of P. balechii, P. nudum, P. punctulatum (tabulata section) among the tropical phytoplankton flora of the South China Sea.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Doan-Nhuetal2016,
title = {ENSO and anthropogenic impacts on phytoplankton diversity in tropical coastal waters},
author = {H. Doan-Nhu, L. Nguyen-Ngoc, Nguyen C.T.},
url = {http://www.sciencedirect.com/science/article/pii/S007966111500213X},
doi = {https://doi.org/10.1016/j.pocean.2015.10.004},
year = {2016},
date = {2016-01-01},
journal = {Progress in Oceanography},
volume = {140},
pages = {1-13},
abstract = {16-year phytoplankton data were analysed to assess ENSO and anthropogenic impacts on biodiversity and community structure at 3 locations (Nha-Trang and Phan-Thiet Bays and near Phu-Qui Island) in South Centre Viet Nam to understand (1) the primary scales of change in phytoplankton community structure, and traditional and taxonomic diversity indices; (2) the significance of environmental changes and/or climate variability on phytoplankton diversity; and (3) the usefulness of these long-term data for analysing future impacts of anthropogenic and climate changes. Traditional and taxonomic diversity indices were compared and tested in linkage with environmental conditions and ENSO. Nutrient data indicated stronger environmental impacts in Phan-Thiet Bay, milder in Nha-Trang Bay and less noticeable near Phu-Qui Island. There were measurable impacts of both anthropogenic and ENSO on phytoplankton at different locations in various parameters, e.g. species number, diversity and community structures. The lowest diversity was recorded in the most anthropogenically impacted site, Phan-Thiet Bay. Although a stronger impact on phytoplankton was recorded in ENSO year in Phan Thiet Bay, quantitative separation between anthropogenic and ENSO impacts using phytoplankton biodiversity indices was impossible. In the waters with less anthropogenic impacts, ENSO effects on taxonomic diversity was better indicated by negative phytoplankton responses to the ONI index (Nha-Trang Bay) and recovery of phytoplankton after the ENSO events (near Phu-Qui Island). Among the diversity indices, the taxonomic diversity indices (e.g. Δ+ and Λ+) better described impacts of ENSO than the traditional ones.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Trinh2014,
title = {Seasonal and spatial distribution of mesozooplankton in a tropical estuary, Nha Phu, South Central Viet Nam},
author = {Truong Si-Hai Trinh and Nguyen Cho and Nguyen-Ngoc Lam and Jensen K. Thomas},
url = {http://dx.doi.org/10.2478/s11756-013-0289-9},
doi = {10.2478/s11756-013-0289-9},
isbn = {1336-9563},
year = {2014},
date = {2014-04-01},
journal = {Biologia},
volume = {69},
number = {1},
pages = {80--91},
abstract = {This study provides a description of mesozooplankton (holo- and meroplankton) abundance, biomass and diversity patterns inside and outside a tropical estuary (Nha Phu Estuary, Khanh Hoa, Viet Nam). In total 185 zooplankton species have been recorded during the study period (2009--2010), copepods contribute with the largest share of species (more than 100), Tunicata with 20, Cnidaria with 17 and Chaetognatha with 9 species. At the most species rich site the number of zooplankton species varies between 55 and 123. The number of species and the annual variation in numbers declines towards the head of the estuary (14--37 species). In contrast, the highest numbers of individuals occur in the inner part of NPE. Calanoids that are the most abundant group of the copepods occur in densities up to 28.2 ind. L−1 (Aug. 9). At `Outer NPE' and `Outside NPE' the maximum density of calanoids is 5.8 and 10.7 ind. L−1, respectively. The declining diversity of zooplankton towards the head of the estuary is also supported by various indices (Shannon's index, Margalef's index). A cluster analysis on similarity of species supports a clustering of the inner NPE sites vs the other sites. There is a general separation between the dominant copepod species in the inner (Bestiola sp., Acartia pacifica, Pseudodiaptomus incisus) and outer (Paracalanus gracilis, Acrocalanus gibber, Subeucalanus subcrassus, Oithona rigida, Corycaeus andrewsi, Oithona plumifera) part of the estuary though a few species are common in both areas (Paracalanus crassirostris and Euterpina acutifrons). The zooplankton community at the inner NPE is subjected to more variable hydrographic conditions (salinity in particular) than the communities at the other sites where more stable conditions prevail. A short residence time in the inner part of the estuary due to the tide is supposed to impede a strong horizontal structuring of the zooplankton community.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}