Observations on the Bottom Fauna Near Plymouth During a Dinoflagellate Bloom in 1982

1984 ◽  
Vol 64 (3) ◽  
pp. 732-733
Author(s):  
G. R. Forster
Keyword(s):  
Bottom Fauna ◽  
Aberrant Behaviour ◽  
Inshore Waters ◽  
Calm Weather ◽  
Gyrodinium Aureolum ◽  
Dinoflagellate Bloom ◽  
Damaging Effects

In July and August 1982 a bloom of Gyrodinium aureolum spread from its normal mid-Channel position to inshore waters off Plymouth. During some particularly calm weather in July and early August the presence of this bloom coincided with aberrant behaviour and some mortality of the bottom fauna. From previous observations in 1978 (Forster, 1979) it seemed probable thatthese damaging effects were related to the presence of the bloom. As soon as possible diving was carried out on positions where mortalities of affected species had been reported, or where previous observations had been made so that any changes could be easily recognized.

The impact of a Gyrodinium aureolum bloom on inshore young fish populations

1987 ◽  
Vol 67 (2) ◽  
pp. 293-297 ◽  
Author(s):  
G. W. Potts ◽  
J. M. Edwards
Keyword(s):  
Coastal Waters ◽  
Fish Populations ◽  
Young Fish ◽  
Local Fauna ◽  
Brown Colour ◽  
Stable Conditions ◽  
Inshore Waters ◽  
Gyrodinium Aureolum ◽  
The Impact

Blooms of the dinoflagellate, Gyrodinium aureolum have been recorded on the coasts of Europe and are fully reviewed by Tangen (1977) and Boalch (1979). The significance of these blooms is considerable, and with the increase in the eutrophication of inshore waters they are now an important factor influencing the ecology of coastal waters (Boalch, 1984). Their numbers increase to concentrations in excess of five million cells per litre during warm, stable conditions resulting in the waters becoming a greenish-brown colour, ‘slimy’ and with a characteristic smell (Boalch, 1979; Jenkinson, 1986). At these concentrations there are reports that local fauna may be adversely affected and certain species will die.

Some effects of a dinoflagellate bloom (Gyrodinium aureolum) on the mussel, Mytilus edulis

1979 ◽  
Vol 59 (2) ◽  
pp. 522-524 ◽  
Author(s):  
J. Widdows ◽  
M. N. Moore ◽  
D. M. Lowe ◽  
P. N. Salkeld
Keyword(s):  
Adverse Effects ◽  
Mytilus Edulis ◽  
Red Tide ◽  
Oxygen Depletion ◽  
Marine Organisms ◽  
Invertebrate Species ◽  
Northern European ◽  
Mass Occurrence ◽  
Gyrodinium Aureolum ◽  
Dinoflagellate Bloom

There have been several reports in recent years of the mass occurrence or blooms of the dinoflagellate Gyrodinium aureolum Hulburt in northern European Waters (Ballantine & Smith, 1973; Helm et al. 1974; Pingree et al. 1975; Pingree, Holligan & Head, 1977; Tangen, 1977). Gyrodinium aureolum is probably one of the most common ‘red-tide’ dinoflagellate species in these waters and some of the blooms of G. aureolum (ranging from 100 to 20000 cells ml-1) have been followed by the mass mortality of various fish and invertebrate species (Tangen, 1977). It has been suggested that the adverse effects of G. aureolum on marine organisms are caused by (a) the production of toxins and/or (b) the oxygen depletion during darkness due to dinoflagellate respiration and decomposition of cells.

The Effect of Exogenous Fluoride on the Calcium PUMP, Ciliary Activity, and Shell Formation of the Fingernail Clam, Musculium Transversum

1982 ◽  
Vol 40 ◽  
pp. 58-59
Author(s):  
Anthony Paparo ◽  
Judy A. Murphy ◽  
Robert Dean
Keyword(s):  
Mississippi River ◽  
Calcium Pump ◽  
Bottom Fauna ◽  
Ciliary Activity ◽  
Shell Formation ◽  
Middle Reach ◽  
Shell Matrix ◽  
Fingernail Clams ◽  
Ca Carbonate

In the mid-1950's, fingernail clams virtually disappeared from a 100-mile section of the IL River, a tributary of the Mississippi River, due to unknown causes. A survey of the bottom fauna of the IL River in 1979, revealed that the clams were still absent from the middle reach of the River, where they had been abundant prior to the die-off in the 1950's. Some factor(s) in the River currently prevent the clams from recolonizing areas where they were formerly abundant. Recently, clams exposed to fluoride developed abnormal grooves in the shell matrix. Fluorides are known to be protoplasmic poisons removing essential body calcium by precipitation. Since the shell consists primarily of Ca carbonate, this investigation examines the possible role of fluoride on shell formation and the poisoning of the Ca pump which can directly inhibit lateral ciliary activity on the gill.

BIO-OCEANOGRAPHER, ZOOLOGIST LEV IVANOVICH MOSKALEV (04.01.1935–04.12.2020)

2020 ◽  
Vol 48 (4) ◽  
pp. 168-171
Author(s):  
E. M. Krylova ◽  
A. N. Mironov ◽  
A. V. Gebruk
Keyword(s):  
Deep Sea ◽  
Bottom Fauna ◽  
Ocean Bottom ◽  
Scientific Career ◽  
Shirshov Institute ◽  
Popular Book ◽  
Scientific Papers

The article is dedicated to the memory of L.I. Moskalev – renowned bio-oceanographer, zoologist who spent his entire scientific career at the Laboratory of Ocean Bottom Fauna. L.I. Moskalev participated in more than 30 deep-sea voyages, spent 200 hours diving in manned submersibles “Pisces” and “Mir”, published about 100 scientific papers and a popular book «Masters of the Deep» (2005). Colleagues will remember Lev Moskalev – an extraordinary and deep person and a true patriot of the Laboratory and P.P. Shirshov Institute of Oceanology

The ecological state of the Elefsis Bay prior to the operation of the athens sea outfall

1994 ◽  
Vol 30 (10) ◽  
pp. 161-171 ◽  
Author(s):  
A. J. Theodorou
Keyword(s):  
River Discharge ◽  
Thermal Stratification ◽  
Lower Layer ◽  
Ecological State ◽  
Annual Cycles ◽  
Untreated Wastewater ◽  
Resistant Species ◽  
Acartia Clausi ◽  
Gyrodinium Aureolum ◽  
Agricultural Areas

Nutrient pollution in Elefsis Bay arises mainly from the disposal of Athens untreated wastewater at the eastern entrance of the Bay. The absence of river discharge, lack of cultivated agricultural areas providing runoff and the Bay's limited circulation provide the conditions for the Bay's eutrophication by the discharge of untreated wastewater. In the spring of 1993 this discharge was replaced by a new deep outfall system. To monitor any future changes an assessment of the present ecological state of the Bay is required. Analysis of appropriate data showed that Elefsis Bay accumulates nutrients. In summer a strong thermal stratification causes anoxic conditions to occur in the lower layer. The ecosystem exhibits reduced species diversity and strong oscillations of plankton annual cycles. Flagellates (Cryptomonas sp.) dominate the phytoplankton, followed by dinoflagellates (Gyrodinium aureolum, Prorocentum dentatum) and only in the spring diatoms (Nitzschia) predominate. The zooplankton was dominated by copepods (Acartia clausi) and cladoceran (Podon polyphemoides). Macrobenthos consists of a small number of pollution-resistant species of Polychaeta (Capitela capitata), whilst in summer only one species of Molluscs (Corbula gibba) survives.

In vitro Cytotoxicity and Genotoxicity Analysis of Ten Tannery Chemicals Using SOS/umu Tests and High-content In vitro Micronucleus Tests

2018 ◽  
Vol 21 (4) ◽  
pp. 262-270 ◽  
Author(s):  
Zehao Huang ◽  
Na Li ◽  
Kaifeng Rao ◽  
Cuiting Liu ◽  
Zijian Wang ◽  
...  
Keyword(s):  
Micronucleus Test ◽  
A549 Cells ◽  
Quantitative Structure Activity Relationship ◽  
In Vitro Cytotoxicity ◽  
Cytotoxic Effects ◽  
Qsar Analysis ◽  
Cell Assays ◽  
Micronucleus Tests ◽  
Damaging Effects

Background: More than 2,000 chemicals have been used in the tannery industry. Although some tannery chemicals have been reported to have harmful effects on both human health and the environment, only a few have been subjected to genotoxicity and cytotoxicity evaluations. Objective: This study focused on cytotoxicity and genotoxicity of ten tannery chemicals widely used in China. Materials and Methods: DNA-damaging effects were measured using the SOS/umu test with Salmonella typhimurium TA1535/pSK1002. Chromosome-damaging and cytotoxic effects were determined with the high-content in vitro Micronucleus test (MN test) using the human-derived cell lines MGC-803 and A549. Conclusion: The cytotoxicity of the ten tannery chemicals differed somewhat between the two cell assays, with A549 cells being more sensitive than MGC-803 cells. None of the chemicals induced DNA damage before metabolism, but one was found to have DNA-damaging effects on metabolism. Four of the chemicals, DY64, SB1, DB71 and RR120, were found to have chromosome-damaging effects. A Quantitative Structure-Activity Relationship (QSAR) analysis indicated that one structural feature favouring chemical genotoxicity, Hacceptor-path3-Hacceptor, may contribute to the chromosome-damaging effects of the four MN-test-positive chemicals.

scholarly journals Modal coupling and crosstalk due to turbulence and divergence on free space THz links using multiple orbital angular momentum beams

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhe Zhao ◽  
Runzhou Zhang ◽  
Hao Song ◽  
Kai Pang ◽  
Ahmed Almaiman ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Atmospheric Turbulence ◽  
Channel Capacity ◽  
Orbital Angular Momentum ◽  
Beam Waist ◽  
Modal Coupling ◽  
Divergence Effect ◽  
Power Leakage ◽  
Calm Weather ◽  
Bad Weather

AbstractOrbital-angular-momentum (OAM) multiplexing has been utilized to increase the channel capacity in both millimeter-wave and optical domains. Terahertz (THz) wireless communication is attracting increasing attention due to its broadband spectral resources. Thus, it might be valuable to explore the system performance of THz OAM links to further increase the channel capacity. In this paper, we study through simulations the fundamental system-degrading effects when using multiple OAM beams in THz communications links under atmospheric turbulence. We simulate and analyze the effects of divergence, turbulence, limited-size aperture, and misalignment on the signal power and crosstalk of THz OAM links. We find through simulations that the system-degrading effects are different in two scenarios with atmosphere turbulence: (a) when we consider the same strength of phasefront distortion, faster divergence (i.e., lower frequency; smaller beam waist) leads to higher power leakage from the transmitted mode to neighbouring modes; and (b) however, when we consider the same atmospheric turbulence, the divergence effect tends to affect the power leakage much less, and the power leakage increases as the frequency, beam waist, or OAM order increases. Simulation results show that: (i) the crosstalk to the neighbouring mode remains < − 15 dB for a 1-km link under calm weather, when we transmit OAM + 4 at 0.5 THz with a beam waist of 1 m; (ii) for the 3-OAM-multiplexed THz links, the signal-to-interference ratio (SIR) increases by ~ 5–7 dB if the mode spacing increases by 1, and SIR decreases with the multiplexed mode number; and (iii) limited aperture size and misalignment lead to power leakage to other modes under calm weather, while it tends to be unobtrusive under bad weather.

Haul-out behaviour and densities of ringed seals (Phoca hispida) in the Barrow Strait area, N.W.T.

1979 ◽  
Vol 57 (10) ◽  
pp. 1985-1997 ◽  
Author(s):  
Kerwin J. Finley
Keyword(s):  
Wind Speed ◽  
Early Morning ◽  
Maximum Density ◽  
Stable Population ◽  
The Sun ◽  
High Wind ◽  
Phoca Hispida ◽  
High Wind Speed ◽  
Ringed Seals ◽  
Calm Weather

Numbers of ringed seals hauled out on the ice began to increase in early June. Numbers on the ice were highest from 0900 to 1500 hours Central Standard Time and lowest (average 40–50% of peak) in early morning. Seals commonly remained on the ice for several hours, and occasionally (during calm weather) for > 48 h. Numbers on the ice were reduced on windy days and possibly also on unusually warm, bright and calm days. Seals tended to face away from the wind (particularly with high wind speed) and oriented broadside to the sun. Seals usually occurred singly (60–70% of all groups) at their holes.Numbers of seals hauled out at Freemans Cove remained relatively constant during June (maximum density 4.86/km2), whereas at Aston Bay numbers increased dramatically to a maximum density of 10.44/km2 in late June. The increase was thought to be due to an influx of seals abandoning unstable ice. The density of seal holes at Freemans Cove (5.92/km2) was much higher than at Aston Bay (2.73/km2). The ratio of holes to the maximum numbers of seals (1.12:1) at Freemans Cove represents a first estimate of this relationship in an apparently stable population.

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