The Northern Muddy Intertidal: Seasonal Factors Controlling Erosion and Deposition — A Review

1983 ◽  
Vol 40 (S1) ◽  
pp. s143-s159 ◽  
Author(s):  
Franz E. Anderson
Keyword(s):  
Intertidal Zone ◽  
Higher Plants ◽  
Sediment Resuspension ◽  
Early Spring ◽  
Benthic Diatoms ◽  
Biological Processes ◽  
Algal Mats ◽  
Animal Activity ◽  
Break Up ◽  
Significant Sediment

This review summarizes the seasonal physical and biological processes which take place on and in the muddy intertidal zone during the year and affect the erosion or deposition of sediment. The main physical processes that are considered are the effects of ice, waves, sediment dewatering, rain, and mud and water temperatures. The biological processes include the growth of benthic diatoms, algal mats, and higher plants as well as the effects of bioturbation, pellet formation, biodeposition, and changes in the intertidal microrelief.In the early spring in northern temperate estuaries, ice break-up is the most significant factor affecting muddy intertidal sedimentation. The ice-roughened intertidal has not yet been affected significantly by either plant or animal activity, and is particularly susceptible to sediment resuspension by waves. During the summer, organic processes dominate the intertidal as organisms feed on, pelletize, and bioturbate the sediments. Plant growth, especially benthic diatoms and algal mats, may stabilize the sediment. The few storms during this season combined with lower rainfall insure that the muddy intertidal only rarely undergoes erosion. In fall, seasonal storms increase while both plant and animal activity begin to slow down. Lower rates of bioturbation make the muddy intertidal more resistant to erosion, but the intensity of the fall storms, and higher rainfall, cause significant sediment scouring. With the onset of winter, ice forms over and on the muddy intertidal, reducing resuspension and erosion. However, significant sediment erosion and transportation occurs during winter thaws, when temporary ice break up occurs. But the effect of ice "armoring" all but eliminates sediment resuspension by waves over the muddy intertidal for most of the coldest winter months.Key words: intertidal zone, erosion, deposition

Sexual reproduction and larval development of Rhaphidrilus nemasoma Monticelli, 1910 (Polychaeta: Ctenodrilidae)

1989 ◽  
Vol 67 (10) ◽  
pp. 2345-2351 ◽  
Author(s):  
Pei-Yuan Qian ◽  
Fu-Shiang Chia
Keyword(s):  
British Columbia ◽  
Sexual Reproduction ◽  
Larval Development ◽  
Intertidal Zone ◽  
Vancouver Island ◽  
Benthic Diatoms ◽  
Egg Mass ◽  
High Fecundity ◽  
Egg Masses ◽  
Trochophore Stage

Adult specimens and egg masses of Rhaphidrilus nemasoma were collected in the low intertidal zone from Execution Rock, Bamfield, Vancouver Island, British Columbia, in June of 1986. Each egg mass contained about 1000 eggs. The eggs were green, spherical, and measured 125–145 μm in diameter. Larval development took place within the egg mass until the three-or four-setiger stage, at which time they emerged from the egg mass. Newly emerged larvae crawled on the bottom of the culture beakers and fed on benthic diatoms. Metamorphosis took place soon after emergence and was completed within 2 weeks. Paddle cilia were observed at the early trochophore stage, and their possible function, and the extremely high fecundity of this polychaete, are discussed.

Identification of MdDof genes in apple and analysis of their response to biotic or abiotic stress

2018 ◽  
Vol 45 (5) ◽  
pp. 528 ◽  
Author(s):  
Qing Yang ◽  
Qiuju Chen ◽  
Yuandi Zhu ◽  
Tianzhong Li
Keyword(s):  
Abiotic Stress ◽  
Zinc Finger ◽  
Flower Development ◽  
Higher Plants ◽  
Expression Patterns ◽  
Fruit Trees ◽  
Biological Processes ◽  
Protein Motifs ◽  
Gene Structures ◽  
Dof Transcription Factors

As a classic plant-specific transcription factor family – the Dof domain proteins – are involved in a variety of biological processes in organisms ranging from unicellular Chlamydomonas to higher plants. However, there are limited reports of MdDof (Malus domestica Borkh. DNA-binding One Zinc Finger) domain proteins in fruit trees, especially in apple. In this study we identified 54 putative Dof transcription factors in the apple genome. We analysed the gene structures, protein motifs, and chromosome locations of each of the MdDof genes. Next, we characterised all 54 MdDofs their expression patterns under different abiotic and biotic stress conditions. It was found that MdDof6,26 not only played an important role in the biotic/abiotic stress but may also be involved in many molecular functions. Further, both in flower development and pollen tube growth it was found that the relative expression of MdDof24 increased rapidly, also with gene ontology analysis it was indicated that MdDof24 was involved in the chemical reaction and flower development pathways. Taken together, our results provide useful clues as to the function of MdDof genes in apple and serve as a reference for studies of Dof zinc finger genes in other plants.

scholarly journals Experimental determination of the flood wave transformation and the sediment resuspension in a small regulated stream in an agricultural catchment

2017 ◽  
Vol 21 (11) ◽  
pp. 5681-5691 ◽  
Author(s):  
David Zumr ◽  
Tomáš Dostál ◽  
Jan Devátý ◽  
Petr Valenta ◽  
Pavel Rosendorf ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Initial Conditions ◽  
Sediment Resuspension ◽  
Early Spring ◽  
Wave Transformation ◽  
Flood Wave ◽  
Water Saturated ◽  
Artificial Flood ◽  
Long Channel ◽  
Flood Waves

Abstract. This paper presents the methodology used for artificial flood experiments conducted in a small artificial, trained (regulated) channel on the Nučice experimental agricultural catchment (0.5 km2), central Czech Republic, and the results of the experiments. The aim was to monitor the transformation of the flood wave and the sediment transport within the channel. Two series of experiments were carried out in contrasting initial conditions: (a) in September, when the stream banks were dry, the baseflow was negligible, and the channel was fully overgrown with vegetation; and (b) in March, when the stream banks were almost water saturated, the baseflow was above the annual average, and there was no vegetation present. Within each campaign, three successive flood waves, each with an approximate volume of 17 m3 and peak flow of ca. 40 L s−1, were pumped into the upper part of the catchment drainage channel. The transformation of the flood wave and the sediment transport regime within an approximately 400 m long channel section were monitored by measuring the discharge, the turbidity, and the electrical conductivity in three profiles along the stream. On the basis of the results, it was concluded that there is a considerable amount of deposited sediment, even in the well-trained and straight channel that can be re-mobilized by small floods. Part of the recorded sediment therefore originates from the particles deposited during previous soil erosion events. The flood waves initiated in dissimilar instream conditions progressed differently – we show that the saturation of the channel banks, the stream vegetation and the actual baseflow had a strong influence on the flood transformation and the sediment regime in the channel. The sediment moves quickly in winter and early spring, but in the later part of the year the channel serves as a sediment trap and the resuspension is slower, if dense vegetation is present.

Impacts of Flounder Trawls on the Intertidal Habitat and Community of the Minas Basin, Bay of Fundy

1994 ◽  
Vol 51 (3) ◽  
pp. 650-661 ◽  
Author(s):  
Michael Brylinsky ◽  
Jamie Gibson ◽  
Donald C. Gordon Jr.
Keyword(s):  
Intertidal Zone ◽  
Benthic Diatoms ◽  
Bay Of Fundy ◽  
Intertidal Habitat ◽  
Intertidal Sediments ◽  
Surficial Sediments ◽  
Biological Impacts

Four experimental trawls were made at highwater over the intertidal zone of the Minas Basin and the effects assessed when the tide was out to determine the physical and biological impacts of groundfish trawling on the benthos. The trawl doors made furrows 30–85 cm wide and up to 5 cm deep. The rollers compressed surficial sediments but did not scour a depression. The bridle caused no obvious disturbance. Door furrows and roller marks remained visible for 2–7 mo. No significant impacts were observed on either benthic diatoms or macrobenthos. The macrobenthos was dominated by polychaetes, some of which may have the ability to take evasive action as a trawl approaches. There were few molluscs, crustaceans, or echinoderms present; these taxa have been shown to be more susceptible to trawling damage in studies done elsewhere. Nematode numbers were initially depressed in the door furrows but did recover with time. It is not known whether nematodes were killed or displaced but the latter is thought more likely. Overall, the impacts in this particular environment are judged to be minor, especially since the intertidal sediments of the Minas Basin are already exposed to similar natural stresses imposed by storms and winter ice.

scholarly journals Identification and Functional Prediction of Drought-Responsive Long Non-Coding RNA in Tomato

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 629 ◽  
Author(s):  
Seung Hee Eom ◽  
Hee Ju Lee ◽  
Jin Hyoung Lee ◽  
Seung Hwan Wi ◽  
Sung Kyeom Kim ◽  
...  
Keyword(s):  
Higher Plants ◽  
Biological Processes ◽  
Mrna Targets ◽  
Non Coding Rna ◽  
Starting Point ◽  
Antisense Lncrnas ◽  
Non Coding Rnas ◽  
Mirnas Expression ◽  
Long Non Coding Rna

In higher plants, several lines of evidence suggest that long non-coding RNAs (lncRNAs) may play important roles in the regulation of various biological processes by regulating gene expression. In this study, we identified a total of 521 lncRNAs, classified as intergenic, intronic, sense, and natural antisense lncRNAs, from RNA-seq data of drought-exposed tomato leaves. A further 244 drought-responsive tomato lncRNAs were predicted to be putative targets of 92 tomato miRNAs. Expression pattern and preliminary functional analysis of potential mRNA targets suggested that drought-responsive tomato lncRNAs play important roles in a variety of biological processes via lncRNA–mRNA co-expression. Taken together, these data present a comprehensive view of drought-responsive tomato lncRNAs that serve as a starting point for understanding the role of long intergenic non-coding RNAs in the regulatory mechanisms underlying drought responses in crops.

Mating behaviour of Heterozius rotundifrons (Crustacea : Brachyura : Belliidae): is it a hard or soft shell mater?

2005 ◽  
Vol 56 (8) ◽  
pp. 1107 ◽  
Author(s):  
G. A. Thompson ◽  
C. L. McLay
Keyword(s):  
New Zealand ◽  
Intertidal Zone ◽  
Mating Behaviour ◽  
Field Studies ◽  
Early Spring ◽  
Operational Sex Ratio ◽  
Soft Shell ◽  
Males And Females ◽  
Reproductive Characters ◽  
Water Borne

The Belliidae are a small family of crabs whose relationships with other families are enigmatic and whose composition is controversial. It is by no means certain whether their genera form a monophyletic group. One member of this family is Heterozius rotundifrons, a New Zealand endemic crab that lives in the intertidal zone, sheltering under rocks. In the present study the mating behaviour of this species was examined under laboratory conditions. Mating and moulting are closely linked because H. rotundifrons females only mate immediately after moulting. Females remain attractive to males for almost 3 days. A female-derived water-borne pheromone seems to be the basis of this attraction. Prior to moulting males guard females for up to 5 days. During the female moult some males were observed to assist the female. During copulation both males and females exhibited an unusual limb quivering behaviour and afterwards males guarded the females for 10.5 h, which was extended to 37 h when other males were present. Field studies showed that females moulted during early spring over a period of 1 month. Throughout the year very few females moulted, suggesting that there may be intense competition for mates during the early spring. At all times the operational sex ratio was biased in favour of males. In terms of the evolution of reproductive characters among the Belliidae, Atelecyclidae, Cheiragonidae and Corystidae, H. rotundifrons occupies an intermediate position between the ancestral condition and that seen in Corystes cassivelaunus.

Primary Productivity, Sulfate Reduction and Sulfer Isotope Fractionation in Algal Mats and Sediments of Hamelin pool, Shark Bay, W. A.

1979 ◽  
Vol 30 (6) ◽  
pp. 753 ◽  
Author(s):  
J Bauld ◽  
LA Chambers ◽  
GW Skyring
Keyword(s):  
Sulfate Reduction ◽  
Primary Productivity ◽  
Intertidal Zone ◽  
Photosynthetic Efficiency ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Algal Mats ◽  
Shark Bay ◽  
High Intertidal Zone ◽  
Fractionation Factors

A variety of benthic algal mats grow in the intertidal and subtidal environments of Hamelin Pool. Primary productivity ranged from 17 mhCm-2 h-1 for smooth mat, present in the high intertidal zone, to 113 mgC m-2 h-1 for colloform mat, found only in subtidal areas. Although pustular mat showed high photosynthetic efficiency [9.1 mgC (mg Chla)-1h-1] sulfate reduction was undetectable in underlying sediments. The rates of sulfate reduction in sediments close to intertidal stromatolites and in sediments beneath smooth mat were similar (5 mmol m-2d-1). In the intertidal zone stromatolitic debris has formed sediments in which sulfate reduction is rapid (14-46 mmol m-2d-1). Sulfur isotope distribution indicates a semiclosed system in the latter sediments (δ34S‰,: SO42-, +22.0 to +27.7; S2-, - 11.2 to -14.5) and an open system in the smooth mat sediments (δ34S‰: SO42-,+20.7; S2-, -23.2). Fractionation factors are between 1.033 and 1.044. The geobiological significance of these data is discussed.

scholarly journals Seasonal Variability of Thermal Regime in a Shallow Ice Covered Lake

2003 ◽  
Vol 34 (1-2) ◽  
pp. 107-124 ◽  
Author(s):  
Osama A. Maher ◽  
Joakim Malm
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Systematic Study ◽  
Early Spring ◽  
Ice Formation ◽  
Early Winter ◽  
Physical Processes ◽  
Average Water Temperature ◽  
Average Water ◽  
Break Up

A systematic study was conducted over six years (1994-1999) on a shallow ice covered lake in the Russian Republic of Karelia with the aim of developing better understanding of some physical processes occurring in shallow ice-covered lakes. The average ice-covered period was 182 days while the longest ice-covered period was 193 days. The average lake water temperature at ice formation was 0.5-1.0°C, while the average water temperature just before ice break-up was close to 4°C. The heat flux from water to ice was low during early winter but could increase above 5 Wm-2 (daily average) during the last month before ice break-up. The heat flux from sediment to water was the main source of heat to the water body during early to mid winter being about 2-6 W·m-2 during early winter but decreasing to about 1-2 Wm-2 during early spring.

Responses of Plankton, Turbidity, and Macrophytes to Biomanipulation in a Shallow Prairie Lake

1994 ◽  
Vol 51 (5) ◽  
pp. 1180-1188 ◽  
Author(s):  
Mark A. Hanson ◽  
Malcolm G. Butler
Keyword(s):  
Submerged Macrophytes ◽  
Sediment Resuspension ◽  
Initial Response ◽  
Water Clarity ◽  
Eutrophic Lake ◽  
Early Spring ◽  
Early Summer ◽  
Water Transparency ◽  
First Year ◽  
Fish Kill

We evaluated effects of complete fish kill in a large, shallow, eutrophic lake in Minnesota. Low densitites of Bosmina and Chydorus (< 100∙L−1) were replaced in the early spring/early summer by high densities of larger Daphnia galeata and D. pulex (> 100∙L−1) during the first year after the fish kill (1988). During peak daphnid abundance (May–June), chlorophyll a concentrations and edible phytoplankton were reduced, water transparency increased, and submerged macrophytes expanded. Orthophosphate and ammonia were detectable during clear-water phases, indicating that phytoplankton were not severely nutrient limited. Increased water transparency in subsequent years (1989–90) apparently was related to decreased sediment resuspension and lower algal biomass owing to the expansion of submerged plants. The fish kill invoked a strong initial response that transmitted to the phytoplankton level and increased water clarity. Higher transparency persisted during subsequent years because submerged macrophytes both responded to improved water clarity and subsequently prolonged it. These results support the contention that removal of fish from shallow lakes may invoke "cascading impacts" that enhance water clarity, stimulate macrophytes, and establish a new steady state.

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