scholarly journals Algal Epibionts as Co-Engineers in Mussel Beds: Effects on Abiotic Conditions and Mobile Interstitial Invertebrates

Diversity ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 17 ◽  
Author(s):  
Jorge Gutiérrez ◽  
María Bagur ◽  
M. Palomo
Keyword(s):  
Algal Species ◽  
Habitat Modification ◽  
Physical Habitat ◽  
Mussel Bed ◽  
Abiotic Conditions ◽  
Mussel Beds ◽  
Focal Species ◽  
Individual Effects ◽  
Study Sites ◽  
Reduced Temperature

Mussels and macroalgae have long been recognized as physical ecosystem engineers that modulate abiotic conditions and resources and affect the composition of rocky shore assemblages. Their spatial distributions in the intertidal zone frequently overlap, as many algal species thrive as epibionts on mussel beds. Nonetheless, their potential for combined engineering effects has not been addressed to date. Here we illustrate that Porphyra sp.—a desiccation-resistant macroalga that develops mostly epiphytically onto mussel beds—affects temperature, desiccation levels, and mobile interstitial invertebrates in mussel beds. Specifically, we observed that Porphyra cover (a) reduced temperature at the surface of the mussel bed but not at their base, (b) reduced desiccation both at the surface and base of the mussel bed and, (c) increased the densities of an abundant interstitial species—the amphipod Hyale grandicornis—in several study sites/dates. Additionally, we found that the positive responses of these grazing amphipods to Porphyra were driven by physical habitat modification (engineering) rather than food availability. This suggests that co-engineering by Porphyra and mussels generates abiotic states and focal species responses that would not be predictable from their individual effects. We expect that increased appreciation of co-engineering aids our understanding of complex ecological dynamics.

Distribution and Seasonality of Macroalgae on Oyster Communities of Central Chesapeake Bay

1980 ◽  
Vol 23 (11) ◽  
Author(s):  
Judith L. Connor
Keyword(s):  
Life History ◽  
Sexual Reproduction ◽  
Chesapeake Bay ◽  
Physical Environment ◽  
Algal Species ◽  
Light Availability ◽  
Field Studies ◽  
Spatial And Temporal Distributions ◽  
Red Algal ◽  
Study Sites

AbstractField studies of the benthic macroalgae of fifteen selected Chesapeake Bay oyster communities were conducted over a period of a year (March 1977 to February 1978). Algal distribu tion and seasonal occurrence were studied in relation to changes in the physical environment. Salinity, temperature, and light availability were important factors in the spatial and temporal distributions of algae in these subtidal habitats.Seventeen species of Chlorophyta, Phaeophyta, and Rhodophyta were recorded from the fifteen study sites distributed over 130 kilometers within the Maryland portion of Chesapeake Bay. Species of Chlorophyta were associated with oyster communities throughout the year of study with maximum numbers of species and maximum biomass occurring in spring. Only once was a member of the Phaeophyta encountered; a single filamentous species, Ectocarpus, was collected during winter. Species of Rhodophyta were present throughout the year at the study sites.Most of the algae collected reproduced asexually by spores and/or vegetative fragments. Sexual reproduction occurred in some of the red algal species. The presence of tetrasporic and cystocarpic plants of Dasya baillouviana and Polysiphonia harveyi var. olneyi may indicate that the usual triphasic Florideophycean life history occurs in this estuary.

scholarly journals Assessment of diversity and physico-chemical parameters of cyanobacteria, diatoms and other algal species in the paddy fields of Belagavi district, Karnataka

2020 ◽  
Vol 7 (3) ◽  
pp. 378-382
Author(s):  
Santoshkumar Jayagoudar ◽  
Pradeep Bhat ◽  
Ankita Magdum ◽  
Duradundi Sakreppagol ◽  
Laxmi Murgod ◽  
...  
Keyword(s):  
Algal Species ◽  
Soil Samples ◽  
Chemical Parameters ◽  
Range Estimation ◽  
The North ◽  
Physico Chemical ◽  
Water And Soil Samples ◽  
Study Sites ◽  
Good Range

Algae are the diverse group of organisms in the soil and aquatic environment. The role of them in soil fertility enhancement has been extensively studied worldwide. Belagavi is a tropical agricultural belt in the North Karnataka region with highly fertile soil. Water and soil samples were collected randomly from the paddy field of 15–20 well-distributed spots in 4 selected locations viz Kusumali, Jamboti, Kinaye and Piranwadi. The identification revealed the presence of 94 species and 71 genera in the investigated sites. Among all, 62 species belonged to Bacillariophyceae, 14 species to Chlorophyceae, 10 species to Cyanophyceae, 3 to Xanthophyceae, followed by Trebouxiophyceae and Zygnematophyceae (2 species each) and one species of Ulvophyceae. The maximum number of 62 species was recorded from Kusamali, followed by 49 species in Kinaye, 44 in Jamboti and 35 in Piranwadi. The month of February had the highest number of species (61), decreased to 45 in March, 42 in April and 37 in May. Among the physicochemical parameters analysed for the soil samples, it was found that the pH of the soil is slightly acidic in all the study sites ranged between 5.03–5.85. Further, the electrical conductivity (EC) varied from 0.27–0.345 dS/m, found to be in a good range. Estimation of available micro and macronutrients of soil were measured, and it was found to be at low to moderate levels. The present study indicates the extensive distribution of different classes of algae in the rice fields of four study locations in Belagavi.

scholarly journals Freshwater Mussel Bed Habitat in an Alluvial Sand-Bed-Material-Dominated Large River: A Core Flow Sediment Refugium?

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 174
Author(s):  
Alan D. Christian ◽  
Andrew J. Peck ◽  
Ryan Allen ◽  
Raven Lawson ◽  
Waylon Edwards ◽  
...  
Keyword(s):  
Flow Direction ◽  
Freshwater Mussel ◽  
Physical Habitat ◽  
Stream Power ◽  
Mussel Bed ◽  
Mean Velocity ◽  
Core Flow ◽  
White River ◽  
Bed Material ◽  
Mussel Habitat

Habitat degradation, organismal needs, and other effects influencing freshwater mussel declines have been subject to intense focus by conservationists for the last thirty plus years. While researchers have studied the physical habitat requirements and needs of mussels in small- to medium-sized rivers with variable levels of success, less research has been conducted on mussel habitat in larger non-wadeable rivers, especially at the reach scale, where core flow environmental conditions provide and maintain habitat for freshwater mussels. We designed a quasi-experimental observational field study to examine seven hydrologic energy and material variables laterally and longitudinally at Current and Extirpated mussel bed habitat reaches in lower White River, Arkansas, a large non-wadeable, sand-bed-material-dominated river. As expected, lateral and longitudinal hydrologic variable differences were identified within a reach. Mean velocity, bed velocity, the Froude number, and stream power were all significantly lower at Current mussel bed habitat stations within a sampling reach. Energy regime differences in shear stress and, marginally, stream power were higher at Extirpated mussel bed habitat reaches. Several factors emerged as important to mussel habitat in the White River. First, bed velocity warrants further exploration in terms of both flow strength and flow direction. Second, bedload appears to be the primary contributor to mussel habitat but requires additional exploration within the context of core and secondary flow pathway interactions. The combined empirical evidence from our study supports the flow refugium concept identified for mussel habitats in smaller systems but expands the concept to large non-wadeable streams and includes reach-scale refuge from sediment transport conditions.

scholarly journals Some Fresh Water Algae of Oil Refinery Effluent Drains of Assam, India

Our Nature ◽  
1970 ◽  
Vol 7 (1) ◽  
pp. 139-145 ◽  
Author(s):  
P.P. Baruah ◽  
B. Kakati ◽  
I. Ahmed
Keyword(s):  
Fresh Water ◽  
Algal Species ◽  
Oil Refinery ◽  
Refinery Effluent ◽  
Algal Group ◽  
Study Sites

The present paper deals with the morpho-taxonomic account of some hitherto unknown fresh water algal species of hydrocarbon polluted refinery drains of Assam. Twenty two taxa of class Chlorophyceae, Bacillariophyceae, Euglenineae and Cyanophyceae were identified from three effluent drains of Guwahati Oil Refinery. Cyanophyceae with 11 species was the dominant algal group in the study sites and Oscillatoria was the dominant genus with 8 species.Key words: Fresh water algae, Oscillatoria, oil refinery effluent, AssamDOI: 10.3126/on.v7i1.2561Our Nature (2009) 7:139-145 

scholarly journals Assessment of physical habitat modification in the Bílina River Basin

Limnetica ◽  
2011 ◽  
Vol 30 (2) ◽  
pp. 293-306
Author(s):  
Milada Matoušková ◽  
Martin Dvořák
Keyword(s):  
River Basin ◽  
Habitat Modification ◽  
Physical Habitat ◽  
Bílina River

scholarly journals Spatio-temporal variation of microphytoplankton communities in Obhur Creek, the central Red Sea

2021 ◽  
Vol 50 (1) ◽  
pp. 98-114
Author(s):  
Mohsen M. El-Sherbiny ◽  
Mamdouh A. Al-Harbi ◽  
Anand J. Kumar
Keyword(s):  
Red Sea ◽  
Algal Species ◽  
Open Water ◽  
Nutrient Concentrations ◽  
Phytoplankton Species ◽  
Phytoplankton Abundance ◽  
Physicochemical Factors ◽  
Spatio Temporal ◽  
Study Sites ◽  
Abundance And Distribution

Abstract The abundance and distribution of microphyto-plankton and related physicochemical factors were assessed monthly in Obhur Creek, the central Red Sea. Sampling was carried out near the entrance, the middle and end parts of the creek. During the course of the present study, the Red Sea was characterized by predominantly oligotrophic conditions. Nutrient concentrations were relatively higher in the end part of the creek compared to the two other study sites. Chlorophyll a was also low throughout the year (average: 0.35 ± 0.32 mg m−3), except in May when it showed clear peaks at open-water and middle sites of the creek (1.85 and 1.04 mg m−3, respectively). Phytoplankton abundance followed a similar pattern to that of chlorophyll a with considerably higher abundance at these sites in May (3063.27 × 103 and 1082.34 × 103 individuals m−3, respectively). This unusually higher abundance was mostly due to the proliferation of the diatom Pseudo-nitzschia cf. delicatissima (Cleve) Heiden. Silicate concentrations were statistically significantly correlated with total phytoplankton. A total of 220 phytoplankton species were recorded during the study period (117 diatoms, 99 dinoflagellates and four cyanophytes). Diatoms dominated in the phytoplankton abundance (75%) and were followed by dinoflagellates (20%), while cyanophytes accounted for a minimal proportion. Of all phytoplankton species observed during the study, 21 diatom and four dinoflagellate species were considered as new records for the Red Sea, and two diatom and 14 dinoflagellate species were listed as harmful algal species worldwide.

Limited effects of Sargassum horneri, an invasive alga, on temperate reef fish assemblages

2020 ◽  
Vol 643 ◽  
pp. 115-131
Author(s):  
SC Ginther ◽  
MA Steele
Keyword(s):  
Southern California ◽  
Fish Assemblages ◽  
Algal Species ◽  
Sargassum Horneri ◽  
Negative Effects ◽  
Management Actions ◽  
Temperate Reef ◽  
Temperate Reefs ◽  
Study Sites ◽  
Invasive Alga

Biological invasions can dramatically affect the ecology of invaded regions, and globally have resulted in economic damages that total billions of dollars annually. In recent years, an invasive alga, Sargassum horneri, has become established and spread along the coast of southern California (USA). Using field observations and a field experiment, we explored how this non-native alga influences the structure of fish assemblages on temperate reefs in southern California where S. horneri has become prolific. Fish and algal assemblages were quantified along transects on rocky reefs at depths of 3 and 6 m at 6-8 study sites spanning 5 km on 4 occasions over 1.5 yr. Spatiotemporal variation in the fish assemblage was not strongly correlated with the abundance of invasive S. horneri over this period, although it became less variable as native giant kelp Macrocystis pyrifera disappeared from the study sites due to a warm-water event, during which the invasive S. horneri became more dominant. An experiment removing a total of 4.25 t of S. horneri from 6 × 6 m plots (n = 14) revealed that the invasive alga did not affect fish abundance, species richness, species diversity (H’), or multivariate assemblage structure over a 5 mo period. Overall, we found little evidence of negative effects of S. horneri on fishes even though it drastically changed the underwater landscape. Nevertheless, we advise cautionary management actions to limit the movement of this invasive alga because its effects on other community members, such as other algal species, may be detrimental, and longer-term effects on fishes might develop.

scholarly journals Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2672 ◽  
Author(s):  
Jarosław Kobak ◽  
Małgorzata Poznańska ◽  
Łukasz Jermacz ◽  
Tomasz Kakareko ◽  
Daniel Prądzynski ◽  
...  
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Prey Density ◽  
Zebra Mussels ◽  
Suitable Habitat ◽  
Mussel Bed ◽  
Predator Species ◽  
Mussel Beds ◽  
Feeding Ground ◽  
Proterorhinus Semilunaris

Aggregations of the Ponto-Caspian invasive zebra mussel (Dreissena polymorpha) constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae) densities (from ca. 500 to 2,000 individuals m−2) in a mussel bed make it a more beneficial feeding ground for the racer gobyBabka gymnotrachelus(RG) and western tubenose gobyProterorhinus semilunaris(WTG) compared to sandy and stone substrata (containing the basic prey density of 500 ind. m−2). Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m−2), regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas, contributing to an invasional meltdown in the Ponto-Caspian invasive community.

scholarly journals Diversity of meiofauna and free-living nematodes in hydrothermal vent mussel beds on the northern and southern East Pacific Rise

2007 ◽  
Vol 87 (5) ◽  
pp. 1141-1152 ◽  
Author(s):  
J.T.P. Copley ◽  
H.C. Flint ◽  
T.J. Ferrero ◽  
C.L. Van Dover
Keyword(s):  
Species Richness ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
East Pacific Rise ◽  
Nematode Species ◽  
Mussel Bed ◽  
Generic Level ◽  
Mussel Beds ◽  
The North ◽  
East Pacific

The ecology and biogeography of meiofauna at deep-sea hydrothermal vents have historically received less attention than those of mega- and macrofauna. This study examines the composition of major meiofaunal taxa in beds of the mussel Bathymodiolus thermophilus at hydrothermal vents on the northern and southern East Pacific Rise (EPR) and presents the first comparison of species assemblages of the dominant taxon, the nematodes, among sites spanning 27 degrees of latitude. Meiofaunal samples were collected by submersible from three mussel beds at 9°N on the EPR and four mussel beds between 17 and 18°S in 1999. Estimated ages of the mussel beds at the time of sampling range from 4 to >20 years, enabling investigation of the influence of mussel bed age on meiofaunal assemblages. Overall, the meiofauna of the mussel beds was dominated by nematodes, with copepods constituting the second most abundant meiofaunal group. There was variation in the ratio of nematodes to copepods between sites, however, with copepods more abundant than nematodes in the youngest mussel beds. Apart from polychaete larvae, other meiofaunal groups were generally present at very low abundance (<1%) in the samples and restricted in diversity to gastropod larvae, acari, foraminifera, ostracoda and turbellaria. Seventeen nematode species from 14 genera and 11 families were found in the samples, with no evidence of endemicity to hydrothermal vents at the generic level. Four genera present were not previously recorded at hydrothermal vents. Nematode species richness, species:genus ratios and abundances were low compared with other deep-sea habitats, though the ecological relevance of comparisons with soft-sediment benthos is discussed. Nematode assemblages exhibited high dominance by a few species, with one species of Thalassomonhystera most abundant at five of the seven vent sites. Multivariate analysis of nematode assemblages reveals similarities among sites that do not match geographical proximity. The youngest mussel beds were most similar to each other and exhibited lower species richness than other sites, consistent with colonization of mussel bed habitat by nematodes over time. Similarity in the composition of nematode assemblages among sites separated by ~3000 km indicates that they lie within a single biogeographic province, consistent with that proposed for mussel bed macrofauna. At a generic level, samples exhibited some overlap with nematode assemblages at vents elsewhere on the EPR, on the Mid Atlantic Ridge and in the North Fiji Basin.

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