Effects of wave exposure on the abundance and composition of amphipod and tanaidacean assemblages inhabiting intertidal coralline algae

2015 ◽  
pp. 1-7 ◽  
Author(s):  
M. Bueno ◽  
S.A. Dena-Silva ◽  
A.A.V. Flores ◽  
F.P.P. Leite
Keyword(s):  
Oxygen Concentration ◽  
Habitat Complexity ◽  
Wave Exposure ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Biological Interactions ◽  
Species Identity ◽  
Faunal Assemblages ◽  
Eastern Brazil ◽  
Different Levels

Peracarid crustaceans are an important component of the vagile fauna associated with coralline algal beds, which often characterize the infralittoral fringe of tropical rocky shores. Among other variables affecting faunal assemblages, sedimentation, food supply and oxygen concentration within mats or turfs of coralline algae may greatly depend on the exposure to waves. In this study, peracarid assemblages were compared at replicated rocky shores within different levels of wave exposure, along a coastline in south-eastern Brazil. Overall amphipod diversity (11 species) was much higher than tanaidacean diversity (two species). Correlation analyses did not support any biological interactions between amphipods and tanaidaceans. Habitat complexity, while apparently limiting amphipod populations, did not affect tanaidaceans at a local scale. Amphipod abundance, not assemblage structure, was positively affected by wave exposure, probably improving oxygen concentration levels and renewal of food resources. Rather than abundance, which remains fairly stable, exposure to waves determined species identity in tanaidaceans, withZeuxo coralensisfound at exposed shores andLeptocheliaaff.dubiafound at sheltered shores, except for twoL.aff.dubiaindividuals found at one of the exposed sites. Differences in the supply of sediment and the ability of these species in manipulating grains for tube building may explain such a striking pattern.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

scholarly journals The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs

2009 ◽  
Vol 66 (4) ◽  
pp. 691-698 ◽  
Author(s):  
W. R. Hunter ◽  
M. D. J. Sayer
Keyword(s):  
Habitat Complexity ◽  
Artificial Reef ◽  
Structural Complexity ◽  
Marine Species ◽  
Rocky Reef ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Concrete Blocks ◽  
Belt Transect ◽  
Natural Reefs

Abstract Hunter, W. R., and Sayer, M. D. J. 2009. The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs. – ICES Journal of Marine Science, 66: 691–698. Several north temperate marine species were recorded on subtidal hard-substratum reef sites selected to produce a gradient of structural complexity. The study employed an established scuba-based census method, the belt transect. The three types of reef examined, with a measured gradient of increasing structural complexity, were natural rocky reef, artificial reef constructed of solid concrete blocks, and artificial reef made of concrete blocks with voids. Surveys were undertaken monthly over a calendar year using randomly placed fixed rope transects. For a number of conspicuous species of fish and invertebrates, significant differences were found between the levels of habitat complexity and abundance. Overall abundance for many of the species examined was 2–3 times higher on the complex artificial habitats than on simple artificial or natural reef habitats. The enhanced habitat availability produced by the increased structural complexity delivered through specifically designed artificial reefs may have the potential to augment faunal abundance while promoting species diversity.

scholarly journals Ocular Response to Millimeter Wave Exposure Under Different Levels of Humidity

2019 ◽  
Vol 40 (5) ◽  
pp. 574-584
Author(s):  
Masami Kojima ◽  
Cheng-Yu Tsai ◽  
Yukihisa Suzuki ◽  
Kensuke Sasaki ◽  
Takafumi Tasaki ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Wave Exposure ◽  
Different Levels

Intertidal zonation and seasonality of the marine hydroid Dynamena pumila (Cnidaria: Hydrozoa)

2002 ◽  
Vol 80 (9) ◽  
pp. 1526-1536
Author(s):  
Lea-Anne Henry
Keyword(s):  
Environmental Conditions ◽  
Temporal Dynamics ◽  
Wave Exposure ◽  
Tidal Range ◽  
Bay Of Fundy ◽  
Rocky Shores ◽  
Four Seasons ◽  
The Mean ◽  
Highly Correlated ◽  
Number Of Branches

The vertical zonation and temporal dynamics of the marine hydroid Dynamena pumila were assessed across a wave-exposure gradient on five rocky shores in the Bay of Fundy, Atlantic Canada. Hydroid abundance and occupancy (i.e., percentage occurrence in a quadrat) were measured in 0.25-m2 quadrats at eight vertical elevations for each site over four consecutive seasons. Hydroid abundance and occupancy were highly correlated (R2 = 0.877). Estimates of hydroid fertility (percentage of sexually reproductive colonies) and size (stem height and number of branches) were obtained in five quadrats at every elevation over the four seasons. Abundance peaked at about 37.5–62.5% of the mean tidal range, with maximum abundance at the site with moderate wave exposure. Abundance peaked during the summer and dropped dramatically over the winter, particularly at the more wave-exposed sites. Winter ice scour and unfavourable environmental conditions reduced hydroid abundance, fertility, and size during the winter. This study demonstrates dramatic shifts in the distribution, fertility, and size of a marine hydroid. The importance of wave action, ice scour, and seasonal changes in environmental conditions is highlighted to emphasize their roles in regulating intertidal hydroid communities on boreal rocky shores.

The living community inside the common periwinkle, Littorina littorea

2013 ◽  
Vol 91 (5) ◽  
pp. 293-301 ◽  
Author(s):  
John Buckland-Nicks ◽  
Sarah Ann Chisholm ◽  
Glenys Gibson
Keyword(s):  
Mantle Cavity ◽  
Snail Host ◽  
Coralline Algae ◽  
Littorina Littorea ◽  
Rocky Shores ◽  
Small Community ◽  
Wide Range ◽  
Animal Phyla ◽  
The Common ◽  
Trematode Infections

An extensive community of organisms inhabits the common periwinkle, Littorina littorea (L., 1758), along the wave-swept rocky shores of Canada’s East coast. This community, which includes both facultative and obligate endosymbionts, comprises a diverse array of species from seven animal phyla, including Annelida, Arthropoda, Gnathostomulida, Nematoda, Nemertea, and Platyhelminthes, as well as ciliates and algae. The presence of larger numbers of endosymbionts was found to correlate with specific shell characteristics of the snail host, including a wider aperture and columella, suggesting that these individuals have a larger mantle cavity relative to snails housing a small community of endosymbionts. Snails with large communities of endosymbionts were usually encrusted with coralline algae and often had trematode infections. Although L. littorea has been extensively studied since the last century, the existence of this community of organisms has passed unnoticed. The large diversity of organisms in this community suggests that these snails may provide refugia for a wide range of smaller taxa.

scholarly journals Temporal and spatial variation of rocky shores intertidal benthic communities in Southeast Brazil

2012 ◽  
Vol 102 (4) ◽  
pp. 375-383 ◽  
Author(s):  
Gabriela C. Zamprogno ◽  
Flavio C. Fernandes ◽  
Luiz L. Fernandes
Keyword(s):  
Clustering Analysis ◽  
Benthic Communities ◽  
Wave Exposure ◽  
Rocky Shores ◽  
Temporal And Spatial Variation ◽  
Southeast Brazil ◽  
Intersection Points ◽  
Temporal And Spatial ◽  
Upper Level ◽  
Species Variability

The relationships between environmental factors and temporal and spatial variations of benthic communities of three rocky shores of the state of Espírito Santo, Southeast Brazil, were studied. Sampling was conducted every three months, from August 2006 to May 2007, using intersection points. Chthamalus bisinuatus (Pilsbry, 1916) (Crustacea) and Brachidontes spp. (Mollusca) were the most abundant taxa, occupying the upper level of the intertidal zone of the rocky shore. The species richness was higher at the lower levels. The invasive species Isognomon bicolor (C. B. Adams, 1845) (Mollusca) occurred at low densities in the studied areas. The clustering analysis dendrogram indicated a separation of communities based on exposed and sheltered areas. According to the variance analyses, the communities were significantly different among the studied areas and seasons. The extent of wave exposure and shore slope influenced the species variability. The Setibão site showed the highest diversity and richness, most likely due to greater wave exposure. The communities showed greater variation in the lower levels where environmental conditions were less severe, relative to the other levels.

Juvenile green turtles (Chelonia mydas) in the effluent discharge channel of a steel plant, Espírito Santo, Brazil, 2000–2006

2009 ◽  
Vol 90 (2) ◽  
pp. 233-246 ◽  
Author(s):  
Evelise Torezani ◽  
Cecília Baptistotte ◽  
Sérgio L. Mendes ◽  
Paulo C.R. Barata
Keyword(s):  
Discharge Channel ◽  
Chelonia Mydas ◽  
Steel Plant ◽  
Espírito Santo ◽  
Green Turtles ◽  
Eastern Brazil ◽  
Channel Information ◽  
Effluent Discharge ◽  
Espirito Santo ◽  
Different Levels

This study, carried out from August 2000 to July 2006, began out of the recognition of a special ecological situation, when an aggregation of juvenile green turtles (Chelonia mydas) was found inside the effluent discharge channel of a steel plant located near Vitória, the State of Espírito Santo capital, eastern Brazil. The green turtles were captured through either cast nets or a set net or by hand (one turtle was captured alive on one of the channel banks); after data collection, they were released back into the discharge channel. Information is here reported on the temporal pattern of occurrence, size-classes, residency, presence of tumours and growth rates of tumoured and non-tumoured green turtles in the study area. A total of 640 individual green turtles were captured in the six years; 448 of them were captured just once, and 192 were captured two or more times. Curved carapace length ranged between 25.2 and 77.5 cm. Among the captured green turtles, 59.1% were classified as being in normal body condition and without any tumours, 6.6% were either underweight or emaciated but without any tumours, and 34.4% had tumours, with different levels of the tumour severity score.

scholarly journals Restoring biodiversity in the Mediterranean coralligenous - the MERCES project

2018 ◽  
Author(s):  
Carlo Cerrano ◽  
Tatjana Bakran-Petricioli ◽  
Joana Boavida ◽  
Eliana Ferretti ◽  
Andrea Gari ◽  
...  
Keyword(s):  
Habitat Complexity ◽  
Coralline Algae ◽  
Mediterranean Species ◽  
Restoration Success ◽  
Funded Project ◽  
The Mediterranean ◽  
Taxonomic Groups ◽  
Mass Mortalities ◽  
Generation Sequencing ◽  
The Eu

The temperate coralligenous bioconcretions are mainly built by the accumulation of encrusting coralline algae growing at low irradiance levels. They harbour approximately 10% of marine Mediterranean species (about 1600 species), including long-lived algae and invertebrates. Enhanced by climate change, several pressures affect coralligenous assemblages, leading to increased frequency of mass mortalities and dramatic loss of habitat complexity and biodiversity. The EU-funded project MERCES is developing innovative methodologies to restore macroinvertebrate habitat-forming species from three key taxonomic groups: Cnidaria/Anthozoa, Porifera/Demospongiae and Bryozoa. Restoration protocols are based on fragments/transplants from donor organisms and recruitment-enhancing devices. Collaboration with volunteers (divers and diving operators) in several phases of field activities proved crucial both to minimize underwater working time and to increase the sense of stewardship in a major users’ segment. Additionally, the MERCES project explores how to enhance restoration success by identifying the mechanisms conferring resistance to thermal stress in gorgonians. This is pursued by coupling thermotolerance experiments with next generation sequencing tools and facilitation processes (by comparing the outcomes of mono-specific vs. multi-specific transplanted assemblages). Results will be included in the strategic planning of restoration efforts in the Mediterranean in the context of global change.

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