scholarly journals Co-occurring morphologically distinct algae support a diverse associated fauna in the intertidal zone of Araçá Bay, Brazil

2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Edson A. Vieira ◽  
Heloísa Romeu Filgueiras ◽  
Marília Bueno ◽  
Fosca Pedini Pereira Leite ◽  
Gustavo Muniz Dias
Keyword(s):  
Rocky Shore ◽  
Biotic Interactions ◽  
Light Limitation ◽  
Small Scale ◽  
Rocky Shores ◽  
Associated Fauna ◽  
Close Relationship ◽  
Algal Host ◽  
Species Tolerance ◽  
Terrestrial Insects

Abstract Species diversity is regulated by historical, neutral and niche processes, with species tolerance, dispersal and productivity guiding diversity at larger scales, while habitat heterogeneity and biotic interactions acts in smaller scales. In rocky shores, several organisms provide secondary substrates for mobile fauna, with macroalgae being the most abundant and diverse ones. The patchiness promoted by different macroalgae hosts enhances small-scale heterogeneity and may increase and maintain the diversity of the mobile organisms, since there is a close relationship between the associated fauna and its hosts. In this study we selected three morphologically different macroalgae that coexist in the same rocky shore height in the Araçá Bay, an area under the threat of the nearby harbor expansion, and evaluated the fauna associated to each algal host. Even under similar abiotic pressure (same rocky shore height), the associated fauna of each algal host varied in number and composition, revealing a close relationship. The poorly branched foliose Ulva lactuca sustained a lower density of organisms and was dominated by isopods, while the heavily branched turf and Bostrychietum community showed a high density of organisms, with a dominance of peracarid crustaceans and annelids on the turf and more resistant groups, such as bivalves, acaris and terrestrial insects on the Bostrychietum. Previous studies in the Araçá Bay already revealed a large spatial heterogeneity in the processes and sessile organisms distribution, and here we highlight that this heterogeneity can be observed in an even smaller scale, with different algal hosts mediating the turnover of species in a scale of centimeters and meters, resulting in diversity maintenance of the associated fauna. Since the harbor expansion may prevent the occurrence of macroalgae as a result of light limitation by suspended platforms, we may expect not only a decrease in algal cover but also in the total diversity of the associated fauna in the Araçá Bay.

Molecular diversity and biomass of epilithic biofilms from intertidal rocky shores in the Gulf of Mexico

Biofilms ◽  
2005 ◽  
Vol 2 (2) ◽  
pp. 93-103 ◽  
Author(s):  
J. Narváez-Zapata ◽  
C. C. Tebbe ◽  
B. O. Ortega-Morales
Keyword(s):  
Gulf Of Mexico ◽  
Rocky Shore ◽  
Sea Water ◽  
Rrna Genes ◽  
Small Scale ◽  
Group Method ◽  
Rocky Shores ◽  
Biological Interactions ◽  
Epilithic Biofilms ◽  
Biofilm Community

Epilithic biofilms play key roles in rocky shore ecosystems. The diversity and biomass of epilithic biofilms were determined along a subtropical intertidal rocky shore at Xpicob, Southern Gulf of Mexico (Campeche, Mexico). Biofilm diversity was assessed by polymerase chain reaction (PCR) amplification of partial 16 S rRNA genes using single-strand conformation polymorphism (SSCP). Triplicate 2 cm×2 cm biofilm samples per site were taken randomly from 0.6 m×0.6 m quadrats located in two sampling sites, established 20 m apart within a homogeneous calcareous intertidal platform. Twenty-two partial rRNA sequences, belonging to four bacterial divisions (Cyanobacteria, Bacteroidetes, Actinobacteria and Proteobacteria), were recovered from these biofilms; of these, cyanobacteria were the most abundant (41%). The occurrence of cyanobacterial sequences in most samples, along with the detection of high levels of chlorophyll a and phycobiliprotein, indicates that these organisms are dominant within the biofilms. Consistent with previous reports, thick-sheathed cyanobacteria such as those found in this study (Xenococcus, Myxosarcina and Chroococcidiopsis) are typical in habitats in intertidal zones. In addition, most of the detected organisms from other bacterial lineages had closest relatives displaying biofilm phenotypes that suggested stressful conditions (i.e. desiccation) prevailed in the intertidal shores; this was selecting for biofilm-forming or thick-sheathed organisms as an ecological adaptation to withstand the conditions. Unweighted pair-group method with arithmetic mean (UPGMA) analysis of SSCP profiles indicated that there was significant spatial heterogeneity in biofilm community composition across different scales of analysis and that this heterogeneity was related to the distance at which samples were taken. This analysis showed that certain organisms appeared to be station specific and that the biofilm community structure varied even on a small scale (1 cm). Since no significant differences in bulk sea water or substratum physicochemistry were observed, these results suggest that small-scale variability of environmental conditions, surface properties and/or biological interactions (i.e. allelopathy) may be important factors structuring these biofilm communities.

scholarly journals The Effects of Habitat Heterogeneity at Distinct Spatial Scales on Hard-Bottom-Associated Communities

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 39 ◽  
Author(s):  
Fabiane Gallucci ◽  
Ronaldo A. Christofoletti ◽  
Gustavo Fonseca ◽  
Gustavo M. Dias
Keyword(s):  
Habitat Heterogeneity ◽  
Rocky Shore ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Biotic Interactions ◽  
Habitat Diversity ◽  
Small Scale ◽  
Β Diversity ◽  
Biological Substrate ◽  
Mangrove Roots

For marine benthic communities, environmental heterogeneity at small spatial scales are mostly due to biologically produced habitat heterogeneity and biotic interactions, while at larger spatial scales environmental factors may prevails over biotic features. In this study, we investigated how community structure and β-diversity of hard-bottom-associated meio- and macrofauna varied in relation to small-scale (cm–m) changes in biological substrate (an algae “turf” dominated by the macroalgae Gelidium sp., the macroalgae Caulerpa racemosa and the sponge Hymeniacidon heliophile) in a rocky shore and in relation to larger-scale (10’s m) changes in environmental conditions of the same biological substrate (the macroalgae Bostrychia sp) in different habitats (rocky shore vs. mangrove roots). Results showed that both substrate identity and the surrounding environment were important in structuring the smaller-sized meiofauna, particularly the nematode assemblages, whereas the larger and more motile macrofauna was influenced only by larger-scale changes in the surrounding ecosystem. This implies that the macrofauna explores the environment in a larger spatial scale compared to the meiofauna, suggesting that effects of spatial heterogeneity on communities are dependent on organism size and mobility. Changes in taxa composition between environments and substrates highlight the importance of habitat diversity at different scales for maintaining the diversity of the associated fauna.

Recolonization of Rocky Shores in Cornwall After Use of Toxic Dispersants to Clean Up the Torrey Canyon Spill

1978 ◽  
Vol 35 (5) ◽  
pp. 682-706 ◽  
Author(s):  
A. J. Southward ◽  
Eve C. Southward
Keyword(s):  
Brown Algae ◽  
Rocky Shore ◽  
Common Species ◽  
Grazing Pressure ◽  
Small Scale ◽  
Rocky Shores ◽  
Biological Interactions ◽  
Laminaria Digitata ◽  
General Sequence ◽  
Upper Limit

Fourteen thousand tons of Kuwait crude oil, reduced from 18 000 tons by weathering at sea, was stranded along 150 km of the coast of West Cornwall, England, in March 1967. The oil was treated with 10 000 tons of toxic dispersants during cleaning operations. By itself the oil was not very toxic, although it killed some limpets and barnacles, and most of the mortalities that followed cleaning were due to the dispersants. There was a graded effect. Most animals and some algae were killed on the shores treated heavily with dispersants, while a few animals and most algae survived in places less heavily treated. However, long stretches of coast were contaminated to some extent by drifting of patches of oil and dispersants along the shore and by indiscriminate dispersant use in remote coves. The general sequence of recolonization was similar to that which has been found after small-scale experiments, where the rocks were scraped clean, or where limpets were removed, but took longer to complete. There was first a rapid "greening" by the alga Enteromorpha; then a heavy settlement and growth of perennial brown algae (Fucus species), leading to loss of surviving barnacles. A settlement of limpets and other grazing animals followed, with eventual removal or loss of the brown algae. The final phases were a reduction in the limpet population and a resettlement of barnacles. Lightly oiled, wave-beaten rocks that received light dispersant treatment showed the most complete return to normal, taking about 5–8 yr; heavily oiled places that received repeated application of dispersants have taken 9–10 yr and may not be completely normal yet. Most common species returned within 10 yr, but one rare hermit crab is still missing from places directly treated with dispersants. The early recolonization by algae resulted in a raising of the upper limit of Laminaria digitata and Himanthalia elongata by as much as 2 m in wave-beaten places, demonstrating that grazing pressure by limpets must be one of the factors controlling the zonation of these plants. Later, other species of plants and animals were found higher up the shore than usual, under the shade and shelter provided by the dense canopy of Fucus. Fluctuations in the populations of algae and herbivorous animals during the course of the recolonization illustrate the importance of biological interactions in controlling the structure of intertidal communities. Pollution disturbance affects the herbivores more than plants, hence the point of stability of the community is shifted towards the sheltered shore condition of low species richness and greater biomass. Key words: petroleum, dispersant, rocky shore, Torrey Canyon, recolonization, coastal ecology, pollution

Intensity of Human Predation on Rocky Shores at Las Cruces in Central Chile

1987 ◽  
Vol 14 (2) ◽  
pp. 143-149 ◽  
Author(s):  
L. René Durán ◽  
Juan Carlos Castilla ◽  
Doris Oliva
Keyword(s):  
Activity Pattern ◽  
Rocky Shore ◽  
Rocky Shores ◽  
Central Chile ◽  
Temporal Grouping ◽  
Human Predation

The rocky shore of central Chile is heavily harvested by mariscadores de orilla and skin-divers, but their catches are not considered in the fishery statistics. The aim of the present paper is to estimate the intensity of human predation and annual catch of each of the species taken at Las Cruces, Central Chile. The activity pattern of both categories of collectors demonstrate a temporal grouping. The observation of mariscadores de orilla and skin-divers in 3 sectors of fringe totalling 1,500 m of rocky shore during 12 months allowed us to estimate the annual catch per species caught (kg per year).

scholarly journals Discovery of a new species of genus Typhlodromus Scheuten (Acari: Phytoseiidae: Typhlodrominae) on rocky shore habitat from Lanyu Island

2017 ◽  
Vol 22 (10) ◽  
pp. 1639
Author(s):  
Jhih-Rong Liao ◽  
Chyi-Chen Ho ◽  
Chiun-Cheng Ko
Keyword(s):  
New Species ◽  
Rocky Shore ◽  
Biological Control Agent ◽  
Control Agent ◽  
Morphological Description ◽  
Rocky Shores ◽  
Mountain Areas ◽  
Phytoseiid Mites ◽  
First Time ◽  
A New Species

Phytoseiid mites have been intensively surveyed in Taiwan during the past decades because of their potential as biological control agent. Despite the fact, many regions of Taiwan remain under-explored especially in mountain areas and neighboring islands. Typhlodromus (Anthoseius) crossostephium sp. nov. was collected from Crossostephium chinense (L.) Makino (Asteraceae) on rocky shore habitat during a survey on Lanyu Island. In this paper, presence of a phytoseiid mite on rocky shores is reported for the first time. A detailed morphological description of the new species and a key to the Taiwanese species of subgenus Anthoseius are provided.

Variation in algal assemblages on wave-exposed rocky shores in New South Wales

1998 ◽  
Vol 49 (3) ◽  
pp. 241 ◽  
Author(s):  
A. J. Underwood ◽  
M. G. Chapman
Keyword(s):  
Large Scale ◽  
New South ◽  
New South Wales ◽  
Temporal Patterns ◽  
Explanatory Models ◽  
Small Scale ◽  
Rocky Shores ◽  
Spatial And Temporal Patterns ◽  
South Wales ◽  
Algal Assemblages

Data were collected in New South Wales from replicate sites on five wave-exposed shores separated by hundreds of kilometres at three-monthly intervals for four years, to examine large and small spatial and temporal patterns in low-shore algal assemblages. These data were used to test hypotheses from the models that algal assemblages show large-scale, predictable changes in structure or, alternatively, that variation from time to time is small-scale and differs from shore to shore or site to site on a shore. There was considerable variation at all scales examined — among replicate quadrats within sites, between sites on a shore and among shores. Similarly, assemblages differed from one sampling period to the next and changes in the assemblages over time periods of three months were as great as from year to year. These changes were interactive, with no two sites or shores showing similar temporal patterns. Thus, understanding diversity along a coast-line requires detailed understanding of local processes. Without adequate spatial and temporal replication in sampling designs and without explanatory models, the large and complex variability in intertidal assemblages at different scales cannot be documented and understood.

Rocky shores and development of the Pliocene-Pleistocene Arroyo Blanco Basin on Isla Carmen in the Gulf of California, Mexico

2006 ◽  
Vol 43 (8) ◽  
pp. 1149-1164 ◽  
Author(s):  
James M Eros ◽  
Markes E Johnson ◽  
David H Backus
Keyword(s):  
Sea Level ◽  
Gulf Of California ◽  
Rocky Shore ◽  
Normal Faults ◽  
Rocky Shores ◽  
Last Interglacial ◽  
Marine Terraces ◽  
Shell Beds ◽  
History Of ◽  
Cap Rock

Arroyo Blanco Basin on Isla Carmen preserves a 157 m thick, nearly complete record of Pliocene–Pleistocene history in the Gulf of California. Examples of rocky-shore geomorphology occur on all margins of this trapezoidal-shaped, 3.3 km2 basin. A shoreline is developed in low relief on Miocene andesite from the Comondú Group at the rear of the basin parallel to the long axis of the island. Two end walls trace normal faults that stayed active during the life of the basin and maintained steep rocky shores. The basin is 64% filled by calcarudite and calcarenite derived from crushed rhodolith debris. Other facies include shell beds and stringers of andesite conglomerate that define a 4°–6° ramp. The ramp expanded onshore through Pliocene time, based on a succession of overlapping range zones for 22 macrofossils typical of Lower through Upper Pliocene strata in the Gulf of California. The unconformity exposed 1 km inland at the rear of the basin is between Miocene volcanics and Pleistocene cap rock at an elevation of 170 m above sea level. Whole rhodoliths encrusted on andesite pebbles occur above this unconformity. Presumably, the older Miocene-Pliocene unconformity is buried beneath the ramp. Four marine terraces with sea cliffs notched in Pliocene limestone occur at elevations of 68, 58, 37, and 12 m. The 12 m terrace is associated regionally with the last interglacial epoch between 120 000 and 135 000 years ago. Juxtaposition of ramp and terrace features in the same exhumed basin supports a long history of gradual Pliocene subsidence followed by episodic Pleistocene uplift.

A Lower Pennsylvanian encrusting tabulate coral from a rocky shore environment developed on the Mississippian—Pennsylvanian unconformity surface in northwestern Arkansas

1993 ◽  
Vol 67 (6) ◽  
pp. 1064-1068 ◽  
Author(s):  
Gregory E. Webb
Keyword(s):  
Rocky Shore ◽  
Wave Attenuation ◽  
High Energy ◽  
Limiting Factors ◽  
Rocky Shores ◽  
Highly Sensitive ◽  
Substrate Stability ◽  
Abundance And Diversity ◽  
High Wave Energy ◽  
Unconformity Surface

Paleozoic corals are very rare in rocky shore settings. The only Paleozoic encrusting coral so far reported from this environment is Favosites sp. from Ordovician rocky shore deposits in Manitoba, Canada (Johnson and Baarli, 1987). Reading and Poole (1961) reported corals and brachiopods that occur between, and “coating,” boulders from a Silurian rocky shore in England, but it appears that the corals and brachiopods only occur in the sediment enveloping the boulders, not as encrusters on the surfaces of the boulders. One reason for the sparse record of Paleozoic corals in rocky shore settings is the scarcity of described Paleozoic rocky shore deposits themselves. Johnson (1988) found only 20 examples of Paleozoic rocky shores in a compilation of references on ancient rocky shores from the literature. The paucity of described ancient rocky shores has been attributed to the prevalence in the past of epicontinental seas with little relief upon which to develop rocky shores and with higher wave attenuation farther from shore (Boucot, 1981; Harland and Pickerill, 1984). Johnson (1988) concluded that the major reason for the rarity of ancient rocky shores in the literature is the difficulty with which they are recognized and studied, owing to the relatively poor exposure of most unconformity surfaces. The rocky shore environment was also probably hostile to many Paleozoic coral genera. Recent scleractinian corals may serve as analogues because they are also not very abundant in rocky shore settings despite their great abundance in similar shallow-water, high-wave-energy reefal environments. Turbidity and relative substrate stability may be important limiting factors for corals in rocky shore environments. Many corals are known to be highly sensitive to sediment in the water column. Substrate stability (Wilson, 1987) and the scouring effects of sand in high-energy environments (Palmer and Palmer, 1977) also have been shown to affect the abundance and diversity of organisms encrusting cobbles and boulders.

scholarly journals Effects of human trampling on a rocky shore fauna on the Sao Paulo coast, southeastern Brazil

2009 ◽  
Vol 69 (4) ◽  
pp. 993-999 ◽  
Author(s):  
MN. Ferreira ◽  
S. Rosso
Keyword(s):  
Rocky Shore ◽  
Management Strategies ◽  
Experimental Studies ◽  
Southeastern Brazil ◽  
Rocky Shores ◽  
Density And Biomass ◽  
Turn Over ◽  
Rocky Shore Communities ◽  
Vacation Period ◽  
Chthamalus Bisinuatus

Increased tourist activity in coastal regions demands management strategies to reduce impacts on rocky shores. The highly populated coastal areas in southeastern Brazil are an example of degradation caused by development of industry and tourism. Among different shore impacts, trampling has been intensively studied, and may represent a significant source of stress for intertidal fauna. A randomised blocks design was applied to experimentally study the effects of two different trampling intensities on richness, diversity, density and biomass of the rocky shore fauna of Obuseiro beach, Guarujá, southeastern Brazil. Blocks were distributed in two portions of the intertidal zone, dominated respectively by Chthamalus bisinuatus (Cirripedia) and Isognomon bicolor (Bivalvia). Blocks were trampled over three months, simulating the vacation period in Brazil and were monitored for the following nine months. Results indicate that Chthamalus bisinuatus is vulnerable to trampling impacts. Richness, diversity and turn-over index tended to be higher in trampled plots four months after trampling ceased. In general, results agree with previous trampling studies, suggesting that even low intensities of trampling may cause some impact on intertidal communities. Management strategies should include isolation of sensitive areas, construction of boardwalks, visitor education and monitoring programmes. In Brazil, additional data obtained from experimental studies are necessary in order to achieve a better understanding of trampling impacts on rocky shore communities.

Species associations of congeneric species in a tropical seasonal rain forest of China

2016 ◽  
Vol 32 (3) ◽  
pp. 201-212 ◽  
Author(s):  
Guoyu Lan ◽  
Yunbing Zhang ◽  
Fangliang He ◽  
Yuehua Hu ◽  
Hua Zhu ◽  
...  
Keyword(s):  
Species Interactions ◽  
Rain Forest ◽  
Biotic Interactions ◽  
Second Order ◽  
Small Scale ◽  
Order Effects ◽  
Congeneric Species ◽  
First Order ◽  
Large Trees ◽  
Tropical Seasonal Rain Forest

Abstract:In tropical plant communities with diverse species, many congeners are found to coexist. Do environment or biotic interactions structure the coexistence of congeners in tropical forest communities? In this paper, we aimed to disentangle the effect of environment (first-order effects) and species interactions (second-order effects) on the spatial distributions of tree species. We used a classification scheme and torus-translation to test the first-order interaction of 48 species from 17 genera in a fully mapped 20-ha dipterocarp tropical seasonal rain-forest plot in Xishuangbanna, south-west China. Then we used heterogeneous Poisson null models to reveal significant uni- and bivariate second-order interactions. The results demonstrated that (1) 34 of the 48 studied species showed a significant relation with at least one topographic variable. This confirmed that topographical heterogeneity is important for distribution of these congeners. Spatial segregation (36.6%) and partial overlap (34.8%) were the most common bivariate association types in Xishuangbanna plot, which indicated first-order effects (environment) were strong. (2) For small-scale associations, 51% saplings (1 to ≤ 5 cm) (68.8% for large trees with dbh > 5 cm) of the species showed non-significant associations. For large-scale associations, 61.6% saplings (81.2% for large trees) of the species showed non-significant associations. Lack of significant species interactions provides evidence for the unified neutral theory. In conclusion, both environment and biotic interactions structure congeneric species' coexistence in tropical seasonal rain forest in this region.

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