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.

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.

scholarly journals The Biodiversity of Gastropods In Karapyak Rocky Shores, Pangandaran Region, West Java Province, Indonesia

Omni-Akuatika ◽  
2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Asep Sahidin ◽  
Zahidah Zahidah ◽  
Herman Hamdani ◽  
Indah Riyantini ◽  
Roni Sewiko
Keyword(s):  
Cluster Analysis ◽  
Spatial Distribution ◽  
Rocky Shore ◽  
Rocky Shores ◽  
West Java ◽  
The Family ◽  
Average Abundance

Pangandaran rocky shores have a unique ecosystem and a variant of invertebrate organisms such as mollusk from the gastropod class. This study aims to analyze the biodiversity of gastropods on the rocky shore of Karapyak beach. This research consists of 5 stations. The quadrant set by 1 m x 1 m vertically toward the sea. The result found 773 individuals scattered in nine families. The family of Neritidae dominated (43%), followed by family cyprinoids with 6.3%. Nerita plicata is a species found to dominate in every station with an average abundance (256 ± 10) and/m2. Using the Bray-Curtis cluster analysis, showed variations in the distribution and abundance of different gastropods vertically into the ocean and uniformly distributed horizontally to the shore. Substrate and tidal are the main variables in the spatial distribution of gastropods in the Karapyak beach.

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.

Beyond tides: surge-dominated submersion regimes on rocky shores of central Chile

2019 ◽  
Vol 166 (7) ◽  
Author(s):  
Gabriela Flores ◽  
Rodrigo Cienfuegos ◽  
Sergio A. Navarrete
Keyword(s):  
Rocky Shores ◽  
Central Chile

Middle to Late Ordovician rocky bottoms and rocky shores from the Manitoulin Island area, Ontario

1989 ◽  
Vol 26 (4) ◽  
pp. 642-653 ◽  
Author(s):  
Markes E. Johnson ◽  
Rong Jia-yu
Keyword(s):  
North America ◽  
Rocky Shore ◽  
Late Ordovician ◽  
Depositional Environments ◽  
Lake Huron ◽  
Rocky Shores ◽  
Rare Association ◽  
Brachiopod Fauna ◽  
Rocky Bottoms ◽  
Topographic Relief

The Precambrian Lorrain Quartzite is exposed on Manitoulin, Great Cloche, and Birch islands in Lake Huron off the mainland of Ontario. Metamorphism created a massive unit, which later formed a resistant angular unconformity overlain by a succession of strata deposited from Middle to Late Ordovician times. At the start of Ordovician sedimentation, topographic relief was at least 125 m when the quartzite hills formed an archipelago of small, rocky islands. The Ordovician–Precambrian unconformity provides insight on a changing series of depositional environments over rocky bottoms and rocky shores. Four Ordovician units are well represented. The Swift Current Formation includes some red beds, while the younger Cloche Island and Cobourg formations are carbonates. The Collingwood Formation is a black shale. The first three include eroded quartzite clasts typical of a rocky-shore setting. The unconformity marked by the Collingwood Formation indicates a rapid transgression with little time for the accumulation of eroded quartzite clasts. A rich trilobite and orthid brachiopod fauna was recovered from the Collingwood Formation immediately above the Lorrain Quartzite and it represents a rare association that lived in a rocky-bottom setting. This fauna includes the first-reported occurrence of the genus Triarthrus from Manitoulin Island. The Collingwood transgression is equated with a major rise in sea level widely recognized elsewhere in North America and Scandinavia.

CO2 generation by calcified invertebrates along rocky shores of Brittany, France

2013 ◽  
Vol 64 (2) ◽  
pp. 91 ◽  
Author(s):  
Christian Hily ◽  
Jacques Grall ◽  
Laurent Chauvaud ◽  
Morgane Lejart ◽  
Jacques Clavier
Keyword(s):  
Intertidal Zone ◽  
Rocky Shore ◽  
Regional Scale ◽  
Coastal Environment ◽  
Co2 Production ◽  
Rocky Shores ◽  
Atlantic Region ◽  
The North ◽  
Wide Range ◽  
North Eastern

Many autochthonous and alien macroinvertebrates of the intertidal zone are biocalcifiers, and the present study proposes a first assessment of their calcimass and their annual calcium carbonate (CaCO3) production at a regional scale, along 500 km of the coastline of Brittany, France, which represents a wide range of the rocky-shore habitats commonly encountered in the north-eastern Atlantic region. All sites considered together gave a mean calcimass estimate of 5327 g m–2. The corresponding mean CaCO3 gross production was 2584 g m–2 year–1. The net production (including dissolution) by biocalcification was 2384 g CaCO3 m–2 year–1. Estimations of CO2 production via both calcification and respiration were carried out in particular for the phylum Mollusca and for crustacean barnacles, dominating in terms of calcimass. Mean CO2 production obtained by summing CO2 fluxes related to net CaCO3 production and respiration for all sampled sites was 22.9 mol m–2 year–1. These results illustrate the significance of CO2 production during biogenic CaCO3 precipitation of intertidal invertebrates in such temperate coastal environment compared with tropical zones and the contribution of the shelves to the global CaCO3 budget.

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