Vertical distribution of coralline algae in the rocky intertidal of northern Chile

Hydrobiologia ◽  
1993 ◽  
Vol 260-261 (1) ◽  
pp. 121-129 ◽  
Author(s):  
C. Isabel Meneses
Keyword(s):  
Vertical Distribution ◽  
Rocky Intertidal ◽  
Coralline Algae ◽  
Northern Chile

scholarly journals Disturbance alters ecosystem engineering by a canopy-forming alga

2017 ◽  
Vol 98 (4) ◽  
pp. 687-698 ◽  
Author(s):  
Jacqueline B. Pocklington ◽  
Stuart R. Jenkins ◽  
Alecia Bellgrove ◽  
Michael J. Keough ◽  
Tim D. O'Hara ◽  
...  
Keyword(s):  
Species Richness ◽  
Environmental Conditions ◽  
Ascophyllum Nodosum ◽  
Ecosystem Engineering ◽  
Rocky Intertidal ◽  
Coralline Algae ◽  
Littorina Obtusata ◽  
Invertebrate Species ◽  
Light Levels ◽  
Pulse Disturbance

Canopy-forming fucoid algae have an important role as ecosystem engineers on rocky intertidal shores, where they increase the abundance of species otherwise limited by exposure during low tide. The facilitative relationship between Ascophyllum nodosum and associated organisms was explored using a frond breakage experiment (100%, 50%, 25%, 0% intact-frond treatments) in southern England, to assess the consequences of disturbance. Understorey substratum temperature was on average 3°C higher in 0% and 25% intact-frond treatments than in plots with 50% and 100% intact fronds. Light (as PAR during low tide) doubled in 0% intact-frond treatments in comparison to other treatments (which had similar light levels). Mobile invertebrate species richness declined by on average 1 species per m2 in the treatments with only 25% and 0% intact fronds, and the abundance of Littorina obtusata declined by 2.4–4.2 individuals per m2 in the treatments with 25 and 0% intact fronds. Sessile taxa, including Osmundea pinnatifida and encrusting coralline algae, declined by half on average in the 0% intact-frond treatment. These results suggest that the ability of Ascophyllum to mediate environmental conditions to the understorey is the mechanism responsible for species distributed in the understorey (autogenic ecosystem engineering). The results of this study imply that a pulse disturbance resulting in a 50% breakage of Ascophyllum fronds significantly increases temperature and decreases the abundance of mobile invertebrates usually associated with Ascophyllum. Sessile taxa associated with Ascophyllum can, however, withstand disturbances down to 25% intact Ascophyllum fronds.

Species composition and vertical distribution of chitons (Mollusca: Polyplacophora) in a rocky intertidal zone of the Pacific coast of Costa Rica

2008 ◽  
Vol 88 (4) ◽  
pp. 807-816 ◽  
Author(s):  
K.M. Jörger ◽  
R. Meyer ◽  
I.S. Wehrtmann
Keyword(s):  
Costa Rica ◽  
Species Composition ◽  
Vertical Distribution ◽  
Intertidal Zone ◽  
Rocky Intertidal ◽  
Salinity Range ◽  
Tide Pool ◽  
Exposed Rock ◽  
The Pacific ◽  
Peak Abundance

The present study describes the species composition and vertical distribution of chitons in tide pools and on exposed rock areas of the intertidal zone of Samara, Guanacaste, Pacific Costa Rica. Nine different species of chitons were recorded, and their densities and sizes were determined using quadrate sampling. Physical (period of emersion, temperature and salinity range) and biotic (presence and diversity of food resources) factors were examined to assess their influence on distribution and abundance of each species. Ischnochiton dispar was the predominant species with densities of up to 200 ind m−2, representing 85.4% of all sampled individuals (N = 4193). The size of I. dispar was positively correlated with the size of the inhabited boulders. Two species (I. dispar and Stenoplax limaciformis) showed segregation in size: I. dispar being negatively and S. limaciformis positively correlated to the distance from the shore. Two of the nine species (Chiton stokesii and Acanthochitona hirundiniformis) occurred mainly on rocky areas outside the tide pools with variable amounts of exposure to air during each tidal cycle. In both species the tide pool specimens were significantly smaller than those collected in the rocky areas. Distribution of all other species was restricted to the tide pools and species had their peak abundance in the zones with more moderate conditions and a higher diversity of algae, resulting in the highest chiton diversity in these areas.

Diet of the pulmonate gastropod Onchidella nigricans in the intertidal rocky shore, New Zealand

2009 ◽  
Vol 59 (2) ◽  
pp. 231-240 ◽  
Author(s):  
Andrea Alfaro
Keyword(s):  
Stable Isotopes ◽  
New Zealand ◽  
Algal Species ◽  
Rocky Intertidal ◽  
Coralline Algae ◽  
Gut Contents ◽  
Bare Rock ◽  
Generalist Herbivore ◽  
Δ13c And Δ15n ◽  
Isotopic Signatures

AbstractGut content analyses and stable isotopes (δ13C and δ15N) were used to investigate the food consumption and assimilation of the pulmonate, Onchidella nigricans, within a rocky intertidal platform at Waiwera, northern New Zealand. Analyses of gut contents indicate that this species is a generalist herbivore, which may consume a variety of micro- and macro-algae, although small zooplankton may be ingested, when present. Gut contents of individuals collected from different intertidal habitats (bare rock, Hormosira banksii, green filaments, and coralline algae) reflected the dominant algal species within each habitat, suggesting that food availability does not restrict the grazer's distribution across its range. The radular morphology and small size of this gastropod also support the notion that O. nigricans is a non-selective microphagous feeder. However, stable isotopes on O. nigricans from the four habitats and the dominant algal food types indicate a strong assimilation preference for microalgae. The δ13C values (-15 to -13‰) of O. nigricans were consistent with signatures for intertidal grazers, but δ15N values (8 to 9‰) were relatively high, which may indicate the presence of bacteria and microfaunal detritus in the diet. Clusters of isotopic signatures of individuals from different habitats suggest feeding preferences, which also may be attributed to differences in detrital and bacterial consumption. This study illustrates the importance of using parallel techniques in diet studies.

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