scholarly journals Feeding selectivity of the herbivorous fish Scartichthys viridis:effects on macroalgal community structure in a temperate rocky intertidal coastal zone

1999 ◽  
Vol 184 ◽  
pp. 219-229 ◽  
Author(s):  
FP Ojeda ◽  
AA Muñoz
2018 ◽  
Author(s):  
Alexis Catalán ◽  
Nelson Valdivia ◽  
Ricardo Scrosati

In rocky intertidal environments, the vertical gradient of abiotic stress generates, directly or indirectly, significant spatial variation in community structure. Along shorelines within biogeographic regions, abiotic changes also generate horizontal biological variation, which when measured at large sampling intervals may surpass vertical biological variation. Little is known, however, on how vertical variation compares with horizontal variation measured at multiple spatial scales in habitats with similar environmental conditions. Here, we compare spatial variability in rocky-intertidal communities between vertical stress gradients and three horizontal spatial scales (sampling interval) across habitats experiencing the same wave exposure on the Northwest Atlantic (NWA) and Southeast Pacific (SEP) coasts. For both regions, the vertical variation in species richness and composition (Raup-Crick and Bray-Curtis indices) was higher than the variation measured at all horizontal scales, from a few cm to hundreds of km. The patterns of variation in community structure matched those of abundance for the dominant sessile organisms, the foundation species Ascophyllum nodosum (seaweed) in NWA and Perumytilus purpuratus (mussel) in SEP. This interhemispheric comparison reveals the tight link between environmental and biological variation, indicating that studies comparing spatial scales of biological variation must consider the underlying environmental variation in addition to simply scale alone.


2011 ◽  
Vol 44 (3) ◽  
pp. 298-307 ◽  
Author(s):  
Young-Dae Kim ◽  
Mi-Seun Park ◽  
Tae-Seok Moon ◽  
Jung-Kwan Ahn ◽  
Su-Ji Kim ◽  
...  

Author(s):  
Dandi Saleky ◽  
Simon P.O Leatemia ◽  
Yuanike Yuanike ◽  
Irman Rumengan ◽  
I Nyoman Giri Putra

Gastropods is an important organism that commonly found inhabiting the rocky intertidal area. Distribution pattern of this species is influenced by various factors such as population history, microhabitat, predation and a complex interactions between oceanographic dynamics and ecological features. This study aims to compare the temporal distribution pattern of gastropods at two different rocky intertidal area. This research was conducted at the rocky intertidal area of Amban and Nuni, North Manokwari District, West Papua. Data collection was performed during the daylight and night in April and June 2012 using systematic sampling method. The results showed that both physical and chemical factors are suite for supporting gastropods life. Furthermore, these factors seem to have an impact on gastropod zoning patterns observed in the study area. The similarity index values ​​indicate that the similarity of gastropod species between the two locations is low, which means that the species of gastropods found in each location is quite different. The community structure of gastropod at the study area is stable. In addition, we found that the gastropods diversity were higher during the night than the daylight because gastropods are classified as a nocturnal animals. Key Words: Gastropod; Rocky Intertidal; Community Structure; Nocturnal


2018 ◽  
Author(s):  
Alexis Catalán ◽  
Nelson Valdivia ◽  
Ricardo Scrosati

In rocky intertidal environments, the vertical gradient of abiotic stress generates, directly or indirectly, significant spatial variation in community structure. Along shorelines within biogeographic regions, abiotic changes also generate horizontal biological variation, which when measured at large sampling intervals may surpass vertical biological variation. Little is known, however, on how vertical variation compares with horizontal variation measured at multiple spatial scales in habitats with similar environmental conditions. Here, we compare spatial variability in rocky-intertidal communities between vertical stress gradients and three horizontal spatial scales (sampling interval) across habitats experiencing the same wave exposure on the Northwest Atlantic (NWA) and Southeast Pacific (SEP) coasts. For both regions, the vertical variation in species richness and composition (Raup-Crick and Bray-Curtis indices) was higher than the variation measured at all horizontal scales, from a few cm to hundreds of km. The patterns of variation in community structure matched those of abundance for the dominant sessile organisms, the foundation species Ascophyllum nodosum (seaweed) in NWA and Perumytilus purpuratus (mussel) in SEP. This interhemispheric comparison reveals the tight link between environmental and biological variation, indicating that studies comparing spatial scales of biological variation must consider the underlying environmental variation in addition to simply scale alone.


2017 ◽  
Vol 35 (4) ◽  
pp. 595-603
Author(s):  
Jin suk Heo ◽  
Hyun Il Yoo ◽  
Eun jung Park ◽  
Dong Soo Ha

2012 ◽  
Vol 82 (3) ◽  
pp. 678-691 ◽  
Author(s):  
Tina Šilović ◽  
Vanessa Balagué ◽  
Sandi Orlić ◽  
Carlos Pedrós-Alió

2021 ◽  
Vol 8 ◽  
Author(s):  
Benjamin Weitzman ◽  
Brenda Konar ◽  
Katrin Iken ◽  
Heather Coletti ◽  
Daniel Monson ◽  
...  

Marine heatwaves are global phenomena that can have major impacts on the structure and function of coastal ecosystems. By mid-2014, the Pacific Marine Heatwave (PMH) was evident in intertidal waters of the northern Gulf of Alaska and persisted for multiple years. While offshore marine ecosystems are known to respond to these warmer waters, the response of rocky intertidal ecosystems to this warming is unclear. Intertidal communities link terrestrial and marine ecosystems and their resources are important to marine and terrestrial predators and to human communities for food and recreation, while simultaneously supporting a growing coastal tourism industry. Given that current climate change projections suggest increased frequency and duration of marine heatwaves, monitoring and understanding the impacts of heatwaves on intertidal habitats is important. As part of the Gulf Watch Alaska Long-Term Monitoring program, we examined rocky intertidal community structure at 21 sites across four regions spanning 1,200 km of coastline: Western Prince William Sound, Kenai Fjords National Park, Kachemak Bay, and Katmai National Park and Preserve. Sites were monitored annually from 2012 to 2019 at mid and low tidal strata. Before-PMH (2012–2014), community structure differed among regions. We found macroalgal foundation species declined during this period mirroring patterns observed elsewhere for subtidal habitat formers during heatwave events. The region-wide shift from an autotroph-macroalgal dominated rocky intertidal to a heterotroph-filter-feeder dominated state concurrent with the changing environmental conditions associated with a marine heatwave event suggests the PMH had Gulf-wide impacts to the structure of rocky intertidal communities. During/after-PMH (2015–2019), similarities in community structure increased across regions, leading to a greater homogenization of these communities, due to declines in macroalgal cover, driven mostly by a decline in the rockweed, Fucus distichus, and other fleshy red algae in 2015, followed by an increase in barnacle cover in 2016, and an increase in mussel cover in 2017. Strong, large-scale oceanographic events, like the PMH, may override local drivers to similarly influence patterns of intertidal community structure.


Author(s):  
Mónica Prado-España ◽  
Luis Troccoli-Ghinaglia ◽  
Jacqueline Cajas-Flores

Most fishing and aquaculture activity in Ecuador is concentrated in the Gulf of Guayaquil. However, the nutrient loads from anthropic activities could affect the water quality and the diversity of fishery resources. Surface water samples were collected to determine the temperature, salinity, dissolved oxygen, nutrients, and the community structure of microphytoplankton to determine the trophic status of the coastal zone and the inner estuary. In addition, the relation between the hydrographic variables was established through principal component analysis (PCA), and redundancy analysis (RDA) was used to analyze the effect of the environmental variables on the microphytoplankton communities. Differences in community structure were determined using multidimensional scaling analysis of similarities (MDS-Anosim), and the trophic status was established through the Karydis index. Significant differences were detected between the coastal zone and the inner estuary. Overall, the inner estuary showed a higher trophic level, with higher temperature and nutrient concentrations, and lower values for the salinity, transparency, and dissolved oxygen. Seventeen species of microphytoplankton were identified, of which 78% were diatoms, 18% dinoflagellates, 2% cyanophytes, and 2% silicoflagellates. Significant differences were detected in equitability and diversity, with fewer records in the estuarine area. The RDA showed a positive correlation (0.54; p <0.05) between Paralia sulcata, Thalassionema nitzschioides, Thalassionema frauenfeldii and nutrients and a negative correlation with salinity. In the inner estuary, Nitzschia longissima, Chaetoceros decipiens, and Skeletonema costatum were positively correlated (0.64; p <0.05) with temperature and negatively correlated with phosphate and nitrate. Differences in the community structure existed between zones, with S. costatum, T. frauenfeldii, and T. nitzschioides dominating the inner estuary and N. longissima, Guinardia striata, and Leptocylindrus danicus dominating in the coastal zone. The study area was determined to be mesotrophic. However, in the inner estuary, the values of the trophic index were higher because this area probably receives more directly the contributions from anthropic activities. Surveys with samples less than a mile from the coast are recommended to determine the trophic status in an area closer to the coast and to develop management plans to avoid threats of eutrophication.


Author(s):  
Camilo B. García ◽  
Guillermo Díaz Pulido

The macroalgal intertidal community at a tropical location (Punta de la Loma, Colombian Caribbean) was monitored at irregular intervals from 1992 to 1995. The highly diverse macroalgal community was relatively invariant in cover, taxa and biomass from small spatial scales (square centimeters). At larger spatial scales (square meters), however, there was a small but definitive seasonal pulse in dominance and composition. Sand intrusions over the rocky intertidal represents a strong disturbance reducing macroalgal cover during the dry season. Interannual variation was also detected. La Punta de la Loma appears to be influenced by the regional upwelling conditions.


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