Effects of herbivores, wave exposure and depth on benthic coral communities of the Easter Island ecoregion

The Easter Island ecoregion includes Rapa Nui (Easter Island; RN), with a human population of ~5600, and the uninhabited Salas y Gómez (SyG). Although the culture and terrestrial ecology of RN have been well studied, we know little about the marine environment of these islands, particularly the interplay among herbivores, algae, and corals, and how coral reef communities differ between islands, by wave energy exposure, and between depths. To address the potential roles of herbivores, wave-energy exposure, and depth on the sessile benthic communities, we examined herbivorous fish biomass, sea urchin (Diadema savignyi) density, and algal and coral cover to identify patterns and relationships among these groups. We found significant differences between islands. For example, turf and macroalgae were nearly absent from SyG, whereas D. savignyi density and Kyphosus sandwicensis biomass were ~28- and ~3-fold greater respectively at SyG. Benthic cover of coral and algae and density of D. savignyi significantly differed among levels of wave exposure, especially between wave-protected stations and semi-exposed and exposed stations. Likewise, community structure significantly differed at protected stations. Concordant patterns between herbivores and algae were observed. Therefore, herbivores and wave energy likely play important roles in structuring these benthic communities, especially for algal groups.

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Coral communities condition in varying wave exposure: the gulf of Cazones, Cuba

Revista de Biología Tropical ◽

10.15517/rbt.v64i1.18231 ◽

2016 ◽

Vol 64 (1) ◽

pp. 79 ◽

Cited By ~ 3

Author(s):

Hansel Caballero Aragon ◽

Pedro M Alcolado ◽

Néstor Rey-Villiers ◽

Susana Perera Valderrama ◽

Juliett González Méndez

Keyword(s):

Species Richness ◽

Community Structure ◽

Marine Protected Area ◽

Coral Cover ◽

Coral Community ◽

Wave Exposure ◽

Maximum Diameter ◽

Live Coral ◽

Coral Mortality ◽

Coral Communities

Wave exposure can influence community structure and distribution of shallow coral reefs, by affecting organisms both directly and indirectly. To assess the current stony coral community condition under different degrees of wave exposure at a marine protected area of the Gulf of Cazones (SW Cuba), two expeditions were carried out in May 2010 and June 2012. Four sampling sites were sampled at reef crests (1.5 m deep), and twelve at fore-reefs, at 10, 15 and 20 m deep in four geographic locations. Live coral cover, species richness and composition, colony density, and maximum diameter were assessed using the AGRRA 2001 methodology. Multivariate and non-parametric statistics were applied to compare sites. The coral community structure within reef crests was not homogenous. The observed variability of indicators apparently was determined by great coral mortality events resulting from natural disturbances that occurred in the past (hurricanes, bleaching and diseases). Fore-reef coral communities displayed better condition and lower coral mortality than reef crests. Species richness and coral composition varied, while multivariate and statistical methods did not reveal site grouping with regard to wave exposure. The remaining biological condition indicators were similar among sites, except in the most exposed one, where coral cover and coral size were slightly lower. Wave exposure in the gulf of Cazones seemed not to have a significant influence on differences in condition and structure of the assessed coral communities.

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Reef-building coral communities of Easter Island (Rapa Nui), Chile

Latin American Coral Reefs ◽

10.1016/b978-044451388-5/50021-7 ◽

2003 ◽

pp. 473-494 ◽

Cited By ~ 16

Author(s):

Peter W. Glynn ◽

Gerard M. Wellington ◽

Evie A. Wieters ◽

Sergio A. Navarrete

Keyword(s):

Easter Island ◽

Rapa Nui ◽

Coral Communities

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The coral communities of Lord Howe Island

Marine and Freshwater Research ◽

10.1071/mf9950457 ◽

1995 ◽

Vol 46 (2) ◽

pp. 457 ◽

Cited By ~ 52

Author(s):

VJ Harriott ◽

PL Harrison ◽

SA Banks

Keyword(s):

Coral Cover ◽

Benthic Communities ◽

Tropical Species ◽

Hard Coral ◽

Lord Howe Island ◽

The Pacific ◽

The Status ◽

Coral Communities ◽

Apparent Reduction ◽

Hard Coral Cover

Lord Howe Island (31�33′S, 159�05′E) is surrounded by the southern-most coral reefs in the Pacific Ocean. The status of the benthic communities at Lord Howe Island was quantified in 1992-93 using replicated video-transects at 20 sites in the shallow reefal area (<20 m depth). The cover of hard coral was comparable with coral cover on some tropical reefs, ranging from less than 10% at some reef flat sites to greater than 40% cover at two seaward beach sites. The process of reef formation is apparently slow, and accretion of limestone is localized. A total of 59 scleractinian coral species were recorded during this study (including 19 new records), bringing the total number recorded at Lord Howe Island to 83. The coral communities contain a unique association of tropical species at their southern limits of distribution, and subtropical species which are rare or absent from the Great Barrier Reef. Many of the species that have been recorded from Lord Howe Island are rare, and may have resulted from chance recruitment of only a few larvae. There have been few major changes in the coral communities at Lord Howe Island in the past 16 years. At two inshore sites there was an apparent reduction in hard coral cover in the 1980s.

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Coral assemblages and physico-chemical characteristics of the Whitsunday Islands: evidence of recent community changes

Marine and Freshwater Research ◽

10.1071/mf97046 ◽

1999 ◽

Vol 50 (5) ◽

pp. 427 ◽

Cited By ~ 100

Author(s):

R. van Woesik ◽

T. Tomascik ◽

S. Blake

Keyword(s):

Scleractinian Coral ◽

Coral Species ◽

Coral Cover ◽

Benthic Communities ◽

Coral Recruitment ◽

Coral Abundance ◽

Physico Chemical ◽

Coral Communities ◽

River Mouths ◽

Negative Relationships

Benthic communities were assessed and 22 environmental variables were monitored at seven leeward localities (L1ŒL7) in the Whitsunday Islands, Queensland, Australia. L1 was near the Proserpine and O’Connell river mouths and L7 ~80 km north of the river mouths. Distinct physico Œchemical and biological gradients were evident. Sparse scleractinian coral communities, dominated by faviids, Montipora spp. and encrusting Porites colonies, were present at L1, L2 and L3, whereas diverse reef-building communities, dominated by Acropora spp., were more common at and beyond L4. The number of coral recruits (age <6 months) did not differ significantly among localities, suggesting that coral recruitment was near random and that the environment shapes the adult community from those recruits. The study demonstrates strong negative relationships between chlorophyll a and the following: percentage coral cover, coral species richness and coral abundance. The reef-building capacities of the coral communities and the extent of Holocene reef development were inconsistent at L2 and L3, which is interpreted as a sign of anthropogenic effects.

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First Records and Descriptions of Early Life Stages of Cephalopods from Rapa Nui (Easter Island) and the Nearby Apolo Seamount

Pacific Science ◽

10.2984/73.1.8 ◽

2019 ◽

Vol 73 (1) ◽

pp. 163 ◽

Cited By ~ 1

Author(s):

Sergio A. Carrasco ◽

Erika Meerhoff ◽

Beatriz Yannicelly ◽

Christian M. Ibáñez

Keyword(s):

Early Life ◽

Easter Island ◽

Life Stages ◽

Early Life Stages ◽

Rapa Nui

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FIRST CHARACTERIZATION OF DRILLING PREDATION ON EASTER ISLAND - RAPA NUI

10.1130/abs/2017am-303900 ◽

2017 ◽

Author(s):

Julieta Martinelli ◽

◽

Sandra Gordillo ◽

Maria Carla De Aranzamendi ◽

...

Keyword(s):

Easter Island ◽

Rapa Nui ◽

Drilling Predation

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Daily accumulation rates of marine litter on the shores of Rapa Nui (Easter Island) in the South Pacific Ocean

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2021.112535 ◽

2021 ◽

Vol 169 ◽

pp. 112535

Author(s):

Martin Thiel ◽

Bárbara Barrera Lorca ◽

Luis Bravo ◽

Iván A. Hinojosa ◽

Hugo Zeballos Meneses

Keyword(s):

Pacific Ocean ◽

South Pacific ◽

Easter Island ◽

Accumulation Rates ◽

The South ◽

Rapa Nui ◽

Marine Litter ◽

South Pacific Ocean

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Thermal Imaging Shows Submarine Groundwater Discharge Plumes Associated with Ancient Settlements on Rapa Nui (Easter Island, Chile)

Remote Sensing ◽

10.3390/rs13132531 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2531

Author(s):

Robert J. DiNapoli ◽

Carl P. Lipo ◽

Timothy S. de Smet ◽

Terry L. Hunt

Keyword(s):

Fresh Water ◽

Submarine Groundwater Discharge ◽

Groundwater Discharge ◽

Water Sources ◽

Easter Island ◽

Human Populations ◽

Rapa Nui ◽

Hydrologic Processes ◽

Submarine Groundwater ◽

Aerial Systems

Submarine groundwater discharge (SGD) is an important component of many coastal environments and hydrologic processes, providing sources of nutrients to marine ecosystems, and potentially, an important source of fresh water for human populations. Here, we use a combination of unpiloted aerial systems (UAS) thermal infrared (TIR) imaging and salinity measurements to characterize SGD on the remote East Polynesian island of Rapa Nui (Easter Island, Chile). Previous research has shown that coastal freshwater seeps are abundant on Rapa Nui and strongly associated with the locations of ancient settlement sites. We currently lack, however, information on the differential magnitude or quality of these sources of fresh water. Our UAS-based TIR results from four locations on Rapa Nui suggest that locations of variably-sized SGD plumes are associated with many ancient settlement sites on the island and that these water sources are resilient to drought events. These findings support previous work indicating that ancient Rapa Nui communities responded to the inherent and climate-induced hydrological challenges of the island by focusing on these abundant and resilient freshwater sources. Our results highlight the efficacy of using UAS-based TIR for detecting relatively small SGD locations and provide key insights on the potential uses of these water sources for past and current Rapa Nui communities.

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