Benthic communities at two remote Pacific coral reefs: effects of reef habitat, depth, and wave energy gradients on spatial patterns

Reefs are the richest marine ecosystems. Their benthic communities generate structural complexity and participate in nutrient cycles, providing habitat and food for many marine species. These ecosystems have been threatened by local and global anthropogenic impacts and changes in community structure have led to loss of biodiversity, ecosystem function and services worldwide. Most studies about these structural changes have been conducted in Caribbean and Indo-Pacific coral reefs. In the Southwestern Atlantic, where reefs are naturally algae-dominated, these efforts are incipient, especially at oceanic islands where local anthropic impacts tend to be lower, and natural and climate-induced fluctuations might be easily detected. We conducted the first temporal assessment of benthic communities and the influence of oceanographic parameters between 2013 and 2019 in Fernando de Noronha (FNA), the largest Brazilian oceanic archipelago. We annually sampled benthic communities in FNA’s shallow reefs (2–21 m) using photoquadrats, quantified and gathered organisms in major groups according to their functional roles. We also characterized and tested “sea surface temperature,” “marine heatwaves,” “diffuse attenuation coefficient,” and “wave energy” influence for the same period. The most abundant groups were epilithic algal matrix (EAM; mean annual coverage: 23–60%), macroalgae (15–35%) and calcifiers (15–29%), followed by cyanobacteria (1–37%), suspension/filter-feeders (<2%), zoanthids (<1%) and other invertebrates (<0.1%). EAM was negatively correlated with “marine heatwaves” and positively correlated with “wave energy,” while macroalgae and calcifiers showed opposite responses to “marine heatwaves” and “wave energy,” respectively. Cyanobacteria was positively correlated with “marine heatwaves.” The dominance of EAM and macroalgae was already described for reefs along the Brazilian Province and we demonstrated the persistence of this structure over the years in FNA, with the exception of 2019 when there was a substantial increase of cyanobacteria after a strong marine heatwave. Our results suggest a flickering dynamic between EAM and macroalgae, which vary according to the oceanographic conditions, reinforcing its distinct dynamics from most tropical coral reefs. However, the increase of cyanobacteria added to projections of more frequent and stronger marine heatwaves worldwide indicate possible structural changes in this community. Continued monitoring of community and oceanographic drivers is key for better understanding and predicting changes in important marginal reefs.

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Spatial patterns and ecology of benthic communities on a high-latitude South Florida (Broward County, USA) reef system

Coral Reefs ◽

10.1007/s00338-003-0334-1 ◽

2003 ◽

Vol 22 (4) ◽

pp. 447-464 ◽

Cited By ~ 35

Author(s):

Ryan P. Moyer ◽

Bernhard Riegl ◽

Kenneth Banks ◽

Richard E. Dodge

Keyword(s):

Spatial Patterns ◽

High Latitude ◽

Benthic Communities ◽

South Florida ◽

Broward County ◽

Reef System

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Iceberg Disturbance and Successional Spatial Patterns: The Case of the Shelf Antarctic Benthic Communities

Ecosystems ◽

10.1007/s10021-006-9012-9 ◽

2007 ◽

Vol 10 (1) ◽

pp. 143-158 ◽

Cited By ~ 36

Author(s):

N. Teixidó ◽

J. Garrabou ◽

J. Gutt ◽

W. E. Arntz

Keyword(s):

Spatial Patterns ◽

Benthic Communities

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Scale-dependent spatial patterns in benthic communities around a tropical island seascape

Ecography ◽

10.1111/ecog.04097 ◽

2018 ◽

Vol 42 (3) ◽

pp. 578-590 ◽

Cited By ~ 3

Author(s):

Eoghan A. Aston ◽

Gareth J. Williams ◽

J. A. Mattias Green ◽

Andrew J. Davies ◽

Lisa M. Wedding ◽

...

Keyword(s):

Spatial Patterns ◽

Benthic Communities ◽

Tropical Island

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Spatial patterns in benthic communities and the dynamics of a mosaic ecosystem on the Great Barrier Reef, Australia

Coral Reefs ◽

10.1007/s00338-001-0202-9 ◽

2002 ◽

Vol 21 (1) ◽

pp. 95-104 ◽

Cited By ~ 31

Author(s):

R. Ninio ◽

M. Meekan

Keyword(s):

Great Barrier Reef ◽

Spatial Patterns ◽

Benthic Communities ◽

Barrier Reef

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Four-year monthly sediment deposition on turbid southwestern Atlantic coral reefs, with a comparison of benthic assemblages

Brazilian Journal of Oceanography ◽

10.1590/s1679-87592012000100006 ◽

2012 ◽

Vol 60 (1) ◽

pp. 49-63 ◽

Cited By ~ 23

Author(s):

Clovis Barreira e Castro ◽

Bárbara Segal ◽

Fábio Negrão ◽

Emiliano Nicolas Calderon

Keyword(s):

Coral Reef ◽

Coral Reefs ◽

Benthic Communities ◽

Sediment Deposition ◽

Southwestern Atlantic ◽

Benthic Assemblages ◽

Deposition Rates ◽

Reef Communities ◽

High Sedimentation ◽

Coral Reef Communities

High sedimentation is often related to stress in coral reef communities. Most southwestern Atlantic reefs are characterized by high sedimentation. However, there are no temporal series of sediment deposition rates. We evaluated sediment deposition, the sediment carbonate composition and coral and zoanthid covers on six reefs in Brazil over four-years. Sediment deposition rates varied from near zero to 233 mg cm-2 day-1, with peaks between August and December, and yearly averages ranging from nine to 104 mg cm-2 day-1. Deposition rates presented site-specific correlations with wind, indicating that resuspension must be a major factor. The presence of carbonates varied from 38% to 90%, with two sites showing seasonal differences. Benthic communities were fairly similar among sites, but the analyses suggested particular frequencies at each site. There was no significant correlation between sediment and benthic communities. However, Palythoa caribaeorum usually occur in high sediment deposition areas. Our results did not corroborate previous data that suggested that a 10 mg cm-2 day-1 would be a "critical limit for coral survival". Some coral reefs may be associated with high sedimentation environments including carbonatic fractions, but which does not per se hinder the development of southwestern Atlantic coral reef communities.

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Low connectivity between shallow, mesophotic and rariphotic zone benthos

Royal Society Open Science ◽

10.1098/rsos.190958 ◽

2019 ◽

Vol 6 (9) ◽

pp. 190958 ◽

Cited By ~ 2

Author(s):

Paris V. Stefanoudis ◽

Molly Rivers ◽

Struan R. Smith ◽

Craig W. Schneider ◽

Daniel Wagner ◽

...

Keyword(s):

Community Structure ◽

Coral Reefs ◽

Benthic Community ◽

Benthic Communities ◽

Species Loss ◽

Benthic Community Structure ◽

Mesophotic Coral Ecosystems ◽

Anthropogenic Stressors ◽

Community Turnover ◽

Unique Nature

Worldwide coral reefs face catastrophic damage due to a series of anthropogenic stressors. Investigating how coral reefs ecosystems are connected, in particular across depth, will help us understand if deeper reefs harbour distinct communities. Here, we explore changes in benthic community structure across 15–300 m depths using technical divers and submersibles around Bermuda. We report high levels of floral and faunal differentiation across depth, with distinct assemblages occupying each depth surveyed, except 200–300 m, corresponding to the lower rariphotic zone. Community turnover was highest at the boundary depths of mesophotic coral ecosystems (30–150 m) driven largely by taxonomic turnover and to a lesser degree by ordered species loss (nestedness). Our work highlights the biologically unique nature of benthic communities in the mesophotic and rariphotic zones, and their limited connectivity to shallow reefs, thus emphasizing the need to manage and protect deeper reefs as distinct entities.

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