scholarly journals Temperature regimes impact coral assemblages along environmental gradients on lagoonal reefs in Belize

2016 ◽  
Author(s):  
Justin H. Baumann ◽  
Joseph E. Townsend ◽  
Travis A. Courtney ◽  
Hannah E. Aichelman ◽  
Sarah W. Davies ◽  
...  
Keyword(s):  
Life History ◽  
Community Structure ◽  
Coral Reefs ◽  
Coral Species ◽  
Environmental Gradients ◽  
Coral Community ◽  
Life History Strategies ◽  
Percent Cover ◽  
Chl A ◽  
Reef System

AbstractCoral reefs are increasingly threatened by global and local anthropogenic stressors such as rising seawater temperature, nutrient enrichment, sedimentation, and overfishing. Although many studies have investigated the impacts of local and global stressors on coral reefs, we still do not fully understand how these stressors influence coral community structure, particularly across environmental gradients on a reef system. Here, we investigate coral community composition across three different temperature and productivity regimes along a nearshore-offshore gradient on lagoonal reefs of the Belize Mesoamerican Barrier Reef System (MBRS). A novel metric was developed using ultra-high-resolution satellite-derived estimates of sea surface temperatures (SST) to classify reefs as exposed to low (lowTP), moderate (modTP), or high (highTP) temperature parameters over 10 years (2003 to 2012). Coral species richness, abundance, diversity, density, and percent cover were lower at highTP sites relative to lowTP and modTP sites, but these coral community traits did not differ significantly between lowTP and modTP sites. Analysis of coral life history strategies revealed that highTP sites were dominated by hardy stress tolerant and fast-growing weedy coral species, while lowTP and modTP sites consisted of competitive, generalist, weedy, and stress-tolerant coral species. Satellite-derived estimates of Chlorophyll-a (chl-a) were obtained for 13-years (2003-2015) as a proxy for primary production. Chl-a concentrations were highest at highTP sites, medial at modTP sites, and lowest at lowTP sites. Notably, thermal parameters correlated better with coral community traits between site types than productivity, suggesting that temperature (specifically number of days above the thermal bleaching threshold) played a greater role in defining coral community structure than productivity on the MBRS. Dominance of weedy and stress-tolerant genera at highTP sites suggests that corals utilizing these two life history strategies may be better suited to cope with warmer oceans and thus may warrant protective status under climate change.

scholarly journals River Streamflow, Remotely Sensed Water Quality, and Benthic Composition of Previously Undescribed Nearshore Coral Reefs in Northern Puerto Rico

2021 ◽  
Vol 8 ◽  
Author(s):  
Juan L. Torres-Pérez ◽  
Carlos E. Ramos-Scharrón ◽  
William J. Hernández ◽  
Roy A. Armstrong ◽  
Maritza Barreto-Orta ◽  
...  
Keyword(s):  
Water Quality ◽  
Puerto Rico ◽  
Coral Reefs ◽  
Coral Species ◽  
Coral Cover ◽  
Remotely Sensed ◽  
North Coast ◽  
Acropora Palmata ◽  
Chl A ◽  
Benthic Composition

Land-based sediment stress represents a threat to many coral reefs in Puerto Rico primarily as a result of unrestricted land cover/land use changes and poor best management practices. The effects of such stresses have been documented along most coasts around the island. However, little attention has been paid to reefs located on the north coast, and very little is known about their composition and current state. Here, we present a study characterizing riverine inputs, water quality conditions, and benthic composition of two previously undescribed coral reefs (Tómbolo and Machuca reefs) located just eastward of the Río Grande de Manatí outlet in north-central Puerto Rico. This study utilizes a time series of remotely sensed ocean color products [diffuse vertical attenuation coefficient at 490 nm (Kd490) and chlorophyll-a concentration (Chl-a) estimated with data from the Visible Infrared Imaging Radiometer Suite (VIIRS)] to characterize water quality in this coastal region. In general, the months with relatively high mean daily river streamflow also coincide with months having the highest proportion of eastward wave direction, which can promote the eastward influence of river waters toward the two coral reefs sites. Kd490 and Chl-a showed a higher riverine influence closer to the watershed outlet. Kd490 and Chl-a monthly peaks also coincide with river streamflow highs, particularly at those pixels closer to shore. Tómbolo Reef, located farther eastward of the river outlet, shows a well-developed primary reef framework mainly composed of threatened reef-building species (Acropora palmata, Pseudodiploria) and high coral cover (19–51%). The benthos of Machuca Reef, located closer to the river outlet, is dominated by macroalgae with a significantly lower coral cover (0.2–2.7%) mainly composed of “weedy” coral species (Porites astreoides and Siderastrea radians). Cover of major benthic components correlates with distance from the river outlet, and with gradients in Kd490 and Chl-a, with higher coral cover and lower macroalgal cover farther from the river outlet. Coral cover at Tómbolo Reef is higher than what has been reported for similar sites around Puerto Rico and other Caribbean islands showing its ecological importance, and as up until now, an unrecognized potential refuge of reef-building threatened coral species.

Coral community structure off the Pacific Coast of Colombia: onshore vs. offshore Coral Reefs

2003 ◽  
Vol 499 ◽  
pp. 1-21 ◽  
Author(s):  
Bernado Vargas-Angel
Keyword(s):  
Community Structure ◽  
Coral Reefs ◽  
Pacific Coast ◽  
Coral Community ◽  
The Pacific

scholarly journals The effect of host community functional traits on plant disease risk varies along an elevational gradient

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Fletcher W Halliday ◽  
Mikko Jalo ◽  
Anna-Liisa Laine
Keyword(s):  
Community Structure ◽  
Disease Risk ◽  
Environmental Gradients ◽  
Elevational Gradient ◽  
Host Community ◽  
Interactive Effects ◽  
Life History Strategies ◽  
Herbaceous Plant ◽  
Field Evidence ◽  
Increasing Temperature

Quantifying the relative impact of environmental conditions and host community structure on disease is one of the greatest challenges of the 21st century, as both climate and biodiversity are changing at unprecedented rates. Both increasing temperature and shifting host communities towards more fast-paced life-history strategies are predicted to increase disease, yet their independent and interactive effects on disease in natural communities remains unknown. Here, we address this challenge by surveying foliar disease symptoms in 220, 0.5 meter-diameter herbaceous plant communities along a 1100-meter elevational gradient. We find that increasing temperature associated with lower elevation can increase disease by (1) relaxing constraints on parasite growth and reproduction, (2) determining which host species are present in a given location, and (3) strengthening the positive effect of host community pace-of-life on disease. These results provide the first field evidence, under natural conditions, that environmental gradients can alter how host community structure affects disease.

scholarly journals Shifting communities after­­ typhoon damage on an upper mesophotic reef in Okinawa, Japan

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3573 ◽  
Author(s):  
Kristine N. White ◽  
David K. Weinstein ◽  
Taku Ohara ◽  
Vianney Denis ◽  
Javier Montenegro ◽  
...  
Keyword(s):  
Community Structure ◽  
Coral Reefs ◽  
Scleractinian Coral ◽  
Community Dynamics ◽  
Coral Community ◽  
Long Term Effects ◽  
High Coverage ◽  
Stable Community ◽  
Mesophotic Reef

Very few studies have been conducted on the long-term effects of typhoon damage on mesophotic coral reefs. This study investigates the long-term community dynamics of damage from Typhoon 17 (Jelawat) in 2012 on the coral community of the upper mesophotic Ryugu Reef in Okinawa, Japan. A shift from foliose to bushy coral morphologies between December 2012 and August 2015 was documented, especially on the area of the reef that was previously recorded to be poor in scleractinian genera diversity and dominated by foliose corals. Comparatively, an area with higher diversity of scleractinian coral genera was observed to be less affected by typhoon damage with more stable community structure due to less change in dominant coral morphologies. Despite some changes in the composition of dominant genera, the generally high coverage of the mesophotic coral community is facilitating the recovery of Ryugu Reef after typhoon damage.

Living under stressful conditions: Fish life history strategies across environmental gradients in estuaries

2017 ◽  
Vol 188 ◽  
pp. 18-26 ◽  
Author(s):  
Nils Teichert ◽  
Stéphanie Pasquaud ◽  
Angel Borja ◽  
Guillem Chust ◽  
Ainhize Uriarte ◽  
...  
Keyword(s):  
Life History ◽  
Environmental Gradients ◽  
Life History Strategies

scholarly journals Environmental drivers of disease depend on host community context

2021 ◽  
Author(s):  
Fletcher W. Halliday ◽  
Mikko Jalo ◽  
Anna-Liisa Laine
Keyword(s):  
Community Structure ◽  
Disease Risk ◽  
Environmental Gradients ◽  
Community Context ◽  
Host Community ◽  
Life History Strategies ◽  
Environmental Drivers ◽  
Pace Of Life ◽  
Abiotic Constraints ◽  
The Relationship

AbstractPredicting disease risk in an era of unprecedented biodiversity and climate change is more challenging than ever, largely because when and where hosts are at greatest risk of becoming infected depends on complex relationships between hosts, parasites, and the environment. Theory predicts that host species characterized by fast-paced life-history strategies are more susceptible to infection and contribute more to transmission than their slow-paced counterparts. Hence, disease risk should increase as host community structure becomes increasingly dominated by fast-paced hosts. Theory also suggests that environmental gradients can alter disease risk, both directly, due to abiotic constraints on parasite replication and growth, and indirectly, by changing host community structure. What is more poorly understood, however, is whether environmental gradients can also alter the effect of host community structure on disease risk. We addressed these questions using a detailed survey of host communities and infection severity along a 1100m elevational gradient in southeastern Switzerland. Consistent with prior studies, increasing elevation directly reduced infection severity, which we attribute to abiotic constraints, and indirectly reduced infection severity via changes in host richness, which we attribute to encounter reduction. Communities dominated by fast pace-of-life hosts also experienced more disease. Finally, although elevation did not directly influence host community pace-of-life, the relationship between pace-of-life and disease was sensitive to elevation: increasing elevation weakened the relationship between host community pace-of-life and infection severity. This result provides the first field evidence, to our knowledge, that an environmental gradient can alter the effect of host community structure on infection severity.

scholarly journals Distribution and Community Structure of Coral Reefs In The West Coast Of Sumatra Indonesia

2019 ◽  
Vol 24 (1) ◽  
pp. 51 ◽  
Author(s):  
Rikoh Manogar Siringoringo ◽  
Tri Aryono Hadi ◽  
Ni Wayan Purnama Sari ◽  
Muhammad Abra ◽  
Munasik Munasik
Keyword(s):  
Community Structure ◽  
Coral Reefs ◽  
West Coast ◽  
Coral Species ◽  
Live Coral ◽  
The West ◽  
Accumulation Curve ◽  
Common Genus ◽  
Almost All ◽  
Line Intercept

This paper assesses the distribution and community structure of coral species in six locations along the west coast of Sumatra, namely Mentawai, Bengkulu, Nias, Padang Pariaman, Simeulue, and Central Tapanuli. Data collected using Line Intercept Transect (LIT) method obtained from 55 sites at six locations. The ordination analysis by using PRIMER 7 software indicates the corals do not distributed evenly. In this case, almost all of the corals distributed mainly in Central Tapanuli and followed by Bengkulu, making it the most diverse corals location in the west coast. Mentawai and Padang Pariaman were less diverse and relatively similar as clustered together, but Padang Pariaman reefs had more Montipora and Pocillopora while Mentawai reefs is mainly featured by Pavona and Psammocora. Although Nias reefs clustered into two different clusters, the main reef features were Porites and Pavona. Simeulue reefs appeared characterized by Porites and Psammocora.  Porites known as a very common genus of coral and are found in the widest area of the world's coral reefs. The within-site species richness determined by using species accumulation curve. K-dominance curve showed that Bengkulu and Mentawai seemed to have the lowest cumulative abundance but then crossed over Central Tapanuli at the third most abundance species. There were 52 genera found from six locations, eight of them distributed in all locations. Approximately 90% of which were found in Central Tapanuli. There were no differences between live coral coverage within locations, yet Caswell’s neutral model showed that Mentawai and Bengkulu had more coral species than other locations, indicating that there were likely were less stress environmental conditions occurring in these two locations.

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