scholarly journals Filamentous turf algae on tube worms intensify damage in massive Porites corals

Ecology ◽  
2019 ◽  
pp. e02668 ◽  
Author(s):  
Bert W. Hoeksema ◽  
Roeland J. Schoot ◽  
Dagmar Wels ◽  
Chad M. Scott ◽  
Harry A. Hove

2020 ◽  
Vol 648 ◽  
pp. 111-123
Author(s):  
C Layton ◽  
MJ Cameron ◽  
M Tatsumi ◽  
V Shelamoff ◽  
JT Wright ◽  
...  

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches <1 m2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.



Coral Reefs ◽  
2015 ◽  
Vol 34 (2) ◽  
pp. 625-630 ◽  
Author(s):  
N. Gutiérrez-Isaza ◽  
J. Espinoza-Avalos ◽  
H. P. León-Tejera ◽  
D. González-Solís


2020 ◽  
Vol 167 (7) ◽  
Author(s):  
Benny K. K. Chan ◽  
James C. H. Tan ◽  
Monthon Ganmanee


2017 ◽  
Vol 22 (4) ◽  
pp. 193
Author(s):  
I Gusti Bagus Siladharma ◽  
Widiastuti Karim

The widespread of coral disease may threatened Bali`s marine tourism which is the main asset for the nation prosperity. However, the disease prevalence is still unknown, in particular inshore coral reefs near to tourist spot areas. Therefore, the research aims to investigate the contribution of terrestrial runoff to coral disease prevalence and to examine the relationships between disease prevalence and environmental parameters (nitrate, phosphate, organic carbon and total suspended solids (TSS)) within the population of massive Porites on shallow north Bali reefs. Syndrome, diseases and healthy colonies of massive Porites coral were counted and noted within a 2 x 10 m belt transect at 3 sampling sites. The dominant disease observed was ulcerative white spots (UWS), while the syndromes were pigmentation response and aggressive overgrowth by macroalgae. The highest mean UWS prevalence was at site 3 which was the closest site to runoff (prevalence = 91%).This disease only affected one colony at site 1 and 2, respectively. Disease prevalence had strong relationship with TSS and nitrate, yet it showed weak relationship with phosphate and organic carbon. These results suggest that terrestrial runoff could contribute to the disease prevalence by increasing the TSS, nutrients and organic carbon loading to the inshore ecosystems. High level of organic carbon could severe the disease, particularly when combined with elevated TSS and nutrient, by reducing the coral`s immunity system. Keywords: coral disease, prevalence, terrestrial runoff, Porites, ulcerative white spot, environmental parameter, North Bali.



2021 ◽  
Vol 8 (9) ◽  
pp. 210035
Author(s):  
Amy A. Briggs ◽  
Anya L. Brown ◽  
Craig W. Osenberg

Microbes influence ecological processes, including the dynamics and health of macro-organisms and their interactions with other species. In coral reefs, microbes mediate negative effects of algae on corals when corals are in contact with algae. However, it is unknown whether these effects extend to larger spatial scales, such as at sites with high algal densities. We investigated how local algal contact and site-level macroalgal cover influenced coral microbial communities in a field study at two islands in French Polynesia, Mo'orea and Mangareva. At 5 sites at each island, we sampled prokaryotic microbial communities (microbiomes) associated with corals, macroalgae, turf algae and water, with coral samples taken from individuals that were isolated from or in contact with turf or macroalgae. Algal contact and macroalgal cover had antagonistic effects on coral microbiome alpha and beta diversity. Additionally, coral microbiomes shifted and became more similar to macroalgal microbiomes at sites with high macroalgal cover and with algal contact, although the microbial taxa that changed varied by island. Our results indicate that coral microbiomes can be affected by algae outside of the coral's immediate vicinity, and local- and site-level effects of algae can obscure each other's effects when both scales are not considered.



Eos ◽  
2019 ◽  
Vol 100 ◽  
Author(s):  
Jerimiah Oetting

A new measurement technique has revealed that turf algae communities colonizing dead reefs have a dual role, adding new mineral material to the reefs during the day and taking it away at night.





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