Banca de QUALIFICAÇÃO: BRUNO CHARNAUX LONZETTI

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : BRUNO CHARNAUX LONZETTI
DATE: 18/11/2019
TIME: 14:00
LOCAL: Sala de reuniões - DECOL
TITLE:

Can ocean warming help zoanthids outcompete branching hydrocorals?

KEY WORDS:

Coral health;ocean warming;biotic interactions;future predictions

PAGES: 13
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Given the spatial limitation in reefs, competitive interactions among sessile organisms often occur through physical contact, such as coral-seaweed competition. Ocean warming and acidification may affect the outcomes of these interactions, by changing the competitive ability and recovery potential of the interacting organisms. In South Atlantic, one of the most important competitors to corals is the zoanthid Palythoa caribaeorum, which in warming scenarios will expand its distribution and likely dominate reefs in Northeast Brazil. If this occurs, it would likely outcompete the hydrocoral Millepora alcicornis, one of the most important species to aid structural complexity to Brazilian reefs. We studied the competitive interaction between the zoanthid (P. caribaeorum) and the hydrocoral (M. alcicornis) through field and laboratory experiments, particularly addressing: the effect of physical contact on the hydrocoral´s health (field and laboratory); the recovery potential of hydrocorals, once the contact is ceased (field and laboratory); and how ocean warming potentially affect these processes (laboratory only; 27°C vs. 30°C predicted for 2100). We found that the contact with the zoanthid and a mimetic control had similar negative impact on the hydrocoral, both in the field and in the laboratory, causing paleness in the contact area. Hydrocorals in the field did not recover over a short time span (10 days), but in the laboratory hydrocorals did partially recover the damaged area when in 27°C. Such recovery occurred less intensively in the zoanthid treatment in comparison to the physical mimic treatment, indicating the zoanthid may have chemical compounds that hamper the hydrocoral´s ability to recover. Under warming conditions (30°C), the borders of the areas damaged by the zoanthid were rapidly colonized by filamentous algae, which did not occur for the mimic treatment or replicates at 27°C. Although hydrocorals presented similar symptoms when comparing the current and future temperature scenarios, the recovery potential decreases with warming as it favored colonization by filamentous algae. As ocean warms, the competitive interaction we studied will become more frequent and zoanthids more likely to overgrow the branching hydrocorals, causing reef flattening and potentially loss of diversity. This highlights the importance of understanding how ecological interactions will be affected by global changes, as it allows us to predict future dominance scenarios.

BANKING MEMBERS:
Externo à Instituição - GUSTAVO MUNIZ DIAS
Presidente - 2319234 - GUILHERME ORTIGARA LONGO
Externa à Instituição - NATÁLIA CARVALHO ROOS