Banca de DEFESA: KELLY YUMI INAGAKI

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : KELLY YUMI INAGAKI
DATE: 08/03/2024
TIME: 13:30
LOCAL: Sala de Reuniões DECOL/UFRN e Youtube (https://www.youtube.com/live/zGx2XHdulig?si=tBrE5bBiK-dtPO8f)
TITLE:

DIFFERENT PERSPECTIVES OF ECOLOGICAL INTERACTIONS  BETWEEN CORALS, ALGAE AND HERBIVORES

KEY WORDS:

Siderastrea stellata; Porites astreoides; Millepora alcicornis; Dictyopteris delicatula; Echinometra lucunter; Aplysia sp; Ampithoe marcuzzii; algal palatability; iron  enrichment; climate change

PAGES: 94
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Ecological interactions involve all living beings and ecosystems we know. In reef  systems, corals and algae are important organisms that interact with each other in  positive, negative and neutral interactions, and they can be influenced by top-down  (mediated by consumers) and bottom-up (mediated by producers) effects. Reefs and  their complex interactions are threatened by local and global impacts, which can  change their patterns and outcomes of interactions. In this thesis, we explored coral algal-herbivores interactions under different perspectives. In Chapter I, we did a  systematic review involving the last 20 years of studies (2002-2020) and we asked: i)  where these interactions have been explored globally; ii) what are the main organisms  involved; iii) the most frequent outcomes; iv) the effects of herbivores over the  interactions; and v) the effects of climate change. We found that i) Pacific and  Caribbean regions concetrate 86% of interactions; ii) the main organisms involved are  massive and branching corals, and macroalgae and turf, with some variation among  regions; iii) adults corals are mostly harmed by algae suffering sublethal damages,  while juvenile corals can be both harmed or benefitted mainly by recruitment; iv) most  of the studies evaluate the effects of herbivory in indirect ways (e.g. abundance  correlations), with few experimental efforts; and v) the effects of climate change were  explored in only 10% of studies, negatively affecting coral recruitment and causing  sublethal effects, and reducing algal abundance. In Chapter II, we explored coral-algal herbivore interactions in tropical reef in Brazil, evaluating i) their historical  abundances; ii) the current frequency of coral-algal interactions; iii) the outcome of these interactions; iv) how the warming ocean can influence coral-algal interactions,  and v) if different herbivore could mediate coral-algal interactions in the current and  future scenarios of warming. We found that i) benthic cover is stable in the last  decade, reflecting older registers, with algal dominance (60%) and low coral cover  (5.6%), in a scenario that does not seem related to local biomass of herbivores fishes;  ii) coral-algal interactions are frequent and 96% of them involve the coral Siderastrea  stellata interacting with turf; iii) the majority of interaction lead corals to decrease in  phootsynthetic efficiency but this vulnerability varies among coral species; iv) coral algal interaction are equally harmful for corals in current and future scenarios of ocean  warming, carrying among species; v) the dominant macroalgae is little consumed by  different herbivores, regardless of temperature, which indicates low effects of  herbivores over coral-algal interactions. In Chapter III, we explored the effects of iron  enrichment over algal palatability, evaluating different iron concentrations (control,  100 µg/L, 300 µg/L, 900 µg/L) in three exposure times (days 0, 13/14 and 26/27), and  we found that different iron concentrations did not affect algal palatability, bus we  observe higher consume in the middle exposure time, likely due to balance between  chemical defenses and algal integrity. Thus, we explored coral-algal interactions,  evidencing some global patterns and describing regional patterns that challenge  current paradigms in ecology that herbivory is the main factor mediating coral-algal  interactions.

COMMITTEE MEMBERS:
Externo à Instituição - CARLOS EDUARDO LEITE FERREIRA - UFF
Presidente - 2319234 - GUILHERME ORTIGARA LONGO
Externa à Instituição - MARINA NASRI SISSINI - UFF
Externa à Instituição - NATÁLIA CARVALHO ROOS - UFSB
Externo à Instituição - THIAGO COSTA MENDES - UFF