Date of Publication

4-2026

Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Biology

Subject Categories

Biology

College

College of Science

Department/Unit

Biology

Thesis Advisor

Laurence E. Robles

Defense Panel Chair

Chona Camille V. Abeledo

Defense Panel Member

Antonio Samuel S. Mamauag
Hilarie P. Orario

Abstract (English)

Climate change and anthropogenic activities drive marine ecosystems to become unusually unstable. This leads to corals dying and fishes changing their usual behaviors, highlighting the importance of ecological thresholds to avoid over- or underestimating reef health (Menge et al. 2022). Currently, the Philippines relies on Licuanan’s (2019) “22-33-44 Scale” to monitor reef health. This scale may determine coral species health, but there is limited evidence that it reflects the well-being of reef fishes. To determine if hard coral cover (HCC) thresholds can be applied to fish health, this study inspected the behaviors of model reef organism Butterflyfish (Chaetodon spp.) on several reef sites in Lian, Batangas. Using the General Additive Model (k=5), results reveal a significant nonlinear relationship between exploratory and sociability behaviors with varying HCC, suggesting these two are dynamic. Meanwhile, feeding and aggression remains constant with HCC due to diverse species-specific interactions. Applying Structural Equation Model (SEM) in the GAMs, inflection points can be observed in exploratory and sociability behaviors when HCC is at 22.85% and 29.77%, respectively. These are parallel values to the 22-33-44 scale, indicating that current benchmarks may determine behavior changes in coral covers. Lastly, with Pearson’s correlation, a trade-off can be observed between feeding and exploratory (r = -0.358), supporting the Optimal Foraging Theory where animals adjust their feeding range when resource is limited. Findings strengthen the validity of 22-33-44 scale and encourage its use for reef monitoring.

Abstract Format

html

Abstract (Filipino)

Nawawalan ng katatagan ang mga bahura dulot ng pang-malawakang pagbabago ng klima at mga gawain pantao na nagpapalala nito. Dumarami ang namamatay na korales, habang nagiging di-pangkaraniwan ang kilos ng mga isda, nagpapahiwatig na importanteng malaman kung ano ang kanilang mga limit o threshold upang maagapan agad ito sa wastong paraan (Menge et al. 2022). Sa kasalukuyan, dumidepende ang Pilipinas sa “22-33-44 Scale” ni Licuanan (2019) para mabantayan ang kondisyon ng mga bahura. Nakatutulong man ito masubaybayan ang mga korales, walang patunay na kaya nitong matukoy ang kalagayan ng mga isda. Bagkus, layunin ng pag-aaral na ito na suriin kung ang hard coral cover (HCC) thresholds ay nagsasalamin sa kalagayan ng mga isda sa pamamagitan ng pagsusuri sa kilos ng butterflyfish (Chaetodon spp.) sa Lian, Batangas. Gamit ang General Additive Model (k=5), natukoy na may pagbabago sa eksploratoryo at sosyabilidad ng mga butterflyfish, habang walang pagbabago sa kanilang pagkakain at agresyon. Sa pamamagitan ng Structural Equation Model (SEM), nakita na nagbabago sila ng kilos sa bandang 22.85% at 29.77% HCC, na naaayon 22-33-44 Scale. Gamit naman ng Pearson’s correlation, nakitang nagpapalitan ang pagkakain at eksploratoryong asal (r = -0.358) kapag sumasagad ang HCC, na sumusuporta sa Optimal Foraging Theory. Sa kabuuan, pinatitibay ng mga resulta ang 22-33-44 Scale at ang potensyal nito sa mas komprehensibong pagmomonitor ng mga bahura.

Abstract Format

html

Language

English

Format

Electronic

Keywords

Chaetodontidae; Coral reef ecology

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Embargo Period

4-15-2027

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Available for download on Thursday, April 15, 2027

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