Jovy Ann P. Valera, Najeen Arabelle M. Rula, Jayvee A. Saco, Romel U. Briones, Renan U. Bobiles, Miguel Enrique M. Azcuna
RATIONALE
Many species of reef fish exhibit ontogenetic habitat shifts to maximize growth and survival (Dahlgren and Eggleston 2000). As mobile organisms, fish may seek habitats depending on the requirements at a certain life history stage. Habitat choice may be influenced by factors such as such as food and shelter or other factors such as predator density and abiotic conditions (Eggertsen et al. 2017; Holbrook et al. 1990). Seagrass and mangroves have been determined to be important juvenile habitats for coral reef fish (e.g., Mateo et al. 2011; Verweij et al. 2008). However, studies on the role of seaweed beds in connectivity patterns for reef fish are few. Most studies on seaweeds focus on its major function as primary producers. Some seaweeds are also deemed nuisance because of overgrowth, which leads to phase shifts of reef habitats (Eggertsen et al. 2017). According to Nakamura and Sano (2004), high recruitment of coral-reef fish in seaweed beds possibly indicates ontogenetic movement. Seaweeds serve as three-dimensional habitat structures for many marine organisms and can serve as ecosystem engineers, altering environmental conditions and resources (Connell 2003; Smale et al. 2013). Seaweeds also provide a large surface area for attachment and habitat of epiphytic algae and invertebrates, which serve as food to herbivorous and invertivorous fish (Feitosa and Ferreira 2014, Evans et al. 2013). By providing shelter and refuge for recruits, macroalgal beds have also been found to be an important driver influencing reef fish assemblage compared to corals in some reefs (Medeiros et al. 2010). Percentage cover has been also found to affect fish abundance in macroalgal fields (Evans et al. 2013). Marine protected areas (MPA) are established to protect marine biodiversity, ecosystem, and processes. In the Verde Island Passage, 123 MPAs are being managed among the five provinces of Batangas, Marinduque, Romblon, Occidental and Oriental Mindoro (MPA Support Network 2017). While the attention for protection of coral reefs and mangroves increased, the consideration for seaweed beds to be an MPA is commonly disregarded. Many species of reef fish exhibit ontogenetic habitat shifts to maximize growth and survival (Dahlgren and Eggleston 2000). As mobile organisms, fish may seek habitats depending on the requirements at a certain life history stage. Habitat choice may be influenced by factors such as such as food and shelter or other factors such as predator density and abiotic conditions (Eggertsen et al. 2017; Holbrook et al. 1990). Seagrass and mangroves have been determined to be important juvenile habitats for coral reef fish (e.g., Mateo et al. 2011; Verweij et al. 2008). However, studies on the role of seaweed beds in connectivity patterns for reef fish are few. Most studies on seaweeds focus on its major function as primary producers. Some seaweeds are also deemed nuisance because of overgrowth, which leads to phase shifts of reef habitats (Eggertsen et al. 2017). According to Nakamura and Sano (2004), high recruitment of coral-reef fish in seaweed beds possibly indicates ontogenetic movement. Seaweeds serve as three-dimensional habitat structures for many marine organisms and can serve as ecosystem engineers, altering environmental conditions and resources (Connell 2003; Smale et al. 2013). Seaweeds also provide a large surface area for attachment and habitat of epiphytic algae and invertebrates, which serve as food to herbivorous and invertivorous.
OBJECTIVE
The main objective of the study is to investigate the possible role of seaweed beds as transition habitats for juvenile reef fish in the Verde Island Passage. The study is subdivided to two components with specific objectives as follows:
Component 1: Seaweed and Fish Diversity
a. Investigate the relationship between seaweed species diversity and seaweed-associated reef fish diversity,
b. Identify juvenile and adult fish assemblages
c. Determine age of representative species of fish inferred from otolith microstructure
Component 2: Fish Genetics
To compare and analyze juvenile fish population from seaweed beds versus adult fish population from coral reef areas using molecular markers
ACCOMPLISHMENTS