Influence of historical changes in tropical reef habitat on the diversification of coral reef fishes

Past environmental changes are expected to have profoundly impacted diversity dynamics through time. While some previous studies showed an association between past climate changes or tectonic events and important shifts in lineage diversification, it is only recently that past environmental changes have been explicitly integrated in diversification models to test their influence on diversification rates. Here, we used a global reconstruction of tropical reef habitat dynamics during the Cenozoic and phylogenetic diversification models to test the influence of (i) major geological events, (ii) reef habitat fragmentation and (iii) reef area on the diversification of 9 major clades of tropical reef fish (Acanthuridae, Balistoidea, Carangoidea, Chaetodontidae, Haemulinae, Holocentridae, Labridae, Pomacentridae and Sparidae). The diversification models revealed a weak association between paleo-habitat changes and diversification dynamics. Specifically, the fragmentation of tropical reef habitats over the Cenozoic was found to be a driver of tropical reef fish diversification for 2 clades. However, overall, our approach did not allow the identification of striking associations between diversification dynamics and paleo-habitat fragmentation in contrast with theoretical model’s predictions.

MONITORING CHANGES IN CORAL REEF HABITAT COVER ON BERALAS PASIR ISLAND USING SPOT 4 AND SPOT 7 IMAGERY FROM 2011 AND 2018

Beralas Pasir is part of the Regional Marine Conservation Area (KKLD), which was established by the Bintan Regency Government with Bintan Regent Decree No. 261 / VIII / 2007. Water tourism activities undertaken by tourists on the island have had an impact on the condition of the coral reefs, as have other factors, such as bauxite, granite and land sand mining activities around the island. This research aims to determine changes in the coral reef habitat cover and the condition of the coral reefs around Beralas Pasir Island with a remote sensing function, using SPOT 4 imagery acquired on June 1, 2011 and SPOT 7 imagery from April 5, 2020. Data collection of environmental parameters related to the coral reefs was also made. The image processing used the Lyzenga algorithm to simplify the image classification process. The percentage of coral live cover around the island ranges from 26% -53%; this has experienced a significant change, from 67,560 hectares in 2011 to 38,338 hectares in 2018, a total decrease in the area of 29,222 hectares. Some of the natural factors found in the research which have caused damage to the reefs were Drupella snails, the abundance of Caulerpa racemosaalgae, and sea urchins. The majority of the coral reef types consist of Non-Acropora: Coral Massive, Coral, Coral Foliose, Coral Encrusting, Acropora: Acropora Tabulate, Acropora Encrusting, and Acropora Digitate

The Abundance of Fish Species in Branched (branching) and Table (tabulate) Coral Habitat on Tanjung Beach, Muna Island, Southeast Sulawesi

This research aimed to study the types and abundance of fish which was found in branched and table coral habitat. The quadrate transect method was used at the location of the habitat of branched and table corals. The observation was carried out for 3 days. It was conducted 3 times/day, in the morning, the afternoon, and the evening with ± 10 minutes of observation time for each observation. The method used was transect quadrat 5 m x 5 m with direct observation techniques by means of snorkeling. The types and numbers of individual fish were recorded using the visual census method. Snorkeling was done straightforwardly and looking around by following the contour of the reef. In branching coral habitat, 11 species of fish were found with a total of 66 individuals. On the other hand, on the tabulate reef habitat, there were 9 species of fish with a total of 50 individuals. Both habitats have different types of fish. In the branched coral habitats there were more individual than in the table reef habitats. Fish species found in branched coral habitat and table type fish habitat were different. In branched coral habitats were found more reef fish species than in table coral habitats. These results illustrated that the condition of the coral reefs at Tanjung Beach is still in good condition.

Ecological and Infrastructure Assessment of Kanton (Abariringa) Island, Phoenix Island Protected Area, Kiribati

The remote Kanton (Abariringa) Atoll, in the South Pacific Phoenix Islands Protected Area, was assessed using rapid techniques to describe the infrastructure, fish, coral, birds, vegetation, sharks, turtles, and marine mammals. Median live coral cover was 28% (8%–93%) with 11 coral genera, the most abundant being tabular <i>Acropora</i> spp. A total of 130 species of fish (9365 individuals) showed highest abundance in the fore reef habitat. The most abundant bird was the Brown noddy (<i>Anous stolidus</i>) with 3600 individuals counted. Nine species of plants were identified, with Beach saltbush (<i>Scaevola sericea</i>) being the most abundant. Assessment of the aesthetics of dive sites identified two excellent sites: the shipwreck of <i>President Taylor</i> and the Cascades, with very high abundances of coral and reef fish.