Coral Reef Fishes: Identification, Ecology, and Challenges in a Warming Ocean

Coral reefs are one of the most biodiverse and beautiful environments on the planet. In this tropical environment, fish communities are a key and vital component for maintaining ecosystem balance and health. They colonize any habitat, modifying it, and are in turn affected by it.

Although coral reefs represent less than 1% of the surface of the oceans, they are home to about 25% of known fish species. The fish fauna associated with coral reefs thus represents a fascinating system in terms of richness, complexity and biodiversity, especially in the coral reefs of the Indo-Pacific, where more than 4000 species live overall. In particular, in the coral reefs of the Maldives, which represent about 5% of the area occupied by all the world’s coral ecosystems, more than 1100 species of fish have been recognized, with a variety of shapes, colors and behaviors that reflect the extreme complexity of the reef ecosystem. These multitudes of traits are used by fish to feed, prey, defend themselves or “communicate” and interact with each other and with other organisms, by creating symbiotic association. In addition, the coral reef fish community is also characterized by complex ecological interactions and trophic relationships that generate intricate food webs and ecological networks, whose balances are essential to maintain to support the high ecological functionality of the reef ecosystem. However, also the fish fauna is strongly affected both directly and indirectly by the climate change and the warming of the oceans which are modifying the structure and functionality of the habitat in which they live.

The fish fauna thus constitutes an excellent model for studying the state of health of coral reefs and their biogeographical pattern. Furthermore, considering that the survival of many coastal human communities largely depends on tropical fish, the study and description of a fish community can provide useful information for the management of all human activities involving the sea, from fishing to tourism. The skills acquired in the field of fish biology and ecology can therefore be used both in the sectors related to the protection and conservation of ecosystems, in the fields of fisheries management and tourism, as well as obviously the fields of academic application.

At the end of this theoretical-practical course, the student will acquire notions to:

• Identify the main families, genera and species of tropical fish associated with the reef habitat of Maldives and Indian Ocean.
• Examine the trophic structure of a reef fish community.
• Understand and describe the temporal and spatial variations (nyctimerial rhythms, reef zonation) of fish communities.
• List the main patterns and processes that influence the structure of a fish community.
• Investigate the impact of climate change related stressors on a fish community.
• Design and carry out visual census operations, for the study and monitoring of fish communities.
• Analyze community structure data using taxonomic and functional indices.