Macroalgal communities of coastal ecosystems play a key role in maintaining overall coastal biodiversity. In this study, habitat preference (macroalgal host preference) and temporal changes (season) of epifaunal communities associated to five macroalgal species such as Padina, Sargassum, Ulva, Acanthophora and Gracilaria were observed at seasonal intervals (summer and winter) for 2 years from May 2012 to March 2014 on the Jeddah coastal waters of the Red Sea. Major epifaunal groups observed included polychaetes, amphipods, isopods, gastropods, mussels and crabs. Polychaetes were represented by 10 species followed by amphipods with five species. The abundance of gastropods, polychaetes and mussels showed significant variation between the macroalgae irrespective of morphology. Generally, the abundance of these taxa were high on Padina and low on Sargassum. Significant seasonal changes were observed on the abundance of polychaetes, amphipods and isopods. The abundance of some epifaunal groups showed a significant relationship with environmental parameters such as surface water temperature, salinity, pH and dissolved oxygen content.

The small, isolated populations of the Nicobar megapode Megapodius nicobariensis, currently categorized as Vulnerable on the IUCN Red List, on the Nicobar islands in the Indian Ocean have declined by c. 70% since 1994. The 2004 tsunami is believed to be the major cause of this decline. The populations of megapodes on the islands of Megapode and Trax were wiped out by the tsunami. I estimate from a 2006 survey that 395–790 breeding pairs of the Nicobar megapode now survive on the coasts of the various islands compared to 2,318–4,056 pairs in 1994. The tsunami also adversely influenced nest-site selection and mound-nest ecology: > 50% of mounds were found closer to the shore in 2006 than in 1994, probably because of loss of suitable habitat, and they may become inundated with seawater during high tides. Most of the mound-nests found were constructed after the tsunami and were significantly smaller in volume than those present in 1994. Restoration of suitable habitat is critical for the long-term viability of the Nicobar megapode. However, post-tsunami impacts such as the creation of large-scale plantations in coastal areas, which are encroaching upon megapode habitat, may be severe. Because of the decline in numbers and habitat destruction and hunting the Nicobar megapode probably now qualifies for categorization as Endangered on the IUCN Red List.