Abstract
Marine lakes are unique marine habitats that could provide researchers with new insights into complex ecological and evolutionary processes in the marine realm. This rather scarce and unknown marine ecosystem is found in several disconnected island nations and comprise land-locked Holocene marine basins with inhabitants of marine descent. The relatively small populations isolated in the marine lakes, which represent a combination of multiple heterogeneous environments with varying degrees of isolation to each other and to the open sea, offer unprecedented opportunities for fundamental studies on Holocene evolution in marine taxa, which typically lack fossil records. Approximately 200 marine lakes are thought to be distributed worldwide, of which “Jellyfish Lake” in Palau (Micronesia) is likely the most well known. Studies in Palau have demonstrated that these lakes show untapped potential for studies on marine evolution. Recently, similar marine lakes have been discovered in Indonesia. Pilot studies on these marine lakes in East Kalimantan (2003) and West Papua (2006) revealed that sponges are the most abundant and diverse phylum, with a high number of rare and unknown species, as well as species that are common in the surrounding reef area. We propose to document the unique sponge faunas of Indonesian marine lakes in order to investigate the variation in community composition within and outside of the lakes. In parallel we wish to conduct molecular analyses to assess the level of connectivity and divergence between populations of three key sponge taxa in the marine lakes and in the adjacent seas. The ubiquitous presence of sponges in the marine lakes as well as in the surrounding seas make this a prime taxon to use in the proposed research. We expect to conduct fundamental work towards a general understanding of biogeographical relationships and population structures of benthic marine species. The anticipated results will, furthermore, provide information that can be applied for selecting the most effective and appropriate conservation measures for these vulnerable ecosystems.
Netherlands