Life on the Edge 2005:
Exploring Deep Coral Communities
October 16 - November 4, 2005
Our ongoing studies (2000-present) exploring southeastern US (SEUS) and Gulf of Mexico continental slope coral ecosystems are based on hypotheses that these habitats are ecologically important and productive, yet they are poorly documented. There is increasing evidence that deep water (aphotic) corals are important fish habitat, hold data on ocean climate and productivity, and are hotspots of biodiversity, including new species. Deep coral habitats are more abundant than previously known, and at the same time they are being threatened. The SEUS and Gulf of Mexico may have the most extensive deep coral areas in the US; however, these large regions are poorly explored (even considering recent expeditions). These high profile features may concentrate resources and enhance local productivity in ways similar to seamounts. Also, like seamounts, such unique habitats have escaped detailed examination in the SEUS not only because of their great depths but also because the bottom topography is rugged and the habitats are overlain by extreme currents (i.e., Gulf Stream). Thus, most studies on deep coral banks require expensive unconventional sampling techniques (e.g., manned submersibles). Locating, describing, and mapping deep corals and conducting basic biological studies in these habitats are priorities for our research. Our previous cruises have documented deep coral and outer shelf reef habitats and associated biota, but these missions have only begun to quantify this extensive habitat in the region. Our studies have yielded many new records of biota, new ecological data, new data on habitat distributions/structures, and data on water column trophic connectivity. This cruise continues and expands our explorations of these unique and relatively unknown deep water habitats.
While the SEUS harbors many deep coral species, few create extensive, complex reef structures. Lophelia pertusa, the major mound forming coral in the deep sea, is a cosmopolitan species and is the dominant hard coral deeper than 300 m through the SEUS and Gulf of Mexico. We have concentrated our work around L. pertusa areas (because of its abundance, wide distribution, and structure forming abilities), but our objectives also apply to most hard substrate habitats including mixed corals and sponges.
We will locate and sample poorly studied middle slope coral banks (Lophelia mostly,
360-800 m) from Cape Lookout, NC to southeastern FL (see Mission
Plan). During this expedition we will cover over 650 nautical miles (1,205
km). We will use a manned submersible (Johnson-Sea-Link, JSL) to quantify
biota and habitat on and near reefs via standardized video observations. The JSL will
collect samples of corals and associated invertebrates for various purposes.
Each dive will have multiple objectives, with some tasks given priority. We will
also sample the whole water column using a variety of ship deployed nets. As
an integrated regional exploration of deep coral habitat physical structure and
ecology, this interconnected, multidisciplinary approach should advance our understanding
of critical habitats. Using standardized methods throughout this large area will
allow us to compare complex habitats over depth and geographic regions.
Life on the Edge 2005 Exploring Deep Coral Communities Mission Facts
Oct 19, 2005 Discover the unique tools and advanced computer technology behind the science of seafloor mapping.
Oct 18, 2005Today's dives were in a new area off Cape Lookout and investigated large coral bank systems clustered around an undersea ridge.
Oct 17, 2005 The Johnson Sea-Link submersible slipped beneath the waves for the first dive of the expedition and encountered a bignose shark and brought back lots of samples, including a fish that "walks around" on its fins.