Seamounts are biodiversity hotspots in the deep-sea. Although they are threatened from trawling and seabed mining, much is unknown about the structure, function and connectivity of seamount ecosystems. The Census of Marine Life on Seamounts (CenSeam) was a field program that examined seamounts as part of the global Census of Marine Life that brought together scientists working on seamount ecology, taxonomy, conservation, fisheries, geology, physical oceanography, and informatics to progress seamount science. The expansion of research efforts beyond national programs substantially advanced the understanding of seamounts, which is evident through the numerous scientific papers published on seamount oceanography, ecology, and the vulnerability and management of seamount resources. Clark et al. (2012) summarize the main findings of CenSeam and current research, identify the key questions needed to be asked for spatial planning, identify the future research need for seamount conservation and management, and propose future data and tools needed for seamount conservation and management. Clark et al. conclude that close cooperation and collaboration between scientists, managers, policy agencies, commercial companies, and NGOs at the outset when planning research is essential to the practical success of the research.—Evelyn Byer
Clark MR, Schlacher TA, Rowden AA, Stocks KI, Consalvey M (2012) Science Priorities for Seamounts: Research Links to Conservation and Management. PLoS ONE 7(1): e29232. doi:10.1371/journal.pone.0029232
Clark and colleagues evaluated how well six key ecological aspects of seamounts are understood from recent research. First, Clark et al. summarized information that shows that seamounts are generally not isolated habitats with a highly endemic fauna. On the contrary, they have assemblages of species composition similar to those found in adjacent deep-sea habitat on the continental slope also known as banks. Seamount assemblages differ in structure from the habitat surrounding them in terms of species abundance and frequency. Connectivity between them was found to be highly variable. These differences are not surprising because seamounts are heterogeneous habitats that span a broad depth range, are influenced by diverse oceanographic processes, are situated in diverse geological settings, and are comprised of heterogeneous habitat types. Seafloor type and character on seamounts, just as in non-seamount habitats, are key factors in determining species occurrence, distribution and diversity in the benthos. Third, it is impossible to generalize about the spatial scales over which faunal assemblages of seamounts are structured because communities on seamounts are variable over large spatial scales. The fourth point Clark et al.make is that seamounts are increasingly exploited by humans. Major global threats come from trawling and seafloor mining, principally for poly-metallic sulphides and cobalt-rich crusts. The review follows with the point that seamounts are affected by human exploitation. It cites specific examples of seamounts in New Zealand and Australia where there exist significant differences in the structural complexity of benthic habitats, species numbers and abundance, and the composition and structure of assemblages between fished and unfished seamounts. Moreover, the effects of mining are more uncertain because few studies have been carried out. Lastly, seamounts are very slow to recover from impacts. This conclusion is mainly based on the exceptionally slow growth rates of large, deep-sea megafauna. For example, seamounts off the coast of New Zealand and Australia were observed for 5-10 years after closure to trawling and still had no signs of recovery.
Clark et al. also identified seven areas of research priorities for seamounts over the next decade including identifying seamount locations and physical characteristics, providing descriptions of biodiversity, characterizing spatial scales of population connectivity, providing context for seamounts as part of the deep-sea ecosystem, identifying broader effects of human disturbance, examining recovery dynamics, and looking at the effects of climate change. Clark et al. also suggests expanding and maintaining seamount data and information, improving fisheries data and information by capturing historical data sets into existing global repositories and improving the spatial resolution, producing models of species and assemblage distribution as data compilations become available, determining the extent to which physical and chemical parameters can predict biological information, and refining ecological risk assessment methods so that they are robust, transparent and understandable.