Seamounts are hotspots of pelagic biodiversity in the open ocean

The identification of biodiversity hotspots and their management for conservation have been hypothesized as effective ways to protect many species. There has been a significant effort to identify and map these areas at a global scale, but the coarse resolution of most datasets masks the small-scale patterns associated with coastal habitats or seamounts. Here we used tuna longline observer data to investigate the role of seamounts in aggregating large pelagic biodiversity and to identify which pelagic species are associated with seamounts. Our analysis indicates that seamounts are hotspots of pelagic biodiversity. Higher species richness was detected in association with seamounts than with coastal or oceanic areas. Seamounts were found to have higher species diversity within 30–40 km of the summit, whereas for sets close to coastal habitat the diversity was lower and fairly constant with distance. Higher probability of capture and higher number of fish caught were detected for some shark, billfish, tuna, and other by-catch species. The study supports hypotheses that seamounts may be areas of special interest for management for marine pelagic predators.

[1]  K. Bjorndal,et al.  Historical Overfishing and the Recent Collapse of Coastal Ecosystems , 2001, Science.

[2]  S. Jorgensen,et al.  The Home of Blue Water Fish , 2005 .

[3]  Pierre Fréon,et al.  Review of fish associative behaviour: Toward a generalisation of the meeting point hypothesis , 2000, Reviews in Fish Biology and Fisheries.

[4]  B. Worm,et al.  Rapid worldwide depletion of predatory fish communities , 2003, Nature.

[5]  M. Maunder,et al.  Biomass, Size, and Trophic Status of Top Predators in the Pacific Ocean , 2006, Science.

[6]  K. Tsukamoto.  Oceanic biology: Spawning of eels near a seamount , 2006, Nature.

[7]  H. Lotze,et al.  Predator diversity hotspots in the blue ocean , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[8]  R. Lueck,et al.  Topographically Induced Mixing Around a Shallow Seamount , 1997 .

[9]  T. Morato,et al.  Spatial variability of seabird distribution associated with environmental factors: a case study of marine Important Bird Areas in the Azores , 2009 .

[10]  F. Parrish.  Do Monk Seals Exert Top-Down Pressure in Subphotic Ecosystems? , 2009 .

[11]  Gunnar Stefánsson,et al.  Analysis of groundfish survey abundance data: combining the GLM and delta approaches , 1996 .

[12]  G. Sedberry,et al.  Satellite telemetry tracking of swordfish, Xiphias gladius, off the eastern United States , 2001 .

[13]  D. Pauly,et al.  Fishing down marine food webs , 1998, Science.

[14]  R. Hilborn.  Faith-based Fisheries , 2006 .

[15]  S. Andréfouët,et al.  Enhanced seamount location database for the western and central Pacific Ocean : Screening and cross-checking of 20 existing datasets , 2008 .

[16]  T. Pitcher,et al.  Modelled effects of primary and secondary production enhancement by seamounts on local fish stocks , 2009 .

[17]  Arturo Fabian Eduardo Muhlia Melo,et al.  The occurrence of yellowfin tuna (Thunnus albacares) at Espiritu Santo Seamount in the Gulf of California , 2003 .

[18]  F. Sánchez,et al.  Does Le Danois Bank (El Cachucho) influence albacore catches in the Cantabrian Sea , 2009 .

[19]  M. Lowry,et al.  Lunar landings—Relationship between lunar phase and catch rates for an Australian gamefish-tournament fishery , 2007 .

[20]  C. Fauvel,et al.  Reproductive dynamics of swordfish (Xiphias gladius) in the southwestern Indian Ocean (Reunion Island). Part 2: fecundity and spawning pattern , 2009 .

[21]  B. Mate,et al.  Persistent Pelagic Habitats in the Baja California to Bering Sea (B2B) Ecoregion , 2004 .

[22]  C. Walters,et al.  Interactions of productivity, predation risk, and fishing effort in the efficacy of marine protected areas for the central Pacific , 2005 .

[23]  Andreas Oschlies,et al.  Global Patterns of Predator Diversity in the Open Oceans , 2005, Science.

[24]  Nick Davies,et al.  Stock assessment of yellowfin tuna in the western and central Pacific Ocean , 2005 .

[25]  Fred N. Spiess,et al.  Corals on seamount peaks provide evidence of current acceleration over deep-sea topography , 1986, Nature.

[26]  D. Pauly,et al.  Seamounts : biodiversity and fisheries , 2004 .

[27]  G. Belle,et al.  Explicit Calculation of the Rarefaction Diversity Measurement and the Determination of Sufficient Sample Size , 1975 .

[28]  Fred Wells,et al.  Marine Biodiversity Hotspots and Conservation Priorities for Tropical Reefs , 2002, Science.

[29]  Ransom A. Myers,et al.  Collapse and Conservation of Shark Populations in the Northwest Atlantic , 2003, Science.

[30]  S. Hurlbert.  The Nonconcept of Species Diversity: A Critique and Alternative Parameters. , 1971, Ecology.

[31]  David Malakoff,et al.  New Tools Reveal Treasures at Ocean Hot Spots , 2004, Science.

[32]  R. Mittermeier,et al.  Biodiversity hotspots for conservation priorities , 2000, Nature.

[33]  D. Tittensor,et al.  Effects of temperature on global patterns of tuna and billfish richness , 2008 .

[34]  B. Worm,et al.  Cascading top-down effects of changing oceanic predator abundances. , 2009, The Journal of animal ecology.

[35]  Mark N. Maunder,et al.  Fisheries: Decline of Pacific tuna populations exaggerated? , 2005, Nature.

[36]  E. Barbier,et al.  Impacts of Biodiversity Loss on Ocean Ecosystem Services , 2006, Science.

[37]  Divya A. Varkey,et al.  Evidence of a seamount effect on aggregating visitors , 2008 .