Integrated At-Sea Morphological and Molecular Assessment of Zooplankton Biodiversity in the Northwestern Atlantic Ocean From the Surface to 5000 m

Event Name/Location

4th International Zooplankton Production Symposium, Hiroshima, Japan, May 28-June 1, 2007

Document Type


Publication Date



Zooplankton from northwestern Atlantic tropical/subtropical waters were sampled at five stations from the surface to 5000 m. Environmental data and zooplankton samples were collected with a 102 m opening/closing MOCNESS trawl with 335 μm mesh nets from 5000 to 1000 m. Two smaller MOCNESS sampled the upper 1000 m. Ring net and water bottle casts, and blue-water SCUBA diving were also conducted. A team of taxonomic experts using traditional morphological approaches analysed samples at sea and provided identified specimens for determination of DNA barcodes for species recognition. Over 500 species were identified; >1000 specimens were placed in a queue for barcoding; 87 species were barcoded at sea. For several taxonomic groups, a significant fraction of the region’s known species were collected and identified (i.e. 65 ostracod species were identified of the 140 known species for the Atlantic Ocean were collected, plus at least six undescribed species, and the first DNA barcode for a planktonic ostracod was obtained). Also identified were >40 molluscs, >100 species of cnidarians, several hundred species of copepods, and >100 species of fish. At least 12-15 new species will be described from this effort. The deployment of specially-designed trawls to sample large volumes for small zooplankton is essential to provide an accurate assessment of species diversity at great depths. This study yielded preliminary confirmation of high species diversity and low species abundances in the deep sea. Below 1000 m, even rare species may have huge population sizes and play a critical role in the dynamics of deep-sea environments.