Planktonic Communities
The primary objective of the planktonic communities program is to describe spatial, seasonal and interannual characteristics of the plankton (phytoplankton and zooplankton) communities within the study areas.
Phytoplankton, along with algae that grow attached to sea ice, are the conduit of the sun´s energy into organic “food” at the base of the food chain in the Chukchi Sea. Phytoplankton are assessed as chlorophyll-a concentration from water samples collected with a CTD (conductivity-temperature-depth) rosette. We also measure the concentration of the major nutrients required for their growth in these samples. Zooplankton are the major consumers of phytoplankton, and hence the key pathway to vertebrates such as pelagic fish, seabirds, and even bowhead whales. Zooplankton are collected using two different methods: paired ring nets of medium-size mesh hauled vertically at slow speed for smaller species, and Bongo nets towed off the side of a ship moving at 2 knots for larger, faster species.
Zooplankton 2012
Additional 2012 zooplankton information will be available, please check back later.
Russ Hopcroft, Ph.D.
Principal Investigator
UAF – Institute of Marine Science
120 O’Neill PO Box 757220
Fairbanks, AK 99775
907-474-7842
rrhopcroft@alaska.edu
Zooplankton 2011
Additional 2011 zooplankton information will be available, please check back later.
Russ Hopcroft, Ph.D.
Principal Investigator
UAF – Institute of Marine Science
120 O’Neill PO Box 757220
Fairbanks, AK 99775
907-474-7842
rrhopcroft@alaska.edu
Zooplankton 2010
Water temperatures were intermediate between the previous years, as were chlorophyll and nutrient concentrations. In total, 77 taxonomic categories of zooplankton, including 10 meroplanktonic larval categories, were observed during the 2010 field year. Both holozooplankton and meroplankton abundance and biomass were much higher in 2010 than in previous years, especially for larger-bodied animals. We believe differences in ice-melt timing, water temperatures, northward transport of water masses, nutrients and chlorophyll are influencing the large inter-annual difference observed in the planktonic communities over the past 3 years.
Russ Hopcroft, Ph.D.
Principal Investigator
UAF – Institute of Marine Science
120 O’Neill PO Box 757220
Fairbanks, AK 99775
907-474-7842
rrhopcroft@alaska.edu
Zooplankton 2009
Water temperatures were warm and sampling began well after the sping phytoplankton bloom. In total, 70 taxonomic categories of zooplankton, including 11 meroplanktonic larval categories, were observed during the 2009 field year, and consistently mostly of species observed the previous year. The abundance and biomass of “regular” zooplankton has higher than in 2008, while that of meroplankton was lower than in 2008. As observed in 2008, the different zooplankton communities could be distinguished between the study sites, and a temporal evolution of the community structure was apparent over both areas.
Russ Hopcroft, Ph.D.
Principal Investigator
UAF – Institute of Marine Science
120 O’Neill PO Box 757220
Fairbanks, AK 99775
907-474-7842
rrhopcroft@alaska.edu
Zooplankton 2009
Due to the late ice retreat, the phytoplankton spring bloom was delayed. In total, 76 taxonomic categories of zooplankton were observed, including substantial contribution by larval stages of benthic organisms (called meroplankton). The greatest taxonomic diversity was observed within the copepods (20 species), followed by the jellyfish (9 species), with species typical for the region and largely of Pacific origin. Abundance and biomass estimates of the zooplankton community appeared lower than typical for the region, perhaps due to relatively cold oceanographic conditions experienced during 2008, which slowed the normal growth and development of the zooplankton. Despite the relative proximity of the prospects, they could generally be separated based on community structure. Not surprisingly, a temporal evolution of the community structure was apparent over both prospects.
Russ Hopcroft, Ph.D.
Principal Investigator
UAF – Institute of Marine Science
120 O’Neill PO Box 757220
Fairbanks, AK 99775
907-474-7842
rrhopcroft@alaska.edu