These data are part of an ocean observation study by Stabeno, Napp, and Whitledge sponsored, in part, by the North Pacific Research Board (Project 701; http://doc.nprb.org). The grant was titled "Sentinels for ecosystem change: long term biophysical moorings on the Bering Sea shelf (2007 b?? 2008)." Moorings have been maintained on the southeastern Bering Sea shelf at four sites: M2 (56.9B0N, 164.1B0W) since 1995, M4 (57.9B0N, 168.9B0W) since 1996; M5 (59.9B0N, 171.7B0W) and; M8 (62.2B0N 174.7B0W) since 2004. Shipboard measurements of temperature, salinity, nutrients, chlorophyll, fluorescence and zooplankton were collected around the moorings and along the 70-m isobath on 4 cruises (3MF07, 18 April b?? 6 May; 1HE07, 10 April b?? 12 May; 7MF07, 17 b?? 30 September; 1TT07, 24 September b?? 11 October) to groundtruth the in situ sensors on the moorings and to learn the factors that distinguish the upper water column of the central and southeastern middle shelf.

These data are part of a ocean observation study by Stabeno, Napp, and Whitledge sponsored, in part, by the North Pacific Research Board (Project 517; http://doc.nprb.org). The grant was titled "Sentinels for Bering Sea ecosystem change." Moorings have been maintained on the southeastern Bering Sea shelf at four sites: M2 (56.9B0N, 164.1B0W) since 1995, M4 (57.9B0N, 168.9B0W) since 1996; M5 (59.9B0N, 171.7B0W) and; M8 (62.2B0N 174.7B0W) since 2004. Shipboard measurements of temperature, salinity, nutrients, chlorophyll, fluorescence and zooplankton were collected around the moorings and along the 70-m isobath on 3 cruises (3MF05, 16 April b?? 7 May; 3TT05, May 12 - 28; 8MF05, 21 September b?? 4 October) to groundtruth the in situ sensors on the moorings. This long-term monitoring supports major findings: (1) Over the southeastern shelf, the timing of the spring phytoplankton bloom is determined by the presence of ice, with an early bloom occurring if ice is present after mid-March and a later bloom if there is no sea-ice after mid-March; (2) during 2001-2005, the southeastern Bering Sea shelf underwent a marked warming (~3B0C) that was closely associated with a decrease of sea ice; with shifts in the atmospheric forcing, colder conditions returned to the Bering Sea shelf in the winter 2006 and continued into winter/spring 2007; (3) nutrients supply and summer salinity over the shelf has not significantly changed during the last three decades; (4) in association with the warming there is an indication that the abundance of cold-water zooplankton species (e.g. Calanus marshallae ) has been reduced; (5) from hydrography collected in May and September 2005 along the 70 m isobath starting at M2 in the south and ending at M8 in the north, it is evident that the structure of southern shelf is dominated by temperature, while the northern shelf is dominated by salinity. In addition, the location of the boundary between the southern shelf and northern shelf appears to vary from one year to the next and is mainly, but not completely dependent upon maximum ice extent during the spring.

These data are part of a ocean observation study by Stabeno, Napp, and Whitledge sponsored, in part, by the North Pacific Research Board (Project 410; http://doc.nprb.org). The grant was titled "Long-term observations on the Bering Sea shelf (2004-2005): biophysical moorings at sites 2 and 4 as sentinels for ecosystem change." Moorings were maintained on the southeastern Bering Sea shelf at M2 (56.9B0N, 164.1B0W), and at M4 (57.9B0N, 168.9B0W). Shipboard measurements of temperature, salinity, nutrients, chlorophyll, fluorescence and zooplankton were collected around the moorings on two cruises (3MF04 - April 2004 and 8MF04 - September 2004) to ground truth in situ sensors on the moorings. This long-term monitoring supported major findings: (1) The timing of the spring phytoplankton bloom is determined by the presence of ice, with an early bloom occurring if ice is present after mid-March and later bloom occurring if there is no sea-ice after mid-March; (2) During the last decade, the southeastern Bering Sea shelf has undergone a marked warming (~3B0C) that is closely associated with a marked decrease of sea ice over the southeastern shelf; (3) Nutrients supply and summer salinity over the shelf has not significantly changed during the last three decades; (4) There is an indication that cold water zooplankton species (e.g Calanus marshallae ) are occurring in reduced abundance in association with the warming. While the warming over the southeastern shelf is primarily related to the reduction of ice extent, a combination of other mechanisms are important: the presence over the eastern shelf of a relatively mild air mass during winter since 2000; a shorter ice season caused by a later fall transition and/or earlier spring transition; increased flow through Unimak Pass during winter introducing warm Gulf of Alaska water onto the shelf; and a thermal feedback mechanism whereby warmer, summer ocean temperatures delay the southward advection of sea ice during winter.

The dataset contains records of fish eggs and larvae collected during FOCI assessment surveys. Records include all data pertinent to identify where specimens were collected (lat, lon, date, gear used, max depth of gear, water depth). Specific data on specimens includes scientific name, stage of development, number collected (whole numbers and CPUE), lengths of larvae, and diameters and stages of eggs. In addition, there are comments that explain any irregularities that may have occurred during sample collection; depending on the reason data is being extracted, comments may indicate a sample is not suitable for consideration.

These data were collected under NSF Grant # ARC-0722448 ("BEST: Impacts of Sea-ice on the Hydrographic Structure, Nutrients, and Mesozooplankton over the Eastern Bering Sea Shelf") to Dr. G.L. Hunt, Jr., University of Washington. The eastern Bering Sea shelf supports productive marine ecosystems with extraordinarily valuable fisheries and subsistence resources, but sub-arctic seas are predicted to be one of the regions most sensitive to future warming of the world oceans. Some of the most direct effects of changing climate will be on the extent, duration and timing of sea-ice over the Bering Sea shelf. Sea-ice controls the timing of the spring phytoplankton bloom, the fate of primary production, water column temperature and salinity, and provides a haul out and molting platform for marine mammals. Thus, the most urgent priority of the Bering Sea Ecosystem Study (BEST) is to examine the role of changing sea-ice conditions on the chemical, physical, and biological characteristics of the ecosystem. The first BEST cruise was scheduled on the USCG Healy in April-May 2007, however, physical observations, water column nutrient chemistry, and zooplankton distribution/abundance were not among the ecosystem components funded in the first call for proposals. Project ARC-0722448 funded by NSF after the first call for BEST proposals filled this gap in chlorophyll collections until the remainder of BEST projects could be assembled in 2008.

A total of 105 stations were occupied. There were two sample grids (southeast Alaska and Yakutat Bay) and two transects in the vicinity of Kayak Island. At each station we sampled using paired 20 and 60 cm Bongo frames (150 and 500 micron mesh nets, respectively) and a Sameoto neuston sampler (500 micron mesh net) to estimate the abundance of zoo- and ichthyoplankton. A SeaBird SeaCat (SBE 19 plus) was used with the bongo frames to determine the depth of the samplers in real time and to measure temperature and conductivity. At a few selected stations depth-stratified plankton were obtained with a 1 meter squared MOCNESS (500 micron mesh nets) and at other selected stations microzooplankton were sampled with vertical tows of a CalVET net (53 micron mesh).

A total of 105 stations were occupied. There were two sample grids (southeast Alaska and Yakutat Bay) and two transects in the vicinity of Kayak Island. At each station we sampled using paired 20 and 60 cm Bongo frames (150 and 500 micron mesh nets, respectively) and a Sameoto neuston sampler (500 micron mesh net) to estimate the abundance of zoo- and ichthyoplankton. A SeaBird SeaCat (SBE 19 plus) was used with the bongo frames to determine the depth of the samplers in real time and to measure temperature and conductivity. At a few selected stations depth-stratified plankton were obtained with a 1 meter squared MOCNESS (500 micron mesh nets) and at other selected stations microzooplankton were sampled with vertical tows of a CalVET net (53 micron mesh).

Zooplankton data are abundance by taxanomic group (to species where possible), stage, size and sex. Zooplankton sorting is performed at The Polish Plankton Sorting Institute in Szcecin, Poland. The zooplankton protocol was changed in 2012 to include a wider range of taxaonomic categories for all study areas and to finer taxanomic resolution where possible. Limited biomass information is available using literature values for micrograms carbon of select copepod species. Various gears with different mesh sizes are used to asses different size classes of zooplankton including 20/60cm paired bongos, Tucker, Multinet, MOCNESS, Methot, CalVET and microzooplankton nets hung on nisken bottles.

A total of 64 stations were occupied along onshore-offshore transect lines from the Bering Strait to Barrow Canyon. At each station we sampled zooplankton using a 1m^2 Tucker Sled with 333 micron mesh nets. One net was fished entirely along the bottom. The second net collected zooplankton from the bottom to the surface. Inside this second net was a 150 micron mesh, 25 cm diamter Clarke-Bumpus net to collect the smaller zooplankton species. Both Tucker nets had a calibrated General Oceanics flow meter mounted inside the net mouth. A SeaBird FastCat (SBE 49) was attached to the top of the Tucker Sled to determine the depth of the samplers in real time and to measure temperature and conductivity. A multi-frequecy acoustic systems (TAPS-6) was also mounted on the top of the sled frame for acoustic determination of zooplankton biomass and size composition. The device insonified a small volume directly in the path of the net. During the cruise we recovered a multi-frequency acoustic device that had been moored off of Icy Cape for almost one year and then deployed two more acoustic devices to overwinter.

Our scheduled departure time was delayed due to a combination of weather and shipb??s equipment problems (navigation light, engine). The weather slowed our transit time to Bering Site 2 from approximately 19 hrs to more than 29 hours. Bering Sea Site 2 - When we arrived at site 2, we began CTD/chlorophyll/nutrient/oxygen and bongo ops at the southernmost box station. The station was successfully completed and we slowly b?? due to weather b?? made our way to the westernmost box station b?? averaging between 5 and 6 knots. This station was also successfully completed, but shipb??s personnel concluded that due to a combination of the weather and personnel inexperience in the challenging sea conditions, operations would be suspended. After a safety meeting among shipb??s personnel, it was decided that the survey person, would monitor the operations area for safety considerations. Deployment and recovery of gear that was normally performed by a survey tech and deck hand would now be done by a scientist and a deck hand. Operations resumed at mid-morning - CTD/chlorophyll/nutrient/oxygen and bongo ops at the remaining box stations were completed. The center station was completed with 2 CTD/chlorophyll/nutrient/oxygen/DIC casts, a bongo and triplicate CalVET tows. We waited overnight hoping for improving weather conditions, but in the morning concluded that we should head north to Bering Sea site 5. Bering Sea Site 5 b?? We deployed 2 subsurface moorings (mooring recoveries at this site had been conducted previously on a contract vessel). A CTD/chlorophyll/nutrient/oxygen/DIC casts, a bongo and triplicate CalVET tows were completed after mooring operations. We then completed the box of stations surrounding site 5 b?? with a CTD/chlorophyll/nutrient/oxygen and bongo at each station. Bering Sea Site 4 b?? We deployed 2 subsurface moorings (there were no moorings to be recovered at this site). Two CTD/chlorophyll/nutrient/oxygen/DIC casts, a bongo and triplicate CalVET tows were completed after mooring operations. We then completed the box of stations surrounding site 4 b?? with a CTD/chlorophyll/nutrient/oxygen and bongo at each station. Bering Sea Site 2 b?? A small boat was launched to recover the fragile instruments on the surface buoy tower. A surface mooring and two subsurface moorings were successfully recovered. Two subsurface moorings were successfully deployed. Three CTD/chlorophyll/nutrient/oxygen/DIC casts were completed. CTD and bongo line b?? A line of eight CTD/chlorophyll/nutrient/oxygen and bongo tows - starting at site 2 and working towards site 4 - were completed. The last seven casts included DIC samples.