Dataset: WP2 net metadata - CGoA LTOP

Name: WP2 net meta data from F/V Great Pacific GP0108, GP0207-01, GP0207-02 in the Coastal Gulf of Alaska, Northeast Pacific from 2001-2002 (NEP project)
Published: 2009-02-20
Keywords: biota, oceans

Cite This Dataset

DOI:10.1575/1912/bco-dmo.3011.1

Spatial Extent: N:59.8583 E:-139.9382 S:55.6888 W:-155.2753

Temporal Extent: 2001-07-29 - 2002-08-05

Project:

U.S. GLOBEC Northeast Pacific (NEP)

Program:

U.S. GLOBal ocean ECosystems dynamics (U.S. GLOBEC)

Principal Investigator:

Kenneth O. Coyle (University of Alaska Fairbanks, UAF)

Scientist:

Jamal Hasan Moss (University of Washington, UW)

Contact:

Jamal Hasan Moss (University of Washington, UW)

BCO-DMO Data Manager:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2009-02-20

Restricted:

Validated:

Yes

Current State:

Final no updates expected

WP2 net meta data from F/V Great Pacific GP0108, GP0207-01, GP0207-02 in the Coastal Gulf of Alaska, Northeast Pacific from 2001-2002 (NEP project)

Abstract:

WP2 net meta data from F/V Great Pacific GP0108, GP0207-01, GP0207-02 in the Coastal Gulf of Alaska, Northeast Pacific from 2001-2002.

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Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2009-02-20	National Oceanographic Data Center (NODC)	0115275	2013-12-25
2009-02-20	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.1575/1912/bco-dmo.3011.1	2020-01-16

Description

Gulf of Alaska - LTOP
WP2 net - meta data, 2001-2002

PI: all tows are vertical hauls, 253-micron mesh.

GLOBEC 2000: Gulf of Alaska Long-Term Observation Program
T. Weingartner, L. Haldorson, R. Hopcroft, K. Coyle, T. E. Whitledge (all at University of Alaska, Fairbanks), T. Royer (Old Dominion University)

This project is to conduct the Gulf of Alaska Long-Term Observation Program (GOA-LTOP) as part of Phase II of the Northeast Pacific (NEP) GLOBEC program. The GOA shelf supports a rich ecosystem that includes many commercially important fisheries. The basis for this productivity is enigmatic for the GOA shelf is deep, forced by downwelling-favorable winds, and fed by a massive nutrient-poor coastal freshwater discharge. Both the winds and the freshwater discharge are intimately linked to the strength and position of the Aleutian Low. The GOA ecosystem experiences substantial physical and biological changes on decadal and interannual time scales. Although some of these changes are correlated with various climatic indices a mechanistic understanding of climate change and ecosystem response is unavailable. The generic goal of this LTOP is to understand and quantify temporal (seasonal and interannual) and spatial (cross- and along-shelf) variations in the thermohaline, chemical, and biological properties and relationships of this shelf. Our proposal supports GLOBEC goals that will help: 1) retrospective studies interpret historical data, 2) design a cost-effective long-term monitoring program, 3) provide the seasonal and interannual context for concurrent mesoscale and process studies, and 4) provide boundary conditions and data sets for model evaluation. This 5-year project entails 4 field years and a fifth year for data analyses and synthesis. The field effort involves seven, 9-day interdisciplinary cruises/year in the northern GOA. The study area encompasses the 220-km long, Seward Line (sampled in the 1970s) that extends across the shelf and slope and high resolution sampling of the Alaska Coastal Current (ACC), upstream, downstream, and within Prince William Sound. The ACC is an important shelf habitat for yoy salmon migrating from nursery areas in the sound and into the GOA. The sampling effort (Table A) is year-round and motivated by seasonally significant physical and biological events affecting yoy pink salmon.

Table A. Sampling schedule and rationale for GOA-LTOP. (Key for Winds, Discharge and Stratification: S=strong; M=moderate; W=weak; D=downwelling winds; U=upwelling winds; V=variable; L=low; H=high) Deep water moves onshore during the July-August upwelling period.

Month	Sampling				Physical Rationale			Biological Rationale
Month	CTD	Nutrients	Zoo	Fish	Winds	Disch	Strat	Biological Rationale
March	X	X	X		D S	L	W	Zooplankton migrate from depth (at shelfbreak); transported inshore.
April	X	X	X		D M	L-M	W V	Phytoplankton bloom
May	X	X	X		D M-W	M	M V	Maximum oceanic copepod biomass.
July	X	X	X	X	D/U W	M-H	S	Maximum zooplankton abundance; YOY salmon enter shelf.
August	X	X	X	X	D/U W	M-H	S	Maximum YOY salmon abundance on shelf.
October	X	X	X	X	D S	H	H	YOY salmon on shelf.
December	X	X	X		D S	M	M	Fall-winter pre-conditioning for spring nutrients, small zooplankton.

The sampling protocol follows GLOBEC guidelines and uses gear types and techniques similar to those in the Oregon LTOP that is also a part of the NEP-GLOBEC program. Most of the research will be conducted from the R/V Alpha Helix. Fish sampling will be done from a chartered trawler in July, August, and October. Both vessels will work together during these cruises so that the fishing charter can verify fish targets detected on the acoustics array towed from the Alpha Helix.

This page was last updated on September 22, 2000.
Maintained by:
Hal Batchelder [hbatchelder@coas.oregonstate.edu
College of Oceanic & Atmospheric Sciences
Oregon State University
Corvallis, OR 97331-5503
phone: 541-737-4500; FAX 541-737-2064

Methods & Sampling

The OCC/GLOBEC survey occurred along the coastal waters of the Gulf of Alaska and in Shelikof Strait, AK during 2001-2004. Transects sampled during the survey were perpendicular to shore and extended from nearshore across the continental shelf to oceanic waters beyond the 200-m shelf break. The survey was conducted aboard the contract fishing vessel F/V Great Pacific during 2001-2002 and 2004, and aboard NOAA Ship Miller Freeman during 2003.

Fish samples were collected in a 198-m long mid-water rope trawl with hexagonal mesh wings and body, and a 1.2-cm mesh liner in the codend. The rope trawl was towed at 6.5 to 9.3 km • hour-1, at or near surface, and had a typical spread of 40-m horizontally and 15-m vertically. All tows lasted 30 minutes and covered 2.8 to 4.6 km, and sampling was done during daylight hours; however, tows occurred during night as part of a 24-hour repeat sampling of a single station for one day during 2001 and 2003.

Once the net was hauled aboard, salmon and other fishes were sorted by species and counted. Standard biological measurements including fork length, body weight, and sex were taken from sub-samples of all salmon species. Sub-samples of juvenile pink (Oncorhynchus gorbuscha), chum (O. keta), and sockeye (O. nerka) salmon were frozen whole for laboratory analyses of food habits, otolith hatchery thermal marks (pink and chum salmon), and genetic analysis (chum salmon).

Plankton samples were collected using a 1-m2 Tucker trawl fitted with a 505-um mesh net that was towed near surface (approximately 1 knot) for 5 minutes (2001-2003 surveys). During 2004, plankton samples were collected using a WP-2 net fitted with a 253-um mesh net that was deployed vertically to a depth of 100-m depth. The volume of water filtered by the net was estimated using flow meters. Plankton samples were transferred into vials, preserved in 5% formalin onboard the ship, and stored until a laboratory analysis was completed.

Data Files

File
WP2_meta.csv (Comma Separated Values (.csv), 3.53 KB) MD5:e6269ade4d20adf8d88f4f44be79d3fa Primary data file for dataset ID 3011

More Information about this dataset

Funding Sources

Funding Source	Award Number
National Oceanic and Atmospheric Administration	unknown NEP NOAA
NSF Division of Ocean Sciences	OCE-0109078

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
GP0108	GP0101	2001-07-17	F/V Great Pacific	Edward V. Farley (Chief Scientist)	data info
GP0207-01	GP0201	2002-07-11	F/V Great Pacific	Edward D. Cokelet (Chief Scientist)	data info
GP0207-02	GP0201	2002-07-28	F/V Great Pacific	Chris Kondzela (Chief Scientist)	data info

Instruments

WP-2 Plankton Net

Supplied Description:

WP-2 net: vertical net tow to 100-m; 0.57-m diameter ring; 0.253-mm mesh; samples frozen for C and N isotope analysis.

Instrument Type

Generic Name: WP-2 Plankton Net

Acronym: WP-2

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/NETT0168/

Generic Description:

The WP-2 net is a variety of Ring Net for zooplankton but which is capable of being closed by means of a Nansen bottle-type release messenger weighing 0.8 kg and which can be equipped with a digital flow meter for determining the amount of water passing through the plankton net. The rings may have a variety of sizes (57cm, 70cm, 75 cm, or 1m internal diameter) and the nets which make up this device are in two parts, a cylindrical upper part and a conical lower part. The closing ring is between the two net segments. (more at KC Denmark)

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
haul_id	Tow number/identification.	dimensionless	tow
station	Station code.	dimensionless	station
yrday_local	Local day and decimal time, as 326.5 for the 326th day of the year, or November 22 at 1200 hours (noon).	dimensionless	yrday_local
year	Year, e.g. 2001. in the format YYYY	unitless	year
month_local	Month of year, local time. in the format mm	unitless	month_local
day_local	Day of month, local time. in the format dd	unitless	day_local
time_local_start	starting time of observation, local time , 24 hour clock		time_start_local
lat_start	latitude at starting time of measurement (west is negative)	decimal degrees	lat_start
lon_start	longitude at starting time of measurement (west is negative)	decimal degrees	lon_start
distance_start	{check on this}		no_bcodmo_term
depth_start	{check on this}	meters	depth
depth_tow	maximum depth of tow	meters	depth_cast
comments	free text comments		comment
cruiseid	Cruise identifier	unitless	cruise_id