ERDDAP > info > bcodmo_dataset_755687

Grid DAP Data	Sub- set	Table DAP Data	Make A Graph	W M S	Source Data Files	Acces- sible	Title	Sum- mary	ISO, Metadata	Back- ground Info	RSS	E mail	Institution	Dataset ID
		data	graph		files	public	Historical reconstruction of sea urchin grazing events in Aleutian Island ecosystem from grazing scars, 1965-2004		I   M	background			BCO-DMO	bcodmo_dataset_755687

The Dataset's Variables and Attributes

Row Type	Variable Name	Attribute Name	Data Type	Value
attribute	NC_GLOBAL	access_formats	String	.htmlTable,.csv,.json,.mat,.nc,.tsv,.esriCsv,.geoJson,.odvTxt
attribute	NC_GLOBAL	acquisition_description	String	Clathromorphum species produce annual growth increments (hereafter \"year bands\") in their skeleton (Adey et al. 2013), which contain elemental and isotopic signatures that can be used to reconstruct past oceanographic conditions (e.g., Fietzke et al. 2015). We discovered that such year bands also archive urchin grazing scars, allowing us to measure the timing and frequency of past urchin grazing events on C. nereostratum. Wild specimens of C. nereostratum were thus collected and analyzed in order to reconstruct grazing events in the ecosystem. At each site studied with respect to bioerosion, we collected C. nereostratum specimens (n = 10/site) with hammer and chisel, focusing on individuals without visible signs of grazing on the epithallus. Ship-side, samples were sectioned with a diamond lapidary saw and examined for quality; high quality samples were placed in an oven (50\u00b0C) until dry, then archived for subsequent analysis. Samples collected from Amchitka were of poor quality. Hence for Amchitka, we used specimens collected previously (2004) for this exercise. We also augmented our 2014 collections from Attu with samples previously collected (2008) from the same locale, because many of the 2014 samples did not meet our criteria for reconstruction (see below). Each C. nereostratum specimen (n = 5/island) was mounted to a glass slide, sectioned parallel to the growth axis with a diamond lapidary saw, and polished to 3 microns resolution following established methods (Hetzinger et al. 2009). Each section was then imaged with a camera coupled to a reflected light microscope (GeoTS, Olympus Inc.), which obtains a mosaic of overlapping images and stitches them together to produce a single high-resolution image of the cross-section. This photomosaic was used to carefully identify, age, and count grazing scars that occurred along a transect oriented parallel to the alga's growth axis in the plane of the section. We scored multiple (n = 2-3) transects per sample, given that grazing events do not span the entirety of a year band. The origin of each transect was randomly plotted, then moved to the nearest location on the epithallus that was living and that displayed a flat or convex shape. The transect was then plotted through sequentially older year bands, so long as it: (i) did not cross a fusion between two individual algae; (ii) spanned at least 30 years of growth; and (iii) intercepted year bands that were clearly visible. If any of these criteria were violated, the transect was relocated. Along each transect, we aged and measured the growth (vertical extension) of year bands in 5-year intervals, repeating this process so long as dating could be rigorously performed and end-dates aligned for all transects within a sample. Within each 5-year interval, we assessed the annual frequency of grazing scars - which manifest as a jagged interruption of the growth margin coupled with serial pitting of the reproductive conceptacles - found 5 mm to either side of the transect. Straight growth lines that lacked conceptacles or the occasional empty conceptacle within an otherwise clean growth band was not considered evidence of grazing. In instances where one side of the transect entered an area that violated the above criteria (e.g., passed under an area that had a concave epithallial surface), we analyzed only one side of the transect (10 mm). With this methodology remains the possibility that urchin grazing may have removed entire years of growth, thus obscuring our estimates of grazing frequency and the timing of each grazing event. To address this issue, we compared (double blind) our age models for a subset of samples from Alaid and Ogliuga to ages produced using Uranium series dating (Fietzke et al. 2005). Our age estimates were very similar to those produced by Uranium series dating, indicating we did not lose entire years to grazing. We selected the year 1965 as the cutoff for our reconstruction because ecological records are scant prior to this period (Estes et al. 2010). For C. nereostratum samples collected in 2014, we excluded the 10 most recent years of growth (2014-2005) from our analyses due to a known bias in our collection method; since we collected non-grazed specimens from the wild and retained only the highest quality samples, we biased ourselves against finding evidence of grazing in recent years. For samples collected in 2004 and 2008, such a bias was not evident, at least for those records that met our criteria and were used in the study. For the three 2008 samples used, we excluded the first four years to align chronologies with all other specimens.
attribute	NC_GLOBAL	awards_0_award_nid	String	526658
attribute	NC_GLOBAL	awards_0_award_number	String	PLR-1316141
attribute	NC_GLOBAL	awards_0_data_url	String	http://nsf.gov/awardsearch/showAward?AWD_ID=1316141
attribute	NC_GLOBAL	awards_0_funder_name	String	NSF Arctic Sciences
attribute	NC_GLOBAL	awards_0_funding_acronym	String	NSF ARC
attribute	NC_GLOBAL	awards_0_funding_source_nid	String	390
attribute	NC_GLOBAL	awards_0_program_manager	String	Henrietta N Edmonds
attribute	NC_GLOBAL	awards_0_program_manager_nid	String	51517
attribute	NC_GLOBAL	cdm_data_type	String	Other
attribute	NC_GLOBAL	comment	String	Historical reconstruction of sea urchin grazing events in the Aleutian Islands, 1965-2004 PI's: Steneck (Umaine), J.Estes (UCSC), D. Rasher (BLOS) version: 2019-02-013
attribute	NC_GLOBAL	Conventions	String	COARDS, CF-1.6, ACDD-1.3
attribute	NC_GLOBAL	creator_email	String	info at bco-dmo.org
attribute	NC_GLOBAL	creator_name	String	BCO-DMO
attribute	NC_GLOBAL	creator_type	String	institution
attribute	NC_GLOBAL	creator_url	String	https://www.bco-dmo.org/
attribute	NC_GLOBAL	data_source	String	extract_data_as_tsv version 2.3 19 Dec 2019
attribute	NC_GLOBAL	date_created	String	2019-02-13T20:13:05Z
attribute	NC_GLOBAL	date_modified	String	2019-02-25T20:18:35Z
attribute	NC_GLOBAL	defaultDataQuery	String	&time<now
attribute	NC_GLOBAL	doi	String	10.1575/1912/bco-dmo.755687.1
attribute	NC_GLOBAL	Easternmost_Easting	double	179.38346
attribute	NC_GLOBAL	geospatial_lat_max	double	52.9336
attribute	NC_GLOBAL	geospatial_lat_min	double	51.40901
attribute	NC_GLOBAL	geospatial_lat_units	String	degrees_north
attribute	NC_GLOBAL	geospatial_lon_max	double	179.38346
attribute	NC_GLOBAL	geospatial_lon_min	double	-178.66258
attribute	NC_GLOBAL	geospatial_lon_units	String	degrees_east
attribute	NC_GLOBAL	infoUrl	String	https://www.bco-dmo.org/dataset/755687
attribute	NC_GLOBAL	institution	String	BCO-DMO
attribute	NC_GLOBAL	keywords	String	bco, bco-dmo, biological, chemical, collection, data, dataset, date, depth, depth_feet, dmo, end, end_period, erddap, events, grazing, grazing_events, growth, growth_increment_um, increment, island, latitude, longitude, management, name, oceanography, office, period, preliminary, replicate, sample, sample_ID, site, site_name, start, start_period, time, time_period, transect
attribute	NC_GLOBAL	license	String	https://www.bco-dmo.org/dataset/755687/license
attribute	NC_GLOBAL	metadata_source	String	https://www.bco-dmo.org/api/dataset/755687
attribute	NC_GLOBAL	Northernmost_Northing	double	52.9336
attribute	NC_GLOBAL	param_mapping	String	{'755687': {'collection_date': 'flag - time', 'depth_feet': 'flag - depth', 'longitude': 'flag - longitude', 'latitude': 'flag - latitude'}}
attribute	NC_GLOBAL	parameter_source	String	https://www.bco-dmo.org/mapserver/dataset/755687/parameters
attribute	NC_GLOBAL	people_0_affiliation	String	University of Maine
attribute	NC_GLOBAL	people_0_affiliation_acronym	String	U Maine DMC
attribute	NC_GLOBAL	people_0_person_name	String	Robert S. Steneck
attribute	NC_GLOBAL	people_0_person_nid	String	526659
attribute	NC_GLOBAL	people_0_role	String	Principal Investigator
attribute	NC_GLOBAL	people_0_role_type	String	originator
attribute	NC_GLOBAL	people_1_affiliation	String	University of California-Santa Cruz
attribute	NC_GLOBAL	people_1_affiliation_acronym	String	UC Santa Cruz
attribute	NC_GLOBAL	people_1_person_name	String	James Estes
attribute	NC_GLOBAL	people_1_person_nid	String	51389
attribute	NC_GLOBAL	people_1_role	String	Co-Principal Investigator
attribute	NC_GLOBAL	people_1_role_type	String	originator
attribute	NC_GLOBAL	people_2_affiliation	String	Bigelow Laboratory for Ocean Sciences
attribute	NC_GLOBAL	people_2_person_name	String	Douglas B. Rasher
attribute	NC_GLOBAL	people_2_person_nid	String	480721
attribute	NC_GLOBAL	people_2_role	String	Co-Principal Investigator
attribute	NC_GLOBAL	people_2_role_type	String	originator
attribute	NC_GLOBAL	people_3_affiliation	String	Woods Hole Oceanographic Institution
attribute	NC_GLOBAL	people_3_affiliation_acronym	String	WHOI BCO-DMO
attribute	NC_GLOBAL	people_3_person_name	String	Nancy Copley
attribute	NC_GLOBAL	people_3_person_nid	String	50396
attribute	NC_GLOBAL	people_3_role	String	BCO-DMO Data Manager
attribute	NC_GLOBAL	people_3_role_type	String	related
attribute	NC_GLOBAL	project	String	OA Kelp Forest Function
attribute	NC_GLOBAL	projects_0_acronym	String	OA Kelp Forest Function
attribute	NC_GLOBAL	projects_0_description	String	Extracted from the NSF award abstract: Marine calcifying organisms are most at risk to rapid ocean acidification (OA) in cold-water ecosystems. The investigators propose to determine if a globally unique and widespread calcareous alga in Alaska's Aleutian archipelago, Clathromorphum nereostratum, is threatened with extinction due to the combined effects of OA and food web alterations. C. nereostratum is a slow growing coralline alga that can live to at least 2000 years. It accretes massive 'bioherms' that dominate the regions' rocky substrate both under kelp forests and deforested sea urchin barrens. It develops growth bands (similar to tree rings) in its calcareous skeleton, which effectively record its annual calcification rate over centuries. Pilot data suggest the skeletal density of C. nereostratum began to decline precipitously in the 1990's in some parts of the Aleutian archipelago. The investigators now propose to use high-resolution microscopy and microCT imaging to examine how the growth and skeletal density of C. nereostratum has changed in the past 300 years (i.e., since the industrial revolution) across the western Aleutians. They will compare their records of algal skeletal densities and their variation through time with reconstructions of past climate to infer causes of change. In addition, the investigators will examine whether the alga's defense against grazing by sea urchins is compromised by ongoing ocean acidification. The investigators will survey the extent of C. nereostratum bioerosion occurring at 10 sites spanning the western Aleutians, both inside and outside of kelp forests. At each site they will compare these patterns to observed and monitored ecosystem trophic structure and recent C. nereostratum calcification rates. Field observations will be combined with laboratory experiments to determine if it is a decline in the alga's skeletal density (due to recent OA and warming), an increase in grazing intensity (due to recent trophic-level dysfunction), or their interactive effects that are likely responsible for bioerosion patterns inside vs. outside of forests. By sampling C. nereostratum inside and outside of forests, they will determine if kelp forests locally increase pH via photosynthesis, and thus buffer the effects of OA on coralline calcification. The combination of field observations with laboratory controlled experiments, manipulating CO2 and temperature, will help elucidate drivers of calcification and project how these species interactions will likely change in the near future. The project will provide the first in situ example of how ongoing ocean acidification is affecting the physiology of long-lived, carbonate producing organisms in the subarctic North Pacific. It will also be one of the first studies to document whether OA, ocean warming, and food web changes to ecological processes are interacting in complex ways to reshape the outcome of species interactions in nature.
attribute	NC_GLOBAL	projects_0_end_date	String	2016-08
attribute	NC_GLOBAL	projects_0_name	String	Ocean Acidification: Century Scale Impacts to Ecosystem Structure and Function of Aleutian Kelp Forests
attribute	NC_GLOBAL	projects_0_project_nid	String	526660
attribute	NC_GLOBAL	projects_0_start_date	String	2013-09
attribute	NC_GLOBAL	publisher_name	String	Biological and Chemical Oceanographic Data Management Office (BCO-DMO)
attribute	NC_GLOBAL	publisher_type	String	institution
attribute	NC_GLOBAL	sourceUrl	String	(local files)
attribute	NC_GLOBAL	Southernmost_Northing	double	51.40901
attribute	NC_GLOBAL	standard_name_vocabulary	String	CF Standard Name Table v55
attribute	NC_GLOBAL	summary	String	Historical reconstruction of sea urchin grazing events in the ecosystem, achieved via enumerating the annual frequency of grazing scars that are archived in the calcified matrix of Clathromorphum nereostratum. Intact colonies of C. nereostratum were collected via SCUBA. Reconstructions were performed on polished and imaged sample cross-sections.
attribute	NC_GLOBAL	time_coverage_end	String	2014-07-21
attribute	NC_GLOBAL	time_coverage_start	String	2004-08-14
attribute	NC_GLOBAL	title	String	Historical reconstruction of sea urchin grazing events in Aleutian Island ecosystem from grazing scars, 1965-2004
attribute	NC_GLOBAL	version	String	1
attribute	NC_GLOBAL	Westernmost_Easting	double	-178.66258
attribute	NC_GLOBAL	xml_source	String	osprey2erddap.update_xml() v1.3
variable	time		double
attribute	time	_CoordinateAxisType	String	Time
attribute	time	actual_range	double	1.0924416E9, 1.4059008E9
attribute	time	axis	String	T
attribute	time	bcodmo_name	String	date
attribute	time	description	String	date of collection; formatted as yyyy-mm-dd
attribute	time	ioos_category	String	Time
attribute	time	long_name	String	Collection Date
attribute	time	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P01/current/ADATAA01/
attribute	time	source_name	String	collection_date
attribute	time	standard_name	String	time
attribute	time	time_origin	String	01-JAN-1970 00:00:00
attribute	time	time_precision	String	1970-01-01
attribute	time	units	String	seconds since 1970-01-01T00:00:00Z
variable	island		String
attribute	island	bcodmo_name	String	site
attribute	island	description	String	name of island
attribute	island	long_name	String	Island
attribute	island	units	String	unitless
variable	site_name		String
attribute	site_name	bcodmo_name	String	site
attribute	site_name	description	String	name of collection site
attribute	site_name	long_name	String	Site Name
attribute	site_name	units	String	unitless
variable	latitude		double
attribute	latitude	_CoordinateAxisType	String	Lat
attribute	latitude	_FillValue	double	NaN
attribute	latitude	actual_range	double	51.40901, 52.9336
attribute	latitude	axis	String	Y
attribute	latitude	bcodmo_name	String	latitude
attribute	latitude	colorBarMaximum	double	90.0
attribute	latitude	colorBarMinimum	double	-90.0
attribute	latitude	description	String	latitude of collection site
attribute	latitude	ioos_category	String	Location
attribute	latitude	long_name	String	Latitude
attribute	latitude	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P09/current/LATX/
attribute	latitude	standard_name	String	latitude
attribute	latitude	units	String	degrees_north
variable	longitude		double
attribute	longitude	_CoordinateAxisType	String	Lon
attribute	longitude	_FillValue	double	NaN
attribute	longitude	actual_range	double	-178.66258, 179.38346
attribute	longitude	axis	String	X
attribute	longitude	bcodmo_name	String	longitude
attribute	longitude	colorBarMaximum	double	180.0
attribute	longitude	colorBarMinimum	double	-180.0
attribute	longitude	description	String	longitude of collection site
attribute	longitude	ioos_category	String	Location
attribute	longitude	long_name	String	Longitude
attribute	longitude	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P09/current/LONX/
attribute	longitude	standard_name	String	longitude
attribute	longitude	units	String	degrees_east
variable	depth_feet		double
attribute	depth_feet	_FillValue	double	NaN
attribute	depth_feet	actual_range	double	30.0, 33.0
attribute	depth_feet	bcodmo_name	String	depth
attribute	depth_feet	colorBarMaximum	double	8000.0
attribute	depth_feet	colorBarMinimum	double	-8000.0
attribute	depth_feet	colorBarPalette	String	TopographyDepth
attribute	depth_feet	description	String	depth of sample collection
attribute	depth_feet	long_name	String	Depth
attribute	depth_feet	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P09/current/DEPH/
attribute	depth_feet	standard_name	String	depth
attribute	depth_feet	units	String	feet
variable	replicate		byte
attribute	replicate	_FillValue	byte	127
attribute	replicate	actual_range	byte	1, 5
attribute	replicate	bcodmo_name	String	replicate
attribute	replicate	description	String	replicate individual alga studied
attribute	replicate	long_name	String	Replicate
attribute	replicate	units	String	unitless
variable	sample_ID		String
attribute	sample_ID	bcodmo_name	String	sample
attribute	sample_ID	description	String	unique sample identifier
attribute	sample_ID	long_name	String	Sample ID
attribute	sample_ID	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P02/current/ACYC/
attribute	sample_ID	units	String	unitless
variable	transect		byte
attribute	transect	_FillValue	byte	127
attribute	transect	actual_range	byte	1, 3
attribute	transect	bcodmo_name	String	transect
attribute	transect	description	String	replicate transect within individual
attribute	transect	long_name	String	Transect
attribute	transect	units	String	unitless
variable	end_period		short
attribute	end_period	_FillValue	short	32767
attribute	end_period	actual_range	short	1969, 2004
attribute	end_period	bcodmo_name	String	year_end
attribute	end_period	description	String	upper bound of 5-year period scored
attribute	end_period	long_name	String	End Period
attribute	end_period	units	String	year
variable	start_period		short
attribute	start_period	_FillValue	short	32767
attribute	start_period	actual_range	short	1965, 2000
attribute	start_period	bcodmo_name	String	year_start
attribute	start_period	description	String	lower bound of 5-year period scored
attribute	start_period	long_name	String	Start Period
attribute	start_period	units	String	year
variable	time_period		String
attribute	time_period	bcodmo_name	String	date_range
attribute	time_period	description	String	discrete 5-year time interval scored
attribute	time_period	long_name	String	Time Period
attribute	time_period	units	String	years
variable	growth_increment_um		short
attribute	growth_increment_um	_FillValue	short	32767
attribute	growth_increment_um	actual_range	short	423, 3227
attribute	growth_increment_um	bcodmo_name	String	growth
attribute	growth_increment_um	description	String	net algal growth incurred over 5-year period
attribute	growth_increment_um	long_name	String	Growth Increment Um
attribute	growth_increment_um	units	String	micrometers
variable	grazing_events		byte
attribute	grazing_events	_FillValue	byte	127
attribute	grazing_events	actual_range	byte	0, 5
attribute	grazing_events	bcodmo_name	String	number
attribute	grazing_events	description	String	number of grazing events observed within 5-year period
attribute	grazing_events	long_name	String	Grazing Events
attribute	grazing_events	units	String	unitless

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.