Quarterly Fishery Surveys - Salton Sea [ds428]

SDE Feature Class

Open this dataset in BIOS
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Tags
tilapia, Imperial County, sampling, environment, Salton Sea, corvina, Riverside County, New River, marine, sargo, Alamo River, Whitewater River, inlandWaters, biota, gillnet, croaker, California, fisheries, desert pupfish


Summary

After each quarter's sampling is completed a draft report is prepared, summarizing the numbers and species of fish netted, and calculating the overall and species-based catch-per-unit-effort (CPUE). The primary focus of sampling is to establish presence/absence of species, and populations trends. This report will also offer qualitative comments on the condition and breeding status of each species. After annual repetitions of seasonal sampling, enough data will be collected to allow statistical tests for population trends, significant differences in numbers, seasonality, and site use, by and among the four species of sportfish. These data and analyses will be informative to the management of the fisheries, and the efforts to restore the Salton Sea.

Description

In the spring of 2003, California Department of Fish and Game (CDFG) personnel began quarterly sampling of Salton Sea fish at fourteen stations around the sea, as the basis of a long term monitoring program. To allow comparison of current and future monitoring efforts by CDFG to past results, the protocol was adapted from those previously used by researchers at the Salton Sea. Each quarter, if conditions allow, this protocol will produce about 816 net-hours of sampling. To date data collection was started in the spring of 2003, continuing quarterly. Data collection is ongoing as of 2008. Two seasons were missed due to unavailability of launch sites: Fall 2007 and Winter 2007. *Note: This dataset should be viewed with the 'Quarterly Water Quality Surveys - Salton Sea [ds429]' dataset. Methods: The 11 sampling sites comprise three broad habitat types: pelagic (3 sites), near-shore (8 sites), and estuarine (3 sites). The pelagic sites are in the approximate middles of the north basin, south basin and inter-basin areas of the Sea. The near-shore sites are spaced widely apart, four each, near the west and east shores, to capture as much breadth of habitat as possible. The estuarine sites are in the body of the Sea, close enough to the mouths of the New, Alamo, and Whitewater Rivers, to be under the influence of their outflows. Sampling takes place during each of the putative seasons, as follows: spring- April and May; summer- July and August; fall- October and November; winter- January and February. We attempt to compress the total sampling period into as few days as possible, to the extent that the weather, equipment maintenance, and personnel scheduling constraints allow. Nets are typically set at one or two sites in the morning, and hauled in after approximately 24 hours. The exact number of hours set is recorded for each net, to the nearest quarter-hour. Fish are sampled by deploying multi-panel monofilament gill nets with 6 X 30 foot panels of 0.5, 1, 2, 3, and 4 inch mesh. Two nets are set at all sites at the water's surface. The nets are set far enough apart to allow room for maneuvering a boat during setting and retrieval, usually 100-200 meters. The nets at near-shore and estuarine sites are set in 2.5 to 4.5 meters of water, typically 200-300 meters from the shore. Two additional nets are set at the bottom of water column at the three pelagic sites. The conditions fish experience at the bottom in deep water is different enough from the surface water, in dissolved oxygen, light, food availability and temperature, that this can be considered a discrete habitat, and thus we sample it as though it were a separate site. At the time of each set and retrieval, water depth, water temperature, conductivity, salinity, and dissolved oxygen are measured and recorded. When nets are pulled in the following day, all fish are removed and immediately stored on ice. Data are collected from these fish as soon as possible, almost always the same day they are hauled in. All fish are identified to species level and counted. For the four sport fish in the Salton Sea, (tilapia, Gulf croaker, orangemouth corvina and sargo) weights, lengths (fork length), sex, physical condition, and reproductive status are recorded. Fish above five pounds are weighed to the nearest ounce. Fish below five pounds are weighed to the nearest half ounce. Lengths of fish under 50 centimeters are recorded to the nearest millimeter. Lengths of fish over 50 centimeters are recorded to the nearest centimeter. The sex of adult fish is determined by dissection. A sample of at least ten fish of each species is also dissected to determine physical condition and breeding status. Changes to Protocol after Year One: For previous researchers, deep water habitats provided some low level of productivity for the fisheries, and were important habitat components to sample. During the first year of sampling, however, the three deep water sites (north basin, south basin and inter-basin) were completely unproductive, a costly element of our efforts, and the least probable site for fish use, given the severe reduction in population size which was discovered in 2003. We therefore eliminated sampling at the three deep water sites, which reduced our efforts by 288 net-hours, to a quarterly total effort of 528 net-hours. These sites were left in the protocol, since they will likely provide useful information about population trends and habitat use, should the fisheries rebound to levels which allow robust comparisons among these and the other sampling sites. Footnote: There was a marked change in the weather immediately after our first sampling run on October 13, 2004 resulting in a 6 C drop in water temperature. After seeing how far the number of fish sampled on October 13, 2004 was out of the range of results at subsequent sites, we felt this drop in water temperatures justified resampling the two October 13, 2004 sites. The results were added to the total to compute a CPUE. We originally selected the months of October and November to enclose a putative Fall season, following the convention of Costa-Pierce and Riedels study at the Salton Sea in 1999-2000. This approach assumes a biologically significant change in water temperatures between sampling seasons. We have become more hesitant about assuming that the seasons at the Salton Sea fall within their assigned calendar months, and are so clearly discrete. As we saw during this Fall 2004 sampling period, water temperature changes within a sampling period may be as great or greater than those between sampling periods.

Credits

Use limitations

Extent

West -116.053162 East -115.621208
North 33.518176 South 33.134544

Scale Range

ArcGIS Metadata

Topics and Keywords

Themes or categories of the resource biota, environment, inlandWaters


* Content type Downloadable Data


Place keywords Imperial County, Salton Sea, Riverside County, New River, Alamo River, Whitewater River, California

Theme keywords tilapia, sampling, corvina, marine, sargo, gillnet, croaker, fisheries, desert pupfish

Theme keywords environment, inlandWaters, biota

Thesaurus
Title ISO 19115 Topic Category




Citation

* Title DS0428_20080918
Publication date 2008-09-18


Presentation formats * digital map


Citation Contacts

Responsible party
Organization's name California Department of Fish and Game - Salton Sea Program
Contact's role originator


Resource Details

Dataset languages English(UNITED STATES)


Status under development
Spatial representation type * vector


* Processing environment Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.1.1.3143


ArcGIS item properties
* Name DS0428_20080918
* Location Server=; :; Database=; User=; Version=
* Access protocol ArcSDE Connection

Extents

Extent
Description
ground condition
Temporal extent
Beginning date 2003-04-01
Ending date 2008-07-01

Extent
Geographic extent
Bounding rectangle
Extent type Extent used for searching
* West longitude -116.053162
* East longitude -115.621208
* North latitude 33.518176
* South latitude 33.134544
* Extent contains the resource Yes

Extent in the item's coordinate system
* West longitude -12918978.941500
* East longitude -12870894.026600
* South latitude 3913176.134800
* North latitude 3964286.934800
* Extent contains the resource Yes

Resource Points of Contact

Point of contact
Individual's name Jack Crayon
Organization's name California Department of Fish and Game - Salton Sea Program
Contact's role point of contact


Contact information
Phone
Voice 760 200-9172

Address
e-mail address jcrayon@dfg.ca.gov



Resource Maintenance

Resource maintenance
Update frequency quarterly


Resource Constraints

Legal constraints
Other constraints
none - data may be distributed upon request.

Spatial Reference

ArcGIS coordinate system
* Type Projected
* Geographic coordinate reference GCS_WGS_1984
* Projection WGS_1984_Web_Mercator_Auxiliary_Sphere
* Coordinate reference details
Projected coordinate system
Well-known identifier 102100
X origin -20037700
Y origin -30241100
XY scale 10000
Z origin 0
Z scale 1
M origin 0
M scale 1
XY tolerance 0.001
Z tolerance 2
M tolerance 2
High precision true
Latest well-known identifier 3857
Well-known text PROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator_Auxiliary_Sphere"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",0.0],PARAMETER["Standard_Parallel_1",0.0],PARAMETER["Auxiliary_Sphere_Type",0.0],UNIT["Meter",1.0],AUTHORITY["EPSG",3857]]

Reference system identifier
* Value 3857
* Codespace EPSG
* Version 7.11.2


Spatial Data Properties

Vector
* Level of topology for this dataset geometry only


Geometric objects
Feature class name DS0428_20080918
* Object type point
* Object count 409



ArcGIS Feature Class Properties
Feature class name DS0428_20080918
* Feature type Simple
* Geometry type Point
* Has topology FALSE
* Feature count 409
* Spatial index TRUE
* Linear referencing FALSE



Data Quality

Scope of quality information
Resource level dataset




Data quality report - Conceptual consistency
Measure description
Data assumptions and limitations: Our nets have an area of 900 square feet. CPUE is calculated by dividing the number of fish caught by the length of time the net was fished, and the area of the net. Its units are: fish X hours-1 X square feet-1. Some initially sampled sites were dropped in spring 2004. All comparisons of CPUE that we made are among quarterly data sets that exclude previously sampled deep-water sites from the calculations. The CPUE values for the first year will then be higher overall, but the comparison between years will be valid. Our data are not designed to determine absolute numbers, but to show trends. Data collection was started in the spring of 2003, continuing quarterly. Data collection is ongoing as of 2008. Two seasons were missed due to unavailability of launch sites: Fall 2007 and Winter 2007.




Geoprocessing history

Process
Process name Project_2
Date 2008-05-1214:41:09
Tool location C:\Documents and Settings\KWHITE\Application Data\ESRI\ArcToolbox\My Toolboxes\1MyTools.tbx\Project
Command issued
Include in lineage when exporting metadata No


Process
Process name DefineProjection_1
Date 2008-09-1813:43:54
Tool location C:\Program Files\ArcGIS\ArcToolbox\Toolboxes\Data Management Tools.tbx\DefineProjection
Command issued
Include in lineage when exporting metadata No


Process
Date 2011-07-2108:57:36
Tool location C:\Program Files\ArcGIS\ArcToolbox\Toolboxes\Conversion Tools.tbx\FeatureClassToFeatureClass
Command issued
Include in lineage when exporting metadata No


Process
Date 2013-06-2115:21:41
Tool location c:\program files (x86)\arcgis\desktop10.1\ArcToolbox\Toolboxes\Data Management Tools.tbx\Project
Command issued
Include in lineage when exporting metadata No


Distribution

Distribution format
* Name SDE Feature Class


Transfer options
Online source
Location http://bios.dfg.ca.gov/

Online source
Location ftp://ftp.dfg.ca.gov/BDB/GIS/BIOS/Public_Datasets/400_499/ds428.zip

Fields

Details for object DS0428_20080918
* Type Feature Class
* Row count 409


Field OBJECTID
* Alias OBJECTID
* Data type OID
* Width 4
* Precision 10
* Scale 0
* Field description
Internal feature number.
* Description source
ESRI
* Description of values
Sequential unique whole numbers that are automatically generated.




Field PULL_DATE
* Alias PULL_DATE
* Data type Date
* Width 36
* Precision 0
* Scale 0
Field description
The calendar date on which a net was removed from the water, and fish were counted.


Field SITE
* Alias SITE
* Data type String
* Width 254
* Precision 0
* Scale 0
Field description
The name given to each sampling site, based on a nearby landmark. When more then one net was set at one site, they were designated as (Site name) 1 and (Site name) 2. Sites were sampled with either one or two nets. When a single net was used, it is simply designated by the site name, e.g., "New River". When two nets were used, fish were counted separately for the two nets, so the results were designated as "New River1" and New River 2". It isn't intended to means sites 1 and 2, but nets 1 and 2 at the same site.


Field HABITAT_TY
* Alias HABITAT_TY
* Data type String
* Width 254
* Precision 0
* Scale 0
Field description
One of three groupings of sites base on similarity in depth, distance from shore and/or nearness to a river mouth.


Field NET_HRS
* Alias NET_HRS
* Data type Double
* Width 8
* Precision 19
* Scale 6
Field description
A quantification of the effort expended to sample fish. A net hour, for our study, represents the setting of a single 600 square foot net in the water for one hour.


Field TILAPIA
* Alias TILAPIA
* Data type Double
* Width 8
* Precision 19
* Scale 6
Field description
Mozambique hybrid tilapia (Oreochromis mossambicus X O. urolepis hornorum). A zero value represents an absence.


Field OTHER
* Alias OTHER
* Data type String
* Width 254
* Precision 0
* Scale 0
Field description
Other, non-targeted, fish species that were caught during sampling.


Field CORVINA
* Alias CORVINA
* Data type Double
* Width 8
* Precision 19
* Scale 6
Field description
Orangemouth corvina (Cynoscion xanthulus). A zero value represents an absence.


Field SARGO
* Alias SARGO
* Data type Double
* Width 8
* Precision 19
* Scale 6
Field description
Sargo (Anisotremus davidsoni). A zero value represents an absence.


Field CROAKER
* Alias CROAKER
* Data type Double
* Width 8
* Precision 19
* Scale 6
Field description
Gulf croaker (Bairdiella icistia). A zero value represents an absence.


Field COMMENTS
* Alias COMMENTS
* Data type String
* Width 75
* Precision 0
* Scale 0
Field description
Miscellaneous comments.


Field UTM_E
* Alias UTM_E
* Data type Double
* Width 8
* Precision 19
* Scale 6
Field description
The easting value for the Universal Transverse Mercator based coordinates of a sampling site. NAD83 Datum.


Field UTM_N
* Alias UTM_N
* Data type Double
* Width 8
* Precision 19
* Scale 6
Field description
The northing value for the Universal Transverse Mercator based coordinates of a sampling site. NAD83 Datum.


Field REPORT
* Alias REPORT
* Data type String
* Width 100
* Precision 0
* Scale 0




Field SHAPE
* Alias Shape
* Data type Geometry
* Width 4
* Precision 0
* Scale 0
* Field description
Feature geometry.
* Description source
ESRI
* Description of values
Coordinates defining the features.






Metadata Details

Metadata language English(UNITED STATES)
Metadata character set utf8 - 8 bit UCS Transfer Format


Scope of the data described by the metadata dataset
Scope name * dataset


* Last update 2014-04-28


ArcGIS metadata properties
Metadata format ArcGIS1.0
Metadata style FGDC CSDGM Metadata


Created in ArcGIS for the item 2014-03-0616:18:17
Last modified in ArcGIS for the item 2014-04-2811:42:55


Automatic updates
Have been performed Yes
Last update 2014-04-2811:42:55


Metadata Contacts

Metadata contact
Individual's name Jack Crayon
Organization's name California Department of Fish and Game - Salton Sea Program
Contact's role point of contact


Contact information
Phone
Voice 760 200-9172

Address
e-mail address jcrayon@dfg.ca.gov



Thumbnail and Enclosures

Thumbnail

Enclosure
Enclosure type File
Description of enclosure original metadata
Original metadata document, which was translated yes
Source metadata format fgdc