Coos Bay Crabbing and Clamming detailed spatial data

Identification Information

Citation

Originator: Scott Groth

Publish Date: 12/16/2014

Online Link: None

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Scott Groth

Job Position: Shellfish Biologist

Telephone: 541 888 5515

E-Mail Address: scott.d.groth@odfw.oregon.gov

Description

Abstract: Coos Bay is Oregon's largest estuary with the most active shipping port between San Francisco and the Columbia River. Coos Bay affords robust shellfish harvesting opportunities important to the area’s economy and identity. Proposed industrial development is likely to make direct and indirect changes to areas currently used for shellfish harvest. Appropriate mitigation for these changes can be aided by estimation of summarized use (this document and Ainsworth et al. (2012)) and in greater detail by using spatially explicit data for these activities. In this investigation, we obtained geospatial data on the activity of clammers (people actively clamming) and crabbers (locations of crab buoys). Other shellfish harvest is common (e.g., dock crabbing, bait shrimp, etc.) in Coos Bay, but not evaluated in this study. Methods ODFW performs low tide clam creel surveys which enumerate use by area, lumping counts in to one of eight areas within Coos Bay. In this study, we enhanced these counts by recording specific location data onto aerial photo maps. We matched landmarks on the aerial photos to best estimate position of each working clammer during these surveys. After these data were recorded onto paper maps, the points were transferred to ArcGIS manually. It is our expectation that by using these methods, these data are accurate to within 100 meters. Areas up-bay from the airport were not included as they are used far less frequently and could not be sampled due to time constraints. Those areas are primarily eastern softshell (Mya arenaria) beds within North Slough, Glasgow, Kentuck, and other areas. We captured geospatial data for crab buoys by recording position of individual buoys throughout the year. We selected survey times haphazardly, when timing was convenient for staff schedules. We used the 22’ boat R/V Ophiodon to drive along each side of the bay 87 searching for crab buoys. We drove within 50 meters of each pot and recorded a position using GPS, then later uploaded it to the dataset. Summarized recreational crab harvest data by area and year is available on a preceding study (Ainsworth et al. 2012). https://nrimp.dfw.state.or.us/CRL/Reports/Info/2012-04.pdf

Purpose: The purpose of this data is to have specific understanding on where people clam and crab within lower Coos Bay. This may guide development or mitigation.

Time Period of Content:

Geographic Extent: Lower Coos Bay

Status: Final

Use Constraints:

Format: GIS

Data Quality Information

Lineage-Source: Data referred from, ODFW Information Report number 2014-09: Status of Oregon bay clam fisheries, stock assessment and research.

Data Information

No data information was supplied.

Entity and Attribute Information

Attributes Description: type field describes "pot/ring" or "clammer" the first describes crabbing effort, the second clamming effort

Is a physical copy maintained for reference at Headquarters? Unknown