Date (Publication)

2019-08

Cited responsible party

Organisation name	Individual name	Electronic mail address	Role
DFO	Colin Levings		Principal investigator

Presentation form

Digital document

Name

Canadian Technical Report of Fisheries and Aquatic Sciences No 1111

Other citation details

1770 kb

Purpose

This report provides observations made at a low tide refuge or pit in a sandflat on Sturgeon Bank, Fraser River estuary. The work reported here focussed on medium scale and short term habitat differences in space and time. The size distribution of juvenile chinook was compared on a space scale of tens of me tres, and differences in fish catches, prey abundance, and water characteristics were measured over tidal cycles.

Status

Completed

Maintenance and update frequency

Not planned

Global Change Master Directory (GCMD) Science Keywords v15.9

• Earth Science > Biological Classification > Animals/Vertebrates > Fish > Ray-finned Fishes > Salmons/Trouts

• Earth Science > Biosphere > Aquatic Ecosystems > Estuarine Habitat

DFO Areas

• North Pacific Ocean > Fraser River and BC Interior

Language

English

Character set

UTF8

Topic category

• Biota
• Environment

Description

49°11,-123°14'

Begin

1980-05

End

1980-05

Supplemental Information

In May 1980 catch patterns, sizes,and diets of juvenile chinook salmon (Oncorhynchus tshawytscha) were examined in a low tide refuge in a sandflat on Sturgeon Bank, Fraser River estuary. Purse seine catches increased on falling tides. Fish caught around the perimeter of the refuge with a beach seine were about 10 mm smaller than those from simultaneous purse seining about 80 m offshore. Adult insects were abundant in stomachs in the early part of the ebb cycle, and cumaceans were consistently common in the diet. Neomysis mercedis abundance in stomachs showed a peak shortly after low water. Invertebrate catches in a 1 m deep drift sampler with 6 vertical nets were highest when tidal currents were strongest, increasing over 3 orders of magnitude. Adult insects were caught only in the surface nets, mysids in the bottom 2, and cumaceans were found in all 6 nets. The increased flux of invertebrates on falling tides or concentration of prey in reduced water volumes may influence food availability for fish. Low tide refugia may be critical habitats for juvenile Chinook because of their increased concentrations and vulnerability to environmental effects at these locations.

Distribution format

Name	Version
electronic	none

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
Pacific Salmon Foundation	Isobel Pearsall	pearsalli@shaw.ca	Distributor

OnLine resource

Protocol	Linkage	Name
WWW:LINK-1.0-http--link	https://www.dfo-mpo.gc.ca/science/data-donnees/index-eng.html	DFO Science website
WWW:DOWNLOAD-1.0-http--download	https://soggy2.zoology.ubc.ca/geonetwork/srv/api/records/c023d1b3-e28d-4fba-92b6-8be09f4584d6/attachments/c023d1b3-e28d-4fba-92b6-8be09f4584d6.pdf	c023d1b3-e28d-4fba-92b6-8be09f4584d6.pdf
WWW:DOWNLOAD-1.0-http--download	https://soggy2.zoology.ubc.ca/geonetwork/srv/api/records/c023d1b3-e28d-4fba-92b6-8be09f4584d6/attachments/c023d1b3-e28d-4fba-92b6-8be09f4584d6.xlsx	c023d1b3-e28d-4fba-92b6-8be09f4584d6.xlsx

Hierarchy level

Dataset

Statement

Levings produced paper copy. Fraser scanned with Fujitsu Scansnap s1500 (ABBY Finereader OCR software). Data was extracted through Adobe Reader conversion and manual entry into MS Excel.

Metadata

File identifier

c023d1b3-e28d-4fba-92b6-8be09f4584d6 XML

Metadata language

eng

Character set

UTF8

Hierarchy level

Dataset

Date stamp

2023-12-18T21:37:04.266Z

Metadata standard name

North American Profile of ISO19115:2003 - Geographic information - Metadata

Metadata standard version

NAP - CAN/CGSB-171.100-2009

Metadata author

Organisation name	Individual name	Electronic mail address	Role
Pacific Salmon Foundation	Sarah Fraser	fraser.sarahk@gmail.com	Author

Other language

Language	Character encoding
French	UTF8
English	UTF8