Bristol Channel Plankton Survey - RV Corystes 06/89
Analysis of a plankton survey grid carried out in the Bristol Channel to determine the extent and timing of sole spawning off Trevose Head. Numbers of ichthyoplankton, along with associated positional data and volumes filtered.
dataset
https://data.cefas.co.uk/view/2548
name: Cefas Data Portal
description: The Cefas Data Portal contains metadata records and data sets available to download and connect to in support of our commitment to open science. Data is available in the following formats: CSV, ESRI Shapefile. The data can also be accessed via the WFS and WMS protocols.
function: download
CEFAS2548
https://data.cefas.co.uk
eng
biota
revision
2011-03-25
publication
2008-06-01
publication
2008-06-01
revision
2010-05-18
publication
2012-01-11
publication
2012-01-11
-8.00
-3.50
52.00
50.00
1989-05-18
1989-05-31
publication
2013-12-04
revision
2023-10-31
creation
2013-06-27
notPlanned
Seven cruises (Cory 4 and 6/89, Ciro 3/90, Cory 3, 5, 6, and 8/90 - see separate metadata) were undertaken during 1989-1990 collecting 70-80 samples to estimate the spawning stock biomass of sole (*Solea solea*) in the Bristol Channel area. Identity of all species of fish eggs and larvae determined. **Associated Datasets: **Temperature and salinity "V" profiles are available at each sampling position. Continuous near-surface (3m) temperature and salinity data are available for complete cruises. The plankton grids were successfully completed using the Gulf 76cm High Speed plankton net. Sampler deployment: The sampler was deployed in a double oblique tow from the surface to within 2 m of the seabed. Veering and hauling speeds were manually adjusted to ensure that each depth band was sampled equally. At shallow stations, multiple double oblique dives were necessary to enable a sufficient volume of water to be filtered. A minimum sampler deployment time of 15 minutes was aimed for. On recovery, the net was carefully washed down and the sample collected from the end bag. Each sample was then fixed using buffered formaldehyde solution and transported to the participating laboratories for sorting and identification.Sample analysis: Fish eggs and larvae were picked out from all samples by eye and, whenever practicable, the whole sample was sorted. However sub-sampling was at times necessary. Sub-sampling was carried out using a Folsom splitter. Fish larvae were readily identified unless they had been badly damaged during collection or were prematurely hatched. For some groups such as the sandeels (Ammodytidae) and the group of Gadidae commonly called rocklings, individuals were not identified to the species level. Fish eggs were initially split into three groups on the basis of the presence or absence of oil globules. Those containing either a single or many oil globules could usually be identified to the species level. Eggs with no oil globules were more difficult to identify. Some of these species such as cod (*Gadus morhua*), sprat (*Sprattus sprattus*), long rough dab (*Hippoglossoides platessoides*), dragonet ( *Callionymus* spp.) and plaice (*Pleuronectes platessa*) were identified because of their size or unique features. Unidentified eggs in this group were recorded as egg diameters.Data storage: The raw data were stored on an Access database. The various data files were stored on the database in a series of tables linked by having the content of certain fields in common. All routine calculations, calibration changes and conversions were carried out on the database. The data tables (but not queries etc.) have now been extracted into text files. Plankton data are normally expressed as either number of organisms per m3 or per m2. The number per m3 is obtained by dividing the numbers per sample by the volume filtered, calculated from the sampler flowmeters. Number per m2 is obtained by multiplying the number per m3 by the mean sampled depth during a deployment.
publication
2013-12-10
false
See the referenced specification
publication
2010-12-08
true
See the referenced specification
Unknown
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
originator
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
custodian
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
distributor
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
owner
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
pointOfContact
2023-10-31T10:45:33