2008 - 2009 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Assessment of potential predators of plaice eggs and larvae in the Irish Sea
PREDATE - Detecting predation of fish eggs and larvae
Data on fish counts, lengths and stomach contents analysis from fish caught in the Irish Sea in 2008 and 2009 to investigate the potential predators of plaice eggs. Also included are station data and ichthyoplankton analysis counts.
dataset
http://data.cefas.co.uk/#/View/727/
function: order
CEFAS458bfe71-51eb-4309-b29b-8cc769d86e43
http://www.cefas.co.uk/
eng
OGP
urn:ogc:def:crs:EPSG::4326
biota
revision
2011-03-25
publication
2008-06-01
publication
2008-06-01
-7
-2.5
54.5
53
revision
2010-05-18
revision
2010-05-18
revision
2010-05-18
revision
2010-05-18
revision
2010-05-18
revision
2010-05-18
2008-02-22
2009-02-28
publication
2021-02-03
notPlanned
Research cruises were undertaken on the research vessel CEFAS Endeavour in the eastern Irish Sea on a well described plaice spawning ground located off the North Wales coast in February 2008 and 2009. The full range of predators with the potential to consume plaice eggs and larvae and their spatial and temporal distributions were investigated using vertical plankton samplers, acoustic surveys and various trawls. Stomach samples were taken for subsequent analysis using genetic (TaqMan) probes. Associated measurements of temperature, salinity and depth of the water column were also taken. Plankton samples were collected using a Gulf VII plankton sampler, fitted with a 40cm aperture nosecone and 270mm mesh net. The samplers were deployed on a grid of 12 stations in a double oblique tow from sea surface to near bottom and back. A Valeport Conductivity Temperature and Density (CTD) profiler mounted on the sampler provided depth, salinity and temperature profiles for each plankton tow as well as ‘real time’ flowmeter data. The plankton was gently washed down from the samplers into an end-bag which was removed and the plankton washed into a jar and fixed using buffered formaldehyde solution (4% formaldehyde in distilled water buffered with 2.5% sodium trihydrate (w/v)). The samples were analysed at the CEFAS laboratory, Lowestoft. Fish eggs and larvae were picked out of the preserved samples using low power microscopes, and, whenever practicable, the whole sample was sorted. Sub-sampling, however, was at times necessary and this was carried out using a Folsom splitter. Using this method a fraction of the sample (for example ⅛, ¼ or ½) was worked up as appropriate. Ichthyoplankton from these surveys was identified according to Russell (1976). This was supplemented by various identification guides and keys produced by the International Council for the Exploration of the Sea (Saville, 1964; Macer, 1967; Nichols, 1971; Demir, 1976; Nichols, 1976). Fish eggs were initially split into groups on the basis of 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 are more difficult to separate, particularly in the early stages before embryonic pigmentation develops, and as a result it is not possible to identify a proportion of these. However, egg size was recorded. Fish larvae were generally easy to identify unless they had been badly damaged during collection. For some groups, such as the sandeels (Ammodytidae) and the rocklings (Gadidae), individuals were not identified to the species level. Plankton data were expressed as number of organisms m-³ by dividing the numbers per sample by the volume filtered. The full dataset is stored on ACCESS (Microsoft Inc.) databases held at CEFAS. Bioness multinet and hyperbenthic sledge were deployed to collect plankton samples. Acoustic transect lines were used to locate potential predators of plaice eggs, Sandeel and Portuguese High Headline Trawls were then carried out so stomach samples could be collected.
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
originator
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
custodian
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
pointOfContact
2021-02-03T13:53:31