RV Corystes CORY 1/06
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RV Corystes (74RY) |
| Cruise identifier | CORY 1/06 |
| Cruise period | 2006-01-26 — 2006-02-02 |
| Status | Completed |
| Port of departure | Belfast, United Kingdom |
| Port of return | Belfast, United Kingdom |
| Purpose | Fisheries |
| Objectives | First in a series of 5 surveys in 2006 to assess the Irish Sea cod stock using the egg production method.
Main Objectives: 1. To conduct a plankton survey using a Gulf VII plankton sampler to determine the distribution and abundance of fish eggs and larvae in the Irish Sea, with particular emphasis on cod (Gadus morhua), haddock (Melanogrammus aeglifinus) and plaice (Pleuronectes platessa) eggs. 2. To remove cod-like eggs from fresh plankton samples at sea. To measure, stage and preserve these eggs in ethanol prior to species identification using a DNA technique on return to the laboratory. 3. To collect supplementary sub-surface environmental data using a self-logging package carried on the Gulf VII plankton samplers. 4. To collect surface water samples for analysis of nutrients, chlorophyll and phytoplankton species identification. 5. To collect ovary samples from adult cod, haddock and plaice for fecundity studies. Narrative: It was aimed to complete a standard grid of 112 stations. However, due to technical difficulties, samples were collected at 70 of these stations during the survey period. |
| Chief scientist | Pieter-Jan Schon (Department of Agriculture and Rural Development for Northern Ireland) |
| Project | MH003, Irish Sea cod assessments by egg production |
| Coordinating body | CEFAS |
| Ocean/sea areas | |
| General | Irish Sea and St. George's Channel |
| Specific | Irish Sea |
| Track charts |  (0.02 MB) |
| Measurements | |
| Physical oceanography | |
| Surface measurements underway (T,S) | Description: Continuous recording of surface salinity and temperature via Seabird CTD |
| Water bottle stations | Quantity: number of stations = 25 Description: Samples of surface sea water collected during selected tows. Analysed ashore in order to compare with / validate PRONET CTD values |
| CTD stations | Quantity: number of stations = 6 Description: Vertical CTD profiles collected at selected intervals using ESM2 logging unit |
| CTD stations | Quantity: number of stations = 70 Description: CTD profiles recorded during plankton hauls by a PRONET CTD unit mounted on top of the sampler. |
| Chemical oceanography | |
| Phosphate | Quantity: number of stations = 70 Description: Surface water samples collected at each station for later analysis ashore |
| Nitrate | Quantity: number of stations = 70 Description: Surface water samples collected at each station for later analysis ashore |
| Nitrite | Quantity: number of stations = 70 Description: Surface water samples collected at each station for later analysis ashore |
| Ammonia | Quantity: number of stations = 70 Description: Surface water samples collected at each station for later analysis ashore |
| Silicate | Quantity: number of stations = 70 Description: Surface water samples collected at each station for later analysis ashore |
| Biology and fisheries | |
| Phytoplankton pigs (eg chlorophyll, fluorescence) | Quantity: number of stations = 70 Description: Samples of surface sea water filtered at every station, then preserved by freezing, for subsequent analysis ashore of chlorophyll pigments |
| Phytoplankton | Quantity: number of stations = 24 Description: Samples of surface sea water collected at selected stations, fixed using Lugols iodine, for subsequent analysis ashore |
| Eggs and larvae | Quantity: number of stations = 70 Description: Samples collected using Gulf VII plankton sampler, towed from surface to near bottom in 'V' shaped profile. Eggs and larvae collected in 270 micro metre mesh net. Cod-like eggs picked out and preserved in ethanol for species identification using genetic analysis. Remainder of sample preserved in formalin for identification and enumeration ashore. |
| Other biological/fisheries measurement | Quantity: number of hauls = 10 Description: Ovary samples from trawl-caught female adult cod, haddock and plaice taken for fecundity analysis |
