RRS Challenger CH8/83
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Challenger (74CH) |
| Cruise identifier | CH8/83 |
| Cruise period | 1983-06-06 — 1983-06-20 |
| Status | Completed |
| Port of departure | Plymouth, United Kingdom |
| Port of return | Falmouth, United Kingdom |
| Purpose | Research |
| Objectives | 1. To determine the horizontal and vertical distribution of mackerel eggs and larvae in relation to temperature, salinity, oxygen, chlorophyll, light and plankton concentration.
2. To compare estimates of mackerel egg abundance taken by UOR sampling and by standard 20" plankton sampler hauls. 3. To investigate the horizontal variability of mackerel egg numbers and to estimate the point haul variance of standard plankton hauls for mackerel eggs. 4. To determine the density and buoyancy of mackerel eggs through development. 5. To estimate the natural mortality rate of mackerel eggs. |
| Chief scientist | Stephen H Coombs (Institute of Marine Environmental Research, Plymouth) |
| Project | ICES International Mackerel Egg Survey |
| Coordinating body | ICES |
| Cruise report |  (0.18 MB) |
| Ocean/sea areas | |
| General | North East Atlantic Ocean (limit 40W) |
| Specific | N.E. Atlantic/ Great Sole Bank |
| Track charts |  |
| Measurements | |
| Physical oceanography | |
| Surface measurements underway (T,S) | Quantity: track kilometres = 2222.4 |
| Bathythermograph | Quantity: number of profiles = 54 |
| Water bottle stations | Quantity: number of samples = 4 Description: S surface only |
| Subsurface temperature and salinity measurements | Quantity: track kilometres = 1666.8 |
| Biology and fisheries | |
| Phytoplankton pigs (eg chlorophyll, fluorescence) | Quantity: track kilometres = 1666.8 |
| Zooplankton | Quantity: number of stations = 12 |
| Eggs and larvae | Quantity: number of samples = 68 Description: survey:distribution,energy transfers,population |
| Acoustic reflection on marine organisms. | Quantity: track kilometres = 2222.4 |
