Planktonic organisms are the primary source of food for the top level of the marine food chain, the fish. Yet only part of the plankton is ingested by fish, the remainder sediments to the bottom to provide food for benthic organisms (which may in turn be grazed by demersal fish) and to contribute to a detrital sink. Although the relative proportions of the plankton entering each of these compartments is still a matter of debate, some indication of its importance as a resource can be gauged from the North Sea fishery that has yielded 2-3 Mt per year since the mid-1960s. Calculations for the North Sea of the annual production of phytoplankton, zooplankton, fish and benthos as energy equivalents are contrasted with the annual energy yields of oil and gas. Since 1948 the plankton of the North Sea has been monitored at a depth of 10 m by the Continuous Plankton Recorder ( CPR ) survey. Results for two large areas which encompass the Brent, Beryl and Forties oilfields are presented. Between 1948 and 1982 the plankton of these areas showed similar large changes in population structure in both phytoplankton and zooplankton with almost tenfold changes in levels of biomass during this 35 year period. The development of oil-related activities is discussed in relation to the plankton time-series with comment on possible causes of the changes which are believed to be the result of natural variability.


BMJ Open ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. e037558
Author(s):  
Anne Waje-Andreassen ◽  
Øyvind Østerås ◽  
Guttorm Brattebø

ObjectivesFew studies have described evacuations due to medical emergencies from the offshore installations in the North Sea, though efficient medical service is essential for the industrial activities in this area. The major oil- and gas-producing companies’ search and rescue (SAR) service is responsible for medical evacuations. Using a prospective approach, we describe the characteristics of patients evacuated by SAR.Design and settingA prospective observational study of the offshore primary care provided by SAR in the North Sea.MethodsPatients were identified by linking flight information from air transport services in 2015/2016 and the company’s medical record system. Standardised forms filled out by SAR nurses during the evacuation were also analysed. In-hospital information was obtained retrospectively from Haukeland University Hospital’s information system.ResultsA total of 381 persons (88% men) were evacuated during the study period. Twenty-seven per cent of missions were due to chest pain and 18% due to trauma. The mean age was 46.0 years. Severity scores were higher for cases due to medical conditions compared with trauma, but the scores were relatively low compared with onshore emergency missions. The busiest months were May, July and December. Weekends were the busiest days.ConclusionThree times as many evacuations from offshore installations are performed due to acute illness than trauma, and cardiac problems are the most common. Although most patients are not severely physiologically deranged, the study documents a need for competent SAR services 24 hours a day year-round. Training and certification should be tailored for the SAR service, as the offshore health service structure and geography differs from the structure onshore.


Nature ◽  
1964 ◽  
Vol 201 (4920) ◽  
pp. 670-670
Author(s):  
H. B. MILNER

Sign in / Sign up

Export Citation Format

Share Document