| Date | November 2009 | Marks available | 2 | Reference code | 09N.3.SL.TZ0.19 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Suggest | Question number | 19 | Adapted from | N/A |
Question
A colony of a marine diving bird, Brunnich’s guillemot (Uria lomvia), lives on the southern limits of the Arctic on Coats Island. Brunnich’s guillemots feed principally on Arctic cod (Arctogadus glacialis) which are characteristic of Arctic waters.
The graph shows the changes in ice cover on Coats Island over a period of 19 years.
At Coats Island, chick mass at 14 days was measured in most years between 1988 and 2002. The scattergraph below shows the results, plotted against proportion of ice cover.
Outline the changes in ice cover shown in the data above.
Suggest one reason for the changes in ice cover.
Outline the relationship between ice cover and the mass of 14-day-old chicks on Coats Island.
Suggest reasons for the relationship.
Predict, with a reason, the change in the mass of chicks in the years ahead.
Markscheme
ice cover has decreased (slightly);
the data show much variability/fluctuates;
warmer air/atmosphere/water temperatures/global warming (bringing about more ice melt)
increase in summer ice cover has a positive effect on mass increase;
high proportion of ice cover has little effect / (slightly) negative effect on chick mass/growth;
changes in (water) temperature/climate change influence fish populations/ food available for chick growth;
changes in habitat affect chick growth / rearing of chicks;
mass may go down as proportion of ice cover has decreased;
mass may increase as most recent data shown in (bar) graph shows increasing proportion of ice area;
Examiners report
Most candidates were able to detect the fluctuation in data, but few saw an overall decreasing trend.
Most candidates, if not all, had this answer correct.
Most candidates answered this question correctly.
Most candidates were able to detect one reason for the relationship (mostly change in habitat affecting chick growth). Very few realised that the change in temperature influences the fish populations, thus affecting food availability for chicks.
Most candidates answered this question correctly.
