| Date | May 2019 | Marks available | 2 | Reference code | 19M.1.SL.TZ0.9 |
| Level | Standard Level | Paper | Paper 1 | Time zone | Time zone 0 |
| Command term | Outline | Question number | 9 | Adapted from | N/A |
Question
The resource booklet provides information on the Coral Triangle. Use the resource booklet and your own studies to answer the following.
Outline two possible effects of climate change on marine coastal ecosystems within the Coral Triangle.
Markscheme
This question requires “Resource Booklet - May 2019 SL paper 1”, available under the "your tests" tab > supplemental materials.
higher water temperatures could lead to coral bleaching/death;
higher water temperatures could change migration patterns of some species/cause some species to migrate to cooler water;
higher water temperatures could adversely affect reproduction of some species;
higher water temperatures leads to loss of biodiversity because some species are unable to adapt/have a very narrow acceptable temperature range;
higher water temperatures decreases dissolved oxygen levels resulting in death of fish;
higher temperatures could increase gross primary productivity/warm water species;
higher temperatures can cause mangroves to dry out that reduce habitat for some species;
ocean acidification/lower water pH adversely affects calcifying species/shellfish/corals/calcareous plankton;
more intense/frequency of storms/currents could damage coral reefs/seagrass/mangroves /coastal ecosystems;
sea-level rise could reduce (shallow water) conditions required for mangroves/corals/seagrasses / sea-level rise could flood mangrove ecosystem;
sea-level rise could increase coastal erosion / sea-level rise could increase sediment flow into the ocean reducing light penetration/primary production within marine coastal ecosystems;
increase in precipitation could lower the water salinity that can adversely affect some species / lower precipitation could increase water salinity that can adversely affect some species;
Do not accept only “WWF predictions” without reference to specific factor altered by climate change that leads to specified impact on ecosystems within Coral Triangle.
Do not accept only ‘climate change / change in temperature’.
N.B “Higher temperature” is acceptable for “higher water temperature”.
[2 max]
Examiners report
There were some excellent responses. Some responses lacked the detail necessary, e.g. referring to climate change in general or to changes in either water pH or temperature without reference to direction of change. A few responses incorrectly suggested a decrease in global temperatures and associated colder climate.
