| No | Do macrophytes play the same important role in brackish lakes compared to freshwater lakes? |
| A lake receiving water from the marine enviroment. Typical salinity around 0.5 (WFD) - 15promille | What defines a brackish lake? |
| Yes. They are found along our coasts and approximately 1/3 og the total lake area in DK are brackish lakes. Many brakish lakes often have a large area. | Are brackish lakes common in DK? |
| Brackish lakes receive marine water where salinity in saline lakes increases due to evaporation. Saline lakes are often found in mountain regions and arid areas. | How do brackish lakes differ from saline lakes? |
| Due to high chlorophyll concentrations. | Why are brackish lakes often very green? |
| Generally the Danish brackish lakes are nutrient rich and turbid like most freshwater lakes. | How is the general nutrient content and turbidity of brackish lakes in DK? |
| Egg-develop: Pike-perch
Fish larvae: Pike | Salinity is important for fish survival and reproduction. What fish group is most resistent to high salinity in each of these two reproduction steps. |
| ¨h | Mention some common fish species in brackish lakes. |
| highest diversity at intermediate salinity | Explain the figure. |
| No - some stuudies show highest richness at low salinity | Are highest species richness always found at intermediate salinities? |
| sticklebacks - they dominate nutrient-rich brackish lakes becuase they are very tolerant | What is a very common fish species at high nutrient levels in brackish lakes? |
| - lower biomass of fish in brackish lakes
- abundance of fish in nutrient rich brackish lakes are as high as in the freshwater lakes | What are some differences between fish in freshwater and brackish lakes? |
| In nutrient rich brackish lakes - especially if sticklebacks are dominating | Where is the Neimysis integer very common? |
| They may compensate each other - no explanition of how ;) | How comes these two predator species are high in abundance at the same time? |
| No - it is a hard life! They dont have same possibility to hide in macrophytes and there is a high predator preassure compared to many freshwater lakes. | Is it fun to be a zooplankton in brackish lakes? ;) |
| generally lower in brackish lakes than in freshwater lakes - low possibility for top-dpwn control of phytoplanktoon in brackish lakes | How do you expect the grazing pressure on phytoplankton to be in brackish lakes? |
| Daphina disappear at higher salinities. Instead less effecient filtering zooplankton like rotifers starts to dominate. | How does the zooplankton community change with salinity? |
| h | Summarize some differences between shallow freshwater lakes and brackish lakes. |
| Describe the submerged plant community in brakish lakes | For moss and isoetid we only have one common species - a little more for the two others - but relativly few species are common in brakish systems in general |
| What are those two species dominating the submerged plants in eastern Vejler? | Chara (kransnålsalge) and Potamogeton pectinatus (vandaks) |
| What are the difference in secchi depth due to macrophyte cover in fresh vs brackish lakes? | Higher secchi depth in freshwater lakes with high macrophyte cover. In brakish lakes we don't see the same tendency - meaning that a high macrophyte cover does not reduce the turbidity in brackish lakes. |
| Are macrophytes important for other reasons in brakish lakes? | Yes. |
| How will the increasing risk of drought in the future affect the salinity in lakes? | Risk of increasing salinity in future with all the different consequences this will lead to like change in fish and zooplankton composition. |
