Figure 1
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Figure 5
Figure 6
Sensitivity of taxa used for calculating the Benthic Quality Index (BQI), where 1 = tolerant and 15 = very sensitive
| Sensitivity value (Si) | Taxa |
|---|---|
| 1 | Oligochaeta, Insecta larvae ind. |
| 5 | all polychaetes, Hydrobiidae, Macoma balthica |
| 10 | Amphibalanus improvisus, Cyathura carinata, Idotea chelipes, Idotea granulosa, Jaera spp., Corophium multisetosum, all gammarids, Theodoxus fluviatilis, Cerastoderma glaucum, Mya arenaria, Mytilus edulis |
| 15 | Idotea balthica, Bathyporeia pilosa, Crangon crangon |
Frequency of occurrence (%) of taxa on Długa Mielizna on bare sand (Sand), vegetation-covered sand (Plants + sand) and on plants (Plants) (in bold – taxa observed only in places with plants)
| Species | Sand | Plants + sand | Plants |
|---|---|---|---|
| Nematoda | 7 | 75 | 76 |
| Oligochaeta | 53 | 100 | 82 |
| Piscicola pojmanskae Bielecki, 1994 | 0 | 0 | 29 |
| Hediste diversicolor (O. F. Müller, 1776) | 87 | 100 | 82 |
| Marenzelleria spp. Mesnil, 1896 | 40 | 81 | 12 |
| Pygospio elegans Claparéde, 1863 | 80 | 94 | 12 |
| Amphibalanus improvisus (Darwin, 1854) | 0 | 13 | 29 |
| Mysis relicta Lovén, 1862 | 0 | 0 | 6 |
| Praunus flexuosus (Müller, 1776) | 0 | 0 | 6 |
| Cyathura carinata (Krøyer, 1847) | 13 | 19 | 6 |
| Idotea balthica (Pallas, 1772) | 0 | 13 | 100 |
| Idotea chelipes (Pallas, 1766) | 27 | 94 | 100 |
| Idotea granulosa Rathke, 1843 | 0 | 13 | 41 |
| Idotea juv. | 0 | 25 | 100 |
| Jaera spp. Leach, 1814 | 0 | 6 | 35 |
| Bathyporeiapilosa Lindström, 1855 | 7 | 0 | 0 |
| Corophium multisetosum Stock, 1952 | 20 | 13 | 6 |
| Gammarus inaequicauda Stock, 1966 | 0 | 0 | 6 |
| Gammarus locusta (Linnaeus, 1758) | 7 | 13 | 41 |
| Gammarus oceanicus Segerstråle, 1947 | 0 | 0 | 18 |
| Gammarus zaddachi Sexton, 1912 | 0 | 25 | 53 |
| Gammarus tigrinus Sexton, 1939 | 13 | 25 | 29 |
| Gammarus salinus Spooner, 1947 | 0 | 50 | 88 |
| Gammarus spp. Fabricius, 1775 | 0 | 0 | 12 |
| Gammarus juv. | 7 | 44 | 100 |
| Crangon crangon (Linnaeus, 1758) | 7 | 6 | 6 |
| Insecta larvae ind. | 7 | 81 | 88 |
| Theodoxus fluviatilis (Linnaeus, 1758) | 0 | 6 | 6 |
| Hydrobiidae Stimpson, 1865 | 100 | 100 | 100 |
| Cerastoderma glaucum (Bruguiére,1789) | 20 | 81 | 65 |
| Macoma balthica (Linnaeus, 1758) | 67 | 81 | 24 |
| Mya arenaria Linnaeus, 1758 | 80 | 100 | 53 |
| Mytilus edulis Linnaeus, 1758 | 27 | 94 | 100 |
| Einhornia (Electra) crustulenta (Pallas, 1766) | 7 | 0 | 24 |
| fish eggs and larvae | 0 | 0 | 12 |
| Gobiidae | 0 | 0 | 24 |
| Total number of taxa | 19 | 24 | 31 |
Class ranges on bare sand (Sand) and on the vegetation-covered bottom (Plants + sand)
| Class range | |||||
|---|---|---|---|---|---|
| Sand | 5.8-4.6 | 4.5-3.4 | 3.3-2.2 | 2.1-1.0 | <1 |
| Plants+sand | 8.4-6.7 | 6.6-5.0 | 4.9-3.3 | 3.2-1.6 | <1.6 |
| Very good | Good | Moderate | Poor | Bad | |