Cramond report - Coursework Example

The plausible reason for this could be differential deposition by the varied compositions of the shore water. Point Estimate Upper CL Lower CL Salinity East Wednesday 32.4 32.9 31.9 Salinity West Wednesday 21 24.3 17.7 Salinity East Friday 32 33.9 31.1 Salinity West Friday 25.2 28.7 21.7 Based on the nature of sediments present a large number of varied species could be present on either side of the causeway. An analysis of the number of species growing at both the sites on each day was also done to further enhance the assessment.

The east sand and west mud were analyzed for macrofauna and lugworms. Macrofauna comprise of the shallow water communities that live on or in sediment, or attached to hard substrates majorly living in marine, estuarine or freshwater environments. Annelid worms, bivalves, gastropods, crustaceans, tunicates, and insect larvae are some of the most commonly encountered macrofauna in estuarine and coastal areas. Lugworms are present as coiled castings on the beach during low tides and are otherwise rarely seen as they dig into the sand.

East Sand Wednesday West Mud Wednesday East Sand Friday West Mud Friday Shellfish - cockles 6 0 0 0 Shellfish - Macoma 0 33 30 11 Shellfish - winkles 0 6 0 1 Crustaceans - Corophium 17 41 0 244 Crustaceans - shrimps 2 20 0 1 Ragworms 21 29 21 56 Sandmason worms 0 0 26 0 Other polychaete worms 7 5 23 17 Amongst the macrofauna the species considered were Shellfish – cockles, Shellfish – Macoma, Shellfish – winkles, Crustaceans – Corophium, Crustaceans – shrimps, Ragworms, Sandmason worms and some other polychaete worms (data shown in table 2).

Ragworms were the most uniformly present organisms on all days and in all salinity conditions indicating their non-specific nature of growth. Shellfish – cockles, Sandmason worms and Shellfish – winkles on the other hand had a very specific nature of abundance indicating their high sensitivity to even the slightest change in salinity conditions. Shellfish – cockles were less abundant (only 6 in number) and found only on the East Sand and that too only on Wednesday. Sandmason worms grew abundantly in the East sand on Friday only.

Shellfish – winkles grew scarcely on West Mud on Wednesday and hardly grew on the West Mud on Friday with only 1 organism found that day. Shellfish – Macoma were found to grow on both the east sand and west mud and were dependant only on the salinity conditions present. They were able to grow on salinity estimates of up to 32 only. Crustaceans – Corophium was unable to tolerate high saline conditions and they grew on the east sand on Wednesday but died by the next day. However, their growth on the west mud was very favorable as they grew fairly well on Wednesday and their growth increased exponentially by the following day as they were found to reach a number of 244 from 41 the previous day.

Other polychaete worms like the Ragworms grew on both the places in all days but their abundance was highest on the east sand on Friday. Lugworms were counted during as late as possible in the low tide period as they are otherwise very rarely found on the beach. Raw lugworm counts were scarce ranging from 0-5 only. Lugworms were present scarcely on the west mud on Wednesday but became nil by Friday probably due to change in salinity conditions. Similar pattern of abundance was seen on the east mud as