Spring 2004 Species Survey
Jennifer Fleming

Discussion

     On the Marine Biology trip seven different locations were trawled. The locations were Alligator Harbor, Turkey Point Shoal, Lanark Shoal (Mid-Flats), Lanark Sand Bar, Lanark Shoal, East of Turkey Point Shoal, and between Turkey Point and Alligator Harbor. The depths ranged from four to ten feet. The class trawled at the three different times, morning (10:30 a.m.), noon (11:45 a.m.), and evening (2:30-4:25 p.m.). The temperature for these seven locations ranged from 78-80ºF. Looking at the results from the graphs it was found that Arthropoda and Chordata were the two most dominate phylums. The most dominant species were found to be Pinnixa retinens and Lagodon rhomboids.

     The graph from location 1 at Alligator Harbor showed that the dominant phylum was Chordata and the dominant species collected was Lagodon rhomboids. The collection was obtained during a ten-minute trawl, at a depth of about five feet. The trawl was a 10:30 am during low tide, with a water temperature of 78 ºF.

     The graph from location 2 at Turley Point Shoal shows that the dominant phylum was Arthropoda and the dominant species collected was Pinnixa retinens. The collection was obtained during a ten-minute trawl, at a depth of about five to ten feet. The trawl was at 11:34 am during slack tide, with a water temperature of 79 ºF.

     The graph from location 3 at Lanark Shoal (Mid-Flats) shows that the dominant phylum was Chordata and the dominant species collected was Pinnixa retinens. The collection was obtained during an eight-minute trawl, at a depth of about four-eight feet. The trawl was at 2:30 pm during high tide, at a water temperature of 80 ºF.

     The graph from location 4 at Lanark Sand Bar showed that the dominant phylum was Arthropoda and the dominant species collected was Pinnixa retinens. The collection was obtained during a ten-minute trawl, at a depth of eight to ten feet. The trawl was at 2:30 pm during high tide, at a water temperature of 79 ºF.

     The graph from location 5 at Lanark Shoal showed that the dominant phylum was Arthropoda and the dominant species collected was Pinnixa retinens. The collection was obtained during a twelve-minute trawl, at a depth of five to ten feet. The trawl was at 11:25 pm during slack tide, at a water temperature of 79 ºF.

     The graph from location 6 at East of Turkey Point Shoal shows that the dominant phylum was Chordata and the dominant species was Lagodon rhomboids. This collection was obtained during an eight-minute trawl, at a depth of five to eight feet. The trawl was a 10:30 am during low tide, at a water temperature of 78 ºF.

     The graph from location 7 between Turkey Point and Alligator Harbor showed that the dominant species was Lagodon rhomboids. The collection was obtained during a thirty-minute trawl, at a depth of twenty feet. The trawl was a 1:45 pm during high tide, at a water temperature of 80 ºF.

     The graph of the number of species collected at different depths showed that there were more organisms collected at a depth of five to ten feet. These locations were Turkey Point Shoal and Lanark Shoal. In both of these locations, Arthropoda was the most dominant phylum and Pinnixa retinens the most dominant species. The water temperature was 79 ºF in both of these locations and both trawls were done during slack tide. It can be implied that this is the best depth in which to collect Pinnixa retinens.

     The graph of the number of species collected at different times shows that more species are collected around noon, and two were done at 10:30 am and two between 2:30-4:25. Although three trawls were done, the data supports that the largest collections were done during noon out of the collections. The two largest trawls were at locations Turkey Point Shoal and Lanark Shoal. Arthropoda was the dominant phylum and Pinnixa retinens was the dominant species.

     The graph of the number of species collected at various tides showed that more organisms were collected during slack tide. The trawls at Turkey Point Shoal and Lanark Shoal were collected during slack tide. Similarly, the graph of the number of species collected at various temperatures also shows that locations two, four, and five are the most abundant at 79 ºF. 79 ºF is the most abundant temperature because three trawls were done at this temperature instead of two. The data showed that when the water temperature is warmer, more species are found.

     Overall, the trawls at Turkey Point Shoal were the locations with the greatest abundance. By the graphs, it was also apparent that these two locations had the best depth, time of day, and type of tide. It is most likely that the number and different species is most dependent on location.