Question

one of the most common plants in atlantic salt marshes is cordgrass. periwinkle snails cling to the top of tall cordgrasses during high tide. the tall cordgrasses provide protection from the snails’ predators, such as the blue crab. while the snails do not feed directly on the cordgrass, the snails can damage the cordgrass when they graze on algae and fungi that grow on the grasses. if the snail population grows too large, it can decrease cordgrass growth. in a further study to investigate the relationship between salinity and blue crab density, the researchers monitored five sites in one saltwater marsh. each site was the same size. salinity data, in practical salinity units (psu), and the number of blue crabs at each site are shown in the following graphs. number of blue crabs at sites 30 25 20 15 10 5 0 site 1 site 2 site 3 site 4 site 5 salinity of the water at sites 30 25 20 15 10 5 0 site 1 site 2 site 3 site 4 site 5 which of the following is a reasonable claim the researchers can make based on the data in the graphs? crab populations are most limited where salinity range between 10 and 15 psu. salinity does not influence crab populations because the number of crabs fluctuates across the five sites. crabs are more abundant in areas with high salinity than in areas with low salinity.

Explanation:

By observing the two bar - graphs, we can see that at sites with higher salinity values (e.g., Site 1 and Site 2), the number of blue crabs is relatively larger compared to sites with lower salinity values (e.g., Site 3 and Site 4).

Answer:

C. Crabs are more abundant in areas with high salinity than in areas with low salinity.