Categories measured include physical factors such as salinity, contaminant levels in sediments, bacteria levels and fish populations. Sources of contaminants from Marina operations are associated with oil and grease from fueling and from motor or engine operation, from antifouling compounds found in hull paint, from disposal of household detergents and cleaners, and drainage from parking lots. High tides usually sweep trash that has been left by fishermen and pedestrians along the jetties into the water, along with fecal matter from birds and dogs. In spite of these factors, the Marina is subjected to more impacts from sources outside the Marina than from within. The average sediment accumulation rate at the mouth of Ballona Creek is about 24,000 cubic yards per year.
Large storm drains also lead into several of the basins from areas east of the Marina.
Studies are currently underway to determine the input of contaminants from the Marina versus those from Ballona Creek . Human fecal material may reach the Marina in various ways, including boaters that may flush heads illegally or holding tanks that may leak. Trash trucks are washed out in the area draining into Oxford basin as well. Rainfall consistently boosts the coliform bacteria counts to very high numbers. Mother's Beach in the Marina is one of the most polluted beaches in the Bay.