Shellfish Facts February 2001

The problem: fecal ○○○○ Why Do Shellfish Need Clean Water? coliform bacteria Shellfish do not need clean water to grow, BUT shellfish must have clean water to be safely eaten. That is because , , and are filter feeders – they get their by pumping and filtering massive amounts of water through their bodies Unacceptable levels of fecal each day. [A pacific pumps 65 gallons of water through its coliform bacteria are to body every day!] blame for the shellfish harvesting closures in As water passes through the the Nisqually Reach shellfish, they filter out particles for and Henderson Inlet. So what’s the big fuss about fecal coliform? food. But shellfish are not choosy. They filter out all particles – “Nonpoint pollution” is The pollution causing the shellfish harvesting closures is including any chemicals, biotoxins the source of the fecal fecal coliform – not just the variety of E-coli that causes (), and bacteria and viruses. coliform bacteria in serious illness from undercooked contaminated . And you can’t tell by looking at these areas. Unlike (Although the two contaminants are cousins, so to speak.) them what they’ve been filtering. If “point” pollution – You may have heard reports about how the presence of the water contains human sewage, which refers to a coliform in water tests caused people to boil their drinking animal wastes, disease-producing single identifiable water. Actually, most fecal coliforms are ordinarily harmless organisms, or chemicals, then these source like a pipe – to humans. It’s the company they keep – pathogenic contaminants concentrate in nonpoint pollution is bacteria and viruses – that can cause illness and disease. shellfish tissue as well. The accu- caused by one or mulated contaminants can make many activities that Fecal coliform occurs naturally in the gut of warm-blooded people sick. take place across the animals – such as cows, birds, people and raccoons – and landscape. These usually isn’t a concern until it shows up in our water or So that is why commercial shellfish activities include food. It gets there from contaminated stormwater runoff, growing areas are classified and human habits and poor farm management, waste from pets and wildlife, leaking routinely monitored to determine lifestyles, and natural sewers, and failing septic systems. how clean the water is – and it events. must be very clean. This helps

○○○○○○○○○○○○○○○○○○○○○ ensure that shellfish reaching markets, restaurants, and our kitchens are Here in the northwest, heavy rainfalls safe to eat. compound the problem by washing pollutants into our streams, lakes and inlets. Nonpoint pollution compounds In essence, shellfish are like sieves, Nonpoint pollution never goes away; it constantly changes as we change our filtering particles from the tidewater activities on the land. The best we can do is manage the problem, and we must that washes over them. Shell- do so continuously to ensure clean water in the future. capture fecal coliform bacteria along with other For example, extensive work can clean up identified pollution sources along a particles they use for particular stream or shoreline, while problems in other areas go uncorrected. food. Water quality problems often reoccur in the same area as time passes and owners change. New property owners are sometimes unaware of the need for ○○○○○○○○○ ongoing septic maintenance and use of best farm-management practices. Farm Produced by the Thurston County operations also change over time. Livestock numbers can increase overnight, so Environmental Health Division farm plans and practices must keep pace to make sure the additional animal 2000 Lakeridge Dr. S.W., Olympia, WA 98502. waste does not pollute the water. Managing nonpoint pollution is a big challenge Phone: 754-4111. www.co.thurston.wa.us for us all.