Southern Resident orcas in the Salish Sea are facing population decline at the hands of a severe drop in salmon numbers. Noise pollution from ship traffic, the pollution of the ecosystem and bioaccumulation of toxins in Southern Resident orcas are other massive stressors on the population.
Bioaccumulation occurs when toxics enter the food chain and predators begin to consume contaminated prey. As orcas consume more and more contaminated salmon, they also consume the toxics in the fish, accumulating dangerously high levels of pollution in their fat reserves. Like all marine mammals, orcas rely on the energy in their fat for when prey is scarce. This is an all-too common occurrence for Southern Residents. Chinook salmon, their primary prey, have collapsed across the west coast, leaving fewer fish for the whales.
Without abundant salmon runs, the orcas metabolize the stored fat and energy in their blubber. Doing so also floods their bodies with toxic chemicals, which can make them sick. Milk produced for calves is also made from these toxic fat stores, which may be a driving factor behind the high calf mortality and low reproductive rates in the population. Pollution enters the Salish Sea from several sources, but some of the most concerning are old, derelict vessels and wood pilings in the water and polluted stormwater runoff. This pollution makes conserving and restoring Southern Resident orcas extremely difficult.
Old ships and vessels abandoned in the water leak out oil, lubricant and other harmful substances used to construct the vessel or in the cargo onboard. Creosote treated wood pilings, which used to support old docks and mooring facilities, also taint the Salish Sea. Coal tar creosote, a substance containing up to 10,000 chemicals, was commonly used to protect wooden support structures from decaying in the water. By far the largest source of pollution in the Salish Sea is polluted stormwater runoff.
Luckily there are clean ups already underway in the Salish Sea. The Washington Department of Natural Resources (DNR) has two programs that are actively removing both derelict vessels and creosote pilings. The DNR’s derelict vessel removal program began in 2002, and it has removed over 700 vessels that were polluting the Salish Sea. The DNR’s creosote removal program has, to date, removed roughly have of the creosote pilings in Puget Sound.
Derelict Vessel Removal
While the program has greatly reduced pollution from these old vessels, more can be done. Vessel removal can be expensive, and the DNR’s program is unable to remove all the identified derelict vessels in a given funding cycle. The state could also do more to prevent vessels from becoming derelict in the first place, which not only prevents pollution from contaminating the Salish Sea and orcas, but it also is significantly less expensive than removing vessels from the water. Additional funding from the legislature could improve and expand on the DNR’s programs, allowing the department to do more in a given year. Furthermore, coordination and collaboration with other government agencies can greatly improve the efficiency of removal and prevention efforts. Through updated record keeping, increased education efforts and improved collaboration, local governments, state departments and federal agencies could efficiently and effectively leverage their resources and expertise to have an even greater impact on removing these polluting vessels and preventing others from sinking to the bottom of the Salish Sea.
The DNR also manages the state’s creosote removal program. Unfortunately, due to decreases in funding, the remaining pilings have not been removed. Like the derelict vessel removal program, an influx of funding from the state could finish the job and remove all of the creosote pilings from Puget Sound. This would reduce one of the most toxic sources of pollution from the Salish Sea.
Stormwater Runoff Reduction
Stormwater runoff remains one of the most difficult challenges to address because it is the largest source of pollution affecting the Salish Sea, and it comes from everywhere and everyone. While this may make the problem seem daunting, there are several simple, concrete ways that local governments and individuals can reduce the amount of stormwater pouring into the Salish Sea. One of the best tools we have at our disposal is raingardens; bowl-shaped gardens that collect stormwater and naturally absorb and filter the water.
Studies have shown that when stormwater is treated through biofiltration systems, like raingardens, the filtered water is clean enough for salmon. By installing raingardens, homeowners and local governments can address one of the biggest threats facing the Salish Sea while also beautifying homes and neighborhoods. Large raingardens installed in public places are becoming more common in communities around Western Washington. Currently, the stormwater treatment facility at Point Defiance Park in Tacoma is the largest biofiltration system in the world, treating much of the stormwater runoff from West End neighborhood before it pours into Commencement Bay.