Hood Canal Dissolved Oxygen Program (HCDOP)
Hood Canal has long been treasured as one of the most scenic places in the Pacific Northwest. It also used to be one of the most productive water bodies, sustaining generations of people on it’s bountiful fish and shellfish.
The canal’s natural beauty and recreational opportunities are a haven for boaters, divers, angers, bird watchers, as well as hikers.
What seems to be the problem?
For all it’s beauty, Hood Canal is suffering from low levels of dissolved oxygen (DO), a critical indicator of water quality health.
This problem hit the spotlight in Spring 2002, and again in the Fall of 2003, when thousands of dead fish and other marine life washed up on.
Hood Canal beaches, like people, these creatures need oxygen to breathe. Without adequate oxygen, they were essentially suffocating.
A couple years later, low DO conditions again caused wide spread fish kills in the Hood Canal. Scientists, divers, and citizens reported that more than 30 species of fish died, including large lingcod, rockfish, several types of perch, eel-like fish, sculpins, flatfish and sand lance. The conditions were also so hard on crustaceans. Observers found dead spot prawns, rock crabs, and Dungeness crabs.
What causes low levels of DO?
Poor overall water circulation Stratification of water that discourages mixing of surface-to-deeper water People are contributing nutrients, especially nitrogen, to the canal through runoff from
fertilizing, septic systems, and other practices. Excess nutrients cause plankton and algae to reproduce at a rapid state, or ‘bloom‘. As the tiny organisms die, they sink to the bottom of the canal where they decompose, using up vital oxygen in the process.
Low DO and fish kills in Hood Canal’s southern end are nothing new.
Evidence of dead marine life dates back to the 1950’s and even earlier than that. The difference today, is that the low DO conditions last longer and are more widespread. The most severe conditions occur from Hoodsport to Belfair in the southern half of the Canal. Now, severely low dissolved oxygen plagues deep water in the southern half of the canal year-round.
What’s being done to help Hood Canal?
38 organizations including state agencies, universities, tribal and local governments, nonprofit organizations and research institutes have formed a partnership to address the problem of low DO in Hood Canal: the Hood Canal Dissolved Oxygen Program. The ‘HCDOP‘ monitors, analyzes and develops corrective actions to address the low DO problem in the canal.