ABSTRACT

This paper is reprise of scientific studies published in the proceedings of the NAUI 107, 1974. A group of scientist/divers who saw an opportunity explore and qualitatively and quantitatively describe a unique aquatic ecosystem. The endeavor required development and implementation of a rigorous biological monitoring program in a challenging dive location, I.e., the bottom Of the last free flowing reach of the Columbia River.

THE RESEARCH DIVING AT HANFORD

My first job following graduate school was as a Battelle Research Scientist at the Hanford nuclear site located in southeast Washington state. The area is described as ‘”semi-arid” averaging only 6-7 inches Of precipitation per year. My adjustment to this arid environment after the greenery of the willamette Valley and University of Oregon campus was a little difficult.

The Hanford site was set aside by the federal government in January 1943. The 560 square mile site was chosen for two main reasons. First, Hanford provided the isolation required for the mission Of the Manhattan Project and the war effort. The second reason was the Columbia River. From 1944 to 1971 the river served as a source of cooling waters for the eight plutonium producing nuclear reactors. The cooling waters were discharged back to the Columbia significantly warmer.

Th 58 mile Hanford Reach river begins below Priest Rapids dam and continues unrestricted and free flowing until the north end of the McNary Pool at Richland WA. The Columbia riverine habitat may be one of the most studied aquatic systems on record. Th resident fauna and flora had been monitored and studied continuously since 1943. However, as rigorous as the aquatic and terrestrial environmental studies had been one aspect of the aquatic biology remained unstudied. i.e. the benthos. The characteristics of the river bottom materials and the strong currents were thought to exceed the capabilities Of contemporary techniques and sampling devices long used in lake and ocean bottom studies. The substrate consists of rocks ranging in size from gravel to large boulders. In the lower Hanford section there are unique formations of sand. rocks and clay forming outcroppings or pinnacles, some as large as a bus. This defeatist assessment Of scientific ability to inventory and understand the benthic biology Of the Columbia River existed until a group of scientists/divers analyzed and solved the problem.

The diving conditions Of the free flowing Hanford Reach are comparable to Puget Sound at tide exchange. Water temperatures follow the seasons. Winter waters range from freezing to 40-450F. In the summer water temperature can reach the low 70’s. The current is strong enough to open the purge button on a single hose regulator and can dislodge a diver’s face mask. The depths in the studies ranged from 8•40feet. (Page et al). Underwater visibility also varied with Season. The cold waters of winter depress plankton productivity and visibility could be 15 teet or more. Snow melt and the spring freshet decreased the water clarity. Often a driver could reach further than he could see. The diving conditions during most of the study period were challenging. However, we had built a unique group Of divers in the Battelle Northwest Ecosystem Department. We dove the Columbia regularly. Limited visibility and current diving was nothing new to us.

In the early 1970’s Battelle Northwest contracted with Washington Public Power Supply System (WPPSS) to develop aquatic environmental characterization and monitoring in the main channel

Of the Columbia River. Two nuclear power plants were to be located in the southeast sector of Hanford, north of Richland WA. Cooling waters for the reactors would be diverted from and returned to the river. Federal and Washington state environmental policies and regulatory law at that time required comprehensive knowledge Of all aspects of the aquatic biology and assessment of potential impacts to the ecology due to such use of the waters. The time had come to develop information on the Columbia River benthic environments and biology.

When the first drafts of the study plan were reviewed by Battelle management the reactions were skeptical that the proposed reliance on divers was even feasible. Nonetheless we pressed on and developed a sampling system . an array of multiple sample stations would be installed on the river bottom and regularly serviced by dive teams. Similar studies had been done elsewhere (Mason. et al., 1967; Gale and Thompson, 1974) but never in riverine systems as complex as those in the Hanford reach. The final design of each single sampling staton consisted Of a pair of anchors (Figure 1 each with a mooring line to a buoy on the surface The primary anchor in the figure marked the site and moored the dive boat. A secondary anchor was placed 70 feet directly downstream of the main anchor. Th dive protocol requires divers to placed retrieve sampling devices at specific locations on a year-around rigorous monitoring schedule.

In order to study the benthos, removable samplers were placed in the riverbed . The samplers were actually barbecue baskets filled with river rocks selected to duplicate the river bed in the vicinity of the proposed power plant water intakes and discharges. After a predetermined time period, the baskets would be removed and replaced with fresh baskets. The benthic organisms that had colonized n the baskets would be removed , sorted by species, and counted. The life forms would include periphyton, worms, aquatic insects, freshwater sponges, snails and crayfish.

The strong river currents made positioning extremely difficult for both the dive boats and divers. In our preliminary drift dives of the study area, we realized even heavily weighed divers wold be unable to hold position in order to perform the sampler maintenance required in the study. To

DIVE TEAM ON A MONTHLY VISIT TO ONE OF MULTIPLE STATIONS. THE TASK WAS TO

RETRIEVE A SAMPLE BASKET FROM THE ARRAY AND REPLACE IT WITH A FRESH BASKET.

hold a twenty-three foot dive vessel, the samplers and at least one team of dives in a stationary position our anchors would have to be massive . In our early attempts, we used conventional boat anchors and large blocks concrete. All of these singly or in clusters were unable to hold the boat. Our final design called for the precise placement of four-ton steel bridge footings as the primary or upstream dive boat mooring anchors. Located seventy feet downstream , is the second bridge footing marking the sampling station anchors. Shackled to this secondary anchor is the sample tree with is a 20 foot length of PVC pipe equipped with eyebolts placed at measured. evenly spaced intervals. The spacing allows the diver to located, remove and replace specific baskets by feel alone in zero viability.

The upstream buoy is used to moor the dive vessel which, once secured, stands by to receive the downstream buoy line as it is hauled along side by the diver pickup boat. Once the line is secured to the stern of the dive vessel, and the pickup boat has moved off to its standby position. the dive is ready to commence. The buoy line attached to the secondary anchor also serves as the diver descent line when rigged as seen in Figure 1 .

With the boats in position, two divers take their positions on the aft dive platform where the dive master conducts an equipment check on each diver, briefs the dive team on more time and releases the divers. Holding firmly onto the descent line, the first diver enters the water followed thirty seconds later by the second divider. Once in the water, the divers angle their bodies toward the bottom and allow the current to assist them during their hand-over-hand descent to the bottom. The divers proceed to rernove the station thermograph and replace it with a fresh one while awaiting the arrival of the replacement basket samplers which are sent down the descent line by the surface personnel.

With the fresh sampler clipped in place on the ample tree, the divers must now bag the sampler to be removed. Bagging prevents loss of organisms or contamination by non-station dwellers on the trip to the surface. The bagging operation must be accomplished using one hand since the diver’s other hand must be used to maintain position On the tree. Early in the program we learned the second diver could grasp the first diver’s tank valve and sample tree hardware to allow his buddy to quickly bag the sample basket. To aid in ascent while carrying ten or twelve pounds of river rock, the diver inflates his buoyancy compensator to slowly rise to the surface. Once on the surface, with one hand securely grasping the bagged basket, the diver immediately signals that he is OK to the dive tenders in the pickup boat. The tenders then close on the divers, pick up the sample, and assist the divers into the boat.

This specialized dive operation required a lot of planning and many attempts at different techniques. Throughout the study program small details were modified for the purpose of easier, safer diving. Safe, efficient dives that were completed at all times Of the year were always the primary goal of the dive team.

The importance of safety was never underrated by the dive team. Each mission was conducted under the direction and surveillance of a dive master. The buddy system , safety checks, equipment maintenance, medical checkups, safety meetings, and first-aid and giving medicine reviews, were all integral parts Of the dive effort. Each work dive was a team effort. The buddy system was followed at all times. If a dive team separated, the mission would be aborted and the divers surfaced. While diving. the teams stay in constant communication by use of a buddy line or hand or sneeze signals, Each diver and surface support man was trained in both basic and advanced first-aid; plus a good knowledge ot diving first-aid. First-aid kits, complete with oxygen, were always present aboard the dive boats. Radio communications could be established Tri-Cities hospitals in the event of an emergency and could be maintained during transit The divers also wore medic alert tags which provided phone numbers for diving doctors and information facilities such as the Virginia Mason Hyperbaric facility in Seattle, WA.

REFERENCES

Somers, Lee H. Cold weather and Under Ice $Guba Diving. NAUVNDA Technical Publication Nilmher Four, 1973

Page, T. , E. G. Wolf, N.H. Gray, and M. J. Schneider, Ecological Comparison of the Hanford No 1 and the WN-2 Sites on the Columbia River. Battle Northwest Laboratories Publication, 1974.

Mason, W. T. , J.BJB. Anderson and G.E. Morrison, A Limnology Filled, Artificial SubstrateFloat Unit for Collecting Macro-invertebrates in Large Stream. The Progressive Fish Culturist. vol. 29. NO.4, page 74, 1967.

Gale, W.F.. and J. D. Thomson, Placement and Retrieval QfArtiticial Substrate samplers by SCUBA . Progressive Fish Culturist. vol. 36, No. 4, pp. 231-232, 1974.

Barraclough, S.A., D.A. Neitzel, MO, Schneider, T.L. Page, E.G. Wolf , and E.W. Lusty, The Four Ton Weight Belt or Research Diving in the Cnlltmhia River. National Association of Underwater Instructors, Proceedings Of the Seventh International Conference on Underwater Education. page 42., 1974