Final senior thesis session tackles seafood processing waste, Chena River property values

Nicole Swensgard, left, and Laurel Gale, right, presented their senior thesis work April 30.

The final senior thesis presentations of the spring found Laurel Gale giving her proposal, “Ecological effects on benthic infauna by seafood processing waste discharges in Alaska,” and Nicole Swensgard reporting on the completion of her thesis: “How does access to the Chena River affect property values?”

“Coastal areas in the Gulf of Alaska have been utilized by the commercial seafood processing industry since the nineteenth century,” Laurel Gale said. Over time the waste outfall generated from seafood processors has begun to affect the benthic infauna, marine organisms that live near shore areas, dwell in sediment, are slow moving, and vary in size from the microscopic bacteria to animals such as mollusks or sea cucumbers.

Current regulations are under the national Discharge Elimination Permit, managed by the Environmental Protection Agency and the State of Alaska. With the “grind and dump” policy, material must fit through a half-inch screen; the discharge area must be one square acre, with a 100-foot mixing zone. No effluent slicks can show on the water surface and non-compliance results in fines and/or shutdown of the plant.

“Each year billions of gallons of seafood processing waste is pumped into near shore area ecosystems in Alaska,” Gale said. Of Alaska’s 880 seafood processors, 90 create 95 percent of total effluent outfall. Each processor is allowed 10 million pounds per year of solid waste residue that settles. A single processor in Cordova is permitted to discharge up to one million gallons per month.

Discharge effluent does not decompose quickly because of the already low oxygenated environmental conditions. The waste acts as super nitrogenous waste and causes affects similar to the eutrophication process in fresh water systems. The added nutrients cause algal blooms, increased bacterial activity, reduced oxygen, and the death of infaunal communities which creates dead zones. Also, there is physical suffocation of the infauna as the effluent blankets the sediments and organisms can’t reach water with siphons and tubules, resulting in their death.

To lose benthic infauna removes a key component of the food chain, affecting the Steller’s sea eider, Steller’s sea lion, sea otters, benthic feeding fishes, and even humans. The decrease of habitat for higher trophic levels and the decrease of water quality occur in both chemical and physical parameters.

Benthic organisms are useful as indicator species for disturbed areas because they tend to remain in place and typically react to long range environmental changes. They are believed to reflect the biological health of marine areas.

Gale said seafood processing effluent effects have not been studied much. One of the few studies in Alaska was done by Burrell and Feder in 1982. They found infauna markedly decreased or absent in areas with seafood processing effluent. New concerns are increased oceanic dead zones, floating bacterial mats, and decreasing health and fecundity of marine species. She cited skin infections in sea birds and nematode infections in benthic feeding mammals as examples.

Gale’s hypothesis is that compared to unaffected areas, places with seafood waste will show a decrease of biodiversity of benthic infauna, an increase of opportunistic taxa, and a decrease in biomass. She will be evaluating the response of benthic organisms to seafood processing waste in Dutch Harbor and Port Valdez. She also predicts a decrease in habitat for higher trophic levels, decrease in water quality, and decrease of available food by removal of a food chain level.

Nicole Swensgard reported on her year of researching how access to the Chena River affects property values in city limits. She floated the Chena slowly to ascertain the exact situation along the river. “Property along the river is valued as an amenity,” Swensgard said. She realized that other places have established vegetated buffers along river corridors and it did not diminish the value of the land. The benefits are reducing erosion and protecting habitats.

Using the GIS database from the Fairbanks North Star Borough website, Swensgard charted that residential land on the river is valued at $4.98 per square foot inside the city limits and $1.86 per square foot outside the city limits. The most interesting part of her study was that vegetated buffer lots are worth the same as riverfront lots both inside and outside the city limits.

She plotted 50 lots adjacent to vegetated buffers and 389 riverfront lots along the Chena River from Fort Wainwright to the mouth of the Chena River. “I found no significant difference in riverfront and vegetated buffer properties along the river, therefore establishing such vegetated buffers would not decrease property values or tax revenues to the community," Swensgard said..