Ag Impacting Humboldt Bay – February 10, 2012
HUMBOLDT BAY – A newly-released draft coho salmon recovery plan includes assessments of Arcata-area watersheds and names agriculture-related impacts as a main threat to Humboldt Bay habitat.
The National Marine Fisheries Service’s recovery plan covers Northern California and Southern Oregon. Watershed by watershed, it assesses coho population levels and habitat conditions and recommends projects that will encourage recovery and allow coho to be de-listed from the Endangered Species Act.
Agricultural practices “pose a very high threat to all life stages” of coho in Humboldt Bay’s watersheds, according to the plan. Grazing in riparian areas and nutrient loading are primary impacts and the diking of tidelands and installation of tide gates has “eliminated the majority of the intertidal rearing habitat around Humboldt Bay,” the plan states.
About 85 percent of the bay’s original salt marsh and tidal slough habitat is “no longer available to coho salmon,” according to the plan.
The plan also calls attention to the habitat impacts of industrial development, including port development. It states that development of the Harbor District’s Redwood Marine Terminal Dock in Samoa would “degrade habitat in an area where juvenile coho salmon concentrate.”
The plan names urban development as another high-level threat. “Future development may degrade existing tidally influenced habitat” and increase the volume of discharge from Arcata’s wastewater treatment plant, according to the plan.
Jacoby Creek is named as one of four of the Humboldt Bay area’s “main spawning tributaries.” It supported a robust adult coho population in the 1800s but a “noticeable decline” was seen by the 1940s.
Monitoring in Jacoby Creek followed the removal of a fish passage barrier in 2001 and the plan reports that in 2008, the number of adult coho observed only amounted to 10 fish. It was the lowest number observed since the base year.
But there’s been “recent evidence of juvenile coho salmon rearing” in Jacoby Creek and other Arcata watersheds. \The plan’s recommended recovery actions include “restoring the natural watershed processes” and expanding coho accessibility to rearing habitats such as tidally-influenced wetlands.
“Innovative incentive programs, alternative land-use scenarios and partnerships” are recommended as development and other land use activities proceed.
The plan notes that the City of Arcata has a Creek Management Plan (CMP) that “provides policy direction for new and modified development along creeks in order to control watershed erosion, enhance riparian habitat, protect instream habitat and flows, and promote restoration.”
National Marine Fisheries Service biologists took public comment on the draft plan at a Jan. 31 meeting at the Humboldt Area Foundation in Eureka.
The plan’s implementation is voluntary and presumably relies heavily on the availability of grant funding.
An audience of about 40 people was mostly made up of representatives of environmental groups, and doubts were expressed about the viability of grant funding.
Members of some groups are concerned about how the plan’s categorizations will affect their odds of gaining grants.
The plan’s comment period ends March 5. There was agreement among audience members at last week’s meeting that it should be extended.