Lower Columbia River and Estuary Subbasin Priorities

To:  Karl Weist, Northwest Power and Conservation Council

From: Debrah Marriott, Executive Director
         Scott McEwen, Director of Technical Programs

Date: October 4, 2005

Re: Lower Columbia River and Estuary Subbasin Priorities

The following fish and wildlife priorities were directly derived from the Lower Columbia River and Estuary Subbasin Plan and its accompanying Management Supplement. These subbasin priorities are supported by the Board of Directors of the Estuary Partnership and were further discussed at a September 29, 2005 Science Work Group meeting of the Lower Columbia River Estuary Partnership. Those in attendance at that meeting included:

York Johnson-ODEQ; Agnes Lut-ODEQ; Yvonne Vallette-USEPA; Lyndal Johnson-NOAA; Robert Anderson-NOAA; Greg Fuhrer-USGS; Joe Rinella-USGS; Ian Waite-USGS; Jennifer Morace-USGS; Ron Thom-Battelle; Gary Johnson-Battelle; Amy Borde-Battelle; Ester Lev-Wetlands Conservancy; Tracey Yerxa-BPA; Frank Loge-UC Davis; Scott McEwen-Estuary Partnership; Matt Burlin-Estuary Partnership; Jill Leary-Estuary Partnership.

Hydrology the Driving Factor

The hydrology of the lower Columbia River is governed largely by the Columbia River hydropower system. The hydropower system affects nearly every aspect of ecosystem function, particularly habitat formation and maintenance, which in turn help determine water quality, which affects the composition of biological communities. Despite the dominant influence flow has on the restoration of downstream landscapes, the management of this system is largely governed through the development of Biological Opinions by the National Marine Fisheries Service and through the development of implementation plans by the Action Agencies. For this reason, the Subbasin strategies that were developed to address flow did not appear appropriate for the ?locally driven priority and project selection? as envisioned in this potential Oregon solicitation framework. 

The Following Are The Top Three Local Prioritized Strategies For Fish Populations

1) Protect and Restore Habitat

This priority strategy affects salmonids and white sturgeon at the egg incubation, juvenile, and adult life stages; juvenile and adult Pacific lamprey. Aquatic species need a broad range of habitat types in the proper proximities to one another, at the right time, to satisfy feeding, refuge, breeding, and rearing requirements. Disconnected habitat, a lack of habitat, lack of habitat diversity, or lack of access to habitat obviously reduces the spatial structure, abundance, productivity, and life history diversity of species.

In the lower Columbia River and estuary, habitat loss can be attributed to the conversion of wetlands and estuaries to other uses, such as urban and agricultural development, and the effects of flow alterations, dams, dikes, and dredging (see Section 2.1.3.2.2 in the subbasin plan). Diking is particularly detrimental because it completely removes habitat from the estuarine system. Dikes reduce overbank flow, further disconnecting the river from its floodplain and altering flow-related processes that otherwise would create off-channel and peripheral habitat (see Section 2.1.3.2.3 in the subbasin plan). It is estimated that 84,000 acres of historic floodplain are now disconnected from regular wetting by tides and freshets due to the construction of dikes and tidegates. In addition, a lack of connectivity with the floodplain contributes to the microdetritus-based food web, as opposed to the more natural macrodetritus food web. Currently, floodplain land uses and a lack of funds to acquire lands preclude large-scale habitat reclamation (through dike breaching, for example). 

More specifically, the subbasin measures that addressed habitat restoration for focal species included:

Measure 1: Restore tidal swamp and marsh habitat in the estuary and tidal freshwater portion of the Lower Columbia River.

Measure 4: Restore connectedness between river and floodplain

Measure 5: Protect and restore riparian and wetland habitat condition and function.

Measure 6: Restore impaired sediment transport processes affecting the Columbia River lower mainstem

Measure 9: Implement mitigation and enhancement measures to provide access to productive spawning and rearing habitat.

2) Address Toxic Contaminants

The effects of toxic contaminants can be mitigated through the removal, treatment, or containment of hot spots or by addressing contaminants at their source, such as through the establishment of best management practices that address stormwater and point source discharges. In either case, more specific data are required on contaminant sources and the location and extent of contaminant effects before specific management actions can be taken. This strategy affects juvenile salmonids and Pacific lamprey, and white sturgeon in the egg incubation and juvenile stages.

Agricultural practices and industrial and urban development in the lower Columbia region have resulted in the accumulation of legacy toxic contaminants such as DDT, DDE, polychlorinated biphenyls (PCBs), and metals in sediments, fish tissue. (see Section 2.1.3.2.5 of the subbasin plan). DDT and PCBs have been detected at elevated concentrations in juvenile salmonids, and a variety of organochlorines and toxic metals have been found to be above guidance levels in fish tissue and sediment in the lower 150 miles of the mainstem Columbia. In fact, the Oregon and Washington health departments have issued advisories regarding consumption of certain fish species (carp, peamouth, and sucker) because of elevated levels of PCBs, DDT, and DDE in the Columbia. Other contaminants of concern in the lower mainstem include dioxins, furans, and various pesticides.

Sublethal concentrations of contaminants affect the survival of aquatic and terrestrial species by increasing stress, predisposing organisms to disease, delaying development, and disrupting physiological processes, including reproduction (see Section 2.1.3.2.5 in the subbasin plan). In juvenile salmonids, contaminant exposure can result in decreased immune function and generally reduced fitness. Fall Chinook and chum may be particularly susceptible to contaminant exposure because they prefer peripheral shallow-water habitats where contaminants are known to accumulate. Pacific lamprey, too, may be susceptible because contaminants collect in the fine sediments where lamprey burrow. Toxic contaminants may also be affecting white sturgeon.

3) Slow the Introduction of Non-native Species

Implementing this strategy would involve instituting best management, regulatory, and education measures to prevent additional species invasions; establishing a moratorium on intentional introductions of non-native species; and evaluating and managing the impacts of non-native species on salmonids and sturgeon. This strategy addresses juvenile salmonids, juvenile and adult white sturgeon, and Pacific lamprey.

In the Columbia River estuary and lower mainstem, non-native species number more than 70, including 37 fish species and 16 plants (see Section 2.1.5.2 in the subbasin plan). The benefits of this strategy would be high because of the numerous negative impacts of introduced species on both native species and the ecosystem. Numerous fish, wildlife, and plant species have been introduced into the Columbia estuary and lower mainstem ecosystem. Non-native species are particularly adept at capitalizing on altered habitats such as those in the lower Columbia and estuary that have been affected by hydrosystem development and water regulation (see Section 2.1.5.2 in the subbasin plan). Once established alter food web dynamics, transmit diseases and parasites, and may outcompete native species. They represent permanent alterations of the biological integrity of the ecosystem.

More specifically, the subbasin measures that addressed habitat restoration for focal species included:

Measure 10:  Implement regulatory, control, and education measures to prevent additional species invasions.

Measure 11:  Establish a moratorium on intentional introductions of aquatic species and importation of high risk species.

The Following Are The Top Two Local Prioritized Strategies For Wildlife Populations

1) Protect and Restore Habitat

Terrestrial species need a broad range of habitat types in the proper proximities to one another, at the right time, to satisfy feeding, refuge, breeding, and rearing requirements. Disconnected habitat, a lack of habitat, lack of habitat diversity, or lack of access to habitat obviously reduces the spatial structure, abundance, productivity, and life history diversity of species.

Habitat loss can contribute to increased density of focal species, which in the case of Columbian white-tailed deer has increased their vulnerability to parasites and foot-rot disease and made them more susceptible to population losses from flooding (see Section 5.2.2.1.4 in the subbasin plan). For bald eagles, human encroachment on nesting sites is known to reduce breeding success. Habitat loss and recreational and development pressures can exacerbate this problem. Non-focal species that would benefit from this strategy include: osprey, yellow warbler, red-eyed vireo, dusky Canada goose, and sandhill crane.

Habitat loss can be attributed to the conversion of wetlands and estuaries to other uses, such as urban and agricultural development, and the effects of flow alterations, dams, dikes, and dredging (see Section 2.1.3.2.2 in the subbasin plan). Diking is particularly detrimental because it completely removes habitat from the estuarine system. Dikes also reduce overbank flow, further disconnecting the river from its floodplain and altering flow-related processes that otherwise would create off-channel and peripheral habitat (see Section 2.1.3.2.3 in the subbasin plan). In addition, a lack of connectivity with the floodplain contributes to the microdetritus-based food web, as opposed to the more natural macrodetritus food web. Currently, conflicts with floodplain land uses and a lack of funds to acquire lands preclude large-scale habitat reclamation (through dike breaching, for example). More specifically, the measures that addressed habitat restoration for focal species include:

Measure 1: Restore tidal swamp and marsh habitat in the estuary and tidal freshwater portion of the Lower Columbia River.

Measure 4: Restore connectedness between river and floodplain

Measure 5: Protect and restore riparian and wetland habitat condition and function.

Measure 6: Restore impaired sediment transport processes affecting the Columbia River lower mainstem

2) Address Toxic Contaminants

The effects of toxic contaminants could be addressed through the removal, treatment, management or containment of hot spots or by addressing contaminants at their source, such as through best management practices that address stormwater and point source discharges. In either case, more specific data are needed on contaminant sources and the location and extent of contaminant effects before specific management actions can be taken.

The strategy is consistent with the following key assumptions, which are based on assessment data and analysis in Chapter 2 of the subbasin plan: Agricultural practices and industrial and urban development in the lower Columbia region have resulted in the accumulation of toxic contaminants such as DDT, DDE, polychlorinated biphenyls (PCBs), and metals in sediments, mammal tissue, and bald eagle eggs in the lower mainstem and estuary (see Section 2.1.3.2.5 of the subbasin plan). In the case of bald eagles, concentrations of PCBs, pesticides, and dioxins in eggs collected along the lower Columbia were at levels associated with reduced breeding success. Contaminants such as DDE and PCBs, which bioaccumulate in adult birds over time, are known to decrease eggshell thickness and reduce the number of young produced per occupied nest. Although studies show that levels of DDE and total PCBs declined from the mid-1980s to the mid-1990s, values still exceed estimated no-effect levels for bald eagles (see Section 2.1.3.2.5 in the subbasin plan). Productivity at new breeding sites along the Columbia is much higher than at old breeding sites (particularly those in the lower 60 miles of the river), suggesting that pairs at the older sites are more affected by contaminants than pairs at the newer sites. Productivity is lowest for bald eagles nesting between River Miles 13 and 31 (see Sections 2.1.3.2.5 and 2.1.4.10 in the subbasin plan).