Poole Slough Acquisition, Assessment, and Planning

 

Project Location: Yaquina estuary, Lincoln County, 44.62°N, longitude 124.02°W

 

Background: The project will directly result in permanent conservation of 150 acres in the lower Yaquina estuary. The project parcel contains diverse estuarine, riparian and upslope habitats including 17 acres of estuarine habitat, a 20 acres riparian zone immediately adjacent to the estuary and the rest in 60 to 80 year old naturally regenerated forest land. Indirectly, this project builds on The Wetlands Conservancy’s ownership and management of 500 acres of salt marsh and timber habitats in McCaffery and Poole Sloughs and conservation management of an additional 3,500 acres of adjacent upland habitat by Pacific Forest Trust and further conservation lands in the watershed managed by the Siuslaw National Forest and the City of Toledo and provide a continuous ridge top, riparian and estuarine habitat connection. Adding the proposed acquisition to the currently conserved areas, more than 80% of the McCaffery and Poole Sloughs will be in conservation ownership and management in perpetuity.

 

Purpose: The Yaquina Bay and River is an important production system for coho, chum, Chinook salmon and winter steelhead trout as well as resident and sea-run throat trout. The coho population is viable, the Chinook population is stable and the chum salmon, which spawn in Mill Creek are one of the most southern populations of the species. Additionally, NOAA has designated the lower reaches and sloughs in the Yaquina system as Critical Habitat for the ESA listed Green Sturgeon and the most recent ESA listing of Eulachon, which potentially utilize those same reaches of the lower Yaquina. Herring has been documented spawning in estuary and Poole Slough. Tidal wetlands provide a variety of functions that are vital to salmonids, with a significant body of research on the role estuaries and estuarine wetlands play in the salmonid life-cycle. Estuaries appear to be most heavily used by juveniles different than adults which pass through the estuaries on their way to their natal stream reaches in the upper portions of the basin to spawn. For example, tidal marshlands are located in the area where salt water from the ocean mixes with fresh water from streams and rivers. This mixing provides "osmotic transition zones" that allow juvenile salmonids to adapt gradually to salt water. Deeply incised tidal channels provide shelter from predators, and tidal flushing keeps water temperatures cool and dissolved oxygen concentrations high. Marshlands that are frequently inundated by tides are extremely productive and support a wide range of invertebrates that are prey for salmonids (Brophy, 1999). Estuarine habitat provides three primary functions for juvenile salmonids beyond the temporary residency during their migration to the sea. These functions include providing a transition area for sea water acclimation, refuge from predation, and productive foraging areas. Residency within estuarine areas by salmonids smolts and fry vary significantly from the longest being up to ½ year by juvenile Chinook, to approximately 1 month for chum salmon. And sea-run cutthroat have a specific life-history of using the estuary a majority of their marine lives before returning to their natal stream to rear and spawn. There is presence of either juvenile and adult salmon and steelhead in our estuaries throughout the whole year with the peak use being the juvenile residency from April to August. Estuaries are particularly valuable nursery areas for larval and juvenile fishes and shellfishes. During summer peaks, as many as 70 species of juvenile fishes forage in Oregon estuaries. Over 70% of salt marsh habitat in Yaquina Bay has been lost to historic filling, diking, and ditching activities. This project will result in permanent protection of decreasing coastal wetland marsh types that are zoned in a way that would allow environmentally disruptive activities that could threaten marsh integrity. The proposed conservation and long term stewardship actions are key to the implementation of protection on one the highest priority sites in the Yaquina estuary as determined by the assessment completed by the MidCoast Watersheds Council (Brophy, 1999) and The Yaquina Estuary Conservation Plan (Bauer, Lev, Miller, Christy, 2011). The project area is especially diverse in salmon species, in part because it is low-gradient floodplain close to the estuary. This project will further enhance the habitat’s ability to support these species.

 

Species that benefit: 

Green sturgeon (Acipenser medirostris)
Pacific herring (Clupea pallasi)
Bay shrimp (Crangon franciscorum)
Dungeness crab (Cancer magister)
California halibut (Paralichthys californicus)
English sole (Parophrys vetulus)
Starry flounder (Platichthys stellatus)
Shiner perch (Cymatogaster aggregata)
Steelhead (Oncorhynchus mykiss)
Coho salmon (Oncorhynchus kisutch)
Chinook salmon (Oncorhynchus tshawytscha)
Staghorn sculpin (Leptocottus armatus)
Pacific Oysters, Horseneck gaper, Northern anchovy, Spring Chinook, surf smelt, top smelt, three spined stickleback

 

Evaluating success: A detailed 5-year monitoring plan will be developed by TWC. The objective of the long-term monitoring will be to determine the improvement to the habitat through the acquisition and restoration projects. This monitoring effort will document the benefit and establish that the area is on a trajectory to success and self-sustaining habitat function. Watching and documenting the change over time will also guide future conservation and restoration priorities and projects in the Lower Yaquina system. There will be annual reporting for the first five-year period followed by less frequent intervals as the project enters the long-term stewardship phase. It is anticipated that within a 5-year period the property will be set on a trajectory to self-sustaining habitats and ecological function and processes. The annual monitoring for this project will build on the monitoring of the 2014 placement of large woody debris adjacent to the acquisition parcel and several adjacent areas in MacCaffery and Poole Slough, where presence and absence monitoring of the ESA listed coho and a subset of forage fish, native oysters are being conducted. Year one we will collect baseline presence absence of anadromous, forage fish and bird species. We will gather any and all historic data on species occurrences numbers and habitat condition at the time of the surveys. Using the historic data and current data and observing changing over time, we will define criteria for optimal species diversity and numbers for the future.

 

Project partners: Oregon Department of State Lands, Oregon Department of Fish and Wildlife, NMFS, EPA Research Lab, Mid Coast Watersheds Council, Siletz Tribe, US Fish and Wildlife Service, Lincoln County, Adjacent landowners, Native Fish Society, Pacific State Marine Fisheries Commission, Audubon Society of Portland, Siuslaw National Forest

 

USFWS Climate change strategies addressed by this project:

3.1 Take conservation action for climate-vulnerable species.
3.2 Promote habitat connectivity and integrity.
3.5 Conserve coastal and marine resources.

 

National Conservation strategies addressed by this project:

1. Protect intact and healthy waters.
3. Reconnect fragmented fish habitats.