Vegetation: The lower Coos watershed supports many invasive plants such as European beachgrass which has significantly altered the Lower Bay subsystem.
Aquatic Invertebrates: Over 60 non-native aquatic invertebrates species occur in the Coos estuary; additional invasions are likely.
Despite the potential for significant ecological and economic effects, little is known about the status of most of these species.
Terrestrial Invertebrates: No invasive terrestrial invertebrate populations are currently established in the project area, though local forests are at risk of invasion.
Vertebrates: Evidence indicates the local presence of large populations of invasive nutria, and small declining populations of non-native American shad and striped bass.
This section includes the following data summaries: Vegetation,
Aquatic Invertebrates, Terrestrial Invertebrates, and Vertebrates—
which describe invasive and other non-native species in the Coos estuary
and lower Coos watershed.
Local distribution of each species is discussed where information is available. Sources include invasive species response plans, which often include targeted monitoring efforts (e.g., Howard et al. 2007; ODF 2014a and 2014b) and statewide species profiling efforts (ODA 2014). Information from scientific publications (e.g., Posey 1988 and Hacker et al. 2012) and Online spatial databases (e.g., USDA 2015a) were also referenced. The vast majority of early non-native vegetation species detections have come from local biologists noticing unusual plants (e.g. information personally communicated by A. Brickner 2015).
A Background section summarizes the information available describing the local or regional environmental and economic effects of each non-native or invasive vegetation species.
A Background section summarizes what little information is available describing the local or regional environmental, economic and public health effects associated with non-native or invasive aquatic invertebrates.
Even though other spatial data exist, to simplify this data summary only maps with the most comprehensive monitoring information (e.g. gorse and purple loosestrife) or those with location information of early invaders
(e.g., Spanish heath and old man’s beard) were included.
Non-Native and Invasive Aquatic Invertebrates: Only a few systematic surveys of invasive aquatic invertebrate species have been undertaken in the project area (e.g. Laferriere et al. 2010, Davidson 2006 and 2008), therefore there are large data gaps in our understanding of their distribution in the Coos estuary. Likewise, knowledge of environmental and economic effects of many aquatic species is lacking.
Non-Native and Invasive Terrestrial Invertebrates: The available information about the threat of non-native and invasive insect introductions to the project area is based on projections from academic and government agency scientists, and local experts. However, since recent technological advances have resulted in the accelerated movement of goods and people across the globe, the spread of invasive insects has become increasingly difficult to monitor and predict (Hulme 2009). While these expert opinions represent the best available information, it’s possible that unforeseen events (e.g., previously unaccounted for vectors of transport) could lead to the introduction of non-native and invasive species not currently anticipated by the experts. In some cases, species
that pose the highest risks have appeared intermittently in Oregon (e.g., gypsy moths). Early detection rapid response programs have eliminated these threats before they have become established locally. However, if isolated populations have gone undetected, it’s possible that additional, yet to be discovered threats may currently exist within or in proximity to the project area.
Non-Native and Invasive Vertebrates: Striped bass and American shad data come from long-term Oregon Department of Fish and Wildlife (ODFW) monitoring efforts whose priorities shifted over time (ODFW 2009 and 2013). ODFW initially sampled (starting in 1965) all fishes in the Coos system, but shifted its focus to American shad and striped bass beginning in the late 1970’s. As American shad and striped bass populations declined, ODFW’s long-term monitoring focus shifted in 2006 to Chinook salmon. American shad
and striped bass (along with other fishes) are still identified and counted during Chinook sampling. But American shad and striped bass population and distribution data should only be considered comprehensive between the late 1970’s and 2006.
There are additional limitations to the American shad and striped bass data in the sampling methods used. Seining methods have remained standard over the years, but fish identification varies by staff abilities. In addition,
the seining effort was not identical in all years (some sites were missed— especially after the sampling focus shifted to Chinook) and during some years sampling was skipped altogether. Finally, seining methods may have
inadvertently introduced bias into the sampling since seining is not effective at capturing all fish (e.g., larger more mobile fish species).
Finally, descriptions of the health of American shad and striped bass rely on older information from the primary literature (e.g., Carlton 1989), and some theses (e.g., Anderson 1985).
Nutria data are limited as no standard protocols have been adopted to assess nutria distribution or abundance in Oregon. Sheffers and Sytsma (2007) used district ODFW wildlife biologists’ best estimates to create a relative nutria density distribution map for Oregon (Figure 2 in the data summary). Although these scientists have an intimate knowledge of the watersheds in which they work, they were not always able to estimate relative nutria densities, leaving a large number of sub-watersheds unrepresented. Since these were judgment calls based on best professional
knowledge, conclusions based on this map should be used with caution.
Comprehensive nutria density and distribution data are lacking for the project area and for Oregon in general, despite anecdotal evidence suggesting the local presence of relatively large sustaining populations and structural damage to local marsh habitats and human infrastructure.