Salish Sea Marine Bird Project 2010-2012
In 2010, SeaDoc hired Nacho Vilchis as a postdoctoral fellow to do a two-year investigation into marine bird populations in the entire Salish Sea ecosystem.
Birds don't care which side of the international border they're on, but most government and non-governmental organizations in the Salish Sea work only in one country. SeaDoc, however, has a mandate to do transboundary work. We're pulling together the best science done on both sides of the border to understand what's happening in the entire ecosystem.
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Over 170 bird species use the Salish Sea, a 17,000 square kilometer inland sea shared by British Columbia and Washington State.
Multiple data sets compiled over the last 30 to 40 years have shown some species’ populations to increase, while many others to have drastic declines. However, isolation of research conducted in Canada and the United States has made pinpointing mechanisms driving population change for the entire ecosystem exceptionally difficult.
The main goal of this project is to investigate possible ecosystem-level mechanisms driving declines of multiple species in the entire Salish Sea.
Our end-goal is to identify management strategies impacting multiple species and encouraging ecosystem-level recovery in Canada and the United States.
Our approach is to use data collected by numerous Canadian and America research programs and identify ecosystem-wide population trends for an ecologically and phylogenetically diverse suite of Salish Sea resident seabird species and develop viable hypotheses explaining declines. We plan to take an epidemiologic and population modeling approach and evaluate the relationship between marine bird trends and demographic factors, behavioral traits, environmental stressors and other processes known to drive population dynamics.
This will allow us to identify species-specific risk factors for species in decline and commonalties of stable species.
Bird species depending on the Salish Sea, an inland sea ecosystem of Washington (USA) and British Columbia (Canada), for habitat and food sources are presently in jeopardy.
How? Just count the ways.
First, human population along the shorelines of the Salish Sea continues to expand. The Salish Sea coastal region has a current population of approximately 7 million people, with a forecasted increase to over 9 million in 2025.
- A growing population has catalyzed changes to the Salish Sea shoreline, physically changing the integrity of the coast by dredging and dike building.
- Land and sea in the Salish Sea are intimately connected by the numerous estuary and river delta systems.
- Higher coastline development has the unfortunate consequence of altering seabird nesting habitats as well as the degree land buffers storm water drainage.
- Higher development increases the concentration of contaminants rain and snowmelt carries into the Salish Sea. On a daily basis, 68 metric tons of toxins are estimated to flow into the Salish Sea, an issue that clearly affects foraging and habitat of many seabird populations.
Secondly, direct and indirect effects of fishing are known to have affected Salish Sea seabirds.
- Incidental fishing mortality, or bycatch, is one the most common anthropogenic sources of worldwide seabird mortality, and the Salish Sea is no exception.
- Coastal gill-net fisheries are common practice in the Salish Sea, at times taking diving seabirds.
- Indirectly, loss or dumping of old nets can lead to ghost fishing by derelict fishing gear that can persist underwater for up to ten years.
- Additionally, in some cases commercial fishing can deplete forage fishes affecting seabird populations.
And last, it is now well accepted that climate variability can affect seabirds in a number of ways.
- Seabirds, which in general are long-lived, migrating top-predators, can integrate the health of marine habitats over several spatial and temporal scales.
- Unforeseen consequences of ocean warming can alter cyclical patterns of ocean systems. For example, changes in the frequency and intensity of spring upwelling can alter the base of the food web in a way that seabirds are not accustomed deal with for extended periods of time.
What we know
The Salish Sea harbors an amazing phylogenetic and ecologic diversity of seabirds, yet in the last thirty years nearly half of the total number of individuals using the Salish Sea has disappeared.
While we think that some species are making less use of Salish Sea habitats and others are reproducing less, some have simply vanished. For example, during this same time-frame about a third of the most common wintering species are thought have declined in numbers, with a quarter of species having declined by more than 50%.
Because of the trans-boundary nature of the Salish Sea, isolation of research in US and Canadian environmental agencies inhibits the ecosystem-level approach needed to address changes in seabird populations.
Seabirds from a marine ecosystem that knows no boundaries should be addressed by a holistic ecosystem approach also ignoring boundaries.
What we want to find out
Do species with populations in decline have common risk factors? Our main goal for this project is to develop strong hypotheses explaining Salish Seabird population trends, by assessing species-specific trends for the last 35 years using data collected by various research programs.
We wish to identify management strategies that will positively impact multiple species and encourage ecosystem-level recovery.
Our end-goal will be to pinpoint risk factors responsible for population change and address them via policy and conservation measures.
In addition to working on species-specific recovery plans of declining populations, developing hypothesis explaining ecosystem-level drivers responsible for declines of multiple species is of paramount importance for the recovery of Salish Sea marine birds.
Our approach will be threefold.
- First, pull data sets from numerous sources into one database and appropriately standardize the data in accordance to methodology disparity.
- Second, spatially and temporally subdivide the data set at different scales; large and small.
- And third model standardized measures of abundance, presence absence or dominance as a function of time and habitat at different temporal and spatial scales.
We will then associate risk factors to species and corresponding habitats by assessing forage and habitat availability and quality and oceanographic variability.
Once we determine our best-fit models we will also use a sensitivity analysis to determine the variability of our models to changes in the values of the parameters and structure of the model. This will help us gauge the strength of these models by giving us a measure of their uncertainty.