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John Y. Takekawa

Abstract (from SpringerLink): The distribution patterns of sessile organisms in coastal intertidal habitats typically exhibit vertical zonation, but little is known about variability in zonation among sites or species at larger spatial scales. Data on such heterogeneity could inform mechanistic understanding of factors affecting species distributions as well as efforts to assess and manage coastal species and habitat vulnerability to sea-level rise. Using data on the vertical distribution of common plant species at 12 tidal marshes across the US Pacific coast, we examined heterogeneity in patterns of zonation to test whether distributions varied by site, species, or latitude. Interspecific zonation was evident at...
Sea‐level rise (SLR) impacts on intertidal habitat depend on coastal topology, accretion, and constraints from surrounding development. Such habitat changes might affect species like Belding's savannah sparrows (Passerculus sandwichensis beldingi; BSSP), which live in high‐elevation salt marsh in the Southern California Bight. To predict how BSSP habitat might change under various SLR scenarios, we first constructed a suitability model by matching bird observations with elevation. We then mapped current BSSP breeding and foraging habitat at six estuarine sites by applying the elevation‐suitability model to digital elevation models. To estimate changes in digital elevation models under different SLR scenarios, we...
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Broad survey lines, island radial survey lines, coastal survey lines, and focal-area (Santa Barbara Channel) survey lines were surveyed during each oceanographic season: spring (May), fall (September), and winter (January) during 1999 (May and September), 2000 (January, May, September), 2001 (January May, September), and 2002 (January). Aerial survey methods follow Mason et al. (2007). Specifically, we recorded all sightings of marine animals, vessels, and floating objects from twin-engine, high wing aircraft (Partenavia P-68s, Aspen Helicopters, Oxnard, CA, or California Department of Fish and Game) along pre-determined 100-meter (50 meters per side) strip transects at 60 meters above sea level. Surveys were flown...
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