Morro Bay Research Articles

Survey for Morro Bay Kangaroo Rat: A Rare Mammal of Uncertain Status

AbstractThe Morro Bay kangaroo rat Dipodomys heermanni morroensis is a small, nocturnal, burrowing rodent endemic to the vicinity of Morro Bay in San Luis Obispo County, California. It was listed as endangered pursuant to the U.S. Endangered Species Act in 1973. Despite many searches over three decades, the Morro Bay kangaroo rat has not been captured or sighted in the wild since 1986. While recognizing that the Morro Bay kangaroo rat may be extinct, two of us in a previous paper also speculated it may be persisting at extremely low density in isolated colonies and recommended surveying with wildlife scent-detection dogs and baited camera traps. We searched with a wildlife scent-detection dog and baited camera traps in four historically occupied areas and detected no Morro Bay kangaroo rats. Unfortunately, our data combined with all other existing data do not allow us to conclude whether the Morro Bay kangaroo rat is extinct or extant. Essentially, the International Union for the Conservation of Nature international standard has not been met to make a definitive determination of extinction. That is, a species should be considered extinct only when there is no reasonable doubt that the last individual has died. We acknowledge that because of resource limitation we surveyed only a small sample of the numerous patches of habitat in the expansive landscape. Further, we now consider the Morro Bay sand spit (total area 4.35 km2, foredunes 3.75 km2), a peripheral area, as potentially part of the geographic range with suitable habitat, and it has never been searched. Therefore, considering all available information, we conclude that the Morro Bay kangaroo rat must be considered as possibly extant. We recommend that search efforts continue in several specific areas, including the Morro Bay sand spit. If the Morro Bay kangaroo rat still exists, it will be challenging and difficult to rediscover because of its likely low density and patchy distribution in the expansive landscape, combined with its small size, nocturnal nature, and secretive lifestyle.

A multidecadal Bayesian trend analysis of harbor porpoise (Phocoena phocoena) populations off California relative to past fishery bycatch

AbstractHarbor porpoises, Phocoena phocoena, off California, comprise four recognized population stocks: Morro Bay (MOR), Monterey Bay (MRY), San Francisco‐Russian River (SFRR), and Northern California‐Southern Oregon (NCSO). The three southernmost stocks experienced substantial bycatch in gill net fisheries during the 1970s and 1980s. While the SFRR stock received full protection from gill nets in 1989, the MOR and MRY stocks continued to experience at least some bycatch through 2001–2002. We examined long‐term population trends for these four harbor porpoise stocks, based on two sets of systematic, aerial line‐transect surveys conducted off California during summer/fall of 1986–2017. We applied a Bayesian hierarchical framework to specify a process model of population density and an observation model of porpoise counts during line‐transect surveys. Growth rates were estimated for periods with and without bycatch. Posterior distributions indicate the MOR, MRY, and SFRR stocks, respectively, grew at 9.6%, 5.8%, and 6.1% per year after gill nets were largely or fully eliminated for each stock. Abundance off northern California appears stable or slightly increasing. This study provides a first empirical estimate of maximum net reproductive rate for harbor porpoise (at least 9.6%), and demonstrates that porpoise populations can recover from substantial gill net impacts if bycatch is eliminated.

Large-scale erosion driven by intertidal eelgrass loss in an estuarine environment

Seagrasses influence local hydrodynamics by inducing drag on the flow and dampening near-bed velocities and wave energy. When seagrasses are lost, near-bed currents and wave energy can increase, which enhances bottom shear stresses, destabilizes sediment, and promotes suspension and erosion. Though seagrasses are being lost rapidly globally, the magnitude of change in sediment stabilization following ecosystem-wide eelgrass loss has rarely been measured. In this study, we explored the geomorphological changes associated with an unprecedented estuary-wide collapse of a seagrass (eelgrass, Zostera marina) in Morro Bay, CA, USA. Morro Bay has historically suffered from accelerated sedimentation and accretion. However, following massive eelgrass loss since 2010, over 90% of locations that previously had eelgrass experienced erosion. Elevation losses (erosion) reached 0.50 m in some places (mean loss of 0.10 m) with as much as a 50% decrease (median decrease of 13.6%) in elevation (i.e., increase in depth) compared to pre-decline levels. In comparison, the mouth of the estuary, where eelgrass was largely retained, had only 27.7% of the locations with prior eelgrass experiencing erosion and underwent a mean elevation increase (accretion) of 0.32 m. Thus, the loss of eelgrass appears to have altered dynamics at the seabed and transitioned large regions of the estuary from an environment that promotes deposition and accretion to one that promotes suspension and erosion. Large-scale erosion following seagrass loss may be predictive of future shoreline and coastal habitat changes and is likely to be exacerbated by increased storm surge and sea level rise expected with climate change.

Uromyces rebeccae, sp. nov., a newly described rust on the federally endangered plant, California sea-blite (Suaeda californica)

ABSTRACT Rust disease was observed on populations of Suaeda californica near Morro Bay, California. The pathogen was identified as a species of Uromyces based on teliospore and urediniospore morphology and nuc 28S rDNA sequence analysis. The isolate was compared with previously described species of Uromyces that infect members of Chenopodiaceae, prompting a taxonomic reevaluation of Uromyces species on Suaeda. Herein, Uromyces rebeccae is described. It can be differentiated from the closely related U. chenopodii (syn.: Aecidium chenopodii-fruticosi; U. giganteus) based on host range, teliospore morphology, and 28S sequence data. The new combination, Uromyces chenopodii-fruticosi, is made for Aecidium chenopodii-fruticosi, the oldest name for Eurasian Suaeda rust. Finally, it was determined that U. giganteus likely does not occur in the United States and that the rust of S. taxifolia in the United States likely comprises a third, yet unnamed taxon, different from both U. rebeccae and U. chenopodii-fruticosi. This is the first record of a rust fungus on S. californica. An identification key for Uromyces species reported on Chenopodiaceae is provided.

Species recovery and recolonization of past habitats: lessons for science and conservation from sea otters in estuaries.

Recovering species are often limited to much smaller areas than they historically occupied. Conservation planning for the recovering species is often based on this limited range, which may simply be an artifact of where the surviving population persisted. Southern sea otters (Enhydra lutris nereis) were hunted nearly to extinction but recovered from a small remnant population on a remote stretch of the California outer coast, where most of their recovery has occurred. However, studies of recently-recolonized estuaries have revealed that estuaries can provide southern sea otters with high quality habitats featuring shallow waters, high production and ample food, limited predators, and protected haul-out opportunities. Moreover, sea otters can have strong effects on estuarine ecosystems, fostering seagrass resilience through their consumption of invertebrate prey. Using a combination of literature reviews, population modeling, and prey surveys we explored the former estuarine habitats outside the current southern sea otter range to determine if these estuarine habitats can support healthy sea otter populations. We found the majority of studies and conservation efforts have focused on populations in exposed, rocky coastal habitats. Yet historical evidence indicates that sea otters were also formerly ubiquitous in estuaries. Our habitat-specific population growth model for California’s largest estuary—San Francisco Bay—determined that it alone can support about 6,600 sea otters, more than double the 2018 California population. Prey surveys in estuaries currently with (Elkhorn Slough and Morro Bay) and without (San Francisco Bay and Drakes Estero) sea otters indicated that the availability of prey, especially crabs, is sufficient to support healthy sea otter populations. Combining historical evidence with our results, we show that conservation practitioners could consider former estuarine habitats as targets for sea otter and ecosystem restoration. This study reveals the importance of understanding how recovering species interact with all the ecosystems they historically occupied, both for improved conservation of the recovering species and for successful restoration of ecosystem functions and processes.

Fishing Community Sustainability Planning: A Roadmap and Examples from the California Coast

Fishing communities are facing a variety of challenges including declines in participation, reduced access to fish resources, aging physical infrastructure, gentrification, competition from foreign imports, the “graying” or aging of their fleets, along with a host of environmental stressors. These factors can represent threats to the continued viability of individual fishing communities. Such communities are clearly in need of tools that will enable them to plan strategically and to be more proactive in charting a sustainable future. This manuscript provides a roadmap for how to engage fishing communities in a bottom-up strategic planning process termed “fishing community sustainability planning” by describing implementation efforts in four diverse California ports: Morro Bay, Monterey, Shelter Cove, and Eureka. The process draws from the literature on sustainability and community development to assess fishing community sustainability around four broad categories: economics and markets; social and community; physical infrastructure and critical services; environment and regulation. Process steps included developing a project team and community coalition, analyzing baseline data, conducting interviews with waterfront stakeholders, hosting public workshops, and drafting a Fishing Community Sustainability Plan (FCSP) that includes concrete recommendations for how a community’s fishing industry and waterfront can be improved. Experiences from the four ports reveal that fishing community sustainability planning can be adapted to a variety of contexts and can contribute tangible benefits to communities. However, there are limitations to what community-scale planning can achieve, as many regulatory decisions that affect communities are enacted at the state or national level. Combining community-level planning with scaled-up fishing community sustainability planning efforts at the state and federal level could help overcome these limitations. FCSP planning is one tool fishing communities should consider as they seek to address threats and plan for their long-term viability.

Hydrodynamics in a shallow seasonally low-inflow estuary following eelgrass collapse

Hydrodynamics play a critical role in mediating biological and ecological processes and can have major impacts on the distribution of habitat-forming species. Low-inflow estuaries are widespread in arid regions and during the dry season in Mediterranean climates. There is a growing need to evaluate dynamics and exchange processes in these systems and the resultant ecological linkages. We investigate the role that hydrodynamics play in shaping environmental gradients in a short and seasonally low-inflow estuary located along the central California coast. Since 2007, eelgrass meadows in Morro Bay have declined by more than 90%, representing the collapse of the major biogenic habitat. Despite the large-scale decline, eelgrass beds near the mouth of the bay remain resilient, suggesting that conditions in certain areas of the bay might allow or impede eelgrass retention and recovery. Oceanographic moorings were deployed throughout the bay during the summer dry season to assess spatial differences in environmental conditions and hydrodynamics across gradients in eelgrass survival. Relative to the mouth of the bay, the back bay water mass was significantly warmer (hyperthermal), more saline (hypersaline), less oxygenated, and more turbid, with longer flushing times, all of which have been identified as significant stressors on seagrasses. Moreover, there is weak exchange between the mouth and the back bay that effectively decouples the two water masses during most periods. Though the causes of the decline are not clear, gradients in environmental conditions driven by bay hydrodynamics appear to be preventing eelgrass recovery and restoration attempts in the back bay and keeping this region in an alternative state dominated by unvegetated intertidal mudflats. Ecosystems in low-inflow estuaries may be especially prone to ecological regime shifts or collapse and may require precautionary monitoring and management. This system and the dramatic ecological change that it has experienced, demonstrate the critical role that hydrodynamics play in ecosystem health and habitat suitability.

How Population Decline Can Impact Genetic Diversity: a Case Study of Eelgrass (Zostera marina) in Morro Bay, California

Seagrass populations are in decline worldwide. Eelgrass (Zostera marina L.), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, the estuary in Morro Bay, California, has lost 95% of its eelgrass. Population bottlenecks like this one often result in severe reductions in genetic diversity; however, this is not always the case. The decline of eelgrass in Morro Bay provides an opportunity to better understand the effects of population decline on population genetics. Furthermore, the failure of recent restoration efforts necessitates a better understanding of the genetic underpinnings of the population. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic events. The genetic diversity and population structure of Morro Bay eelgrass have not been assessed until this study. We also compare Morro Bay eelgrass to Bodega Bay eelgrass in Northern California. We conducted fragment length analysis of nine microsatellite loci on 133 Morro Bay samples, and 20 Bodega Bay samples. We found no population differentiation between the remaining beds in Morro Bay and no difference among samples growing at different tidal depths. Comparisons with Bodega Bay revealed that Morro Bay eelgrass contains three first-generation migrants from the north, but Morro Bay remains considerably genetically differentiated from Bodega Bay. Despite the precipitous loss of eelgrass in Morro Bay between 2008 and 2017, genetic diversity remains relatively high and comparable to other populations on the west coast.

Predicting Surface Oil Transport in California Using a High-Resolution Regional Ocean Modeling System (ROMS) and the National Oceanic and Atmospheric Administration's (NOAA's) Trajectory Analysis Planner (TAP)

The Bureau of Ocean Energy Management (BOEM) and Bureau of Safety and Environmental Enforcement (BSEE) Pacific Region conduct oil spill risk analyses to determine potential impacts to environmental resources. Oil spill trajectory modeling is conducted to predict the movement and fate of spilled oil, if a spill occurred, from existing offshore oil and gas operations in southern California. To improve BOEM and BSEE Pacific Region's ability to conduct oil spill risk analyses for southern California, BOEM partnered with the University of California, Los Angeles (UCLA) to run a multi-year hind cast (re-analysis) of winds, waves, and currents along the coast of California. UCLA created a high-resolution (1 km) ROMS hind cast for the 10 year period 2004–2013 from Morro Bay, California to the border with Mexico. The project was conducted in three phases: (1) Surface winds were calculated at high horizontal and temporal resolution and validated using existing datasets; (2) A wave model was forced by the wind model results and validated through in situ measurements; and (3) The ocean model was run at high resolution and includes temperature, salinity, and currents; it assimilated in situ data and was forced by the hind cast atmospheric model results. BOEM is subsequently partnering with NOAA, to utilize the surface currents and winds from the ROMS hind cast analysis with NOAA's General NOAA Operational Modeling Environment (GNOME) to produce multiple trajectories for NOAA's TAP. Using realistic oil spill scenarios over a range of different regional oceanographic regimes (such as upwelling, relaxation, and eddy-driven flow), TAP will calculate the probabilities of oil contacting parcels of water and shoreline were any oil to spill from southern California oil platforms. This will enable analysts to understand where an oil spill may travel, how long it could take to get there, and the likelihood of spilled oil contacting their resource area. An online TAP viewer with the GNOME-generated data from this study will be publicly available along with the ROMS hind cast data for oil spill response planning along with other oceanographic modeling needs.

THE MORRO BAY FAUNA: EVIDENCE FOR A MEDIEVAL DROUGHTS REFUGIUM ON THE CENTRAL CALIFORNIA COAST

A robust collection of mammal, bird, fish, and shellfish remains from an 8,000-year residential sequence at Morro Bay, a small, isolated estuary on the central California coast, shows a strong focus on marine species during the Middle-Late Transition cultural phase (950–700 cal B.P.), which largely coincides with the Medieval Climatic Anomaly (MCA). Previous studies have provided modest evidence for increased fishing and rabbit hunting during the MCA in adjacent regions, but the Morro Bay findings suggest a distinctive marine-focused subsistence refugium during the period of drought. Specifically, the sequence shows striking all-time peaks in marine and estuarine birds, fish NISP/m3, and fish/deer + rabbits during the MCA. Heavy exploitation of fish, aquatic birds, rabbits, and shellfish suggests that the bow and arrow, which seems to have arrived in the area at this time, had little impact on local subsistence strategies.

Bioimpedance monitoring of cellular hydration during hemodialysis therapy.

Introduction The aim of this paper is to describe and demonstrate how a new bioimpedance analytical procedure can be used to monitor cellular hydration of End Stage Renal Disease (ESRD) patients during hemodialysis (HD). Methods A tetra-polar bioimpedance spectroscope (BIS), (UFI Inc., Morro Bay, CA), was used to measure the tissue resistance and reactance of the calf of 17 ESRD patients at 40 discrete frequencies once a minute during dialysis treatment. These measurements were then used to derive intracellular, interstitial, and intravascular compartment volume changes during dialysis. Findings The mean (± SD) extracellular resistance increased during dialysis from 92.4 ± 3.5 to 117.7 ± 5.8 Ohms. While the mean intracellular resistance decreased from 413.5 ± 11.7 to 348.5 ± 8.2 Ohms. It was calculated from these data that the mean intravascular volume fell 9.5%; interstitial volume fell 33.4%; and intracellular volume gained 20.3%. Discussion These results suggest that an extensive fluid shift into the cells may take place during HD. The present research may contribute to a better understanding of how factors that influence fluid redistribution may affect an ESRD patient during dialysis. In light of this finding, it is concluded that the rate of vascular refill is jointly determined with the rate of "cellular refill" and the transfer of fluid from the intertitial compartment into the intravascular space.

Tectonic Subsidence of California Estuaries Increases Forecasts of Relative Sea-Level Rise

Even along the generally uplifting coast of the Pacific US, local geologic structures can cause subsidence. In this study, we quantify Holocene-averaged subsidence rates in four estuaries (Carpinteria Slough, Goleta Slough, Campus Lagoon, and Morro Bay) along the southern and central California coast by comparing radiocarbon-dated estuarine material to a regional sea-level curve. Holocene-averaged rates of vertical motion range from subsidence of 1.4 ± 2.4, 1.2±0.4, and 0.4 ± 0.3 mm/year in Morro Bay, Carpinteria Slough, and Goleta Slough, respectively, to possible uplift in Campus Lagoon (−0.1 ± 0.9 mm/year). The calculated rates of subsidence are of the same magnitude as rates of relative sea-level rise experienced over the late Holocene and effectively double the ongoing rates of relative sea-level rise experienced over the last five decades on other parts of the coast. The difference in rates of vertical motion among these four estuaries is attributed to their geological settings. Estuaries developed in subsiding geological structures such as synclines and fault-bounded basins are subsiding at much higher rates than those developed within flooded river valleys incised into marine terraces. Restoration projects accounting for future sea-level rise must consider the geologic setting of the estuaries and, if applicable, include subsidence in future sea-level rise scenarios, even along the tectonically uplifting US Pacific Coast.

Decline of the Endangered Morro Bay Kangaroo Rat in California

AbstractThe Morro Bay kangaroo rat Dipodomys heermanni morroensis occurs in the vicinity of Morro Bay (specifically in and near Los Osos) in western San Luis Obispo County in coastal central California. It was listed as endangered pursuant to the U.S. Endangered Species Conservation Act in 1970 and subsequently the U.S. Endangered Species Act in 1973. Field research from the late 1950s to the mid-1980s has documented a rapid population decline. Despite many efforts, researchers have not captured the Morro Bay kangaroo rat since 1986, and the last captive individual died in 1993. We review the biology and conservation status of the Morro Bay kangaroo rat, including taxonomy and genetics, soil type and burrows, history of decline, primary causes of decline, breeding in the wild and in captivity, habitat restoration, and threats. In particular, there are two primary causes of decline. First, development (urban, agricultural, and industrial) has resulted in direct loss of habitat. Second, in the absence of fire, the early seral stages of coastal dune scrub (optimal habitat) have matured to later successional stages of vegetation, which are denser and with substantially fewer annual food plants, and which negatively impact the locomotion of kangaroo rats and change the diversity of the small mammal community with a likely increase in competition. In 2016 only pockets of habitat remain, with optimal habitat comprising an estimated 1% of the historical geographic range. Although researchers have not demonstrated predation by domestic cats, it is likely a major threat and we suspect it has contributed to the decline based upon a review of the literature. In 2011 we observed potential signs of the Morro Bay kangaroo rat at two historical areas, which suggests it may be persisting at extremely low densities in a few isolated colonies. In addition, we could not obtain permission to survey on four private properties with potential habitat. In consideration of the vast loss and fragmentation of its habitat, along with the continuing and pervasive threats, the Morro Bay kangaroo rat is clearly conservation-reliant. We believe that without urgent human intervention, the Morro Bay kangaroo rat will soon become extinct if it is not already.

Community Sustainability Planning as a Tool for Increased Environmental Sustainability: The Case of Two California Cities

Based on their professional work, :illiam Riggs and +enry Pontarelli argue that Community 6ustainability Plans can achieve community reliance through a balance of social, economic, and ecological factors. They discuss their approach and take lessons from case studies in two California cities, Morro Bay and Monterey.

Offset of Latest Pleistocene Shoreface Reveals Slip Rate on the Hosgri Strike-Slip Fault, Offshore Central California

Abstract The Hosgri fault is the southern part of the regional Hosgri–San Gregorio dextral strike‐slip fault system, which extends primarily in the offshore for about 400 km in central California. Between Morro Bay and San Simeon, high‐resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by an ∼265 m wide slope interpreted as the shoreface of a latest Pleistocene sand spit. This sand spit crossed an embayment and connected a western fault‐bounded bedrock peninsula and an eastern bedrock highland, a paleogeography resembling modern coastal geomorphology along the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral slip rate of 2.6±0.9 mm/yr, considered a minimum rate for the Hosgri given the presence of an active western strand. This slip rate indicates that the Hosgri system takes up the largest share of the strike‐slip fault budget and is the most active strike‐slip fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high‐resolution bathymetry in characterization of active offshore faults. Online Material: (1) High‐resolution bathymetric data for the cross‐Hosgri slope and (2) metadata that describes data collection, processing, and formatting.

Cardiorespiratory coupling of sympathetic outflow in humans: a comparison of respiratory and cardiac modulation of sympathetic nerve activity to skin and muscle

What is the central question of this study?Muscle sympathetic nerve activity (MSNA) is well known to be modulated by the arterial baroreceptors and respiration, but what are the magnitudes of cardiac and respiratory modulation of skin sympathetic nerve activity (SSNA), which primarily subserves thermoregulation?What is the main finding and what is its importance?Using direct microelectrode recordings of MSNA and SSNA in awake humans, we show that the magnitude of respiratory modulation of SSNA is identical to that of MSNA, the primary difference between the two sources of sympathetic outflow being the greater cardiac modulation of MSNA. This emphasises the role of the baroreceptors in entraining sympathetic outflow to muscle. It is well known that microelectrode recordings of skin sympathetic nerve activity (SSNA) in awake human subjects reveal spontaneous bursts of activity with no overt modulation by changes in blood pressure or respiration, in contrast to the clear cardiac and respiratory modulation of muscle sympathetic nerve activity (MSNA). However, cross-correlation analysis has revealed that, like individual muscle vasoconstrictor neurones, the firing of individual cutaneous vasoconstrictor neurones is temporally coupled to both the cardiac and respiratory rhythms during cold-induced cutaneous vasoconstriction, and the same is true of single sudomotor neurones during heat-induced sweating. Here, we used cross-correlation analysis to determine whether SSNA exhibits cardiac and respiratory modulation in thermoneutral conditions and to compare respiratory and cardiac modulation of SSNA with that of MSNA. Oligounitary recordings of spontaneous SSNA (n = 20) and MSNA (n = 18) were obtained during quiet, unrestrained breathing. Respiration was recorded by a strain-gauge transducer around the chest and ECG recorded by surface electrodes. Respiratory and cardiac modulation of SSNA and MSNA were quantified by fitting polynomial equations to the cross-correlation histograms constructed between the sympathetic spikes and respiration or ECG. The amplitude of the respiratory modulation (52.5 ± 3.4%) of SSNA was not significantly different from the amplitude of the cardiac modulation (46.6 ± 3.2%). Both were comparable to the respiratory modulation of MSNA (47.7 ± 4.2%), while cardiac modulation of MSNA was significantly higher (89.8 ± 1.5%). We conclude that SSNA and MSNA share similar levels of respiratory modulation, the primary difference between the two sources of sympathetic outflow being the marked cardiac modulation of MSNA provided by the baroreceptors.

Big changes to a small bay: introduced species and long-term compositional shifts to the fouling community of Morro Bay (CA)

Invasive species are cited as being a threat to communities and ecosystems worldwide, yet few studies have demonstrated invader impacts at these scales. Lack of historic data makes capturing large-scale community shifts problematic. We assessed long-term changes in invertebrate composition to the fouling community of a small estuary with relatively little boat traffic and no ballast water input (Morro Bay, CA). We also compared relative invasiveness of Morro Bay to international harbors (San Francisco Bay and Los Angeles/San Diego harbors). While the proportion of introduced species has not significantly changed from historic records, introduced species now occupy 86.00 % of the primary substrate. Other community shifts include; (1) a state shift to an invasive bryozoan (Watersipora subtorquata) dominated community, (2) a decrease in Mollusc richness and, (3) substantial shifts in abundance of certain species. Compared to larger more actively used harbors, Morro Bay has proportionally fewer introduced species (12.00 %) than San Francisco Bay (50.79 %) or Los Angeles/San Diego Harbors (26.23 %). Our study documents changes to a small relatively isolated estuary with little boat traffic and no ballast water input. We discuss the potential role of invasive species and other natural and anthropogenic factors as drivers of these community wide shifts. Specifically, we discuss how reintroduction of the Southern Sea Otter (Enhydra lutris nereis), an increase in sea stars (Pisaster spp.), climate change and interaction amongst potential drivers support the patterns of shifts in the Morro Bay community.

Predicted eelgrass response to sea level rise and its availability to foraging Black Brant in Pacific coast estuaries

Managers need to predict how animals will respond to habitat redistributions caused by climate change. Our objective was to model the effects of sea level rise on total eelgrass (Zostera marina) habitat area and on the amount of that area that is accessible to Brant geese (Branta bernicla), specialist grazers of eelgrass. Digital elevation models were developed for seven estuaries from Alaska, Washington, California (USA), and Mexico. Scenarios of future total eelgrass area were derived from combinations of estuarine specific sediment and tectonic rates (i.e., bottom change rate) with three rates of eustatic sea level rise (ESLR). Percentages of total eelgrass areas that were accessible to foraging Brant were determined for December when the birds overwinter at more southerly sites and in April as they move north to sites where they build body stores on their way to nesting areas in Alaska. The modeling showed that accessible eelgrass area could be lower than total area due to how daytime low-tide height, eelgrass shoot length, and the upper elevation of eelgrass determined Brant-reaching depth. Projections of future eelgrass area indicated that present-day ESLR (2.8 mm/yr) and bottom change rates should sustain the current pattern of estuarine use by Brant except in Morro Bay, where use should decrease because eelgrass is being ejected from this estuary by a positive bottom change rate. Higher ESLR rates (6.3 and 12.7 mm/yr) should result in less Brant use of estuaries at the northern and southern ends of the flyway, particularly during the winter, but more use of mid-latitude estuaries. The capacity of mid-latitude estuaries to function as Brant feeding refugia, or for these estuaries and Izembek Lagoon to provide drift rather than attached leaves, is eventually limited by the decrease in total eelgrass area, which is a result of a light extinction affect on the eelgrass, or the habitat being pushed out of the estuary by positive tectonic rates. Management responses are limited to the increase or decrease of sediment supply and the relocation of levees to allow for upslope migration of eelgrass habitat.

Ichthyosporidium weissii n. sp. (Microsporidia) Infecting the Arrow Goby (Clevelandia ios)

Gonadal infections by a novel microsporidium were discovered in 34% (13/38) of arrow gobies, Clevelandia ios, sampled over a 3-yr period from Morro Bay Marina in Morro Bay, California. Gonadal tumors had been reported in arrow gobies from this geographic area. The infected gonads, found primarily in females, typically appeared grossly as large, white-gray firm and lobulated masses. Histological examination revealed large, multilobate xenomas within the ovaries and no evidence of neoplasia. Typical of the genus Ichthyosporidium, the large xenomas were filled with developmental stages and pleomorphic spores. Wet mount preparations showed two general spore types: microspores with mean length of 6.2 (7.0-4.9, SD=0.6, N=20) μm and mean width of 4.3 (5.3-2.9, SD=0.8) μm; and less numerous macrospores with mean length of 8.5 (10.1-7.1, SD=1.0, N=10) μm and mean width of 5.5 (6.2-4.8, SD=0.5) μm. Transmission electron microscopy demonstrated stages consistent with the genus and 35-50 turns of the polar filament. Small subunit rDNA gene sequence analysis revealed that the parasite from arrow gobies was most closely related to, but distinct from Ichthyosporidium sp. based on sequences available in GenBank. We conclude that this microsporidium represents a new species of Ichthyosporidium, the first species of this genus described from a member of the family Gobiidae and from the Pacific Ocean.

Morro Bay by Threes

Morro Bay by Threes Ralph Menendez (bio) This would be a beautiful place if it weren’t for those ugly towers. What eyesores!” That offhand comment, broadcast from a nearby table at Dorn’s Café in the central California coast town of Morro Bay, set in motion the following photo essay. It got me thinking about and questioning the ways iconic visual landmarks interact to anchor our judgments about natural landscapes and built environments in California, especially along the precious coastline—in this case, the dramatic juxtaposition of Morro Rock, a volcanic plug that is home to the venerable and protected peregrine falcon, and the three concrete towers of a nearby power plant built in the early 1950s, the objects of scorn that morning in Dorn’s. From the windows of the café overlooking the embarcadero, the sightlines are especially dramatic and full of tension. With barely a quarter turn of the head, you can follow a dog-leg causeway from the monolithic Rock, looming 581 feet over the Morro Bay estuary like a giant asteroid stuck in the sand, to the three 45-story cylindrical sentinels that exhaust the power plant’s steam generators. Erect and irrepressible, both are inescapable sights from just about everywhere in town. You can pick them out easily along a 30-mile corridor of rugged coastline from Point Sal to the south, all the way to the abalone farm north of Cayucos. These two incongruous landmarks also form the poles of a political flashpoint familiar to many towns and cities along California’s coastline. For at least 40 years, environmental groups opposed to coastal development, and developers eager to feed Californians’ appetite for coastal living have drafted these powerful visual symbols in support of their causes. Several years ago, [End Page 173] the chamber of commerce produced a brochure that proudly displayed the smokestacks of its major sponsor, Pacific Gas & Electric. As pro-growth sentiment waned, the brochure designers pasted an inset photograph of a seagull over the plant’s smokestacks. “Morro Bay by Threes” probes the hardening of visual categories in the turbid debate over the future of the California coastline as it plays out locally in a conversation between, literally, a rock and a hard place. Each photograph realigns or repositions one pole of a familiar civic landscape—the eyesores under scrutiny at Dorn’s—and in so doing, tries to redirect, even subvert, some of their authority and narrative power as icons of unsightliness and developmental rapacity. The photographs are invitations to view fixed positions from new vantage points. I am not fond of the smokestacks. I won’t rue their eventual demolition. Nor am I trying to take a position or stake an ideological claim. Having lived many years under the gaze of rock and tower, I find the sightlines here are personal, perhaps to the point of eccentric. They reveal angles and vantage points of an eye that has looked long and hard and, hopefully, beyond familiar conventions and ways of seeing. They uncover a certain symmetry, ambiguity, complexity, and dignity from the injury of a landscape’s ailing and contested parts. [End Page 174] Click for larger view View full resolution Three slip pilings in front of Anchor Memorial Park on the Embarcadero. Built in 1953, the Morro Bay power plant stands on a 140-acre former U.S. Navy base. The plant consists of four steam turbine generators, a boiler furnace, a seawater intake unit, a switching station, and three 450-foot-tall stacks. For practical and aesthetic reasons, the turbine-generator building is clad in fluted aluminum siding. At a dedication ceremony on July 8, 1955, one speaker proudly declared the plant “as modern as tomorrow.” © 2012 RALPH MENENDEZ [End Page 175] Click for larger view View full resolution Three umbrellas on the patio of Dorn’s Breakers Café at the foot of Morro Bay Blvd. Most of the electricity generated at the plant, over 600,000 kilowatts in its heyday, was transmitted to the San Joaquin Valley to meet the growing needs of commercial agriculture, industry, and the post–World War II population bloom in Fresno and Bakersfield. A small fraction of the power was...