Oysters, crabs, and burrowing shrimp: Review of an environmental conflict over aquatic resources and pesticide use in Washington State’s (USA) coastal estuaries

Washington State’s coastal estuaries are productive shallow water environments that support commercial fisheries for Dungeness crabs (Cancer magister) and English sole (Parophrys vetulus) by providing 0+(settlement to age l) populations with critical refuge and foraging habitats until subadults migrate to the nearshore coast. Intertidalmudflats also constitute prime areas for commercial oyster (Crassostrea gigas) culture, an, important industry for the coastal communities of Willapa Bay and Grays Harbor that supply much of the nation's oysters. Conflicts over natural resources and estuarine utilization have arisen over the last 37 yr due to the use of carbaryl (an organo carbamate pesticide) by oyster growers on their grounds to control populations of burrowing thalassinidean shrimp (Neotrypaea californiensis and Upogebia pugettensis). Burrowing shrimp, which have an indirect negative effect on oyster survival and growth through bioturbation and sediment destabilization, are killed by carbaryl, as are 0+ and subadult Dungeness crabs, 0+English sole, and other non-target species prsent on the tideflats at the time of application. The pesticide is delivered at 9 kg ha^?1 directly to the mudflat as a wetable powder during low tides in July and August. Commercial crabbers and other groups who have economic, recreational, and environmental interests in the estuaries have generally opposed use of the chemical that oyster growers maintain is essential to sustain production levels. For years, government natural resource agencies that regulate the use of carbaryl lacked critical information needed to effectively manage the program. An Environmental Impact Statement (EIS) and Supplemental EIS have provided much of that data and helped shape management decisions with regard to establishing carbaryl concentration rates and total allowable spray area. Additional research is needed to develop more economically and environmentally sound policies for shrimp control based on burrowing shrimp-oyster interactions on an estuarine-wide scale. In this paper we review issues pertaining to oyster culture, the use of carbaryl to control burrowing shrimp populations, and effects on non-target species, drawing upon research from, published articles as well as unpublished data collected by the authors. We also discuss what is known of burrowing shrimp life history and ecology and emphasize the importance of integrating information on shrimp, such as timing of recruitment, variability in year class strength, and patterns of habitat use, into carbaryl control policies or alternative strategies that may be developed in the future. We recommend controlled experimentation be done to examine the ecological effects of delaying carbaryl application to some ghost shrimp beds until October after peak recruitment of 0+ ghost shrimp has occurred, allowing the number of hectares treated each year to vary based on fluctuations in pest population densities, and modifying the substrate by applying a dense layer of oyster shell to the mudflat (shell pavement) to reduce recruitment of ghost shrimp.     

City vs Country: The demise of the brewing industry in country New South Wales,c .1898-1932

At the end of the 1880s, eight in ten breweries in the colony of New South Wales were located in country (non-metropolitan) areas, and these accounted for about 25 per cent of total colonial beer production. The number of country breweries experienced a dramatic decline after the 1880s, reaching only two by 1932. This process occurred in three more-or-less discrete stages: until about 1900, when internal restructuring reduced the number from about 65 to about 40; a decade or two after 1900 when, facilitated by the Sydney-centred railway network, city competition further reduced the number; and a period, mainly in the 1920s, typified by takeovers of country by city breweries. Additionally, the elimination of border duties after Federation introduced Melbourne competition to brewers in the southern part of the state.     

Unstructured mesh generation and landcover-based resistance for hydrodynamic modeling of urban flooding

Urban flood inundation modeling with a hydrodynamic flow solver is addressed in this paper, focusing on strategies to effectively integrate geospatial data for unstructured mesh generation, building representation and flow resistance parameterization. Data considered include Light Detection and Ranging (LiDAR) terrain height surveys, aerial imagery and vector datasets such as building footprint polygons. First, a unstructured mesh-generation technique we term the building-hole method (BH) is developed whereby building footprint data define interior domain boundaries or mesh holes. A wall boundary condition depicts the impact of buildings on flood hydrodynamics. BH provides an alternative to the more commonly used method of raising terrain heights where buildings coincide with the mesh. We term this the building-block method (BB). Application of BH and BB to a flooding site in Glasgow, Scotland identifies a number of tradeoffs to consider at resolutions ranging from 1 to 5 m. At fine resolution, BH is shown to be similarly accurate but execute faster than BB. And at coarse resolution, BH is shown to preserve the geometry of buildings and maintain better accuracy than BB, but requires a longer run time. Meshes that ignore buildings completely (no-building method or NB) also support surprisingly good flood inundation predictions at coarse resolution compared to BH and BB. NB also supports faster execution times than BH at coarse resolution because the latter uses localized refinements that mandate a greater number of computational cells. However, with mesh refinement, NB converges to a different (and presumably less-accurate) solution compared to BH and BB. Using the same test conditions, Hunter et al. [Hunter NM, Bates PD, Neelz S, Pender G, Villanueva I, Wright NG, Liang D, et al. Benchmarking 2D hydraulic models for urban flood simulations. ICE J Water Manage 2008;161(1):13–30] compared the performance of dynamic-wave and diffusive-wave models and reported that diffusive-wave models under-predicted the longitudinal penetration of the flood zone due to important inertial effects. Here, we find that a relatively coarse-mesh implementation of a dynamic-wave model suffers from the same drawback because of numerical diffusion. This shows that whether diffusion is achieved through the mathematics or numerics, the effect on flood extent is similar. Finally, several methods of distributing resistance parameters (e.g., Manning n) across the Glasgow site were evaluated including methods that utilize aerial imagery-based landcover classification data, MasterMap^® landcover classification data and LiDAR-based feature height data (e.g., height of shrubs or hedges). Results show that landcover data is more important than feature height data in this urban site, that shadows in aerial imagery can cause errors in landcover classification which degrade flood predictions, and that aerial imagery offers a more detailed mapping of trees and bushes than MasterMap^® which can locally impact depth predictions but has little impact on flood extent.     

Long-term perspective on the relationship between phytoplankton and nutrient concentrations in a southeastern Australian estuary

Sixteen years (1997–2013) of physicochemical, nutrient and phytoplankton biomass (Chlorophyll-a (Chl-a)) data and a decade (2003-2013) of phytoplankton composition and abundance data were analyzed to assess how the algal community in a temperate southeastern Australian estuary has responded to decreased chronic point source nitrogen loading following effluent treatment upgrade works in 2003. Nitrogen concentrations were significantly lower (P < 0.05) following enhanced effluent treatment and Chl-a levels decreased (P < 0.05) during the warmer months. Temperature and nutrient concentrations significantly influenced temporal changes of Chl-a (explaining 55% of variability), while salinity, temperature, pH and nutrient concentrations influenced phytoplankton abundance and composition (25% explained). Harmful Algal Bloom (HAB) dynamics differed between sites likely influenced by physical attributes of the estuary. This study demonstrates that enhanced effluent treatment can significantly decrease chronic point source nitrogen loading and that Chl-a concentrations can be lowered during the warmer months when the risk of blooms and HABs is greatest.     

Bioremediation Management Reduces Mass Discharge at a Chlorinated DNAPL Site

Adaptive site management and aggressive bioremediation in the source zone of a complex chlorinated dense nonaqueous phase liquid (DNAPL) site reduced total chlorinated hydrocarbon mass discharge by nearly 80%. Successful anaerobic bioremediation of chlorinated hydrocarbons can be impaired by inadequate concentrations of electron donors, competing electron acceptors, specific inhibitors such as chloroform, and potentially by high contaminant concentrations associated with residual DNAPL. At the study site, the fractured bedrock aquifer was impacted by a mixture of chlorinated solvents and associated daughter products. Concentrations of 1,1,2,2‐tetrachloroethane (1,1,2,2‐TeCA), 1,1,2‐trichloroethane (1,1,2‐TCA), and 1,2‐dichloroethane (1,2‐DCA) were on the order of 100 to 1000 mg/L. Chloroform was present as a co‐contaminant and background sulfate concentrations were approximately 400 mg/L. Following propylene glycol injections, concentrations of organohalide‐respiring bacteria including Dehalococcoides and Dehalogenimonas spp. increased by two to three orders of magnitude across most of the source area. Statistical analysis indicated that reaching volatile fatty acid concentrations greater than 1000 mg/L and depleting sulfate to concentrations less than 50 mg/L were required to achieve a Dehalococcoides concentration greater than the 10⁴ cells/mL recommended for generally effective reductive dechlorination. In a limited area, chloroform concentrations greater than 5 mg/L inhibited growth of Dehalococcoides populations despite the availability of electron donor and otherwise appropriate geochemical conditions. After implementing a groundwater recirculation system targeting the inhibited area, chloroform concentrations decreased permitting significant increases in concentrations of Dehalococcoides and vinyl chloride reductase gene copies.     

Constraints on the source of lunar cataclysm impactors

Multiple impact basins formed on the Moon about 3.8 Gyr ago in what is known as the lunar cataclysm or Late Heavy Bombardment. Many workers currently interpret the lunar cataclysm as an impact spike primarily caused by main-belt asteroids destabilized by delayed planetary migration. We show that morphologically fresh (class 1) craters on the lunar highlands were mostly formed during the brief tail of the cataclysm, as they have absolute crater number density similar to that of the Orientale basin and ejecta blanket. The connection between class 1 craters and the cataclysm is supported by the similarity of their size-frequency distribution to that of stratigraphically-identified Imbrian craters. Majority of lunar craters younger than the Imbrium basin (including class 1 craters) thus record the size-frequency distribution of the lunar cataclysm impactors. This distribution is much steeper than that of main-belt asteroids. We argue that the projectiles bombarding the Moon at the time of the cataclysm could not have been main-belt asteroids ejected by purely gravitational means.     

Is the Collapse of Mud Shrimp (<Emphasis Type="Italic">Upogebia pugettensis</Emphasis>) Populations Along the Pacific Coast of North America Caused by Outbreaks of a Previously Unknown Bopyrid Isopod Parasite (<Emphasis Type="Italic">Orthione griffenis</Emphasis>)?

A dramatic increase in prevalence of the recently discovered bopyrid isopod parasite, Orthione griffenis, likely introduced in the 1980s from Asia to the Pacific coast of North America, coincided with the 2002 collapse of a population of its burrowing mud shrimp host, Upogebia pugettensis, in Willapa Bay, Washington that had been stable since monitoring began in 1988. An examination of whether O. griffenis infections were sufficient to cause this decline and other recently noted U. pugettensis population collapses in Pacific Coast estuaries was conducted. O. griffenis prevalence was the highest in large reproductive-sized female shrimp and caused an estimated average 68% loss of U. pugettensis reproduction in Yaquina Bay, Oregon over a 5-year period. O. griffenis prevalence fluctuated from year to year, but trends were similar in all estuaries sampled. Uninfected shrimp transplanted back into locations from which they had disappeared acquired the parasite, suggesting that O. griffenis is extremely effective at finding its host even in estuaries with very low host density. Since both U. pugettensis and O. griffenis have pelagic larval stages, their population dynamics are also influenced by coastal nearshore oceanography and estuarine recruitment success. Coastwide lack of estuarine recruitment appears to coincide with declines in density of a co-occurring thalassinid shrimp, Neotrypaea californiensis, but cannot alone explain U. pugettensis population collapses. Although patterns observed to date could be explained by the presence of either a native or introduced parasitic castrator, assumptions of a resilient co-evolved host–parasite relationship do not apply for introduced species, so continued efforts to follow the spatial extent and consequences of the O. griffenis–U. pugettensis host–parasite relationship are warranted.     

Regional slaty cleavage formation and fold axis rotation by re-use and reactivation of pre-existing foliations: the Fiery Creek Slate Belt, North Queensland

A deformation history, comprised of six separate deformation events of differing intensity, has affected the rocks of the South Palmer River region of the the Hodgkinson Province, north Queensland. Within this region, a zone of pervasive slaty cleavage, herein termed the Fiery Creek Slate Belt, has developed as a result of the superposition of fabrics formed during several of these events. The most important processes in the formation of this composite cleavage were the re-use and reactivation of the favourably oriented, steep, N-S-trending S₂ foliation by the intense fourth deformation event, D₄. This produced micro-, meso- and macroscopic folds in an originally shallow S₃ foliation, produced during the intervening D₃ deformation, with an axial planar S₂–S₄ foliation. The D₄ stretching lineation, L⁴₄, plunges subvertically to steeply north and indicates that shear during D₄ was oriented steeply north-south. In the Fiery Creek Slate Belt, D₂ fold axes are interpreted to have formed in much shallower orientations than their present moderately N-S-plunging to subvertical orientations. We consider this to be a result of D₄ shear, which caused variable degrees of rotation of D₂ fold axes toward the D₄ stretching lineation due to subparallelism of the bulk shortening directions of the D₂ and D₄ events. Near-total destruction of the pre-D₄ foliations during slaty cleavage formation has produced a misleading impression of a simple deformation history. There is no relationship between metamorphic grade and intensity of slaty cleavage development.     

Non-standard structure formation scenarios

Observations on galactic scales seem to be in contradiction with recent high resolution N-body simulations. This so-called cold dark matter (CDM) crisis has been addressed in several ways, ranging from a change in fundamental physics by introducing self-interacting cold dark matter particles to a tuning of complex astrophysical processes such as global and/or local feedback. All these efforts attempt to soften density profiles and reduce the abundance of satellites in simulated galaxy halos. In this contribution we are exploring the differences between a Warm Dark Matter model and a CDM model where the power on a certain scale is reduced by introducing a narrow negative feature (`dip'). This dip is placed in a way so as to mimic the loss of power in the WDM model: both models have the same integrated power out to the scale where the power of the Dip model rises to the level of the unperturbed CDM spectrum again. Using N-body simulations we show that that the new Dip model appears to be a viable alternative to WDM while being based on different physics: where WDM requires the introduction of a new particle species the Dip stems from anon-standard inflationary period. If we are looking for an alternative to the currently challenged standard ΛCDM structure formation scenario, neither the ΛWDM nor the new Dip model can be ruled out with respect to the analysis presented in this contribution. They both make very similar predictions and the degeneracy between them can only be broken with observations yet to come. This revised version was published online in August 2006 with corrections to the Cover Date.     

Photometric survey of the irregular satellites

We present BVRI colors of 13 jovian and 8 saturnian irregular satellites obtained with the 2.56 m Nordic Optical Telescope on La Palma, the 6.5 m Magellan Baade Telescope on La Campanas, and the 6.5 m MMT on Mt. Hopkins. The observations were performed from December 2001 to March 2002. The colors of the irregular satellites vary from grey to light red. We have arbitrarily divided the known irregular satellites into two classes based on their colors. One, the grey color class, has similar colors to the C-type asteroids, and the other, the light red color class, has colors similar to P/D-type asteroids. We also find at least one object, the jovian irregular J XXIII Kalyke, that has colors similar to the red colored Centaurs/TNOs, although its classification is insecure. We find that there is a correlation between the physical properties and dynamical properties of the irregular satellites. Most of the dynamical clusters have homogeneous colors, which points to single homogeneous progenitors being cratered or fragmented as the source of each individual cluster. The heterogeneously colored clusters are most easily explained by assuming that there are several dynamical clusters in the area, rather than just one, or that the parent body was a differentiated, heterogeneous body. By analyzing simple cratering/fragmentation scenarios, we show that the heterogeneous colored S IX Phoebe cluster, is most likely two different clusters, a grey colored cluster centered on S IX Phoebe and a light red colored cluster centered on S/2000 S 1. To which of these two clusters the remaining saturnian irregulars with inclinations close to 174° belong is not clear from our analysis, but determination of their colors should help constrain this. We also show through analysis of possible fragmentation and dispersion of the six known uranian irregulars that they most likely make up two clusters, one centered on U XVI Caliban and another centered on U XVII Sycorax. We further show that, although the two objects have similar colors, a catastrophic fragmentation event creating one cluster containing both U XVI Caliban and U XVII Sycorax would have involved a progenitor with a diameter of ∼395 km. While such an event is not impossible it seems rather improbable, and we further show that such an event would leave 5-6 fragments with sizes comparable to or larger than U XVI Caliban. The stable region around Uranus has been extensively searched to limiting magnitudes far beyond that of U XVI Caliban. The fact that only U XVI Caliban, the larger U XVII Sycorax and four much smaller objects have been found leaves us with a distribution not compatible with a catastrophic event with such a large progenitor. The most likely solution is therefore two separate events creating two uranian dynamical clusters.