Regional extinction of a conspicuous dorid nudibranch (Mollusca: Gastropoda) in California

Felimare californiensis (=Hypselodoris californiensis) was once common throughout the Southern California Bight (SCB) and California Channel Islands. This well-known shallow-water nudibranch, which specializes on dysideid sponges, has persisted for decades in Mexico, but in California disappeared from its entire range by 1984. Since reappearing in 2003, it has been found only at Santa Catalina Island, plus sightings of single individuals in 2011 at Santa Cruz Island and San Diego. The decline of F. californiensis in California was documented using published historical records, museum collections, unpublished field accounts, and images posted online. The loss of this emblematic species is unique among Californian nudibranchs, including (1) its congener Felimare porterae (=Mexichromis porterae), with which it appears to overlap in diet, and (2) opisthobranch species with similar historical geographic ranges and mode of development. The decline in F. californiensis is not predicted by warming trends and climate variation over the past 40 years, including the strong El Niño events of 1983 and 1998. Coastal pollution from the large human population in southern California may have impacted Dysidea amblia, the primary reported prey of F. californiensis. Historical overcollecting of the nudibranch and habitat loss through the development of major ports likely also contributed to its decline. Sightings since 2003 are consistent with a nascent recovery, as elements of water quality have improved in the SCB in recent decades.     

Impacts associated with the recent range shift of the aeolid nudibranch <Emphasis Type="Italic">Phidiana hiltoni</Emphasis> (Mollusca,Opisthobranchia) in California

In 1977, Phidiana hiltoni (O’Donoghue in J. Entomol Zool (Pomona College, Claremont, California) 19:77–119, 1927) began spreading northward from Monterey, California. By 1992, it had reached Duxbury Reef (37° 53′ 23″ N, 122° 41′ 59″ W), 100 km to the north, where other nudibranchs subsequently appeared to decline. The role of P. hiltoni in this decline was investigated through diet analysis, feeding trials, and comparison of historical and recent abundance data. In the wild, P. hiltoni preyed largely on hydroids, but also showed evidence of predation on nudibranchs. In the laboratory, P. hiltoni attacked most of the dendronotid and aeolid nudibranchs presented to it, ingesting small individuals whole. The pooled abundance of nudibranchs vulnerable to attack by P. hiltoni declined an average of two-thirds at Duxbury Reef since its arrival, compared to (1) no change in the non-vulnerable species and (2) no change in either group at two other sites where P. hiltoni was one to two orders of magnitude less abundant. Phidiana hiltoni therefore appears to have caused this decline, likely through a combination of direct predation and competition for prey. A brief larval period, combined with cyclonic re-circulation in the lee of Point Reyes, may be driving self-recruitment of P. hiltoni at Duxbury Reef, as well as hindering further northward spread.     

Improvements to standard methodologies for the analytical determination of metals in stationary-source emissions samples

Deficiencies with the current European reference method for the analysis using inductively couple plasma-mass spectrometry of metals in samples from stationary emissions sources are presented based on experimental data obtained from real samples. The effect of these deficiencies on the quality and accuracy of data is highlighted with biases of up to 40% being observed in real samples. Suggestions to improve the performance of the standard method are presented. In particular, the beneficial effect of using a drift correction procedure to account for the decrease in instrument sensitivity observed during an analytical measurement series is demonstrated. It is shown that this corrective procedure results in substantial improvements to the accuracy of data produced.     

What Price Cheap Food?

This paper is the report of a meetingthat gathered many of the UK's most senioranimal scientists with representatives of thefarming industry, consumer groups, animalwelfare groups, and environmentalists. Therewas strong consensus that the current economicstructure of agriculture cannot adequatelyaddress major issues of concern to society:farm incomes, food security and safety, theneeds of developing countries, animal welfare,and the environment. This economic structure isbased primarily on competition betweenproducers and between retailers, driving foodprices down, combined with externalization ofmany costs. These issues must be addressed by acombination of legislation, restructuring ofthe market, and use of public funds. Themeeting included workshops that made otherrecommendations for research and education. Themost urgent requirement is recognition thatchange is needed and development of a visionfor what that change must achieve.     

Theoretical studies of the conformations and 19F NMR spectra of linear and a branched perfluorooctanesulfonamide (PFOSAmide)

Technical perfluorooctanesulfonate (PFOS) and its derivatives, such as perfluorooctanesulfonamide (PFOSA), are not clean compounds but, instead, complex mixtures of linear and branched isomers, and other compounds including sulfonate homologues. Questions have been raised as to whether the linear and the branched isomers behave differently in the environment. However, little is known about the physical properties or the finer details of the structures of the individual branched isomers. This study sought an effective computational method to model the preferred conformations of PFOS derivatives, and the energy differences between them and to determine if these results can be used to explain the temperature dependence of their NMR spectra. Good predictions of the 19F chemical shifts were obtained for some PFOSA-type molecules with a computational approach [B3LYP-GIAO/6-31++G(d,p)//B3LYP/6-31G(d,p)] that is relatively inexpensive. Large 5JFF couplings found in one of the branched isomers could be rationalized on the basis of the relevant F-F distances in the optimized structure. At low temperatures, the splitting observed in the NMR spectrum at C-1 for these sulfonamides can be explained by the existence of the two conformers predicted by the computations.     

Foliar absorption of intercepted rainfall improves woody plant water status most during drought

A large proportion of rainfall in dryland ecosystems is intercepted by plant foliage and is generally assumed to evaporate to the atmosphere or drip onto the soil surface without being absorbed. We demonstrate foliar absorption of intercepted rainfall in a widely distributed, continental dryland, woody-plant genus: Juniperus. We observed substantial improvement in plant water status, exceeding 1.0 MPa water potential for drought-stressed plants, following precipitation on an experimental plot that excluded soil water infiltration. Experiments that wetted shoots with unlabeled and with isotopically labeled water confirmed that water potential responded substantially to foliar wetting, that these responses were not attributable to re-equilibration with other portions of the xylem, and that magnitude of response increased with water stress. Foliar absorption is not included in most ecological, hydrological, and atmospheric models; has implications for interpreting plant isotopic signatures; and not only supplements water acquisition associated with increases in soil moisture that follow large or repeated precipitation events, but also enables plants to bypass soil water uptake and benefit from the majority of precipitation events, which wet foliage but do not increase soil moisture substantially. Foliar absorption of intercepted water could be more important than previously appreciated, especially during drought when water stress is greatest.     

Movements of farmed and wild Atlantic cod (Gadus morhua) released in Trinity Bay,Newfoundland

Fishery scientists and managers are investigating the feasibility of enhancing annual recruitment to the northern Atlantic cod (Gadus morhua L.) stock complex off Labrador and northeastern Newfoundland through the release of farmed fish back into the sea. Release of newly matured fish and adults with farm-advanced fecundity would increase the spawning biomass. Enhancement efforts might be measurably successful in major bays that are year-round habitats for cod. To determine if farmed cod would remain and spawn in Trinity Bay, 14 fish with surgically implanted transmitters were released in November 1992. Sonic tracking confirmed that farmed cod released on the western side of Trinity Bay overwintered within the bay, and integrated with wild cod approaching spawning condition in April 1993. Blood plasma antifreeze levels confirmed that these wild cod had overwintered inshore in subzero waters. A spawning aggregation was found in July 1993, providing evidence that northern cod reproduce in Newfoundland bays. These findings suggest that it may be possible to increase the number of cod spawning inshore through the release of farmed fish.