Impact of the California sea lion (Zalophus californianus) on salmon fisheries in Monterey Bay, California

To assess the impact of California sea lions (Zalophus californianus) on salmon fisheries in the Monterey Bay region of California, the percentages of hooked fish taken by sea lions in commercial and recreational salmon fisheries were estimated from 1997 to 1999. Onboard surveys of sea lion interactions with the commercial and recreational f isheries and dockside interviews with fishermen after their return to port were conducted in the ports of Santa Cruz, Moss Landing, and Monterey. Approximately 1745 hours of onboard and dockside surveys were conducted—924 hours in the commercial fishery and 821 hours in the recreational fishery (commercial passenger fishing vessels [CPFVs] and personal skiffs combined). Adult male California sea lions were responsible for 98.4% of the observed depredations of hooked salmon in the commercial and recreational fisheries in Monterey Bay. Mean annual percentages of hooked salmon taken by sea lions ranged from 8.5% to 28.6% in the commercial fishery, 2.2% to 18.36% in the CPFVs, and 4.0% to 17.5% in the personal skiff fishery. Depredation levels in the commercial and recreational salmon fisheries were greatest in 1998—likely a result of the large El Niño Southern Oscillation (ENSO) event that occurred from 1997 to 1998 that reduced natural prey resources. Commercial fishermen lost an estimated $18,031−$60,570 of gear and $225,833−$498,076 worth of salmon as a result of interactions with sea lions. Approximately 1.4−6.2% of the available salmon population was removed from the system as a result of sea lion interactions with the fishery. Assessing the impact of a growing sea lion population on fisheries stocks is difficult, but may be necessary for effective fisheries management

The Gomi legacy

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Food habits of California Sea Lions (Zalophus californianus) and their impact on Salmonid Fisheries in Monterey Bay, California

In the ocean commercial troll and recreational salmon fishery in Monterey Bay California, California sea lions (Zalophus califomianus) will swim near or follow fishing boats and will depredate fish once hooked. The objectives of the study were to determine the percentage of salmon taken by pinnipeds in commercial and recreational fisheries, identify relative importance of prey items seasonally consumed by sea lions, and determine the proportion of salmonids in the sea lion diet on a seasonal basis. From April 1997 through September 1998, 1041 hours of onboard and dockside surveys of the commercial and recreational salmon fisheries were conducted at the three ports in Monterey Bay, California. Sea lions depreadated 7.9 % of the fish hooked in the commercial fishery in 1997 and 28.6 % in 1998,8.4 % (1997) and 18.3 % (1998) of the CPFV fishery, and 15.6 % (1997) and 17.5 % (1998) of the private skiff fishery. Increased depredation rates in both the commercial and recreational salmon fisheries in 1998 were most likely the result of the large EI Nino Southern Oscillation event that occurred in 1997-1998 during which a greater number of sea lions were present in central California. Prey hardparts identified in sea lion fecal samples collected in Monterey Bay indicated that schooling fishes were the predominant prey fish species, such as market squid (Loligo opalescens), Pacific sardine (Sardinops caeruleus), northern anchovy (Engraulis mordax), and rockfish (Sebastes sp.). Sea lions consumed similar prey species in the summer and fall 1997, winter 1997-98, and spring 1998 (PSI> 70.0) with market squid and northern anchovy being the dominant prey species. However, prey composition changed significantly during the summer 1998 and fall 1998 (PSI < 46.0) because of the increased importance of sardine and rockfish in the diet and the decreased importance of market squid. This report does not intend to imply that salmonids are not a prey species for pinnipeds in the Monterey Bay region, but highlights the difficulties encountered in establishing the role of salmonids in the pinniped diet when analyzing fecal samples. (PDF contains 38 pages)

Genomic variation in a widespread Neotropical bird (Xenops minutus) reveals divergence, population expansion, and gene flow

Elucidating the demographic and phylogeographic histories of species provides insight into the processes responsible for generating biological diversity, and genomic datasets are now permitting the estimation of histories and demographic parameters with unprecedented accuracy. We used a genomic single nucleotide polymorphism (SNP) dataset generated using a RAD-Seq method to investigate the historical demography and phylogeography of a widespread lowland Neotropical bird (Xenops minutus). As expected, we found that prominent landscape features that act as dispersal barriers, such as Amazonian rivers and the Andes Mountains, are associated with the deepest phylogeographic breaks, and also that isolation by distance is limited in areas between these barriers. In addition, we inferred positive population growth for most populations and detected evidence of historical gene flow between populations that are now physically isolated. Even with genomic estimates of historical demographic parameters, we found the prominent diversification hypotheses to be untestable. We conclude that investigations into the multifarious processes shaping species histories, aided by genomic datasets, will provide greater resolution of diversification in the Neotropics, but that future efforts should focus on understanding the processes shaping the histories of lineages rather than trying to reconcile these histories with landscape and climatic events in Earth history.Comment: 61 pages, 4 figures (+3 supplemental), 3 tables (+6 supplemental

Facing the Future: Financing Productive Schools

Synthesizes the School Finance Redesign Project's findings on policy options for redesigning the system to focus resources on promoting student learning. Calls for student count-based funding, integrated data collection, innovation, and accountability

Baryon Asymmetry, Supersymmetry and Gravitational Anomalies

We discuss two independent issues about the baryon asymmetry of the universe. First, assuming that it is generated by an unspecified source at high temperatures, we study the effects of non-perturbative $SU(2)_W$ dynamics above the electroweak scale, in the context of supersymmetric models. We find that there is a substantial difference with the nonsupersymmetric case with the net effect of relaxing previous bounds on B and L violating interactions. In particular supersymmetry allows neutrino masses as large as 10 eV (preferred by solar neutrino and COBE data and measurable at future neutrino oscillation experiments). Second, we argue that the existence of a mixed lepton number-gravitational anomaly in the standard model will induce B-L violating interactions. These transitions would be catalized by Einstein-Yang-Mills instantons or sphalerons and could create a primordial B-L asymmetry at Planck temperatures or lower. Gravity (and the anomaly structure of the standard model) could then be the ultimate source of the baryon asymmetry. We analyze the viability of the presently known gravitational instantons and sphalerons to realize this scenario. (Talk presented by FQ at the Texas/Pascos Conference, Berkeley Dec.1992.)Comment: 8 pages,FTUAM-93-07 NEIP93-001, harvma

High Percentages of Reclaimed Asphalt Affect the Performance of Asphalt Binder

More than 90 percent of the road and highway network in the United States is paved with asphalt concrete. Maintenance and periodic rehabilitation require a continuous supply of aggregates and asphalt binder, both of which are becoming increasingly scarce and expensive. Recycling and reusing these resources can reduce costs and improve sustainability. The most common recyclable material used in road construction is reclaimed asphalt pavement (RAP), which is milled asphalt surface layers that have been removed from existing pavements before new asphalt overlay is placed. Reclaimed asphalt roofing shingles (RAS) are another potential source of asphalt binder.There is growing interest in allowing significantly higher percentages of RAP and RAS in asphalt mixes used on state and local roadways. However, making this change has raised concerns regarding how these composite binders may influence the performance and durability of asphalt mixes, depending on the blends of different virgin and reused binders. Researchers at the UC Pavement Research Center investigated the use of higher percentages of RAP and RAS as a partial replacement for the virgin binder in new asphalt mixes and their effect on pavement performance in California. This research brief summarizes findings from that study.View the NCST Project Webpag

Altruistic Behavior and Habit Formation

This paper examines whether altruistic behavior is habit forming. We take advantage of a data set that includes a rich set of information concerning individuals’ donations of cash and time as adults as well as information about whether they were involved with charitable activities when they were young. The basic premise is that if altruistic behavior when young is a good predictor of such behavior in adulthood, then this is consistent with the notion that altruistic behavior is habit forming. Using U.S. data, we examine both donations of money and time, and find that engaging in charitable behavior when young is a strong predictor of adult altruistic behavior, ceteris paribus. A major issue in the interpretation of this result is that the correlation between youthful and adult altruistic behavior may be due to some third variable that affects both. While it is impossible to rule out such a possibility, we are able to control for family influences that likely could affect lifetime attitudes toward altruism. We find that, even taking this factor into account, altruistic behavior as a youth plays a significant role in explaining adult behavior. This result applies to donations of money and time to a variety of types of non-profit organizations.altruistic behavior, donations, nonprofit fundraising

Advanced composites wing study program. Volume 1: Executive summary

The effort necessary to achieve a state of production readiness for the design and manufacturing of advanced composite wing structure is outlined. Technical assessment and program options are also reviewed for the wing study results