Evaluating Population Viability and Conservation Options for The Endangered Puaiohi

Ph.D. University of Hawaii at Manoa 2016.Includes bibliographical references.Evolution in the Hawaiian Islands has produced a unique assemblage of forest birds. Unfortunately, many of these species are highly endangered or extinct. Despite numerous threats and great effort aimed at saving endemic birds, we lack basic science necessary for understanding many species of concern, including the endangered puaiohi (Myadestes palmeri). Currently, the puaiohi’s breeding population is estimated at 500 birds restricted to the Alaka‘i Wilderness Preserve on Kaua‘i. Given its small population and restricted range, understanding the conditions that affect the species’ population dynamics is essential. Hence, the goals of this dissertation were to: investigate links between precipitation and temperature in the puaiohi’s range and reproductive success; represent puaiohi population dynamics under current and potential management scenarios to determine management’s potential efficacy in aiding species recovery; and, investigate which management activities might supply the most cost-effective species management. Management scenarios included rat management, habitat improvement (habitat restoration or supplemental feeding), provision of nest boxes, and translocation of an additional population to another island. Total rainfall in the previous wet season and mean rainfall during the breeding season positively correlated with most nest success variables. Female and juvenile survival most influenced puaiohi population viability, indicating that management should focus on increasing female and juvenile survival. Rat control, even at conservative levels, was the most effective method of increasing puaiohi abundance. While translocation offers hope of increasing puaiohi population and decreasing extinction risk, success depends on the conditions established at the release site. In addition, re-establishment of the puaiohi captive breeding program may be necessary to provide enough birds to translocate. Management costs over the 25 years modeled ranged from $378,701 to$245,213,905, with translocation being one of the most cost-effective means of managing puaiohi and supplemental feeding the least. Cost-efficiency of rat control varied based on scale and method, and restoration of habitat was moderately cost-effective. Findings indicate that practical, attainable management activities can increase puaiohi and bring it back from the brink of extinction. These findings provide a model for other endangered species conservation efforts

The Processing Pathway of Prelamin A

The conversion of mammalian prelamin A to mature lamin A proceeds through the removal of 18 amino acids from the carboxyl terminus. The initial step in this processing is the isoprenylation of a CAAX box cysteine. This proteolytic event is distinctive for prelamin A among the known prenylated mammalian proteins. Since the carboxyl terminus of prelamin A is removed during maturation, it is not obvious that this protein would undergo the two reactions subsequent to prenylation observed in other CAAX box proteins-the endoproteolytic removal of the carboxyl-terminal 3 amino acids and the subsequent methylation of the now carboxyl-terminal cysteine. To characterize the maturation of prelamin A further, we have developed a CHO-K1 cell line that possesses a dexamethasone-inducible human prelamin A against a genetic background of high mevalonate uptake. Utilizing this cell line in association with antibodies specific to the transgenic prelamin A, we have been able to demonstrate directly in vivo that prelamin A undergoes farnesylation and carboxymethylation prior to conversion to lamin A, as is the case for other prenylated proteins. We have demonstrated previously that in the absence of isoprenylation, conversion of prelamin A to lamin A is blocked, but that unprocessed prelamin A is transported to the nucleus where it can still undergo maturation. Consistent with the implications of these prior studies, we now demonstrate the presence of both subunits of farnesyl-protein transferase in the nucleus

The iron isotopic composition of subglacial streams draining the Greenland ice sheet

In this study, we present the first measurements of iron (Fe) stable isotopic composition (δ56Fe) of subglacial streams draining the Greenland Ice Sheet (GIS). We measure the δ56Fe values [(δ56Fe, ‰ = (56Fe/54Fe)sample/(56Fe/54Fe)standard − 1) × 103] of both dissolved and suspended sediment Fe in subglacial outflows from five distinct land-terminating glaciers. Suspended sediments have δ56Fe values that lie within the crustal array (δ56Fe ∼ 0‰). In contrast, the δ56Fe values of dissolved Fe in subglacial outflows are consistently less than 0‰, reaching a minimum of −2.1‰ in the outflow from the Russell Glacier. The δ56Fe values of dissolved Fe vary geographically and on daily time scales. Major element chemistry and mineral saturation state modeling suggest that incongruent silicate weathering and sulfide oxidation are the likely drivers of subglacial stream Fe chemistry, and that the extent of chemical weathering influences the δ56Fe of dissolved Fe. The largest difference in δ56Fe between dissolved and suspended load is −2.1‰, and occurs in the subglacial system from the Russell glacier (southwest GIS). Major element chemistry indicates this outflow to be the least chemically weathered, while more mature subglacial systems (i.e., that exhibit greater extents of subglacial weathering) have dissolved loads with δ56Fe that are indistinguishable from suspended sediments (Δ56Fesuspended-dissolved ∼ 0‰). Ultimately, the dissolved Fe generated in some subglacial systems from the GIS is a previously unrecognized source of isotopically light Fe into the hydrosphere. The data illustrate that the dissolved Fe supplied by subglacial weathering can have variable δ56Fe values depending on the degree of chemical weathering. Thus, Fe isotopes have potential as a proxy for subglacial chemical weathering intensity or mode. Finally, based on our regional Fe concentration measurements from each glacial outflow, we estimate a flux weighted continental scale dissolved iron export of 2.1 Gg Fe yr−1 to the coastal ocean, which is within the range of previous estimates

Exploring the importance of authigenic clay formation in the global Li cycle

Lithium isotopic (δ7Li) and elemental concentrations of pore fluids and carbonates from IODP Site U1338 Hole A (eastern equatorial Pacific Ocean) suggest that clay authigenesis (i.e., in situ precipitation) is a significant sink for Li in carbonate-rich sedimentary sections. Systematic variations in pore fluid δ7Li with depth in the section suggest that clay authigenesis can (i) strongly decrease pore fluid Li concentrations with depth and (ii) fractionate Li isotopically to a considerable degree (Δ ∼ 5–21‰ relative to seawater). We hypothesize that clay authigenesis in carbonate-rich sections occurs due to the presence of reactive biogenic silica, and reactive transport modeling supports the contention that the pore fluid δ7Li depth profile at Site U1338 is best explained by faster authigenesis at depth. The significance of clay authigenesis in carbonate-rich sediments is two-fold: if global in scale, (i) it can generate sizeable output fluxes in the global Li cycle, and (ii) the evolution of the sedimentary system over time can markedly impact the isotopic composition of the global Li output flux. We compile ODP and IODP pore fluid Li data from 267 sites; of these, 207 have Li pore fluid concentration gradients in the upper 50–100 meters that indicate the sites as diffusive sinks of Li. We then estimate that clay authigenesis in carbonate-rich sediments could reasonably generate a Li output flux on the order of ∼1.2·1010 moles/year, which is comparable to the gross input fluxes in the modern Li cycle. A series of reactive transport simulations illustrate how clay authigenesis might impact the isotopic composition of the output flux of Li from the global ocean. The suggestion is that applying a constant fractionation factor from the global ocean over time is likely incorrect, and that secular changes in the δ7Li of the output flux will be driven by rates of authigenesis, burial rates, and the depth extent of authigenesis in the sedimentary section. Utilizing a time-dependent, depositional diagenetic model, the δ7Li values of bulk carbonate are shown to be a consequence not of recrystallization alone, but recrystallization in the presence of clay authigenesis. Further, our model results are used to illustrate how carbonate δ7Li may be used to constrain the temporal evolution of clay authigenesis in the sedimentary section. Ultimately, this work suggests that the Li isotopic composition of bulk carbonates can be altered diagenetically. However, such alteration is not a detriment, but provides useful information on those diagenetic processes in the sedimentary column that impact the global Li cycle. Thus, Li isotopes in bulk carbonates have the potential to elucidate diagenetic controls on the global Li cycle over long time scales

Economic costs of protecting islands from invasive alien species

Funding Information: This work was conducted following a workshop funded by the AXA Research Fund Chair of Invasion Biology and is part of the AlienScenario project funded by BiodivERsA‐Belmont Forum Project “Alien Scenarios” (BL: FWF project no. I 4011‐B32). The authors also acknowledge the French National Research Agency (ANR‐14‐CE02‐0021) and the BNP‐Paribas Foundation Climate Initiative for funding the InvaCost project and enabling the construction of the database, with particular thanks to C. Diagne. T.W.B. acknowledges funding from the European Union's Horizon 2020 research and innovation program Marie Skłodowska‐Curie fellowship (grant 747120). J.F.L. thanks the Auburn University School of Forestry and Wildlife Sciences for travel support to attend the InvaCost workshop. Funding for E.A. came from the AXA Research Fund Chair of Invasion Biology of the University of Paris Saclay. We also thank J. Albers and 2 anonymous reviewers and for their comments that strengthened this manuscript. Publisher Copyright: © 2022 The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.Peer reviewedPublisher PD

Economic costs of invasive rodents worldwide : the tip of the iceberg

ACKNOWLEDGEMENTS We are extremely grateful to the organizers of the InvaCost workshop that allowed the genesis of this project, as well as to all contacted people who kindly answered to our requests for information about the costs of invasive rodents. We thank L. Nuninger and C. Assailly for their work in the initial project, and María Angulo and Nuria Cerdá for their help in generating the Fig. 3. Last, the authors thank Dr. Steffen Oppel and another anonymous reviewer for their thorough revision of the article which greatly improved it. Funding Information: This work was supported by the French National Research Agency (ANR-14-CE02-0021) and the BNP-Paribas Foundation Climate Initiative for funding the Invacost project which allowed the construction of the InvaCost database. This work was initiated following a workshop funded by the AXA Research Fund Chair of Invasion Biology. This research was also funded through the 2017-2018 Belmont Forum and BiodivERsA joint call for research proposals, under the BiodivScen ERA-Net COFUND programme. Funds for Elena Angulo and Liliana Ballesteros-Mejia came from the AXA Research Fund Chair of Invasion Biology of University Paris Saclay. Christophe Diagne was funded by the BiodivERsA-Belmont Forum Project ‘‘Alien Scenarios’’ (BMBF/PT DLR 01LC1807C). Ross N. Cuthbert received funding from the Leverhulme Trust (ECF-2021-001). Thomas W. Bodey received funding from the European Union’s Horizon 2020 research and innovation programme Marie Skłodowska-Curie fellowship (Grant No. 747120). Jean Fantle-Lepczyk received travel support to attend the Invacost workshop from Auburn University School of Forestry and Wildlife Sciences. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Strontium isotope fractionation of planktic foraminifera and inorganic calcite

We have investigated the strontium isotope fractionation (Δ88/86Srcarb–aq) between inorganic calcite and aqueous Sr2+ ions by precipitation experiments at a constant temperature of 25 °C and precipitation rates (R) ranging from 102.3 to 104.2 μmol/m2/h. Strontium isotope ratios were measured using the 87Sr–84Sr double spike technique. It was found that strontium isotope fractionation in these calcites is strongly dependent on the precipitation rate: View the MathML source The measured δ88/86Sr values are significantly correlated with previously measured δ44/40Ca and Sr/Ca values of the same calcite samples: Δ88/86Srcarb–aq=+0.18∗Δ44/40Cacarb–aq-0.01 View the MathML source The slope of 88Sr/86Sr versus 44Ca/40Ca fractionation is 0.18 ± 0.04 and compatible with a kinetic fractionation during dehydration of the strontium and calcium ions, but not with isotope fractionation in a diffusive boundary layer. Using published equilibrium Δ44/40Cacarb–aq and View the MathML source values we estimate the equilibrium isotope fractionation of strontium to be very close to zero (Δ88/86Sreq(carb–aq) = −0.01 ± 0.06‰). This estimate is confirmed by strontium isotope values of natural inorganic calcites that precipitated very slowly in basalts of the ocean crust. The results from the inorganic calcites are used to explain strontium isotope fractionation of planktic foraminifera. Specimens of two warm water species (Globigerinoides ruber and Globigerinoides sacculifer) were picked from the Holocene section of a Caribbean sediment core. We found no significant difference in δ88/86Sr between the two species. In addition, G. ruber specimens from Marine Isotope Stage 2 in the same core show δ88/86Sr values identical to the Holocene specimens. The strontium isotopes of both foraminifera species are strongly fractionated (Δ88/86Srcarb–aq = −0.248 ± 0.005‰) when compared to published data of other major marine calcifiers. Applying the results from the inorganic precipitation experiments we find that the strong foraminiferal strontium isotope fractionation can be explained by calcification in a largely open system at high precipitation rates, comparable in magnitude to rates known from scleractinian reef corals. This interpretation is in good agreement with the kinetic calcification model for planktic foraminifera by Kisakürek et al. (2011), which was based on calcium isotopes and elemental Sr/Ca ratios

Isotopic and molecular distributions of biochemicals from fresh and buried Rhizophora mangle leaves†

Rhizophora mangle L. (red mangrove) is the dominant species of mangrove in the Americas. At Twin Cays, Belize (BZ) red mangroves are present in a variety of stand structures (tall >5 m in height, transition ~2–4 m and dwarf ~1–1.5 m). These height differences are coupled with very different stable carbon and nitrogen isotopic values[1] (mean tall δ(13)C = -28.3‰, δ(15)N = 0‰; mean tall δ(13)C = -25.3‰, δ(15)N = -10‰). To determine the utility of using these distinct isotopic compositions as 'biomarkers' for paleoenvironmental reconstruction of mangrove ecosystems and nutrient availability, we investigated the distribution and isotopic (δ(13)C and δ(15)N) composition of different biochemical fractions (water soluble compounds, free lipids, acid hydrolysable compounds, individual amino acids, and the residual un-extractable compounds) in fresh and preserved red mangrove leaves from dwarf and tall trees. The distribution of biochemicals are similar in dwarf and tall red mangrove leaves, suggesting that, regardless of stand structure, red mangroves use nutrients for biosynthesis and metabolism in a similar manner. However, the δ(13)C and δ(15)N of the bulk leaf, the biochemical fractions, and seven amino acids can be used to distinguish dwarf and tall trees at Twin Cays, BZ. The data support the theory that the fractionation of carbon and nitrogen occurs prior to or during uptake in dwarf and tall red mangrove trees. Stable carbon and nitrogen isotopes could, therefore, be powerful tools for predicting levels of nutrient limitation at Twin Cays. The δ(13)C and δ(15)N of biochemical fractions within preserved leaves, reflect sedimentary cycling and nitrogen immobilization. The δ(15)N of the immobilized fraction reveals the overlying stand structure at the time of leaf deposition. The isotopic composition of preserved mangrove leaves could yield significant information about changes in ecosystem dynamics, nutrient limitation and past stand structure in mangrove paleoecosystems