Looking beyond the horizon: An early warning system to keep marine mammal information relevant for conservation

1. Important marine mammal areas (IMMAs) are discrete portions of habitat, important to marine mammal species, that have the potential to be delineated and managed for conservation. Although IMMAs are not a blueprint for marine protected areas or other conservation designations, they are useful for providing a foundation for marine spatial planning and systematic conservation planning that can then lead to protected areas or special spatial regulations. To be most useful for supporting management and conservation, however, the information coming out of IMMAs needs to reflect current conditions.
2. An ‘early warning system’ is proposed with a generic set of indicators to flag when marine mammal species in IMMAs require management interventions due to changing distributions or decreasing populations. Rather than signifying that quantitative thresholds have been reached, these indicators comprise alerting information derived from visual or acoustic census, satellite imagery analysis, whale‐watching logs, or increases in mortality reported by stranding networks that can trigger additional targeted research.
3. Although it is possible that in some regions data will be sufficient to provide quantifiable indicators, the system is meant to rely on existing data sources, and be adaptable to the circumstances of each region.
4. Regional expert groups can utilize early warning system information and feed it into IMMA‐related spatial planning in two ways: by nominating additional areas of interest, and by providing a scientific rationale for revising IMMA boundaries, to be considered at the next decadal IMMA regional expert workshop.
5. IMMA‐driven consolidation of information that is as current as possible will prove valuable for enhancing regional cooperation to conserve marine mammals, and will be useful as countries implement new protected areas to conserve marine mammals and other marine biodiversity.

     

The importance of environment and life stage on interpretation of silky shark relative abundance indices for the equatorial Pacific Ocean

Recent large fluctuations in an index of relative abundance for the silky shark in the eastern Pacific Ocean have called into question its reliability as a population indicator for management. To investigate whether these fluctuations were driven by environmental forcing rather than true changes in abundance, a Pacific‐wide approach was taken. Data collected by observers aboard purse‐seine vessels fishing in the equatorial Pacific were used to compute standardized trends in relative abundance by region, and where possible, by shark size category as a proxy for life stage. These indices were compared to the Pacific Decadal Oscillation (PDO), an index of Pacific Ocean climate variability. Correlation between silky indices and the PDO was found to differ by region and size category. The highest correlations by shark size category were for small (<90 cm total length [TL]) and medium (90–150 cm TL) sharks from the western region of the equatorial eastern Pacific (EP) and from the equatorial western Pacific. This correlation disappeared in the inshore EP. Throughout, correlations with the PDO were generally lower for large silky sharks (>150 cm TL). These results are suggestive of changes in the small and medium silky indices being driven by movement of juvenile silky sharks across the Pacific as the eastern edge of the Indo‐Pacific Warm Pool shifts location with ENSO events. Lower correlation of the PDO with large shark indices may indicate that those indices were less influenced by environmental forcing and therefore potentially less biased with respect to monitoring population trends.     

Juniper Consumption Does Not Adversely Affect Meat Quality in Boer-Cross Goats

Goat browsing can be used as an alternative brush management option for redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus asheii Buch) juniper instead of more expensive and invasive brush control methods, assuming consumption of juniper does not adversely affect the marketability of offspring. Some wildlife species reportedly retain juniper flavor when consumed. We determined if juniper consumption affected meat quality or flavoring of Boer-cross kid carcasses. Twenty recently weaned, Boer-cross wethers were randomly assigned to one of four treatments with treatments fed different amounts of juniper (0%, 10%, 20%, 30% juniper in the diet). All goats were fed juniper for 28 d at the Angelo State University (ASU) Management, Instruction, and Research Center. All goats were also fed a feedlot ration to meet maintenance requirements (2% body weight). Juniper intake varied (P < 0.05) between all treatments (0%, 10%, 20%, 30%) primarily because treatments were fed different amounts of juniper. Following a 28-d trial, goats were harvested at the ASU Food Safety and Product Development Laboratory. Carcass characteristics including live weight, hot carcass weight, dressing percentage, loineye area, body wall fat thickness, and leg circumference were similar (P > 0.05) among treatments. Sensory characteristics including tenderness, juiciness, flavor intensity, off-flavor, and overall acceptability were also similar (P > 0.05) among treatments. Landowners can utilize goats as a biological management tool without adversely affecting goat meat quality or flavoring.     

Energy and Carbon Costs of Selected Cow-Calf Systems

Fossil fuel-derived inputs can increase cow-calf production per unit of land or labor but can raise financial and environmental concerns. Eleven US cow-calf systems from nine ecological regions in Iowa, South Dakota, Tennessee, and Texas were analyzed to determine quantities of energy used and carbon (C) emitted due to fossil fuel use (excluding emissions from soils and biota) and to determine how management and environment influenced those quantities. Total energy and C cost, calculated cow^?1 or ha^?1, were highly correlated (0.99). Energy use cow^?1 and ha^?1 varied greatly across systems, ranging from 3 000 to 12 600 megajoules (MJ) · cow^?1 · yr^?1 and from 260 to 20 800 MJ · ha^?1 · yr^?1. As stocking rate increased, MJ · cow^?1 increased at an increasing rate. Differences in quantity of fertilizer accounted for most variation in energy use. Fertilizer allowed higher stocking rates but reduced energy efficiency of liveweight marketed. Compared to intensive, higher stocking rate systems, rangeland systems based on native or naturalized forages used little or no fertilizer, but used more energy cow^?1 for crude protein (CP) supplementation, fencing, and pickup trucks. Across all systems, energy used to produce winter feed ranged from 0% to 46% of total energy. Northern systems used higher percentages of total energy for winter feed and fed for more days year^?1, but southern systems that included large amounts of bermudagrass (Cynodon dactylon L.) hay used the most MJ · cow^?1 for winter feed. Systems with high MJ · cow^?1 were vulnerable to shocks in energy prices. Reducing energy use and C emissions from cow-calf operations is possible, especially by reducing fertilizer and hay use, but would likely reduce productivity ha^?1. Forages with high nitrogen use efficiency, locally adapted plants and animals, and replacement of hay with unfertilized dormant forage and CP supplementation could reduce energy use.     

Efficacy of Seed Aging and Gibberellin Treatments for Manipulating Apical Dominance,Tuber Set and Size Distribution of cv. Shepody

The cultivar Shepody has excellent early processing qualities and produces above average tuber yields but sets relatively few tubers that often become excessively large relative to market demand. Optimizing tuber set and size of Shepody for seed and frozen processing markets currently entails adjusting in-row spacing and vine kill date. However, arresting tuber growth by vine killing for size control sacrifices yield potential. Aging seed by storing at 12, 22, and 32°C for 80-, 450-, and 900-degree days, or gibberellin (GA) treatments, were evaluated as more direct approaches for modulating stem number (apical dominance), tuber set, and size distribution relationships. Shepody proved to be inherently resistant to high temperature-induced age-priming treatments. In contrast to other cultivars studied previously, age-priming Shepody seed during storage had no effect on plant emergence and the resulting increases in stem number, tuber set, and associated decreases in average tuber weight were marginal. By contrast, GA applied as seed dip or spray effectively hastened plant emergence, reduced apical dominance, increased tuber set, and decreased average tuber size. The magnitude of these GA-induced effects depended on concentration and application technique (seed dip versus spray). For frozen processing, GA applied as a seed dip at 1 mg L^-1 added an additional tuber per plant and decreased average tuber size by 15% without affecting U.S. No. 1 tuber yields and gross returns; however, 2 and 3 mg L^-1 GA decreased U.S. No. 1 tuber yields and crop value by an average of 16 and 14%, respectively. Spray applications of 2–6 mg L^-1 GA also reduced U.S. No. 1 tuber yield and frozen processing value. Conversely, the increase in tuber set (1.5 tubers plant^-1) and associated 25% reduction in average tuber weight induced by 2 mg L^-1 GA applied as either dip or spray increased gross crop values on a seed contract by 25 and 38%, respectively. The differential efficacies of dip versus spray applications of GA on tuber set and size distribution were likely attributable to differences in GA deposition on the seed. Applying low concentrations of GA to cut seed of Shepody as either a dip (1–2 mg L^-1) or spray (2 mg L^-1) effectively modulated tuber set and size to significantly increase gross returns for seed, and to better satisfy the needs of processors for more moderate size tubers.     

Auxin Modulates Gibberellin-Induced Effects on Growth,Yield, and Raw Product Recovery for Frozen Processing in Potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.)

Tuber shape phenotype is an important determinant of raw product (≥7.6-cm-long French fries) recovery for frozen processing. Tuber length-to-width (L/W) ratios ≥1.8 translate to maximum yield of raw product; however, some cultivars produce tubers with much lower L/W ratios. While gibberellin (GA) can be used to elongate tubers, it also decreases tuber size and can thereby attenuate raw product recovery. We investigated the utility of GA and naphthaleneacetic acid (NAA) combination treatments for modifying tuber set, size, and shape to increase yield of raw product from ‘Payette Russet’ and ‘Alturas’; two late-season frozen-processing cultivars that often produce tubers with undesirably low L/W ratios. Models describing L/W ratio and fry yield by tuber size class were developed to translate total U.S. No. 1 tuber yields (>113 g) into yield of raw product. Increases in the L/W ratios of 113–284-g tubers had a greater effect on recovery of French fries (% fresh wt) than for tubers >284 g. Undersize (<113 g) and oversize (>340 g) tubers yielded 0 and 96% fries, respectively, regardless of L/W ratio. GA applied as a seed treatment effectively hastened emergence and altered tuber shape by increasing the L/W ratios of ‘Alturas’ and ‘Payette Russet’ tubers, enhancing total fry yield for the 113–340-g tubers by 24–46%, depending on concentration and application technique (dip, spray, in-furrow). However, GA also decreased apical dominance and shifted tuber size distribution away from >284-g tubers toward higher yields of <170-g tubers, erasing the gains in fry yield when all size classes (>113 g) were considered. When combined with GA, NAA maintained apical dominance, attenuated the shift in tuber size distribution, had no effect on the GA-induced increase in tuber L/W ratio, and only partly moderated the GA-induced stimulation of plant emergence. Raw product yield from ‘Payette Russet’ increased 12–39% in spray application trials by using NAA to confine the effect of GA to tuber shape and limit the loss of U.S. No. 1 tubers to undersize. Increases in tuber L/W ratio with GA/NAA seed treatments translated to increased yield of fries only when the relative concentrations were adjusted to minimize loss of >284-g tubers and gain in undersize tubers, as dictated by cultivar sensitivity to GA. ‘Alturas’ was less sensitive to GA than ‘Payette Russet’ for shifts in tuber size distribution but not shape, resulting in 17% increase in raw product with GA alone in pre-plant seed spray application studies. GA/NAA combination treatments provide an effective approach to manipulate tuber size distribution and enhance the yield of raw product for frozen processing in cultivars with a rounder tuber shape phenotype.     

Influence of harvest date on seed yield and quality in forage kochia

Forage kochia (Bassia prostrata) is used for rangeland reclamation and livestock and wildlife forage, but limited research has been conducted on its seed production. Therefore, this research evaluated the effect of harvest date on seed weight, germination, and seed yield of forage kochia subspecies virescens and grisea. Seed was harvested from individual plants for 3 years during October, November, and December. October harvest had the lightest 100-seed weights, with the November harvest slightly heavier than December, for most accessions. Cultivar Snowstorm and breeding line Sahsel, both subsp. grisea, had the greatest 100-seed weights in November, 155 and 143 mg, respectively, whereas, cv. Immigrant (subsp. virescens), the standard for forage kochia, ranked among the least for 100-seed weight. For most accessions, germination was lowest from the October harvest (11%–43%), with greater germination with November and December harvested seeds (43%–64%). Viable seed yields were greatest in November with the exception of two accessions, which peaked in October, indicating earlier maturity. Results indicate that forage kochia usually reaches optimum seed maturity by early November, after plants are exposed to freezing temperatures; however, earlier maturing accessions exist in both subspecies virescens and grisea.     

Is spawning stock biomass a robust proxy for reproductive potential?

Reference points based on fishing mortality (F) and spawning stock biomass (SSB) are a requirement of many fisheries management frameworks. SSB is assumed to be a proxy for stock reproductive potential (SRP). Limit reference points based on SSB are used to indicate the level of biomass below which productivity is affected. SSB fails to account for changes in fecundity, egg viability and sex ratio, and it has been argued that total egg production (TEP) provides a better reflection of SRP. We explore how accounting for TEP impacts limit reference points and evidence for a relationship between stock and recruit. Time series of SSB and TEP are compared for three North Sea stocks: cod (Gadus morhua), herring (Clupea harengus) and plaice (Pleuronectes platessa). Dynamics based on TEP are different from those based on SSB for cod and plaice, but the stock–recruit relationships were not ‘improved’ using TEP. Shifts in productivity (spawner per recruit) occur in all three time series and SSB underestimated uncertainty. Yet again, it was shown that assumptions of stationarity about fish population productivity are incorrect. We argue that the use of TEP does improve the realism in our understanding of stock dynamics, and demographically, more complex management strategy evaluation is required to develop management procedures that are robust to uncertainty and integrate F and the demographic health of a stock. Empirical feedback control systems based on fisheries independent indices including surveys of eggs, larvae, recruits, juveniles or spawning adults should be evaluated and compared to traditional approaches.     

EFFECT OF DELAYED EMERGENCE ON CORN (ZEA MAYS L.) GRAIN YIELD

Uneven crop stands result in a reduction in corn yield production. This study was conducted to determine the effect of delayed emergence on corn yields and the effect of nitrogen (N) applications to compensate for yield reductions. The design used was a randomized complete block, with 4 sequences of delayed planting (0,4,7,and 10 days after planting) and 3 rates of nitrogen fertilizer (0, 40, 80 kg N ha^?1). At maturity, individual plants were tagged in sets of three and hand harvested. Corn ears were shelled, and yield per plant calculated. Grain yield of the delayed plant compared to that of the neighbors was reduced by 27, 8, 20 and 12 kg ha^?1day^?1 for 2007 LCB1, 2007 LCB2, 2010 LCB1 and 2010 LCB2, respectively. Over locations and years, the mean grain yield decrease of the delayed plant versus neighboring plants for each day delay was 122 kg ha^?1.     

Intake of Salt Cedar by Two Different Breeds of Sheep

Salt cedar (Tamarix spp.) readily invades and dominates riparian areas and lake basins throughout the western United States. Traditional control efforts (chemical and mechanical control) are expensive and provide limited long-term control. The salt cedar leaf beetle (Diorhabda elongata) provides a method of biological control through reduction in cover. However, population establishment of leaf beetles in some locations is often difficult because of environmental conditions. In previous research, goats readily consumed salt cedar, offering an alternative method of reducing salt cedar cover. For this study, we determined if sheep would consume salt cedar and consume a similar amount as goats. Twelve Rambouillet and 12 Suffolks lambs were fed salt cedar once daily (Trial 1) and three times daily (Trial 2). Intake of salt cedar by sheep was compared between breeds and with intake of salt cedar by goats (n = 10). Salt cedar was fed once a day in Trial 1 for 30 min over 15 d. Intake was recorded daily for individual animals. In Trial 2, salt cedar was offered three times daily for 13 d with intake recorded. There were no differences (P > 0.05) between breeds of sheep. In addition, sheep consumed more salt cedar than goats except on the last day of the study. When salt cedar was offered three times daily, both breeds of sheep increased intake and gained weight over the 13 d of feeding in Trial 2. By the end of the study, intake appeared to still be increasing. Collectively, these results illustrate that both Rambouillet and Suffolk sheep will consume a similar amount of salt cedar as goats and will provide another species of livestock that can be potentially used to reduce salt cedar cover.