国产贝母属（百合科）的系统学研究

作者通过实地调查，栽培观察，大量查阅标本，对国产贝母属(Fritillaria L.)的形态性状作了深入的分析，认为贝母属中植株大小，茎生叶先端卷曲与否，花的数目、花梗的长短、花被片颜色等性状易受生境的影响;而鳞茎所具鳞片的数目，植株最下一轮叶的形状及排列，花部蜜腺的形状，花柱柱头的分裂程度，雄蕊花丝在发育完后的长短，蒴果的形状等性状受生境的影响较小，但在栽培情况下，这些性状有时也会发生变化．此外，作者首次报道了部分国产贝母属种类的核型和花粉形态．在此基础上对我国贝母属进行了系统整理，将正式发表的138个分类名称（包括80个种、52个变种、5个变型、1个栽培变型）归并成24种l变种，并对国产贝母组(Seclion Fritillaria)的种间关系作了初步探讨;同时，对该属的次级分类也作了修订．根据有关，F.karelinii花粉学和细胞学资料，以及邻近4个种的形态特征及分布特点，我们支持J.G..Baker(1874)的观点将该类群保留在贝母属内而不同意A.S.Lozin-Lozinskaya(1935)，A.Takhtajan(1987)将其单立成属也不同意W.B.Turrill &J.R.Sealy(1980)将其并入贝母组(Sect.Fritillaria)，而将该类群做为贝母属中的一个新组——砂贝母组(Sect.Rhinopetalum (Fish. ex Alex.) Y.B.Luo)．并认为该组与贝母组关系较近．作者通过上述工作及查阅世界各地有关贝母属的文献，认为贝母属内最原始的类群是Sect. Fritillaria，而Sect.Petillium，Sect.Rhinopetalum和Sect.Theresia是演化水平中等的类群．Sect.Liliorhiza则是演化水平最高的一类．通过对该属组(Section)级及种级分布式样的分析，认为伊朗一土兰区不仅是组的多度中心，并且也是多样化中心;在种级水平上，地中海区是分布的多度中心，而种级多样化中心则在伊朗一土兰区;此外，在伊朗一土兰区还保留着一些较原始的类群，因而，该区可能是贝母属的起源中心，最后，作者对贝母属的起源时间、散布途径及现代分布格局形成的原因进行了初步探讨．

Review of size- and age-dependence in batch spawning: implications for stock assessment of fish species exhibiting indeterminate fecundity

Most assessments of fish stocks use some measure of the reproductive potential of a population, such as spawning biomass. However, the correlation between spawning biomass and reproductive potential is not always strong, and it likely is weakest in the tropics and subtropics, where species tend to exhibit indeterminate fecundity and release eggs in batches over a protracted spawning season. In such cases, computing annual reproductive output requires estimates of batch fecundity and the annual number of batches—the latter subject to spawning frequency and duration of spawning season. Batch fecundity is commonly measured by age (or size), but these other variables are not. Without the relevant data, the annual number of batches is assumed to be invariant across age. We reviewed the literature and found that this default assumption lacks empirical support because both spawning duration and spawning frequency generally increase with age or size. We demonstrate effects of this assumption on measures of reproductive value and spawning potential ratio, a metric commonly used to gauge stock status. Model applications showed substantial sensitivity to age dependence in the annual number of batches. If the annual number of batches increases with age but is incorrectly assumed to be constant, stock assessment models would tend to overestimate the biological reference points used for setting harvest rates. This study underscores the need to better understand the age- or size-dependent contrast in the annual number of batches, and we conclude that, for species without evidence to support invariance, the default assumption should be replaced with one that accounts for age- or size-dependence.

Seasonal and interannual variation in juvenile salmonids and associated fish assemblage in open waters of the lower Columbia River estuary

The transition between freshwater and marine environments is associated with high mortality for juvenile anadromous salmonids, yet little is known about this critical period in many large rivers. To address this deficiency, we investigated the estuarine ecology of juvenile salmonids and their associated fish assemblage in open-water habitats of the lower Columbia River estuary during spring of 2007–10. For coho (Oncorhynchus kisutch), sockeye (O. nerka), chum (O. keta), and yearling (age 1.0) Chinook (O. tshawytscha) salmon, and steelhead (O. mykiss), we observed a consistent seasonal pattern characterized by extremely low abundances in mid-April, maximum abundances in May, and near absence by late June. Subyearling (age 0.0) Chinook salmon were most abundant in late June. Although we observed interannual variation in the presence, abundance, and size of juvenile salmonids, no single year was exceptional across all species-and-age classes. We estimated that >90% of juvenile Chinook and coho salmon and steelhead were of hatchery origin, a rate higher than previously reported. In contrast to juvenile salmonids, the abundance and composition of the greater estuarine fish assemblage, of which juvenile salmon were minor members, were extremely variable and likely responding to dynamic physical conditions in the estuary. Comparisons with studies conducted 3 decades earlier suggest striking changes in the estuarine fish assemblage—changes that have unknown but potentially important consequences for juvenile salmon in the Columbia River estuary.

Fish consumption by harbor seals (Phoca vitulina) in the San Juan Islands, Washington

The harbor seal (Phoca vitulina) is a large-bodied and abundant predator in the Salish Sea ecosystem, and its population has recovered since the 1970s after passage of the Marine Mammal Protection Act and the cessation of bounties. Little is known about how this large predator population may affect the recovery of fish stocks in the Salish Sea, where candidate marine protected areas are being proposed. We used a bioenergetics model to calculate baseline consumption rates in the San Juan Islands, Washington. Salmonids (Oncorhynchus spp.) and herring (Clupeidae) were the 2 most energetically important prey groups for biomass consumed by harbor seals. Estimated consumption of salmonids was 783 (±380 standard deviation [SD]) metric tons (t) in the breeding season and 675 (±388 SD t in the nonbreeding season. Estimated consumption of herring was 646 (±303 SD) t in the breeding season and 2151 (±706 SD) t in the nonbreeding season. Rockfish, a depressed fish stock currently in need of population recovery, composed one of the minor prey groups consumed by harbor seals (84 [±26 SD] t in the nonbreeding season). The variables of seal body mass and proportion of prey in seal diet explained >80% of the total variation in model outputs. Prey groups, such as rockfish, that are targeted for recovery may still be affected by even low levels of predation. This study highlights the importance of salmonids and herring for the seal population and provides a framework for refining consumption estimates and their confidence intervals with future data.