Publications

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2018
Mullineaux, LS, Metaxas A, Beaulieu SE, Bright M, Gollner S, Grupe BM, Herrera S, Kellner JB, Levin LA, Mitarai S, Neubert MG, Thurnherr AM, Tunnicliffe V, Watanabe HK, Won YJ.  2018.  Exploring the ecology of deep-sea hydrothermal vents in a metacommunity framework. Frontiers in Marine Science. 5   10.3389/fmars.2018.00049   AbstractWebsite

Species inhabiting deep-sea hydrothermal vents are strongly influenced by the geological setting, as it provides the chemical-rich fluids supporting the food web, creates the patchwork of seafloor habitat, and generates catastrophic disturbances that can eradicate entire communities. The patches of vent habitat host a network of communities (a metacommunity) connected by dispersal of planktonic larvae. The dynamics of the metacommunity are influenced not only by birth rates, death rates and interactions of populations at the local site, but also by regional influences on dispersal from different sites. The connections to other communities provide a mechanism for dynamics at a local site to affect features of the regional biota. In this paper, we explore the challenges and potential benefits of applying metacommunity theory to vent communities, with a particular focus on effects of disturbance. We synthesize field observations to inform models and identify data gaps that need to be addressed to answer key questions including: (1) what is the influence of the magnitude and rate of disturbance on ecological attributes, such as time to extinction or resilience in ametacommunity; (2) what interactions between local and regional processes control species diversity, and (3) which communities are "hot spots" of key ecological significance. We conclude by assessing our ability to evaluate resilience of vent metacommunities to human disturbance (e.g., deep-sea mining). Although the resilience of a few highly disturbed vent systems in the eastern Pacific has been quantified, these values cannot be generalized to remote locales in the western Pacific ormid Atlantic where disturbance rates are different and information on local controls is missing.

2002
Davis, JLD, Levin LA.  2002.  Importance of pre-recruitment life-history stages to population dynamics of the woolly sculpin Clinocottus analis. Marine Ecology-Progress Series. 234:229-246.   10.3354/meps234229   AbstractWebsite

The relative influence of pre- versus post-recruitment life-history events on population size has been the subject of much recent debate. In the marine realm, much work has focused on intertidal invertebrates and on tropical reef fishes, with mixed results. We addressed this problem for a temperate intertidal fish, Clinocottus analis. Our main goal was to determine which life-history stage was most responsible for temporal changes in population size from 1996 to 2000 at 2 sites in San Diego, California, both seasonally and during the 1997 to 1998 El Nino Southern Oscillation (ENSO) event. We approached the problem using cohort analysis and matrix population modeling. Recruitment pulses were evident in population size structure for up to a year, unobscured by post-recruitment mortality, which was not density-dependent, Recruitment was not correlated to spawning adult biomass of 3 mo earlier, suggesting that egg, larval, or early post-settlement processes during those 3 mo determined the magnitude of recruitment, and ultimately, population size. Stage-structured population projection matrices were constructed to compare population growth rates and sensitivities among seasons and between climate periods (El Nino and non-El Nino), Elasticity (prospective) and decomposition (retrospective) analyses of these matrices indicated that the vital rates to which population growth rate (lambda) was theoretically most sensitive were not necessarily those responsible for observed temporal differences in lambda. Although, was most sensitive to juvenile growth and adult survivorship, fertility (which in this model included fecundity and egg, larval, and early post-settlement survivorship), in addition to juvenile growth, drove observed seasonal differences in lambda C. andlis population size decreased during the 1997 to 1998 El Nino event due to a decrease in recruitment, a decrease in batch fecundity (hydrated eggs per female) and, at 1 site, changes in juvenile survivorship, Results of the study emphasize the power of early life-history events to structure C. analis populations on both seasonal and longer timescales.

1994
Levin, LA, Bridges TS.  1994.  Control and consequences of alternative developmental modes in a poecilogonous polychaete. American Zoologist. 34:323-332. AbstractWebsite

The poecilogonous polychaete Streblospio benedicti (Webster) exhibits both planktotrophic and lecithotrophic modes of larval development. The alternative trophic modes are associated with differences in age and size at maturation, offspring number, size and energetic investment, larval planktonic period, morphology and survivorship. This paper reviews a decade of research into the control and consequences of the traits associated with planktotrophy and lecithotrophy in S. benedicti. The dominant control on reproductive and developmental characters is genetic. Significant additive genetic variance has been detected for egg diameter, fecundity, larval planktonic period and aspects of larval morphology. However, environmental factors such as temperature, food quality and photoperiod, and intrinsic factors such as maternal age, exert considerable influence on non-trophic developmental traits (e.g., offspring number, size and energy content). Demographic consequences of development mode are reviewed for field and laboratory demes of S. benedicti dominated by individuals exhibiting either planktotrophy or lecithotrophy. Similar population size structure, fluctuations in abundance, P:B ratios, and estimated population growth rates are achieved through trade-offs between survivorship and fecundity. Development mode may best be viewed as a complex set of traits that are intimately linked developmentally and evolutionarily to other aspects of an organism's life history. Greater insight into the control and consequences of development mode should result from further investigation of these linkages.