Solow Andrew R.

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Solow
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Andrew R.
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Article

Characterizing the error in the estimated age-depth relationship

2003 , Solow, Andrew R.

It is common practice to estimate the age of undated material extracted from a sediment core from radiocarbon or other radiometric dates of samples taken above and below the extracted material. This paper presents a simple expression for the variance of this estimated age. This variance accounts for both 14C dating error and error due to bioturbation.

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Article

Larval responses to turbulence and temperature in a tidal inlet: Habitat selection by dispersing gastropods?

2010-06 , Fuchs, Heidi L. , Solow, Andrew R. , Mullineaux, Lauren S.

Marine larval dispersal is affected by hydrodynamic transport and larval behavior, but little is known about how behavior affects large-scale patterns of dispersal and recruitment. Intertidal habitats are characterized by strong and variable turbulence relative to shelf and pelagic waters, so larval responses to turbulence may affect both dispersal and habitat selection. This study combined observations and theoretical approaches to model gastropod larval responses to multiple physical variables in a well-mixed tidal inlet. Physical measurements and larvae were collected in July 2004 in Barnstable Harbor, Massachusetts (USA). Physical measurements were incorporated in an advection-diffusion model where larval vertical velocity is a function of turbulence dissipation rate, temperature, and the temperature gradient. Modeled larval distributions were fitted to observed concentration profiles by maximum likelihood to estimate larval behavioral velocity (swimming or sinking) as a function of environmental conditions. These quantitative behavior estimates were used to test hypotheses about behavioral differences among groups and to assess the relative impact of different cues on overall larval behavior. Larvae of five common gastropod species from different coastal habitats reacted most strongly to turbulence but had genus-specific responses to environmental cues. Larvae of a species from tidal inlets (the mud snail Nassarius obsoletus) had near-zero velocities under calmer conditions and sank in strong turbulence. In contrast, larvae from exposed beach habitats (Crepidula spp. and Anachis spp.) sank in weak turbulence and swam up in strong turbulence, with additional responses to temperature and temperature gradient. Larval responses also differed between small and large size classes and between flood and ebb tides. Behavior of mud snail larvae would contribute to retention inside the inlet and near adult habitats, whereas behavior of beach snail larvae would contribute to rapid export from muddy inlets lacking suitable adult habitats.

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Article

Environmental health and the coastal zone

2002-11 , Stegeman, John J. , Solow, Andrew R.

Reconciling coastal development and the maintenance of a quality environment represent an enormous management challenge to both public and private interests. Wise management of coastal areas will require an understanding of the nature of dynamic physical, chemical, and biological interactions in the coastal zone, knowledge of how changes in other components of the Earth system affect coastal zones and their role in global cycles, and insight into how to best use these areas as coastal populations increase. Maintaining the integrity and health of the coastal zone is essential to the quality of marine biological resources and, ultimately, of human life.

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Article

On the maximum observed wind speed in a randomly sampled hurricane

2010-03-01 , Solow, Andrew R.

There is considerable interest in detecting a long-term trend in hurricane intensity possibly related to large-scale ocean warming. This effort is complicated by the paucity of wind speed measurements for hurricanes occurring in the early part of the observational record. Here, results are presented regarding the maximum observed wind speed in a sparsely randomly sampled hurricane based on a model of the evolution of wind speed over the lifetime of a hurricane.

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Article

On non-stationarity of ENSO

2003-09-13 , Solow, Andrew R. , Huppert, Amit

Evolutionary spectral analysis has been used to study changes through time in the variability of ENSO-related time series. However, the significance of estimated evolutionary spectra has not been formally assessed. This paper describes a test for non-stationarity based on an estimate of the evolutionary spectrum and a time series bootstrap procedure. The test is applied to the seasonal time series of sea level pressure at Darwin. No significant non-stationarity is found.

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Preprint

Inferring functional extinction based on sighting records

2016-04 , Jaric, Ivan , Gessner, Jörn , Solow, Andrew R.

The term functional extinction is used to describe a permanent failure of reproduction or recruitment in a population. Functional extinction results in a truncation of the age distribution, but this can be very difficult to detect in poorly studied populations. Here, we describe a novel statistical method for detecting functional extinction based on a sighting record of individuals of known or estimated ages. The method is based on a simple population dynamics model and simulation results show that it works well even with limited data. The method is illustrated using a sighting record of the ship sturgeon (Acipenser nudiventris) in the Danube River. The results indicate that this population is functionally extinct, most likely by 2002. Management implications of this finding are discussed.

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Article

Species–area relationships always overestimate extinction rates from habitat loss : comment

2013-03 , Axelsen, Jacob Bock , Roll, Uri , Stone, Lewi , Solow, Andrew R.

The species–area relationship summarizes the relationship between the average number of species in a region and its area. This relationship provides a basis for predicting the loss of species associated with loss of habitat (e.g., Pimm and Raven 2000). The approach involves two steps. First, as discussed in more detail below, the species–area relationship is used to predict the number of species that are endemic to the habitat at risk based on its area. Second, these endemic species are assumed to become extinct should this habitat be lost. In a controversial paper, He and Hubbell (2011) argued that the way in which the species–area relationship is used to predict the number of endemic species is incorrect when individual organisms are aggregated in space and argued that this explains a discrepancy between predicted and observed extinction rates associated with habitat loss. The controversy surrounding the paper focused primarily on the second part of their argument (Brooks 2011, Evans et al. 2011, He and Hubbell 2012, Pereira et al. 2012, Thomas and Williamson 2012). Here, we focus on the details underlying the first part.

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Preprint

Interannual variability of Alexandrium fundyense abundance and shellfish toxicity in the Gulf of Maine

2005-05-03 , McGillicuddy, Dennis J. , Anderson, Donald M. , Solow, Andrew R. , Townsend, David W.

Six years of oceanographic surveys of Alexandrium fundyense concentrations in the Gulf of Maine are combined with shellfish toxicity records from coastal monitoring stations to assess covariations of these quantities on seasonal to interannual time scales. Annual mean gulf-wide cell abundance varies by less than one order of magnitude during the time interval examined (1993-2002). Fluctuations in gulf-wide annual mean cell abundance and shellfish toxicity are not related in a consistent manner. This suggests that interannual variations in toxicity may be regulated by transport and delivery of offshore cell populations, rather than the absolute abundance of the source populations themselves.

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Article

Supply-side approaches to the economic valuation of coastal and marine habitat in the Red Sea

2013-03-07 , Hoagland, Porter , Kite-Powell, Hauke L. , Jin, Di , Solow, Andrew R.

The degradation of natural fish habitat in the ocean implies lost economic benefits. These value losses often are not measured or anticipated fully, and therefore they are mainly ignored in decisions to develop the coast for industrial or residential purposes. In such circumstances, the ocean habitat and its associated ecosystem are treated as if they are worthless. Measures of actual or potential economic values generated by fisheries in commercial markets can be used to assess a conservative (lower-bound) value of ocean habitat. With this information, one can begin to compare the values of coastal developments to the values of foregone ocean habitat in order to help understand whether development would be justified economically. In this paper, we focus on the economic value associated with the harvesting of commercial fish stocks as a relevant case for the Saudi Arabian portion of the Red Sea. We describe first the conceptual basis behind supply-side approaches to economic valuation. Next we review the literature on the use of these methods for valuing ocean habitat. We provide an example based on recent research assessing the bioeconomic status of the traditional fisheries of the Red Sea in the Kingdom of Saudi Arabia (KSA). We estimate the economic value of ecosystem services provided by the KSA Red Sea coral reefs, finding that annual per-unit values supporting the traditional fisheries only are on the order of $7000/km2. Finally, we develop some recommendations for refining future applications of these methods to the Red Sea environment and for further research.

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Preprint

A rotation test for behavioural point-process data

2008-03 , DeRuiter, Stacy L. , Solow, Andrew R.

A common problem in animal behavior is determining whether the rate at which a certain behavioural event occurs is affected by an environmental or other factor. In the example considered later in this paper, the event is a vocalization by an individual sperm whale and the factor is the operation or non-operation of an underwater sound source. A typical experiment to test for such effects involves observing animals during control and treatment periods and recording the times of the events that occur in each. In statistical terminology, the data arising from such an experiment – the times at which events of a specified type occur – represent a point process (Cox & Lewis 1978). Events in a point process are treated as having no duration. Although this is not strictly correct for behavioural events, the approximation is reasonable when the duration of events is small in relation to the interval between them.

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Book chapter

Improving the accuracy and utility of harmful algal bloom forecasting systems

2006-05 , Anderson, Donald M. , Keafer, Bruce A. , McGillicuddy, Dennis J. , Solow, Andrew R. , Kleindinst, Judith L.

One of the goals of harmful algal bloom (HAB) research has been to develop predictive capabilities for blooms. Major steps have been made towards this goal, including the development of physical-biological models of HAB species that simulate bloom dynamics in specific regions. In the Gulf of Maine region of the northeastern U.S., models have been developed that have considerable skill in simulating blooms of Alexandrium fundyense, the causative organism for paralytic shellfish poisoning (PSP) outbreaks in the region. This model is now being used for both short-term and long-term forecasts. This paper describes several ongoing activities that will improve the accuracy and usefulness of the model and forecasts. These include efforts to streamline or minimize the sampling and analysis requirements of annual A. fundyense cyst surveys, efforts to quantitatively describe or characterize the severity of predicted outbreaks, and plans to obtain real-time data on Alexandrium cell abundance and toxicity that can be assimilated into the models. Together, these and other activities are moving us towards an operational forecasting system for Alexandrium blooms in the region.

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Article

On the incompleteness of the historical record of North Atlantic tropical cyclones

2008-06-03 , Solow, Andrew R. , Beet, Andrew R.

There is some question as to whether the historical record of observed North Atlantic tropical cyclones prior to the advent of satellite coverage is complete. This question is central to understanding the historical trend in tropical cyclone activity and the effect of environmental factors on it. To address this question, a statistical model of the relationship between annual cyclone counts between 1870 and 2004 and sea surface temperature and the state of the Southern Oscillation is extended to allow for non-decreasing observation probability prior to 1966. The estimated observation probabilities increase from 0.72 in 1870 to 1 in 1964. Allowing for record incompleteness reduces the estimated effect of sea surface temperature on annual tropical cyclone activity.

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Software

Stochastic Dominance Test (MATLAB and R Code)

2015-02-23 , Moberg, Emily A. , Solow, Andrew R.

This is a MATLAB function which can be run as a .m file. It takes locational data (x), with associated abundances (ax) at those locations from one time period and locational data (y), with associated abundance (ay) at those locations from a later time period and tests for stochastic dominance of the distribution of the data (y,ay) to that of the data (x,ax). The number of bootstraps are also specified. The same function is also included in the R programming language (R Core Team. (2014) R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing. Vienna, Austria. http://R-project.org.).

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Article

Optimal multiproxy reconstruction of sea surface temperature from corals

2004-10-08 , Solow, Andrew R. , Huppert, Amit

Past sea surface temperatures have been reconstructed using coral measurements of single geochemical proxies. There is some interest in improving reconstruction by combining results from different proxies. The construction of the optimal multiproxy reconstruction is described. The approach is illustrated using some data from New Caledonia.

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Article

Resource allocation for Lagrangian tracking

2016-06-02 , Jones, Benjamin T. , Solow, Andrew R. , Ji, Rubao

Accurate estimation of the transport probabilities among regions in the ocean provides valuable information for understanding plankton transport, the spread of pollutants, and the movement of water masses. Individual-based particle-tracking models simulate a large ensemble of Lagrangian particles and are a common method to estimate these transport probabilities. Simulating a large ensemble of Lagrangian particles is computationally expensive, and appropriately allocating resources can reduce the cost of this method. Two universal questions in the design of studies that use Lagrangian particle tracking are how many particles to release and how to distribute particle releases. A method is presented for tailoring the number and the release location of particles to most effectively achieve the objectives of a study. The method detailed here is a sequential analysis procedure that seeks to minimize the number of particles that are required to satisfy a predefined metric of result quality. The study assesses the result quality as the precision of the estimates for the elements of a transport matrix and also describes how the method may be extended for use with other metrics. Applying this methodology to both a theoretical system and a particle transport model of the Gulf of Maine results in more precise estimates of the transport probabilities with fewer particles than from uniformly or randomly distributing particle releases. The application of this method can help reduce the cost of and increase the robustness of results from studies that use Lagrangian particles.

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Article

Seasons of Syn

2019-11-19 , Hunter-Cevera, Kristen R. , Neubert, Michael G. , Olson, Robert J. , Shalapyonok, Alexi , Solow, Andrew R. , Sosik, Heidi M.

Synechococcus is a widespread and important marine primary producer. Time series provide critical information for identifying and understanding the factors that determine abundance patterns. Here, we present the results of analysis of a 16‐yr hourly time series of Synechococcus at the Martha's Vineyard Coastal Observatory, obtained with an automated, in situ flow cytometer. We focus on understanding seasonal abundance patterns by examining relationships between cell division rate, loss rate, cellular properties (e.g., cell volume, phycoerythrin fluorescence), and environmental variables (e.g., temperature, light). We find that the drivers of cell division vary with season; cells are temperature‐limited in winter and spring, but light‐limited in the fall. Losses to the population also vary with season. Our results lead to testable hypotheses about Synechococcus ecophysiology and a working framework for understanding the seasonal controls of Synechococcus cell abundance in a temperate coastal system.

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Preprint

Testing models of thorium and particle cycling in the ocean using data from station GT11-22 of the U.S. GEOTRACES North Atlantic section

2016-03-31 , Lerner, Paul , Marchal, Olivier , Lam, Phoebe J. , Anderson, Robert F. , Buesseler, Ken O. , Charette, Matthew A. , Edwards, R. Lawrence , Hayes, Christopher T. , Huang, Kuo-Fang , Lu, Yanbin , Robinson, Laura F. , Solow, Andrew R.

Thorium is a highly particle-reactive element that possesses different measurable radio-isotopes in seawater, with well-constrained production rates and very distinct half-lives. As a result, Th has emerged as a key tracer for the cycling of marine particles and of their chemical constituents, including particulate organic carbon. Here two different versions of a model of Th and particle cycling in the ocean are tested using an unprecedented data set from station GT11-22 of the U.S. GEOTRACES North Atlantic Section: (i) 21 228;230;234Th activities of dissolved and particulate fractions, (ii) 228Ra activities, (iii) 234;238U activities estimated from salinity data and an assumed 234U/238U ratio, and (iv) particle concentrations, below a depth of 125 m. The two model versions assume a single class of particles but rely on different assumptions about the rate parameters for sorption reactions and particle processes: a first version (V1) assumes vertically uniform parameters (a popular description), whereas the second (V2) does not. Both versions are tested by fitting to the GT11-22 data using generalized nonlinear least squares and by analyzing residuals normalized to the data errors. We find that model V2 displays a significantly better fit to the data than model V1. Thus, the mere allowance of vertical variations in the rate parameters can lead to a significantly better fit to the data, without the need to modify the structure or add any new processes to the model. To understand how the better fit is achieved we consider two parameters, K = k1=(k-1 + β-1) and K/P, where k1 is the adsorption rate constant, k-1 the desorption rate constant, β-1 the remineralization rate constant, and P the particle concentration. We find that the rate constant ratio K is large (≥0.2) in the upper 1000 m and decreases to a nearly uniform value of ca. 0.12 below 2000 m, implying that the specific rate at which Th attaches to particles relative to that at which it is released from particles is higher in the upper ocean than in the deep ocean. In contrast, K/P increases with depth below 500 m. The parameters K and K/P display significant positive and negative monotonic relationship with P, respectively, which is collectively consistent with a particle concentration effect.

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Article

An ENSO shift revisited

2006-11-21 , Solow, Andrew R.

An influential 1996 paper presented a statistical analysis showing that the prolonged ENSO warm event of the early 1990's was inconsistent with the historical pattern of ENSO variability and therefore concluded that there had been a shift in ENSO behavior possibly connected to global warming. A fundamental problem with this earlier analysis is that the data used to test for a shift in ENSO behavior were not independent of the data used to identify the hypothetical shift. A new analysis is presented that avoids this problem by using more recent data. The results raise a question about the earlier finding.

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Article

Method for reconstructing climate from fossil beetle assemblages

2004-04-19 , Huppert, Amit , Solow, Andrew R.

Fossil beetle remains have been used to reconstruct temperatures. One method by which these reconstructions are made--the Mutual Climatic Range method--is based on the overlap of the observed modern climatic ranges of the beetles present in a fossil sample. A limitation of this method is that it does not exploit variations in the rate of occurrence of a species within its climatic range. We present an alternative method that uses observed variations in this rate in modern data for climate reconstruction. The method is shown to perform well in an experiment using modern data from North America.

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Article

Marine harmful algal blooms (HABs) in the united states: history, current status and future trends

2021-03-03 , Anderson, Donald M. , Fensin, Elizabeth , Gobler, Christopher J. , Hoeglund, Alicia E. , Hubbard, Katherine A. , Kulis, David M. , Landsberg, Jan H. , Lefebvre, Kathi A. , Provoost, Pieter , Richlen, Mindy L. , Smith, Juliette L. , Solow, Andrew R. , Trainer, Vera L.

Harmful algal blooms (HABs) are diverse phenomena involving multiple. species and classes of algae that occupy a broad range of habitats from lakes to oceans and produce a multiplicity of toxins or bioactive compounds that impact many different resources. Here, a review of the status of this complex array of marine HAB problems in the U.S. is presented, providing historical information and trends as well as future perspectives. The study relies on thirty years (1990–2019) of data in HAEDAT - the IOC-ICES-PICES Harmful Algal Event database, but also includes many other reports. At a qualitative level, the U.S. national HAB problem is far more extensive than was the case decades ago, with more toxic species and toxins to monitor, as well as a larger range of impacted resources and areas affected. Quantitatively, no significant trend is seen for paralytic shellfish toxin (PST) events over the study interval, though there is clear evidence of the expansion of the problem into new regions and the emergence of a species that produces PSTs in Florida – Pyrodinium bahamense. Amnesic shellfish toxin (AST) events have significantly increased in the U.S., with an overall pattern of frequent outbreaks on the West Coast, emerging, recurring outbreaks on the East Coast, and sporadic incidents in the Gulf of Mexico. Despite the long historical record of neurotoxic shellfish toxin (NST) events, no significant trend is observed over the past 30 years. The recent emergence of diarrhetic shellfish toxins (DSTs) in the U.S. began along the Gulf Coast in 2008 and expanded to the West and East Coasts, though no significant trend through time is seen since then. Ciguatoxin (CTX) events caused by Gambierdiscus dinoflagellates have long impacted tropical and subtropical locations in the U.S., but due to a lack of monitoring programs as well as under-reporting of illnesses, data on these events are not available for time series analysis. Geographic expansion of Gambierdiscus into temperate and non-endemic areas (e.g., northern Gulf of Mexico) is apparent, and fostered by ocean warming. HAB-related marine wildlife morbidity and mortality events appear to be increasing, with statistically significant increasing trends observed in marine mammal poisonings caused by ASTs along the coast of California and NSTs in Florida. Since their first occurrence in 1985 in New York, brown tides resulting from high-density blooms of Aureococcus have spread south to Delaware, Maryland, and Virginia, while those caused by Aureoumbra have spread from the Gulf Coast to the east coast of Florida. Blooms of Margalefidinium polykrikoides occurred in four locations in the U.S. from 1921–2001 but have appeared in more than 15  U.S. estuaries since then, with ocean warming implicated as a causative factor. Numerous blooms of toxic cyanobacteria have been documented in all 50  U.S. states and the transport of cyanotoxins from freshwater systems into marine coastal waters is a recently identified and potentially significant threat to public and ecosystem health. Taken together, there is a significant increasing trend in all HAB events in HAEDAT over the 30-year study interval. Part of this observed HAB expansion simply reflects a better realization of the true or historic scale of the problem, long obscured by inadequate monitoring. Other contributing factors include the dispersion of species to new areas, the discovery of new HAB poisoning syndromes or impacts, and the stimulatory effects of human activities like nutrient pollution, aquaculture expansion, and ocean warming, among others. One result of this multifaceted expansion is that many regions of the U.S. now face a daunting diversity of species and toxins, representing a significant and growing challenge to resource managers and public health officials in terms of toxins, regions, and time intervals to monitor, and necessitating new approaches to monitoring and management. Mobilization of funding and resources for research, monitoring and management of HABs requires accurate information on the scale and nature of the national problem. HAEDAT and other databases can be of great value in this regard but efforts are needed to expand and sustain the collection of data regionally and nationally.

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