The Nantucket Shoals Flux Experiment (NSFE79). Part I: A Basic Description of the Current and Temperature Variability

Beardsley, Robert C.; Chapman, David C.; Brink, Kenneth H.; Ramp, Steven R.; Schlitz, Ronald

doi:10.1175/1520-0485(1985)015<0713:tnsfep>2.0.co;2

Cited by 171 publications

(190 citation statements)

References 0 publications

Supporting

Mentioning

167

Contrasting

Order By: Relevance

“…L diff is driven by the variability in the currents experienced by larvae spawned at different times or entrained into different coastal eddies (9,14); it could also include the effects of other larval transport mechanisms, such as shipping or fisheries. There is strong weather system-driven (23,24) and interannual variability (25,26) in the coastal current; its SD is comparable to the mean, suggesting that the upper limit on the stochastic component of larval transport should be the magnitude of the mean larval transport L adv (14). Despite these expectations, the variability in larval transport diagnosed by the model from the evolution of the cline is w3.5 times greater than the mean larval transport.…”

Section: Discussion Of the Carcinus Systemmentioning

confidence: 90%

Asymmetric dispersal allows an upstream region to control population structure throughout a species’ range

Pringle

Blakeslee

Byers

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

126

View full text Add to dashboard Cite

In a single well-mixed population, equally abundant neutral alleles are equally likely to persist. However, in spatially complex populations structured by an asymmetric dispersal mechanism, such as a coastal population where larvae are predominantly moved downstream by currents, the eventual frequency of neutral haplotypes will depend on their initial spatial location. In our study of the progression of two spatially separate, genetically distinct introductions of the European green crab (Carcinus maenas) along the coast of eastern North America, we captured this process in action. We documented the shift of the genetic cline in this species over 8 y, and here we detail how the upstream haplotypes are beginning to dominate the system. This quantification of an evolving genetic boundary in a coastal system demonstrates that novel genetic alleles or haplotypes that arise or are introduced into upstream retention zones (regions whose export of larvae is not balanced by import from elsewhere) will increase in frequency in the entire system. This phenomenon should be widespread when there is asymmetrical dispersal, in the oceans or on land, suggesting that the upstream edge of a species' range can influence genetic diversity throughout its distribution. Efforts to protect the upstream edge of an asymmetrically dispersing species' range are vital to conserving genetic diversity in the species.invasive species | marine genetics | phylogeography | physical oceanography N ovel genetic material can appear in a population through mutation, migration, or long-distance dispersal events which may be human-mediated. In a single well-mixed population, the evolution of the frequency of novel neutral alleles will be governed by random genetic drift, not their initial spatial distribution (1). However, spatial structure and complexity can alter this expectation. In a metapopulation linked by migration, alleles introduced into source populations are more likely to persist than those that are introduced into sinks (2-4). Many metapopulations are embedded in complex spatial systems with a preferential direction of migration ("asymmetric dispersal"). In these systems, little is known about the equilibrium frequency of novel alleles or how this frequency depends on the location where these new lineages appear.Asymmetric dispersal is common where propagules are carried long distances by wind or water. In atmospheric, riverine, and oceanic flows, there is usually a predominant flow direction (downstream or downwind) that biases dispersal, and eddies or weather systems that slow or reverse such flow add a stochastic (and potentially upstream) component of migration. For example, many terrestrial plant species have propagules that can be dispersed by the winds (5), and a recent study of the spatial patterns of diversity in moss, liverwort, and lichen flora in the Southern Hemisphere were found to be best explained by the predominantly downwind dispersal (6). Further evidence that asymmetric dispersal can structure a species' genetic patter...

show abstract

Section: Discussion Of the Carcinus Systemmentioning

confidence: 90%

Asymmetric dispersal allows an upstream region to control population structure throughout a species’ range

Pringle

Blakeslee

Byers

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

126

View full text Add to dashboard Cite

show abstract

“…For example, a mean particulate carbon concentration of 24 mg C m-3 was found on the Scotian shelf during 22 January-6 February 1973 (GORDON, 1977), quite similar to the 22.5 mg C m-3 estimated above for February 1984 on the Mid-Atlantic shelf. At a near-bottom, seaward flow of 1.15 cm s-1 (BEARDSLEY et al, 1985;AIKMAN et al, 1988), or 1000 m day-1, a lateral boundary flux of 22-24 g C m-2 day-' may occur during pre-bloom conditions. After initiation of the spring bloom, the average offshore chlorophyll flux from near-bottom current meter and fluorometer time series at the 80-m isobath was 2.2 ng chl cm-2 s-1 between 18 February and 8 April 1984 .…”

Section: Lateral Boundary Fluxesmentioning

confidence: 99%

Arctic carbon sinks: Present and future

Walsh¹

1989

Global Biogeochemical Cycles

View full text Add to dashboard Cite

92-30570I 17With past ONR support from Grant N00014-87-J-1218, we had successfully coupled simple biological models of phytoplankton production (light and nutrient regulation of one size fraction) to time-dependent, 3-dimensional physical models of basin circulation at 25-30 km resolution in the Gulf of Mexico . While these coupled models mimicked seasonal cycles of phytoplankton abundance in basin waters, as estimated by changes in chlorophyll stocks, they failed to replicate fluctuations of biological populations within more complex slope and shelf regions.Accordingly, a more diverse biological model of particle decay within the aphotic zone (3 size classes of phytoplankton, macroaggregates, and zooplankton fecal pellets) was coupled to a static, 2-dimensional model of slope circulation at 0.5 km resolution in the Middle Atlantic Bight (Walsh et al., 1991). By specifying the influx of these particles, both at the shelf-break and from the overlying slope euphotic zone, with variable sinking velocities, the second set of coupled models reproduced seasonal time series of organic carbon caught by moored sediment traps on the slope and rise.A total of 8 publications were derived from this ONR grant: yr-1 , gases, C0 2 , N 2 0, CH4, and freons, to the tenfold that of other high Arctic shelves, atmosphere, is attributed to altered ice/ and may supply 50% of the carbon snow albedo at sea level, i.e., melting of respiration demands within the halocline sea ice.A 5% decline of sea ice extent of the deep Canadian and Eurasian basins in the Arctic and Antarctic from 1979 to via brine-mediated runoff. Continued 1987 may have resulted in increased light melting of ice in the Arctic could availability within previously ice-covered increase by an order of magnitude the polar regions.If such a short-term trend present CO 2 sink of 1-0.i x 109 t C yr'. were to continue, it might lead to a negative biogeochemical feedback, i.e., enhanced extraction of atmospheric CO 2 INTRODUCTION during marine photosynthesis.As a consequence of deep vertical mixing in the The global temperature of surface air Antarctic Ocean, however, primary producincreaseu by 0.4*-0.5*C from 1880 to 1980, tion during the austral summer may have while temperatures of Arctic regions actually declined in response to a reduc-(%64*-90N) instead rose by as much as tion in extent of meltwater regions, where 1.2*-1.5 0 C over this period [Hansen et stratified water columns allow carbon al., 1983]. After 1980, six of the fixation tenfold that of open water.In warmest years in the past century have contrast, within shallow adjacent seas of subsequently been observed , 1981, the Arctic Ocean, where shelf regions are 1983, reflecting tenfold larger than those of the possible early signs of a "greenhouse" warming of the Earth [Hansen and Lebedeff, Copyright 1989Copyright 1988. Initial one-dimensional [Hansen et by the American Geophysical Union. al., 19811 and then three-dimensional climate models of varying sophisticationPaper number 90GB00583. [Mitchell,...

show abstract

“…The along-shelf current, however, can transport larvae away from the region (Polacheck et al 1992, Lozier & Gawarkiewicz 2001. These currents are subject to local forcing such as wind (Noble et al 1985, Houghton et al 1988 as well as remote forcing such as the coldwater intrusions from the Nova Scotian Shelf (Greene & Pershing 2003) and warm core rings from the Gulf Stream (Beardsley et al 1985). Variations in the circulation can lead to interannual changes in larval dispersion and retention.…”

Section: Introductionmentioning

confidence: 99%

Modeling the connectivity between sea scallop populations in the Middle Atlantic Bight and over Georges Bank

Tian¹,

Chen²,

Stokesbury³

et al. 2009

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The dispersion and settlement of sea scallop larvae spawned on Georges Bank (GB) and in the Great Southern Channel (GSC) were explored using an individual-based population dynamics model. The model consisted of 4 pelagic life stages (egg, trochophore, veliger, and pediveliger) and 3 benthic life stages (juvenile, young adult, and adult). It was driven by the 1995 to 2005 hindcast flow field predicted by the Finite Volume Coastal Ocean Model (FVCOM) in the Gulf of Maine (GOM), with spawning stocks specified by field survey data. In 1998In , and 2005, a large amount of larvae drifted southward along the shelf break to the Middle Atlantic Bight (MAB). The potential for long-distance southward transport of larvae was dependent on the upstream flow conditions on the Nova Scotian Shelf, climate forcing, and the timing and location of spawning on GB. The model also predicts considerable larval exchange between the GB and the GSC subpopulations, with 83% of larvae settled in the GSC being spawned on GB, and 46% of larvae settled on GB being spawned in the GSC on average from 1995 to 2005.

show abstract

The Nantucket Shoals Flux Experiment (NSFE79). Part I: A Basic Description of the Current and Temperature Variability

Cited by 171 publications

References 0 publications

Asymmetric dispersal allows an upstream region to control population structure throughout a species’ range

Asymmetric dispersal allows an upstream region to control population structure throughout a species’ range

Arctic carbon sinks: Present and future

Modeling the connectivity between sea scallop populations in the Middle Atlantic Bight and over Georges Bank

Contact Info

Product

Resources

About